halftrackinfo
drive train => drive lines => Topic started by: brit plumber on September 11, 2020, 05:57:28 AM
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I was looking at my rear track idlers and at least the left one points in towards the frame. Does this mean the axle/pin is bent out of alignment? It looks like there’s an adjustable tie bar but I think this to support the idler rather than adjust it. If it’s bent, are they easy to obtain?
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Might not be bent but worn. Either the casting or the shaft might be worn. The left side on my track was flopping around so pulled the pivot shaft out of the frame and had it welded and ground then the casting bored out. Good luck. Those pivot shafts in the frame are a bitch to get out.
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I had that same issue. It leads to rapid ware on the outer idler flange. You might be able to adjust some of it out but tightening that turnbuckle. I had to take apart the turnbuckle, cut a tad off the threads then put it back in and tighten the hell out of it. I also had to put a thick backing plate inside the frame where it bolts to the frame. This is because you can tighten it so much that the frame rail will bulge out if there is no plate. Doing all this got mine straighter, but not perfect. You can also try replacing or swapping around the sockets that are inside the frame. I did that too.
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Thanks Gents, this is one of the parts I’m trying to remove from the frame and she’s proving stubborn. One thing I have on my side is time so I’ll be soaking in penetrating oil on a regular basis and will likely try and add some heat too.
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I pushed the shaft out by laying a bottle jack on its side in the frame, and then tapping the idler back and forth. I just cut the bolts off
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Thanks, I’ve been reading a lot of similar posts and getting a feeling of what’s required. Next time I can get to the track I’ll take a photo of how bad it is. I fear I may need to replace the whole assembly.
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Well I’m having a nightmare stripping this lot down. I managed to get the track spring stop bracket off the frame by using lots of penetrating oil and a FB torque wrench but the big 2.5” idler wheel nut does not want to shift. Even with the FB torque wrench set to 700lb, the wrench bent!
I’m thinking I should remove the whole assembly, heat and cool the nut a few times, submerse it in a few gallons of diesel and then reattach to the frame and try again. (I haven’t got a portable oxy/accet kit to try when attached to the frame).
So my next question is, how should I remove the double spring tensioner if I can’t undo the adjuster lock nut. Are the springs under much compression when the track is off? If I just undo the brackets, am I inviting danger to pay a visit? I may be able to fit coil compressors if they fit.
What are people’s thoughts please?
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You will need to back nut off the spring shaft it’s self plus there shouldn’t be much tension on the spring with the track off.
Don G
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I thought I would need to do that, is it a 2” AF nut? I measured it at 2.2” but the book says 2”. I’m wondering if my callipers has given a false reading as they occasionally do.
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Any chance those are left hand threads on that shaft? Iv never removed that nut on mine , so I don’t know. I do know one side of the halftracks do have left hand threads on the front lug nuts.
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Both should be right hand threads.
Don G.
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Any chance those are left hand threads on that shaft? Iv never removed that nut on mine , so I don’t know. I do know one side of the halftracks do have left hand threads on the front lug nuts.
That was one thing I checked, definitely a RH thread. I can’t find a torque loading for the nut so it maybe that I just need a bigger wrench i.e. a 1500lb version!
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And can anyone confirm the adjuster but is 2” AF? I’ll have to buy a specific 2” AF spanner as my huge adjustable wrench just isn’t up to the job.
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Heat up the nut until red on one side and remove it when it is still hot. Shouldn't be that tight. Most likely rusted on.
Steve
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That’s my problem, my kit isn’t portable, I’ve got a fixed hearth on natural gas. I may have to invest in some portable oxy/acet kit, not sure how it works in the US but for gas to be reasonable money you need a bottle hire contract which is very expensive. The alternative is to buy the bottle with the gas which is more expensive but cheaper than a contract if your an occasional user (this is how I buy my welding gas) I think in the long run I may end up using a set more than I realise.
I was thinking of taking the whole assembly off and heating it on the hearth but I can’t get that spring adjuster nut to move. I think it must be a 2 and 3/16 nut as I’ve been back and measured it again at 2.1985 so allowing for some paint and surface rust it’s likely 2.1875, definitely not the 2” of the manual.
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Gas rig is a must, you can go oxy/propane if it’s cheaper with the propane bottle over there.fuel regulator should work with either.
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A few more bits removed, the spring had no tension so that’s been removed now. Still need to remove the big nut and then I’ll need to remove the inner large nut. So oxy/acetylene is next on the shopping list.
All the documentation shows a nut on the spring adjuster with a jam nut, both of 2.5”. My adjusters only have the one nut of 2.2” AF. Is this another version or possibly a French replacement?
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Not sure, but I have never seen one with the jam nuts, both halftracks I have right now don't have them. Although they are in the documentation indeed. JR Parts sell NOS ones and those don't have the jam nut either. Good to see you got them off!
Rob
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Well when it comes to re-assembly then I’ll likely stick with what was on it until I see otherwise
Today’s efforts were disappointing.
Firstly I ordered 2 x 1” 8TPI studs with nuts etc. so I could compress the volute springs in the crab. Only one arrived.
Secondly I got the size from various posts on the internet where they stated the manual was incorrect. Well it looks like I may have made a mistake as the studs looks bigger that the holes and they won’t bite, not a hope in hell so I think I need some 7/8” stud as per the manual.
Thirdly after the above fail, I got the angle grinder out with the intention of removing some more of the bubba frame. 5 seconds after starting, the grinder stopped as if the battery was flat. I gave it a few seconds and all it would do was rotate backwards for a split second before stoping. So it will be going back to the store tomorrow as it’s only 8 days old!!
The last thing I did was to undo some of the bolts attaching the towing pintle. 7 came undone ok, 3 the nuts had corroded to the point I couldn’t differentiate between what was bolt and what was nut. They will need cutting off with my ...... replacement angle grinder. On the subject of the tow pintle, do I need to undo the big nut to remove the actual pintle from the frame?
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Our halftrack, Lucky 13, has the two nuts; however, it's the early thin single spring so I wonder if that's the difference.
Our all-thread pieces were 1", not 7/8', but maybe there are different sized threaded holes in some of the crabs?
Yes, unfortunately, the large nut has to come off.
Corey
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Firstly I ordered 2 x 1” 8TPI studs with nuts etc. so I could compress the volute springs in the crab. Only one arrived.
Secondly I got the size from various posts on the internet where they stated the manual was incorrect. Well it looks like I may have made a mistake as the studs looks bigger that the holes and they won’t bite, not a hope in hell so I think I need some 7/8” stud as per the manual.
The holes are probably packed tight with 80 years worth of dirt. Mine were packed solid and after driving a long pointed punch into them to break up the dirt, I had to make up a long extension for my air nozzle and blow them out. I had to repeat the process several times to get them clean enough to accept a well-lubed 1"-8 threaded rod.
Jon
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Thanks John, I’ll try chipping away with a long screwdriver and see if anything comes out. Ive also got a 1” x 8TPI taper tap so I’ll see what that does. I’ll have to make sure I attach it well to something or I’ll never get it out again lol.
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I got a good light source in there today and there’s no crap in the holes. I can see a good distance of threads so I pushed a bar in the hole which just fitted. I then compared it to my 1” x 8tpi taper tap and it looks like it is 1 inch. So I just need to figure out a way to get the tap to the bottom of the hole without it dropping off. I’m thinking a 12” extension bar from my socket set. I just need to check to see if the tap square drive is a 1/2”.
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I got a good light source in there today and there’s no crap in the holes. I can see a good distance of threads so I pushed a bar in the hole which just fitted. I then compared it to my 1” x 8tpi taper tap and it looks like it is 1 inch. So I just need to figure out a way to get the tap to the bottom of the hole without it dropping off. I’m thinking a 12” extension bar from my socket set. I just need to check to see if the tap square drive is a 1/2”.
This is what Don used to tap his crab holes out. I stole the picture from his restoration thread.
(http://www.surfacezero.com/g503/data/2156/100_58561.jpg)
Corey
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When it comes time to free up that crab, Iv got a jig I made to free it up. It’s something I’m tired of tripping over, so you are welcome to it. Mine were stuck REAL BAD.
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I got a good light source in there today and there’s no crap in the holes. I can see a good distance of threads so I pushed a bar in the hole which just fitted. I then compared it to my 1” x 8tpi taper tap and it looks like it is 1 inch. So I just need to figure out a way to get the tap to the bottom of the hole without it dropping off. I’m thinking a 12” extension bar from my socket set. I just need to check to see if the tap square drive is a 1/2”.
This is what Don used to tap his crab holes out. I stole the picture from his restoration thread.
(http://www.surfacezero.com/g503/data/2156/100_58561.jpg)
Corey
That’s the exact kind of home made job Im thinking of. My usual problem is it takes me 3 or more attempts to make it and it would have cost half as much to just buy the right tool. But it is twice the fun so worth it.
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When it comes time to free up that crab, Iv got a jig I made to free it up. It’s something I’m tired of tripping over, so you are welcome to it. Mine were stuck REAL BAD.
Thanks for the offer but I’d imagine it’s heavy duty and I’m in the UK so shipping is likely huuuuuuge! How does it work? I span set the boggie cluster to hold up the springs and then jacked up the back to put an axle stand in. The lot was frozen but at least I can knock the axle shafts out of the wheels. I was pleasantly surprised at how easy the nuts came off and the axles moved. It’s a credit to the US steel mills that the steel has lasted so well. Unfortunately corrosion has got the better of some of the buts on the frame, some have even corroded to nothing. I should take a photo to highlight that I can have a perfect nut in one position and then another 2” away can be completely rotten so there’s nothing left. It’s completely bizarre and I’ve never seen anything like it.
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Here’s a bad photo I had on my phone. The bottom arrowed nut has rotted away, the one arrowed above is 50% gone and the one not in view is a little rusty and will undo with little effort. I may have to replace that cross member if I can find another as the steel is quite thin in some areas. This and the other side are the only parts that really concern me on the frame.
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I sure admire your gumption taking on this project! I don't think many people would. They'd consider it too much work and find an easier one. Thanks again for saving this old half-track.
Jon
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Brit plumber,
I stand corrected to my previous reply about the jam nut. The M4A1 I'm restoring does have them. The M16 not though.
Rob
ps. My dual spring adjusting bolt is bend like crazy so don't use this picture for any other comparison.
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Brit plumber,
I stand corrected to my previous reply about the jam nut. The M4A1 I'm restoring does have them. The M16 not though.
Rob
ps. My dual spring adjusting bolt is bend like crazy so don't use this picture for any other comparison.
Perhaps someone realised that a lock nut/jam nut wasn’t required and they were eventually made obsolete?
Looking at your assembly, I initially thought my spring bolt was bent too, but after removing the spring I see it’s not. I think that as there was no tension on the spring, it could pivot upwards and I think my track was unloaded with the strop around the frame and spring which pulled it out of true. After disassembly there’s nothing wrong. Looking at yours, it looks as mine did, that is the spring not seated on the erm......spring seat. Perhaps pushing the spring down and back into alignment may fix it.
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Perhaps someone realised that a lock nut/jam nut wasn’t required and they were eventually made obsolete?
Looking at your assembly, I initially thought my spring bolt was bent too, but after removing the spring I see it’s not. I think that as there was no tension on the spring, it could pivot upwards and I think my track was unloaded with the strop around the frame and spring which pulled it out of true. After disassembly there’s nothing wrong. Looking at yours, it looks as mine did, that is the spring not seated on the erm......spring seat. Perhaps pushing the spring down and back into alignment may fix it.
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Yes, probably! Mine on the M4 really live up to their name! They're jammed!! But that is mostly due to the red oxide paint... It's a real pain... Almost everything is stuck due to that. I've tried chemicals and excessive heat but that orange goo doesn't bodge a bit..
I went to see the moment I read your reply, and it looks like you're totally right!!The spring is a bit out of the seat indeed! and the rod looks straight as I can tell now. Thanks for letting me know! I really appreciate it!
Looks like everyday is still a schoolday!
Rob
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I’m glad to have been of help. After all I’ve asked lots of questions and had lots of useful replies in response so it’s nice to have given something back to the group.
I’ve made some progress today. I found the reason I couldn’t get the threaded bar in to the valute springs, the seat was frozen at an angle so the bars wouldn’t go in. Lots of oil and some heavy blows with a lump hammer squared the seat up enough to get them threaded in. So they were 1” x 8TPI after all!
Everything is free except the 2 axle pins in the 2 sets of bogie wheels. I think this is where cleprechaun crab tool would be handy and some oxy/acetylene bottles.
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And a photo.
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I sure admire your gumption taking on this project! I don't think many people would. They'd consider it too much work and find an easier one. Thanks again for saving this old half-track.
Jon
Thanks Jon, I’ve not much choice as there’s not many (maybe non) unrestored Halftracks available in the UK. Apart from the heavy corrosion around the cross member the rest isn’t too bad. I’m enjoying so that’s the main thing.
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And also credit for the amazing progress you made in this short amount of time! Impressive!
Rob
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Thanks, things will slow down now as the weather worsens and the nights are drawing in.
I see on the g503 that your M16 is a donor track. If you have any M16 specific parts you don’t need and want to sell on. Bare me in mind, I’ve still to find an M16 bulkhead as the 2 previous offers have fallen through.
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Thanks, things will slow down now as the weather worsens and the nights are drawing in.
I see on the g503 that your M16 is a donor track. If you have any M16 specific parts you don’t need and want to sell on. Bare me in mind, I’ve still to find an M16 bulkhead as the 2 previous offers have fallen through.
Yes, shorter days and rain... That is going to slow down things a bit.
Basically I made a deal with the owner (paintball company) that I can pull and use anything that is not visible. In return I will add some rear (armor) and throw a couple buckets of olive drab over it. Once that all is done it will go back to sit it's final days at the paintball pit. So I'm not really able to get anyhing exterior off of it. Besides that, 20 years outside display and paintball mayhem didn't do any good to this old warrior.
Rob
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That’s fair, shame the owner wants to keep it outdoors but it must be worth more to him as a paintball prop than as a valuable asset.
There’s a paintball place near me that has a Chieftain main battle tank as a gate guardian. It’s a well known land mark and they keep it well painted. I hope they keep the rest of it in as nice condition.
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I got the whole back end of the track on axle stands today. Because I can’t get the track tension adjuster nut to adjust and take the tension off the remaining track, I’m trying to find an alternative. I’m thinking of using my spring compressors to hold the spring tension and then pull the track of the idler. I’ve already pulled the outer half of the idler off but I’m worried the spring will release with huge stress on the components if I just slip it off the inner (I’m a wimp when it comes to big springs even though I work with explosives). I’d appreciate hearing any thoughts or alternative ideas.
I also can’t budge the bogie arms on the other side. I’ve tried wedging chisels, using 2 hammers on the end and pullers. The only thing left I can think of is heat, I really need to buy a Oxy/Acet kit.
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Don’t know if this will help I put a chain on rear idler and crossmember then used a screw type boomer to pull rear idler forward. Look closely at picture and you can see it
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Thanks, that’s worth a try. Did you have the same issue with the adjuster?
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"I also can’t budge the bogie arms on the other side. I’ve tried wedging chisels, using 2 hammers on the end and pullers. The only thing left I can think of is heat, I really need to buy a Oxy/Acet kit. "
If your spider (crab) is locked up that's an entirely different wrestling match.
Lots of heat AND pressure might be required.
Both of mine were locked up.
Took several weeks of soaking in penetrating oil, heat and a 100 ton press.
There are posts with guys having to use a lot bigger press than that.
Good therapy….right?? ;)
Keith
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Which part is the spider? The arms are free to move and the bogies are free to move up and down. It appears it’s just the arm that frozen on to the tapered end of the bogie axle if that makes sense.
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I used a chisel, hammer and propane torch and it worked just fine. Drive the chisel in and heat around the end piece (not the bolt) for about 3-4 minutes and give it a shot of PB blaster and give the chisel a few good whacks. Pops right off. Some came out once heated enough.
Propane works just fine!
There is a good photo in the forum "All track related hardware and maintenance" "Rear suspension disassembly"
Paul
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Which part is the spider? The arms are free to move and the bogies are free to move up and down. It appears it’s just the arm that frozen on to the tapered end of the bogie axle if that makes sense.
Sorry.....not spider....crab.
Too much fun this weekend. :D
Getting the shaft out of the crab assembly is sometimes a struggle.
Thanks,
Keith
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A small success today but still progress. Managed to get the idler post nut off today, it took 1200ft lb to get it off but as soon as it went, no more resistance.
Then I couldn’t get the housing off the post, it was that worn, full of hard grease and rust that it took another hour of soaking in oil and working it back and forth before it came off. The post and housing are very worn so I need to think about how I’ll approach fixing them.
Oh and I cut some more of the horrible frame off.
Rain suspended play before I could do much more.
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So this morning I thought I’d remove the towing pintle. Nothings easy, the split pin was not going to budge. I ended up having to drill it out enough to weaken it and then punch out the last 1/2”. Punching out the whole length just wasn’t working, the punch kept disappearing into the whole and getting jammed. But after getting it out, I realised I don’t have a socket of the correct size so I’m waiting on it to arrive.
So that leads me to my next problem. I’m now trying to remove the inner idler post nut but, and there’s always a big but involved, the split pin is also corroded in! And there’s zero chance of getting a drill in there. I tried pulling it out with wire but the head tore through. I think I may have to remove as much of the head and tail as I can and then use the nut as a guillotine and hope not to damage the threads to much. Have others found it just dropped out?
See the photo, also note how rotten those 2 nuts are for the tow pintle bracket. This frame will need some serious work.
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I’ve now decided to pull the hole bogie assembly from the frame as a whole unit and get it back to my place. I’ve removed the nut from the cross tube but the bolt is stuck tight. Is the bolt screwed into the cross tube and locked with the nut or should it just tap out when the nuts removed?
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I decided not to tackle that bolt until I know how it’s fitted but I did have success with getting the bogie arms and crab off. I picked up a little gas lamp until I can sort some acetylene out and it worked a treat. First one pretty much fell off, I put a chisel in and then heated the boss up and the chisel fell out. I was cursing until I realised it fell out because the arm had popped off. The second one took a few more persuasion taps but the other 2 weren’t playing at all. Wasn’t to much of an issue though as I just pushed the whole cluster with frozen arms off the bracket. I’ll get them home and put them on the hearth to free them.
Next step is to remove the stubborn cross tube bolt and the split pin on the idler post inner nut. Not looking forward to that.
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That big nut should come off. Needs alot of heat, cherry red, punch out the pin then use an adjustable or if you can, preferably a socket. Good luck
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I tackled the other side today and got the track adjuster loose using the propane gas lamp on the nut.
Also managed to get the nuts off the crab and bogies and free up the arms. Tomorrow I’ll try and get the bogies out of the way and get the track off.
The problem I’ve got with the inner idler post nut is the split pin is still in the hole. The head has gone and the tails pretty much gone too. I’m thinking I may just try and undo the nut and hope it chops off what’s left of the split pin.
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So your crabs weren't locked up?
That's amazing.
Keith
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So your crabs weren't locked up?
That's amazing.
Keith
Just 2 of the outer arms were frozen. The other 2 were free but I think they were pretty well protected by oil. Considering how rotten the frame is, I’m surprised at how well it’s coming apart. The big cross member (with the 3 holes in the top) has actually rotted through in one place, a whole 1/4” of steel turned to dust. I may have to split the frame to do a decent repair.
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More done today, I can’t remove the split pin from the right idler nut at the moment so it’s been drowned in penetrating fluid and I’ll try again tomorrow.
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I’ve got both sides stripped down now. Typically everything was going well yesterday, I went to remove the bogie frames from the main frame but a single bolt will not budge. It was the first of 16 bolts I removed the nuts from, but found I couldn’t push the bolt out. I forgot about it until I went to remove it as the last one before pulling the frame. I’ve had heat on it, a 5lb lump hammer, a wrench, oil and nothing. Last attempt will be to drill it out!
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Managed to get the bogie frame off today after beat the **** out of the seized bolt. After that I started on removing the rear cross member. Some of the nuts were that rotten that only a thin piece the size of a washer remained. There’s only 6 bolts left holding it in place so hopefully tomorrow that will be off and I’ll look at the idler post inner nuts.
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Can someone tell me what these holes circled in red are for? Were they for a longer idler post brace? There were 2 large bolt stubs with large castellated nuts on the inside. It would appear the heads were gas axed off when the armour was removed.
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Keep up the great work. You are making great progress!
Corey
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My crab jig was simple. You just need away to hold the crab “legs” still while you slide a thick walled set of 6’ pipes over the spring saddles. Then use a large bumper jack on the ends of the pipes. I also tapped in a zert in the center of the crap so I could get some penetrating fluid in there. Then I put a grease gun on the zert to get some pressure in there. A little heat helps too, but take care not to make a bomb.
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Thanks for the replies.
I’ve found some photos on the G503 showing the long brace but the bolts look tiny compared to the ones I pulled. Has anyone ever fitted bolts here?
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The books states for the later type arrangement it should be a pair of 3/4" 16NF x 2 1/2" bolts and the lower one should be a 1/2 20NF x 2".
Crawford
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Thanks for the reply, do you know what those bolts actually do? I know it’s a stupid question but I can’t see then in photos and I have nothing in that area. Did they just hold the armour on to the frame?
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All they do is hold the idler support rod (turn buckle) to the frame (early version), and they go through the bumper washers and help hold on the bumpers.
Steve
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Thanks, I’ve just googled a photo and I see how they go. It all becomes clear when someone point me in the right direction.
I managed to get the second idler post out today. I put as much pressure on it as I physically could with my 20T bottle Jack and it wouldn’t budge. I took 3 of the inner bracket bolts out in case they ovalised the bracket bore and then heated the bracket. It went with an almighty bang and I thought the Jack had exploded. It moved about a 1/4” but chunks of rust were thrown about 6’! Scared the crap out of me.
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Welcome to the world of old rusty restorations
Now change your underwear. Lol
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The shaft on one of my crab assemblies was frozen. I tried everything for months to get it free and I finally sent it to a local machine shop. They put it in a something like a 100 ton press and kept it under pressure. They went do work on other projects and said that it sounded like an explosion when it finally let go. I still laugh when I think about it! ;D
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I would love to say that I’d be ready for it next time.....but I’d still crap myself.