Major Thiokol Problem - Help!

[shopman]

Hey all you super mechanics here abouts…

I really need help! More than you can imagine...

Here's my sad story… About 3 weeks ago my Thiokol 4T10 broke down on the way back up to the cabin. Turned out that the splined shaft that powers the right side track (out of the power selector) stripped out the yoke splines that hooks up to the drive line to the rear end. After trying a number of failed attempts at getting it up the hill with just one side of power… Oh, and in the middle of this, the clutch linkage post also broke - was able to weld it back together and that part is good again. I got it in a spot that we could work on it… by digging a tunnel in the snow underneath it! Once we got the u-joint, bearing and yoke apart I saw how bad it was (completely stripped smooth). Then went on a seek mission to find the correct yoke - or as close as possible, since in the manual it said it was modified to fit. Anyway, found one online and got it here. Amazingly it fit pretty well and today we were able to hook it back up and drive it up the mountain the rest of the way to the cabin with no issues - got it parked and ready for tearing it apart. We took both drive lines apart and found that the left one was also very bad and about to go and the shaft on the left side was even worse than the right… yeah…

We will have to pull the Power Selector take it apart and either get the splines fixed or new shafts made.

Soooo, here is where I really need the help!

1 - Has anyone ever taken apart (rebuilt) the Power Selector unit or know anyone who has?

2 - The manual says that the shafts (they go all the way through the unit on both sides) need to be pressed out… who can I take it to to do that - Transmission guy, Machinist guy, or?? Seals need to be replaced anyway, so I assume they could also do that.

3 - Can a splined shaft like that be rebuilt or is there someone who can make new ones to the same specs and who would I go to for that?

4 - The carrier bearing that holds the yoke in between the output shaft and the driveline… does it look like it should be held in position closer to the power selector and should it have to move as much as it seems to have been? I am wondering what caused this wear and if that is part of it? Someone before has modified this holding plate among other things when the rear ends that are in it were installed at some point in time.

Following are some pictures that may help with your answers and a video of how the 4T10 power selector works in action - this is the first time I have seen how it actually functions too - very cool!

http://youtu.be/OuhAo8IoBsY

Also attached is a pdf of Power Selector Tech Drawing at bottom...

 

[Mainer]

That little pig-tail is still showing even though you've been doing such a fantastic job of transforming her and nursing her back to health. Not the end of the world but maybe a few bucks to fix.

Several guys on here have taken bit and pieces apart to change clutch disks, etc...but I only know one of the guys who did a top-bottom dismantle. He posted his photos and shows the power divider dismantled. I post his 4T4 below for reference... I thought I had printed it out and posted on some paletts but no such luck. I tried search for the thread but the search engine ain't google so it's not showing based on keys that should pop it. I don't recall the forum owner of the machine or I'd just direct you there.

I'll keep looking but hoping the owner may chime up.

Boggie can easily have those made... he can do up R&P's, shortened axles, etc... so certainly can do your dealio. Unless I'm wrong in which case he'll harshly apply skin/hand in a crude fashion.

If this does not work, then let me know. I know two guys with spare sets... I've got the one but I need them. But another guy I know in the midWest has a set that he may part with once you lay your case. Actually, I'll just check with him and see what he says.

You'll know every inch of her soon!

 

[shopman]

Ain't that the truth... I will eventually be the 4T10 guru - like it or not --- oh wait that is you! But, after buying the all powerful "Pig" from the Pig I am learning more than I ever wanted too...

By the time we are done we will have replaced everything though... and I still love her! Just glad I didn't go on an extended drive way up the mountain like I had wanted to recently.

Thanks a ton for the info - I will contact Boggie if he doesn't chime in and straighten you out. We can't really take it apart until the roads dry out - at least another month or so. So, in the mean time will gather all the info we need to get it done. And maybe get another job for my little addiction

I remember seeing that post as well with that cat... he said he rebuilt it... hopefully one of us will find it. And then hope he is still around to be contacted...

 

[Mainer]

I left the guy a message and email... we'll see...

I have a power divider coming and all the running gear... I plan to first take it all apart and refurb it before installing it and document and photo it top-to-bottom just to solve this power divider issue once and for all... first I have to buy more 4T's though cuz the value will go up just like the 6's did when The Weatherby educated the world with his restore!

 

[shopman]

Alright!!! Well I'll just wait and watch...

Unless we get it done first

Then I might be buying more too, because they will become such a sought after commodity - although it's pretty hard to out-dibs the Mainer.






Thanks again for your help so far!

 

[MNoutdoors RIP]

well, we can do it. any good machine shop should be able to make that shaft
even with just a simple milling machine it can be done. it takes more steps. it takes a minimum of three passes for each spline. center once then left and right sides. the rest is is just lathe work. if you can not find someone let me know. another member on here Snowcatpat. he would be another good source.he is Little closer and does very good work.

But if you run into a snag let us know if we were to make it we would make several just because sometime in the future there will be a need .

The Sheriff's department from Carbon county Wyoming sent a man out from Wyoming to here with a broken down differential from there 4VL (SAR Vehicle)and he stayed here until we did a complete rebuild. those shafts were toast also. along with seal surfaces, bearings ,etc.... it was a mess. we did fix it next day aired in bearings and all.
The sheriff called and said they have used it for rescue since .

 

[shopman]

So, I can send it to you and you'll have it back in just a few days... Cool, I could take it to the top of the mountain still this winter!!



Really though... thanks for all the info - that is awesome that you have rebuilt one and it lives on! They really do seem tough and efficient when running well.

Did you find any problems with the gears inside or even have the need to split the case? Did you replace all the clutch discs also? What would you guess causes that kind of wear on splines - is it common?

As I said, I can't get it out for a while and will check around for a good machinist nearby in the mean time - if nobody is up to the task I will certainly call one of the two of you. I would like to do as much of the work on the outside as possible to learn more about it, but obviously don't have the tools to do what you guys do!

Thanks again - I'm feeling better about it!

 

[dlmorindds]

Shopman...like boogie said..no big deal but it is still a big deal...my two cents...hahaha...go through the whole drive system...tear into that rear differential...ya...like both sides and face reality!!!!...Ya, both sides of the rear end may need attention which can be affecting the power divider...just remember..you are in uncharter territory and ultimately will become the master of the 4T!!! Go forth grasshopper!!!

 

[dlmorindds]

By the way the Pig is the Pig...like every other cat that is sold...they all have their quirks and other misrepresented bullshit. Our job is to make these awesome machines straight and true!!

 

[shopman]

Yes, Indeed! A never ending battle to keep them running... and give us a diversion from the humdrum of reality in the real world...

Yes, you are certainly correct about taking the time to make it right, since it will be no easy task to get it out... And we need to have the sprockets revulcanized, so what better time to tear into the rear ends... Who needs a summer anyway...

Mainer & others - I found the thread for the rebuild guy with pictures...
http://www.forumsforums.com/3_9/showthread.php?t=26832

 

[dlmorindds]

Yes, Indeed! A never ending battle to keep them running... and give us a diversion from the humdrum of reality in the real world...

Yes, you are certainly correct about taking the time to make it right, since it will be no easy task to get it out... And we need to have the sprockets revulcanized, so what better time to tear into the rear ends... Who needs a summer anyway...

Mainer & others - I found the thread for the rebuild guy with pictures...
http://www.forumsforums.com/3_9/showthread.php?t=26832

I can't remember if I posted this....Stockton Rubber in CA will revulcanize sprockets like the 4T and the 4v for $350 per sprocket. Nikadog had his done at this place and is happy with the work. Going to a urathane covering via a mold process may be an option since there are quit a few of us indicating a need for some work on our sprockets. Maybe boogie can give us a better idea on doing this option.

Has the left drive shaft been modified on the piglet?

 

[tommu56]

I had to work on a printing press drive line last night and though of this thread.

Why do you need the splines on the end of the shafts? If they were straight and keyed till it gets out past the bulkhead with a straight support bearing
and a straight bore universal joint coupling half keyed to the shaft.
You would get the same result be a lot cheaper the shafts have the spline on them for the movement

just a thought from out side the box

tom

 

[Snowtrac Nome]

shopman there as an epoxy out there made by a company called belzonna yuo can use it to fix the shaft you have now i used it on both me drive hubbs on the snow trac and have hundred's of hours on it with no slop for belzonna to work it must be kept warm and mixed properly but when cured it will be as strong as steel and will weare better a hundred bucks for the kit might be worth it

 

[shopman]

Thanks Again Everyone... I was skiing all weekend for the final weekend of Monarch Ski Area... we ski, camp in parking lot and drink a "couple" beers in 6 degree snowing weather... great fun for winter lovers!

Dan - Yes, you told me about Stockton Rubber... but not the price - that is better than I had heard, so great!
-- Has the left drive shaft been modified on the piglet?
Not by me... but both rear ends were replaced and they hacked up a lot of metal to fit them in evidently. I will check the rear ends and measure all angles, etc - because you may be correct that something to do with the rear ends may have caused some of the problem. Both drive shafts are dented in a couple places.

tommu56 - (keyed vs splined...) I read about something like that on the internet, and some other possible fixes, (and question the need for splines) but we have decided to take out and rebuild as original this time because there are some leaking seals also and want to check and replace the clutches if they need it while we have it out.

dds - thanks for that info on belzonna... sounds like a good solution for something like that or something similar... but, couldn't find a place to get it - sounds like you have to get it through a rep through a company??

 

[Snowtrac Nome]

it's pricy compaired to jb weld you may have to go online to get it and it's pricy but worth every penny when you are out in the middle of no where i once used it to make a 6 volt fly wheel work on a 1600 vw motor after the flywheel came loose took a 3 pound sledge to get the fly wheel off when the motor took a dump later good stuff and all emergancy kits should have it in them