1948 d6 9u track adjuster

[m10878]

got an old 9u threw a track off about 6 months ago and its been sitting since. when trying to compress the adjuster (screw type) it feels froze up me and my pa both on a 2 foot pipe wrench with a 6 foot bar on the end couldnt turn it wondering if were doing something wrong.

we loosened up the 4 bolts right behind the bogie wheel and put the pipe wrench right behing that on the octoganal piece right behind that and tryed with no luck, still havent got it to budge. were kinda guessing on how to do this ecause neither one of us have any experience, any help would be appriciated been searching for a couple hours now with no luck.

[Old Magnet]

Seems like your following the right procedure....there is a limit to the adjustment and if you go beyond you are likely to strip the threads in the adjuster nut.
There is a greese zerk on the nut to help keep them from freezing up assuming they have been greased.
They also freeze/rust to the idler yoke and don't release when the four clamping bolts are loosened....little hammer work and maybe some heat should help.

[m10878]

as always thank you old magnet. i guess the only other question i have is if you know of anyway to make this any easier i read something about putting the pipe wrench on and lifting the carriage up willing to try it but mostly just sounds like a good way to bust a few pipe wrenches. we'll probably get some oxy/cetaline on monday out here nothings open on sunday and it looks like what you were saying about those 4 clamping bolt they do look froze but the sledge hammer didint make much differnce but proably play with it a little bit tomorrow see if we can get it to unfreeze if not apply some heat on monday.

but again thanks magnet

[ccjersey]

Amazing how hard that old grease can weld in there on that thread. Actually, I think it's usually that there's rust in there because of lack of greasing, but between the rust and the hard grease behind it, heating the "nut" while someone bounces up and down on the cheater bar should help a lot.

You probably will want to turn it whichever way has you pushing down on the wrench, at least until you get it to move a turn or two. then I would turn it out (tightening the track) and clean the threads and oil it before you screw it in to put the track back on.

Especially If you have on of those aluminum pipe wrenches, make sure to slide the cheater well up on the handle and not go for broke with the pipe out on the end of the handle.

[edb]

Hi Team,
along with the good info above I have found on some units that the lock bolts are seized/rusted into their holes in the yoke. As a result the yoke cannot spread and release it's locking grip on the adjuster bolt. You might try and drive a wedge into the gap of the split and then try to drive the bolts thru a bit to be sure of some yoke tension release. Some penetrant and heat here can work wonders.
Cheers,
Eddie B.

[m10878]

on those attatchments old magnet added say not to exceed 8 and 1/4 inchs this side is well passed that its closer to 10 inches to a foot if it is off the threads is there an way to get it back on we got the yoke split enough to get the wheel to rock tryed turning it either way with heat and used about a gallon of cutting oil and still getting no where.

[m10878]

there are no exposed threads at all and the shaft is pulled so far out where it tapers down to about half the size is visible toward the spring.

i can get some pictures later on in the day if they would help.

[ccjersey]

If it's screwed all the way out and has been run like that, both the female and male threads are likely battered. As long as your recoil spring bolt is not broken, you can unbolt the "nut", the guide tube the adjuster runs through and the "fork" that bolts on the front idler bearings on each side and lift that all off to get enough room for the idler to move back and get the track back on.

Pictures would be useful. I didn't know that the adjuster screw had any thin sections. I thought it was about the same diameter all the way from end to end, just had a ring cut in it in the front where the yoke clamps on it and threads on the other end. Sounds like that one may have some homegrown engineering done on it! How far out on the end of the track roller frame is the front idler? any frame left sticking out past the bearing blocks in the front? If so, how many track pads/links are there?

Standard tracks were 39 link with small front idlers,
40 with the larger 27" diameter ones which were for dozers mostly, and
45 with the 7 roller track frame and large idlers (pipe layer option)

You may have a set of tracks which has had a link cut out to keep them going.

[m10878]

27" front idlers and 39 links so somethings not adding up. pulling the whole assembly wouldnt help cause we would still have to put it back on with not enough space. has 6 rollers on the bottom and 2 on top. cameras fried so i cant get pictures today. everything is all original but it does look like the adjusters over extended. were gonna have to replace one link my dad cut off any ideas where to get one cheap? front yoke is no longer siezed so im guessing its froze up on the back probably over extended. hoping to have enough clearance when we put a new link on to just put it back together and run it like it was before. kkinda lost at this point.

may have had a link cut out before but i dont understand how the adjuster could get over extended a link short. the adjuster is 9 inches visible from the yoke to the guide tube. didnt think to measure past that.

[Old Magnet]

Probably a bit of history there.
Usually starts when track wears to the point the adjuster strips.
An enterprizing sole could figure out how to recover use by utilizing threads furthur back, but then finds the adjuster screw needs to be longer and splices in an extension. Eventually adjustment winds up at the same point and then a track link is removed to make it work. More time/wear goes by and your back to the fix your are now in.

Not neccessarily in that order but I've seen em all. That's one tractor that Cat designed to sell undercarriage. Made it very difficult to run undercarriage to destruction.