We have a 953 C , 2zn , we put an undercarriage on 3 years ago. The segements are starting to come loose , one bolt then other then the whole segement is loose. We are keeping an eye on it , when I installed them I cleaned both the hub and segement used new trek bolts and tightened to 300 ftlbs torque. After the first few came loose we took a 3/4 impact and poured it to all of them. They are still coming loose. Do I just need to get all new cat bolts , loctite , and torque to spec or what?
Using Cat hardware would be a plus. Also look at the bolt holes and make sure they aren't longated. If they are the only thing you can do is go with the new bolts and keep a close eye on them. One other thing you may do if the holes are messed up, is after you replace the hardware spot weld the segments. Don't weld them solid, just stitch weld them in maybe 3 or 4 places. That will go a long way in keeping them in place until they need to be replaced again. Then when replacing them cut thru the segment just off to the edge of the weld to remove the segment and install a new one, and then stitch weld it in place. Just my 0.02 worth
had a friend with this problem, i think he had cat segments and berco rails. i don't know if he ever got it straightened out or not.
There were some early problems with them coming loose and cat changed the bolts and torque specs. Do you have a regular nut or a square nut on the bolts?
It has the square nut behind. The torque specs I got when installing was from the u/c salesman. It is a little annoying when it is fine then you spend two days up and down the road for bolts and to keep checking them. What do you all think about changing the bolts to cat , loctite and putting 3/4 hammer on and set on it.
Are the bolts and segments Cat? We have customers who put aftermarket on their D8's (more then two dozer's) and they kept coming loose. It finally wallowed out the bolt holes and we replaced the hubs on the finals. They have since changed back to Cat and they haven't had anymore issues.
I'd look in the repair manual for the specs. I was breaking lots of track bolts in my 955L, replacing them by the dozen, even though I was torquing them to the spec I was given and using genuine CAT bolts and nuts. Then I bought my own manual and discovered that you torque the bolts THEN turn them another 120° to stretch them. Only one broken bolt in a year since then.
Most Cat bolts that have a high clamping force use a torque turn. Head bolts, track bolts and sprocket bolts just to name a few. It is a more accurate way to get the correct torque. A 953 sprocket bolt is 130ftlbs plus 120 deg turn(two flats) Antiseize should be used. Snug the bolt first, then torque the inner two bolt before the outer ones.
The bolts are trek , some have been changed to cat. The segements are berco.
When machines come into the shop with loose segments we always replace the segment hardware with new. I agree with Riganddig. Weld the segments together. If your bolt holes are wallowed out I would either replace the hub or you can try welding the segments to the hub. Good luck, Quicktrax
The segments our customer had that came loose were also berco. Are the segments machined flat on the mounting surface or are they just plane castings?
Next chance I'll pull one to look at the back , memory says there was a notch of sorts? Thank you all.