Jde.Track issues/O.C.4

[Lou from Wi.]

Jde,Started the crawler up today and Would you believe the fuel pump we rebuilt with the kit FAILED. Wouldn't pump fuel after about 10 min of running. I wouldn't go for another repair kit. Back on the electric now. Crawler run great.buTTTTTTTTTTTTTTTTTTT now a problem came up(with chain only)when we put the crawler in reverse mode.The crawler is in the air (on Blocks)no contact with the floor at all .When we engauged the track chain it Wanted to bind against the link(right side only)slack was mostly removed so we could watch the movement of the chain, so when in reverse the chain on the sprocket tooth rubbed the link. Now we did the chain on only. Was wondering if the pads had to be on the track and the track lowered so the bottom rollers guided the chain onto the rear sprocket would be necessary to correct the problem of binding/rubbing. Tried to re-position the front idler to adjust the side movement of the chain.Didn;t help at all.From the drivers side,(LS) the chain works O.K.in forward/reverse mode.Thought maybe the track had to be complete(with pads installed) so the lower rollers guided the chain/tracks correctly so the rubbing/binding wouldnt happen. The chain was drawn tight and made NO CONTACT WITH THE LOWER ROLLERS.Is this the problem???? Or could it be that,when up on blocks, the track frame is slightly twisting,causing the chain to run odd and bind on the inside of the sprocket?We took a tape measure and checked the sprocket for any irregularities of side play,but there was none.The front idler are all new (hub and axles)no play in them to cause any wobble or misalignment.Maybe it is something we aren't thinking of,but maybe you have run into it,one time or another.Picture shows dozer on blocks and it is how we tried it,no chain touching floor or bottom rollers.Really APPRECIATE you HELP With this problem so we can fasten on the track plates. Warmest reguards LOU& VICTOR

 

[Anonymous-0]

If your sprocket is in line with the idler the chain should run straight unless something is pushing the chain over. Are there any shims for adjusting the idler? Maybe using a long straight edge or a tight piece of string will tell you if the idler and sprocket are lined up properly. Could one of the blocks holding the machine up be hitting the chain? It looks like there is a spring on each side of the idlers. Could one side be tighter than the other and pulling the idler one way? Just some thoughts. Dave

 

[Lou from Wi.]

Thank s Dave,
No shims on the idler on this model,just axle to bracket on the idler. Blocks are clear of the chain, have clearence to spare.The springs are adjusted to manual specifications of 6 1/4" compressed length.We even tried playing with the spring tension, to no avail.Just going forward, chain is even on the sprocket tooth, just having trouble when reverse is selected, it (chain)wants to rub the inside of the sprocket tooth.Was wondering if JDE would know if it had to have the pads on the chain and be setting on the ground ingageing the bottom rollers for the chain to center on the sprocket with the reverse selected.Going to try several things tomorrow to see if we can solve the problem.Thanks,LOU

 

[Anonymous-0]

It could just be the sprocket isn't completely square. I put new weld on sprocket rims on my Cat and they were very rough castings and the teeth weren't exactly square. It might also just be the way the chain pulls when in reverse. Dave

 

[Anonymous-0]

Lou; I took a straight-edge to your picture on the computer screen. The last two links bend inward. I might be an optical illusion, but just a thought. You said the dozer was rolled over at one time. Good Luck.

 

[Lou from Wi.]

Hi Rich. Thanks for the reply.When we re-pined and re-bushed the track chain all is straight as an arrow. (layed it out on the garage floor which is level)so we hung the chain on the sprocket and front idler roller. Started the crawler to watch the track to see if anything showed up as OUT OF ALIGNMENT. Didn"t appear to be. Ran the crawler and watched the chain going forward. Had clearance on the rear sprocket (even spacing)where it nestles in the grove of the sprocket. Even the front idler assembly spacing looked good. Now the problem came up when we reversed the movement of the chain. Started to run against the rear sprocket (inside groove of the sprocket causing it to bind.Now the chain doesn"t come in contact with the lower rollers because the crawler is up on blocking. The rear sprockes are like NEW and showed no wear what so ever. They were changed by the previous owner cause the original was busted when the unit was up-righted. We replaced the final drive housing (L.S facing the rear of the crawler) new bull gear,trunion etc. Shims included to get preload on the bearings. That worked out fine. Although we used the old Track frame support bracket(inner and outer)but now we noticed there was no shim between the inner bracket and housing. Gonna re-do both inner and outer support brackets with new shim. The Old ones could have been worn so badly when we re-installed the frame and I suspect that has a lot to do with the reverse motion of the chain binding chain to the rear sprocket. Now this is our FIRST attempt at re-working the crawler to make it whole again.We have never under went this venture EVER.We followed the shop manual
specs to do the job RIGHT, but something is amiss and don"t know where it could be.!!!!. Was wondering if Jde(who used to work on track would have any indication as to where the problem may lie or where we went wrong. I know it"s got to be right before we install the pads, otherwise we would not be able to see if it all lines up as it"s supposed to be and NOT BIND AGAINST THE SPROCKET. We re-positioned the front idler to see if it made any difference. IT DIDN"T.!!!
Gonna try and measure the track frame bottom to see if there is any difference in the height of the roller frame from the level floor. What other suggestions would you have that might solve our problem? Bolt spacing on each link is exactly the same where the pads bolt on. All the links are level so the pads will be right when their installed. Any suggestions would be helpfull!!!!!!!!!! Reguards. LOU & VICTOR.

 

[Lou from Wi.]

Dave, The left side (facing the rear) has NO issues with it binding against the sprocket. Just the right side. Done no welding on the chain or sprockets Both sprockets were replaced with like new when the previous owner had it. Old pictures we posted will show the condition of em. Thanks for the reply
LOU.

 

[Anonymous-0]

Lou; After you redo your shims and I know this is alot of work, but if the track chains are symetrical, I would switch sides and see if the issue still persists. This might eliminate any issues being "chain related".

 

[Lou from Wi.]

Thanks RICH,
Thats one of the options we're looking at.We'll try anything to eleviate the problem. Reguards,LOU

 

[Steve in VA]

Lou,
Here"s my 2 cents worth. Since the crawler is lifted and clear of the rollers then it would seem that the only delta between forward and reverse is the top roller. Traveling forward the chain centers on the sprocket; in reverse the top roller may be guiding the chain off-center. None of the earlier posts mentioned inspecting the top roller.

 

[Lou from Wi.]

Steve. Thanks for the input. Our O.C.46 has no top roller. Wish it did, But he found the problem today and now it's fixed, and runs the chain great. LOU