D3B track tensioner problem

[NMBlackBetty]

So we have an '86 Cat d3b (27y) serial. The track tensioner blew out. We're about 6 weeks away from rebuilding the entire undercarriage, from the chain/track down to idlers and tensioners. This blow out couldn't have happened at a worse time, it's 6 weeks to get all the parts as we had to order from many different places as a lot of the parts are "obsolete" from cat we've been told.

I was able to get a repack kit for the tensioner, but taking the track off right now isn't an option. The service manual says the "pin with a dimple" is the pin that will come out, but the entire track chain is so far gone, there is no dimple left to be found. When the new stuff comes in, I'm just cutting it off with a torch.

I've been told "unless you want to lose your head, don't take off the bolts that hold the spring under tension" so without doing that, I don't see any way to get the yolk out of the cylinder to repack it.

Hoping some of you guys who play with this stuff all the time can shed some light.

Photos attached.

 

[pittsburgh cat man]

I can tell you how we did one in a pinch to finish a job. we pushed idler all the way in unbolted yoke at idler pulled idler out to tension the track then used longer bolts and a lot of washers to make up the space between idler and yoke

 

[NMBlackBetty]

I can tell you how we did one in a pinch to finish a job. we pushed idler all the way in unbolted yoke at idler pulled idler out to tension the track then used longer bolts and a lot of washers to make up the space between idler and yoke

Thanks for the tip! Unfortunately I think I would need 9" or more of bolt/washer to make that work, and that wouldn't hold up to the work load on that small yet very long bolt I believe. I'd really like to find a way to get the yolk out and re-pack it quick.

 

[Junkyard]

While I don’t condone it…..I’ve seen a bottle jack used in a pinch. Nothing is more permanent than a temporary fix lol.

 

[NMBlackBetty]

While I don’t condone it…..I’ve seen a bottle jack used in a pinch. Nothing is more permanent than a temporary fix lol.

I've been there, we have a good bit of old iron with temp fixes that have been there for years. Fortunately in this case the rest of the undercarriage is shot and everything is already on order.

Your bottle jack solution, are you talking to cut the yolk and weld a bottle jack in its place? Or am I way off base? We only have maybe 60 hours left on this job on the ranch, then it can sit until the new undercarriage arrives, but I need a solid 60hour fix, that's why I bought the repack kit thinking it would be easy until I read that removal of that spring without a special, expensive tool could take my head off.

 

[Welder Dave]

It's odd it doesn't have a split master link. If the track is really loose with the idler all the way back you may be able to take the track off without splitting it, fix the tensioner and wrestle the track back on. It's no different than a track coming off in the field.

 

[Mcrafty1]

It's odd it doesn't have a split master link. If the track is really loose with the idler all the way back you may be able to take the track off without splitting it, fix the tensioner and wrestle the track back on. It's no different than a track coming off in the field.

If the tracks are that worn out that is definitely possible and is likely the easiest and quickest approach.

 

[Welder Dave]

You can also move the machine to an ideal location to put the track back on where it's easy to lift it if needed.

 

[NMBlackBetty]

You can also move the machine to an ideal location to put the track back on where it's easy to lift it if needed.

I'm blessed with a few port-a-powers and the machine is only 16k lbs

I think the solution I'm going to go with is the good old fashioned F-it approach. I cut some half inch steel plate tonight and tomorrow I'm going to push the track back out and just weld the carriage wheel in place. It will likely eat the rest of the chain in working it that way, but a new chain, shoes, idlers, tensioner, sprockets and carriage wheel will be here in 5.5 weeks so why not right. I can air arc the welds off, grind them down and repair the carriage fave when we rebuild that entire side.

What's the worst that can happen right?

That was sarcasm, I'm quite confident I will end up regretting doing this in a week or two, but for now it gets it pushing earth for a little while.

 

[Welder Dave]

Without the coil spring to absorb shock loads I think you could do some serious damage to final drives if you ran the machine for more than a short distance.