Should I buy this Cat 977H?

[ksliger]

For anyone wondering what filters to use for the transmission and clutch steering filter, I was given the following parts from my local Cat dealer. Both were in stock.

Transmission oil filter: 1R-0659
Steering clutch filter: 1R-0729

 

[Nige]

For anyone wondering what filters to use for the transmission and clutch steering filter, I was given the following parts from my local Cat dealer. Both were in stock.

Transmission oil filter: 1R-0659
Steering clutch filter: 1R-0729

But the $64k question is - do they fit.?

 

[sstocker31]

I would find a reputable private mechanic that has experience working on those older cats rather than taking it to a dealer....probably get it fixed for half the cost

 

[ksliger]

But the $64k question is - do they fit.?

I will be heading there tomorrow morning to swap out filters and transmission, bevel housing, and clutch compartment fluids and filters. I hope to have an answer to your question! And of course I hope the answer is yes, but I am cautiously optimistic.

 

[ksliger]

I would find a reputable private mechanic that has experience working on those older cats rather than taking it to a dealer....probably get it fixed for half the cost

I would very much love to do that. I am going to put out some feelers.

 

[ksliger]

I would find a reputable private mechanic that has experience working on those older cats rather than taking it to a dealer....probably get it fixed for half the cost

I was lucky and found a local mechanic who works on older Cat equipment. We are going to have the 977H dropped off at his place around the first of the year. He is fully setup to do brakes, clutches, and more. I spent some time working on it yesterday in hope of squeaking out a little bit of steering ability with the clutches. I replaced the steering clutch control filter. I drained and topped off the oil in the steering clutch control housing. I put new oil in the bevel housing and both clutch compartments. Now it steers every so slightly to the left and has just a fraction of brake on the left as well. I think it might even be steering a minuscule amount to the right. I am thinking and hoping this is enough to get it loaded up on the trailer. I have ordered some other parts for the old beast and I am still cautiously optimistic that we will bring her back to full life. I will send an update again when there is more to share. Merry Christmas to all!

 

[ksliger]

But the $64k question is - do they fit.?

I am happy to report that all filters purchased from Cat have fit thus far!

The 977H has been dropped off at the local mechanic. I am really hoping to get away with just a brake job. We did notice that the final drives were over filled. The mechanic said this could only happen by the internal (pinion?) seal between the bevel/clutch compartments leaking into the finals. He said this could mean the internal bearings are shot as well. I have read some others say that the machine can be operated with the internal leaking with no issue. Does anyone have any feedback about this? I want to keep repair costs to a bare minimum since I will probably only keep the machine a couple of years. Thanks in advance! Also curious if anyone has an opinion on what a brake job on one of these will cost. It is my understanding that the bands are rare and can't be purchased anymore, so they must be refitted with new liners.

 

[ksliger]

Almost forgot to mention that when I replaced the filters in the clutch compartments, I could see the brake bands. Each looked to have maybe 1/4” of brake lining left. However, the right brake adjuster is turned all the way in and the left one is almost all the way in, and I have no braking on the right and very slight braking on the left. I have read others say not to adjust the pedals and linkage, but wouldn’t that be my next step to try to get some braking before I pay to have new brake lining installed?

 

[63 caveman]

Did you pull the magnetic filter on the transmission? I'm pretty sure there is one.

 

[OzDozer]

The adjuster being screwed all the way in is a good clue to the fact that there's little useable lining left on the bands.
The original linings were riveted on and you could buy "woven" or "nylon" linings. The "woven" variety were metal-impregnated and lasted longer and had a better pedal "feel".

I don't know what the story is today with this obsolete Cat equipment, as regards linings - but of course, asbestos is now banned, and synthetic lining materials now take their place.
I'd be paying a visit to an industrial clutch and brake repairer and see what they can offer by way of relining.
"Bonded" (heat-treated adhesive) linings have taken over from riveting now, so I'd say you should be able to find some company that can supply new bonded linings (attached to your bands) with suitable material.

If the brakes have been re-lined previously, they may have already had bonded linings installed.

Re the leaking pinion shaft seal - this seal comprises a metal-to-metal face seal on the pinion shaft, behind the pinion flange.
Most often, the rubber toric rings that hold pressure on the metal parts of the seal get hard and lose their ability to keep the metal faces held tightly together.

As there's a considerable amount of work involved in the brake band removal, I'd go the whole hog and remove the steering clutches while you're at it, and replace the pinion seals, and the clutch piston seals.

 

[ksliger]

Did you pull the magnetic filter on the transmission? I'm pretty sure there is one.

I did replace the transmission filter. On the 977H it is on the right side of the engine and it does not have a magnetic inner part like the 977 K and L. The old beast does shift and drive forward and backwards perfectly. One thing I have not done yet is clean the suction screen filter in the bottom. I plan on doing that once I figure out my brake issue. Assuming I can get the brakes fixed, I’ll move on and replace the transmission fluid and inspect that screen. Interestingly the transmission fluid looks pretty good. Conversely the bevel housing and clutch housings had milky oil. I did purchase all new gaskets for the covers back there in hopes of keeping water out.

 

[ksliger]

The adjuster being screwed all the way in is a good clue to the fact that there's little useable lining left on the bands.
The original linings were riveted on and you could buy "woven" or "nylon" linings. The "woven" variety were metal-impregnated and lasted longer and had a better pedal "feel".

I don't know what the story is today with this obsolete Cat equipment, as regards linings - but of course, asbestos is now banned, and synthetic lining materials now take their place.
I'd be paying a visit to an industrial clutch and brake repairer and see what they can offer by way of relining.
"Bonded" (heat-treated adhesive) linings have taken over from riveting now, so I'd say you should be able to find some company that can supply new bonded linings (attached to your bands) with suitable material.

If the brakes have been re-lined previously, they may have already had bonded linings installed.

Re the leaking pinion shaft seal - this seal comprises a metal-to-metal face seal on the pinion shaft, behind the pinion flange.
Most often, the rubber toric rings that hold pressure on the metal parts of the seal get hard and lose their ability to keep the metal faces held tightly together.

As there's a considerable amount of work involved in the brake band removal, I'd go the whole hog and remove the steering clutches while you're at it, and replace the pinion seals, and the clutch piston seals.

Thanks for that info. I didn’t realize that a rivetless option was available or possible. Is there a reputable company that you can recommend for sending the bands to? Something tells me it may be hit or miss locally. The service manual describes the removal of the clutches by using the brake band as a sling. So, it all has to come out together. The manual also outlines a brake linkage adjustment process. Is the recommendation to just replace the brake lining and skip the adjustment? I can’t help but wonder if someone messed with this previously and has it buggered. I forgot to mention but I did check the adjustment specification for the clutch controls and both sides were exactly in spec at 3/16” gap per the manual. The pistons moved in and out by hand with firm resistance. This made me think the piston seals may be ok.