1966 D6C final drive leaking

Hello to anyone taking the time to read this post!

I have a 1966 Cat D6C dozer that was manufactured in Japan. The final drive on one side leaks when filled up, while the other side has zero leaks and maintains a consistent fluid level. I'd like to stop the leak and was curious if there are any solutions I should try before taking the whole final drive apart?

In the Ops and MTCE manual, there's a section on "Final Drive Sprocket Hub Bearings" that mentions adjusting the bearings may stop a leak. I'll attach a picture of the page for reference. The procedure mentions using a 4-5 foot bar between the track roller frame and the sprocket to check for movement—if there's play, adjustment is necessary. It goes on to say, "This checking should be made when there are no objects under the track which might put the tractor weight on the sprocket." Does this mean the tractor needs to be jacked up on that side?

Any insight or advice would be greatly appreciated!

Hi, Jprice1101.

On flat ground there is no actual weight on the sprocket as the rim of the sprocket is far enough above the ground level by design that it can't transfer any weight to the ground via the track chain.

If you have any doubts about it, place a small block about 2" thick on the ground and back the tractor up onto the block until the rear bottom track roller is directly over the block.

Hope this helps.

Just my 0.02.

Thank you Deas, I appreciate the advice.

Is there a special tool needed to tighten the hub bearing? I didn't find any mention of one in the book, but the picture shows a unique looking "wrench". Almost like a very large spanner wrench.

Thanks!

Hi, Jprice1101.

I think it is like a large collett wrench but don't quote me. Other than that, a good punch and a hammer might do the trick, although wouldn't give you much idea of what torque was being applied - and I suspect that there might be a torque spec. for it.

Just my 0.02.

Thank you Deas, I think you are under selling yourself. So far you have provided more than 0.02 worth!

Hook spanner wrench might be a term that works. OTC Tools 7308 Adjustable Hook Spanner Wrench W/2 Interchangeable Jaws - Search Shopping

As close as I can come with google.

Most of the finals on the Cats from the 50's have a bit of a leak. No big deal if it leaks it has fluid inside. The owner of a D4D told me don't do that with a next generation of Cats. See a leak take it out of use and it might only be one bearing and a seal. Run the D4 D a few more days and you could figure most everything needs to be replaced inside. Was he just unlucky? Or are the 60' to 80's Cats all like this?