Transmission Cover Gasket

Hey bernie;
I really hope that the repairs you speak of do not include high heat and brass filler rod
I say this because the casting looks like it could crack or bust due to overtightening in areas because it is unsupported at the bolt circle around the outside.
Also will a thick gasket give you linkage alinement problems?
Why not use the blue CAT brand rtv sealant on that case as it is subject only slung oil and not below oil level
only my opinion ,and we all know about opinions!

Greyhead,
Well, you hit it. Shock and awe Saturday. It took my son and I over an hour to seat the cover as my hoist reach is not long enough. Crib and lower, crib and lower a little at a time. I spent an hour carefully tightening around the case alternating on opposite bolts a little at a time with only a short handled ratchet so not to apply too much torque.

Finally we resolved to remove it as the linkage did not match as you suggest and I did not want to pull it down any more. . While working with the main clutch linkage prior to loosening the cover bolts the "pop" occurred. Not a big crack, but a crack. I was sick.

I have a buddy coming over tonight or tomorrow to weld it before I remove it. I will replace the gasket and move on. I build a temp rafter overhead to assist in its re-installation. I really thought the seal material was a better product than the cork gasket. I regret if anything not sticking to the 3/8"...the packing is a pretty dense material but I hammered it to soften it some prior to install.

I was avoiding the RTV-I would opt for the gasket, event he high $$$ from CAT if I thought it were the right tool. Still not sure. Making one is no biggie, but the thickness is still bothersome due to the void in the rim of the case where the gasket is supposed to seat. The thickest material I found is 1/4 inch.

Anyway, the weld will be in place by weeks end. And moving on from there. Regardless it was/is nice to see the cover in place. Good news is I still have not unwrapped the CAT gaskets...

Thanks for looking this over and thinking it through.

bernie

Bernie,
Sorry to hear about the problems. I got to thinking that if there's a hydraulic supplier/shop close, you might call 'em about O-ring stock. It's made in a bunch of different sizes and compositions for those that have the kit to make their own o-rings. Basically ya cut it to length and use some type of Superglue to glue the ends together. Instant o-ring!

When I reworked my steering clutches I reused the old seal. .along with some gookempuckey (RTV Silicone) and haven't seen any sign of a leak yet. As I recall, the old seal had a sort of "D" shape to it but it could have taken that shape from the years it had been in there. A fairly soft o-ring material of the right diameter (3/8" diameter?) would probably do the job.

It is such a silly and simple issue to even bring up. By now anyone seeing my posts knows I put it all out there. I have checked with tranny shop and no oring that big. Your read my mind. I do not want to use silicone unless I have to. I do not want to use the CAT gasket as it just does not look right and too much money.

What would work the best I think is solid wood stove rope gasket imregnated with graphite. Not as dense as the packing I used. The packing was the solution except it is too big...why there is not an extruded cork stock or square/rectangular cork stock available, I am not sure.

I may use a 1/8" homeade I have already started and use silicone filler for the groove.

Welding up the crack this evening. Next step over the weekend.

bernie

Hey, bernie;
Check your local -Motion industries- they will have O-rings of 1/4 to 5/16 dia. you will need to come up with the major dia around the case.
They will ask what mat. buna or viton
buna is the softest and cheaper viton is for higher heat and higher pressure FYI
If not I have rolls of 1/4x1/2 neoprem rubber sticky on one side and oil rated
PM if this will work its a drive but not a long one.

Hey, bernie;
Check your local -Motion industries- they will have O-rings of 1/4 to 5/16 dia. you will need to come up with the major dia around the case.
They will ask what mat. buna or viton
buna is the softest and cheaper viton is for higher heat and higher pressure FYI
If not I have rolls of 1/4x1/2 neoprem rubber sticky on one side and oil rated
PM if this will work its a drive but not a long one.

Your local boiler supply company (large heating systems) has a wide array of bulk gasket material in many different materials and sizes. You want to get to th oldest guy behind the counter. JEFF

On a whim I went to my bearing "go to guy" this afternoon. When I called him he had the 3/8" cord, but only five feet...I knew I needed closer to six...I went over anyway to snoop around-I asked him to get me the bag with the rubber cord...label read "five feet"...I said, hey let's measure it...we did...70 inches...may be close, but I think it will work.

If you need something, try Neil at Tri-State Bearing. Located in Bloomington Vincennes Evansville Indiana at least. Maybe elsewhere.

"...Seek and ye shall find..."

Anyway, thanks for all the suggestions. Planning on getting back to it this evening. Kids are too old to Trick or Treat, so I think I can stay home.

bernie

I'm getting ready to bolt the tranny top back on my D4 7J and was looking through old posts researching the correct gaskets to use when I came across your posts Bernie, thanks for sharing your experience at the time.

How did the 3/8th "O" ring cord work out for sealing the actual gearbox, and what material did you decide on for sealing the rear of the transmission around the steering clutches and behind the crown wheel housing where you didn't use the 3/8th rubber cord? I have access to the rubberised cork in different thickness's, not sure how easy it will be to access that 3/8th "O" ring material, because like you, I'm not married to Paris Hilton so a buck is a buck to me, and $44 for each gaskets sounds like a lot of coin to this little Black Duck!😆
regards
Mike