Sm420 what should i do with it?

[42_NATO]

So finally got the clutch in and now i look at this nasty transmission and wonder why it's covered in so much crime and wonder what I can do should I just clean it up or should I replace gaskets.what do u guys think?

[61K10]

Clean it before any gasket replacement. It's just manual labor lol! My 420 had some under coating sprayed on it and it was tough to remove.

[Softpatch]

Boat anchor !...oh wait were you from tolleson.? like Texas.?
How about counterbalance for barn door.?

[42_NATO]

Originally Posted by 42_NATO

So finally got the clutch in and now i look at this nasty transmission and wonder why it's covered in so much crime and wonder what I can do should I just clean it up or should I replace gaskets.what do u guys think?

pics

[42_NATO]

There was alot of grime slash foam. Not sure it gear oil or some obe sprayed it with somthing

[42_NATO]

Originally Posted by Softpatch

Boat anchor !...oh wait were you from tolleson.? like Texas.?
How about counterbalance for barn door.?

Tolleson arizona

[Chknlyps2]

Originally Posted by 42_NATO

There was alot of grime slash foam. Not sure it gear oil or some obe sprayed it with somthing

Was the bell housing just as dirty? Could be years and years of engine leaks being blown back from the fan and road wind. I have seen many auto trannys caked with grime like that on top and above the torque converter and there is no place they can leak there.

[42_NATO]

Yes the bell housing was the same . the engine leaks from the front seal. But not enough this seems to be old caked on stuff. I thought it may have been from the tranny. I will started the cleaning soon

[sags]

I took mine out and had the same differently- colored grime. The new one I picked up had a foam ring that sits on top under the transmission hump in the cab. I think after 50 years, that ring just melted. Cleaned mine up with a wire brush and lots of scraping. Came out like new. Let me know if you want pics.

[urmyboyblue]

Use some Easy Off on it, let it set for a few and wash it off with a pressure washer. Don't get Easy Off on the rubber boot! Works like a champ.

[66Gilbert]

Originally Posted by sags

I took mine out and had the same differently- colored grime. The new one I picked up had a foam ring that sits on top under the transmission hump in the cab. I think after 50 years, that ring just melted. Cleaned mine up with a wire brush and lots of scraping. Came out like new. Let me know if you want pics.

What sags just mentioned. A lot of that is the foam heat and noise control seal that has melted after 50 years of heat and absorbing some oil. Every SM 420 I have removed looked just like the one pictured above.

[42_NATO]

Originally Posted by 66Gilbert

What sags just mentioned. A lot of that is the foam heat and noise control seal that has melted after 50 years of heat and absorbing some oil. Every SM 420 I have removed looked just like the one pictured above.

Yea thats what it looks like

[42_NATO]

So i finally got it mostly all back together. And she all up and running. Did find a gear oil leak at the rear were the drive line hooks up to it

[oem4me]

The foam seal had melted indeed. My Suburban has low miles and no oil leaks, yet that foam seal had turned to tar and was slowly running down the sides of the trans. I too was puzzled at first about the sticky goo on the driveway.