rear seal

[Michael R.]

PM sent, with thanks.

[Michael R.]

Vehicles built before Serial #13087 may not have these two seals. Using the dimensions indicated, one could grind and machine as applicable for installation of the oil seal.
Publication date 27-4-43.

[Michael R.]

Has anyone had any success finding a modern replacement for this transmission oil seal.
? Perhaps 440265 ?

[rob love]

I just bought one or two for the transmission a few weeks ago.
Looking at my orders, the seal was National 473235 which has a shaft size of 1.687 and fits into a bore of 2.623. If you are using a used gear and it has a groove worn into it, you can sleeve it with a speedi-sleeve pn 99168. I got both sent from Rock auto for $6.49 for the seal and $18.23 for the sleeve. With delivery to Canada it was around $40 Cdn. The sleeve alone costs more than that here, and that is with our government discount.

I actually ordered two of the seals because they are thinner, and was going to stack them. In the end I didn't bother since I installed a sealed bearing on both the input and output shafts of the transmission, so there will be minimal oil getting to the seal anyway.

For the seal at the diff pinion, I found that the rear wheel seal for a 76 Chev 5/4 ton was pretty close to the right shaft size. I turned down the coupler to the correct size, then sleeved it as well for a good finish.

I turned an adapter for the 5/4 seal so it would fit into the differential bore. Took maybe an hour and a half to spin on the lathe, but I did slice my thumb a good one in the process on some of the razor sharp shaving.

I have photos at work that I might post tomorrow if anyone wants to see examples. (the seals and retainer....not my thumb).

Edited to add: I looked up your number Ross and they have no spring so are just for grease retention up to 2000 RPM. The carrier, with 1:1 ratio on 4th gear, is going to exceed that, not to mention you are retaining oil. The 473235 is rated for 3000 foot per minute. Too late tonight to do the math to convert to RPM but siffice to say it is higher than 2000. You have to put pi (3.1415.....) to work to figure it out. Who said we would never use trig in real life.

[Michael R.]

Great, thanks Rob.
I understand the design limitations of the 440 style without a garter spring vs the 470 with garter spring. I did not consider it, being drawn towards the greater width at 0.375 on the 440265 vs 0.311 on the 473235.

[rob love]

Some photos I had on file.

[Lynn Eades]

I'd like to know how critical you guys think these seals are?
While remembering the first 13,000 carriers were built without either seal in them, I can see it might be a problem if a carrier were parked on a serious (rediculous) slope (facing up or down) some of the oil might migrate from the diff. to the gear box, (or vicki verco)
Other than that, I suspect the oil basically stays in one end or the other.
Back in the day, they were never assembled with sealed bearings(as far as I know)
However, someone did though, decide seals were needed and modified the housing to suit, so logic dictates that there was a need.
Is anyone running a carrier that; A. has no seals in it (ie. un modified) and B., Is having problems with oil transfer? (or other issues, like oil in the speedo cable, etc.)
Rob and Michael R, are you guys doing this mod because of problems you have experienced? Or is it because you have later carriers that were made to take seals anyhow?