700R4 rear seal

[batmo]

I recall running accross a thread somewhere about an updated rear seal for the 700 trnas that had a double lip. anyone know where I can find that part number?

my rear seal is leaking, I replaced it when I rebuilt the trans but its been a few years and Im getting a small puddle sometimes.

also it seems it is leaking through the yoke too because I see wetness behind the dampner by the u-joint. how is that possible? mabey its something else?

thanks

[lockdoc]

There is a hole in yoke that had a plastic plug. It's probably not there now. You can weld the hole or similar. I've also heard of stuffing a suberball down the tube.

[SafariRob]

Batmo, when my 89 Astro started leaking ATF out of the transmission tailstock, I also thought the rear seal had given up. But that wasn't the case. Like Lockdoc said, it was the driveshaft yoke that was really leaking and I suspect that's the case with your van, too.
I fixed mine by replacing the driveshaft with the one from my 89 Safari. That's a bit extreme I now realize, but I didn't check into why the yoke was leaking at the time. Since I had the Safari driveshaft stashed away, I just grabbed and installed it.
I still have the original Astro driveshaft, I'll try to get a photo of what causes the problem.

[LaGrasta]

I have this problem too, but very small. Over the years, the leak has slowly been eating away my transmission tailshaft rubber mount. With so many miles on the van, i was just planning on taking care of all this during my expected upcoming tranny swap. I f I can stuff a super ball int eh yoke or something easy like that, I'll take of it now. I'll be following this thread.

[batmo]

There is a hole in yoke that had a plastic plug. It's probably not there now. You can weld the hole or similar. I've also heard of stuffing a suberball down the tube.

I'll look at that first chance I get THANKS!

still intrested in that double lip rear seal Ive read about somewhere if anyone knows.

[robertg]

i was curious about this, too. here's what i found. i looked up a 1990 and a 2000 model astro van.... here's what i found in napa part numbers..

the 1990 rwd model calls for a napa oil seal # 15041. here's the specs per napa's catalog.

I.D.:1.5000"
O.D.:2.3810"
Width:.4530"
Product Features:Spring Loaded w/ Auxiliary Dirt lip

the 2000 rwd model calls for a napa oil seal # 15133. here's a picture and the specs per napa's catalog.

I.D.:1.5030"
O.D.:2.3740"
Width:.3740"
Product Features:Spring Loaded
Auxiliary Dirt Lip w/ Excluder Dirt Boot

i don't think that the slight differences in the o.d. and width on the listing for the 4l60e will make that much of a difference in how it fits into your older transmission.

[batmo]

robertg, great info!

It looks like its definately worth a try to install in the 700