transmission seal

[seasonal services]

I have a 91 f-150, 4.9 straight six, auto, 170,000 miles, and the transmission seal is leaking. I put 2 quarts in it all leaked out in about a minute. I talked to a guy he told me to get a transmission from the junkyard because if the seal is bad the bearing is probaly bad too. I talked to the junkyard and they said just to replace the seal and bearing because ill probaly have the same problem with a junkyard tranny also. So i need some advice on if i should get a whole new one or just replace the seal and the bearing on the one i have.

[lwcmattlifter]

Front seal or rear, and does it have overdrive. Seals get old and brittle, the bearing might be ok. I would say pull the trans and just rebuild it. You got 170,000 on it, thats really good for an automatic. Especially if it has been worked hard.

[xcopterdoc]

No point in rebuilding if you dont have to. Sometimes you end up with something worse than what you have! I dont think there is an actual bearing on the output shaft. I believe its a bushing. The output seal is located in what is refered to as the extension housing. A new extension housing with bushings, minus the seal can be had from Ford for about 300 bucks plus about 10 bucks for the seal and 1.5 hrs labor for install. Thats IF the bushing is bad. If you are mechanically inclined, remove the drive shaft and check for excessive radial (up, down, side to side) play on the output shaft. Also check for anything else amiss, cracked housing, a large groove in the slide in yoke where the seal rides.

[CCWKen]

Doc's right. Don't spend the cash to rebuild it unless it slips or makes noise. You most likely have the Ford AOD trans and it has a bushing and seal at the rear of the extension housing. I'm not sure I'd spend $300 for a rear housing unless it's cracked. The seal, gasket and bushing can be had for about $20. If you have a bushing puller, you don't even have to remove the rear housing and can skip the housing gasket. Otherwise, pull the rear extension. You'll need to remove the lower pan to drain the fluid so get a "filter kit" and fluid too.

Here's some part numbers to start a check. The numbers may be superceided but Ford Parts can find the current number from these.

Rear Seal - E2DZ7052A
Rear Bushing - B3TZ7A034B
Housing Gasket - EOAZ7086A

[xcopterdoc]

Right on Ken.. good info.. theres a TB that recomends front and rear bushings "should" be r/r at the same time. That and the fact that removing those rear bushings without the right stuff is NASTY, I figured it might be a faster and better fix for him to r/r the extension housing.

[xcopterdoc]

I'm showing the same numbers also Ken.. looks good.