1998 f150 extended cab
v-8 auto transmission 4x2
everything stock
roughly 120k miles


so the other day i took a drive down the road and noticed some smoke coming off my truck in my rearview. so i pulled over and opened the hood and everything seemed to be in order. i took a look underneath and there was tranny fluid that got all over and on the cross over exhaust pipe which caused the smoke i had seen.

Looking at the back of the transmission the seal that goes inbetween that and the yolk (correct term?) has just come out.(what is that seal called?) the boot on it is still intact but it had just come out.

truck has not been offroaded and used for casual commuting, so it boggles my mind that the seal would just pop out and when trying to stick it back in to get it home it was more difficult than one would hope. Does this normally happen?

also any tips, tricks, or methods on disconnecting the driveshaft, yolk out, putting the new seal in and putting everything back together??


much thanks to all who can help

 

seal's name is the output shaft seal. Remove driveshaft, install new seal, install driveshaft... very easy job... oh and when you're done... refill trans

 

thanks for your response, I guess im more worried that it just fell out, is that normal or even heard of?

 

Thats odd but I have seen it before, make sure the new seal fits the housing right or you may need a new housing.
Alan

 

Inspect the bushing that the driveshaft yolk rides on. If that's damaged the new seal isn't going to last very long.

 

HI!... I had the same thing happen to my truck years ago. I would usually blow out the tailstock seal after 100MPH. Found out later that the slip yoke was bad . Ford had a huge issue with bad slip yokes on the 97 - 2000 trucks. Metals too soft. The slip yoke would wear out causing a lot of wear on the slip yoke bushing. Then you get a bad vibration and the seal would pop out. Got a after market slip yoke, bushing and seal. My tranny builder expoxied the seal in and I had the diveshat balanced. Never had a problem again and I been over 150MPH in the truck. Check your slip yoke for wear or scratch marks on the shaft that goes into the tailstock. Also look at the slip yoke bushing with a flashlight to make sure it is undamaged.

 

Neal, I am in the process of replacing the transmission mount on my 1999 F-150 with automatic transmission because there is a loud buzz when idling in gear. I suspect oil leaking over the rubber caused the rubber of the mount to deteriorate. Reading your post makes me wonder if my slip yoke is the root cause of all this trouble.

Can you tell us something more about the after market slip yoke you installed? Was installation a big job? I'd be doing anything lying under the pickup on my driveway!

 

sorry to bring this easy subject up once again, this is more of a weekend project for me.. (slow progress)... I have the u joint out and the old seal out but the new seal is a lil tough to get in correctly... it seems that only one side wants to get in crooked due to the tight fit.... any advice?

 

reply might be a little too late but I used a PVC pipe coupler(I think one for 2" pipe fits it perfectly.) Put something flat and hard on 1 end and pound away.