never do the underbody spray at carwashes. i learned the hard way. ran my truck through the car wash yesterday morning. and didnt know that the tailshaft seal had been blown out.. i drove about 200+ miles yesterday and on my way back from Jarrell, Tx the converter started to shutter and vibrations in 1st and 2nd got home smoke is coming from under body i look and the tail shaft seal and bushing had come off and about 4.5quarts of fluid had leaked out. im glad ive got the +3quart pan from B&M or id be screwed. but we got the bushing and seal back in there.. now just gotta clean all the oil off the bumper and tailgate.

sorry no pics i was to pissed off to take them.

 

The carwash spray blew the seal out?

 

HI!... I highly dought it had anything to do with the car wash. The F-150's with the 4R70-W were known for pushing the slipyoke bushing and seal out. Usually due to the slip yoke being messed up and causing a bad vibration. Mine went in for warranty work for this 3 times. You were always complaining about a vibration lately and kept getting your driveshaft re-ballanced. Did you ever get the slip joke replaced with a new one. The factory ones were made out of softer than normal material and would wear out. Many times after going 100mph + I would blow out the slip yoke bushing. When installing the new one make sure you lock it in with some kind of thread locker designed for the bushing.

 

yah it must have thats my only reason for that seal to pop out of there. the high pressure was enough to blast the damn underbody coating off the truck so it musta been what caught the outer lip on that seal and blew it out.

 

yeh it does vibrate above 100mph. i bought a whole new drive shaft complete with the yoke and rear flange. i need to check the balance on it and get new U-joints put in it cause they are pretty stiff. im taking my truck up in a couple weeks to get Pilot to dyno tune it and ill get the drive shaft checked at a place up there. they only charge 35 for balance and about 30 for two new spicer u joints installed. hopefully this drive shaft i bought isnt messed up. only thing i noticed on it was some scratches. but it didnt start to vibrate above 100mph untill about a week ago.

 

Doing a rear lube mod to the 2wd's really helps to prevent these problems. If the seal blew out I bet the bushing is toast.
Alan

 

yeh im working on gettin a new bushing and seal. cause the bushing had some of the copper rubbed off of it. but ive gotta drive it so i put it back in there.

 

lol...you give those under car washes too much credit. I'm assuming you're talking about the one that just sprays a few nice jets of water under the truck...no way that had anything to do with the seal...no way. Billions of cars a year and millions of F150's go through the same thing and don't have a problem with it blowing any seals out. Now if you said it ripped a decal off the side of your truck I'd believe it...you're reaching man...no relation.

 

it had enough to blast the underbody coating off the frame. but im not sure that was just my best guess as to how it all of a sudden came out. it may have already been loose and the jets just caught it and poped it the rest of the way out. but the guy who built my tranny is sticking to his end of the warranty hes giving me a new tailshaft with bushing and boot and seal.

 

That's good that he's hooking you up.

 

HI!... Trust me, when YOU actually get under your truck and try to remove and install the slip yoke bushing and seal yourself, you will see how hard they are to get out. There is 100% NO WAY IN HELL that the water pressure popped them out. The busahing is what wanted to come out, it just pushed the seal out of the way. If I were you, I'd buy a new seal, bushing and slip yoke.

 

yah like i said the guy who built my transmission is giving me a new tail shaft assembly with a new bushing lip seal boot. the slip joke looks fine but im getting it checked out anyways at the driveshaft shop.