Replacing main tranny seal...help

metalman

Registered User
I have been feeling vibrations I don't like in my car. My crank pulley has a slight wobble that I don't like, but I've spoken to others and they aren't concerned. What do ya think? So, I went to check my driveshaft bolts and I noticed dirty fluid sprayed on the underbody of my car near where the driveshaft enters the tranny. It was kinda wet at the red rubber seal there too. I'm assuming that the seal is gone. I put the car in neutral and spun the driveshaft to check the U-joints for wear. I didn't notice wear, but I heard some pretty solid metallic noise comeing from the tranny as I was turning the driveshaft back and forth...Is that anything of concern?

Does is sound like my seal is bad or something more internal?

I read somethings on it. Tell me if I'm correct.
I need to unbolt the driveshaft, lower the gas tank, and drop my exhaust system. Is there any short cuts or tricks involved? Any help would be appreciated!

Metalman
 
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I'm seeing a lot of tranny threads lately...has anyone changed the tranny seal....anyone, anyone, Bueller, Bueller... :D
 
I'm having the same problem on my 5spd. There is fluid slung up under the transmission/driveshaft joint. I'm trying to collect money to change out my exhaust for upgrades while I'm replacing. Also, I heard that the seal starts leaking because a) either the tranny has a something going on in it to allow the output shaft to wobble or b) u-joint going out causing the driveshaft to wobble or c) seal just wears out. Either way, it causes the seal to leak. I'll be interested in what others say as I don't know how to identify if the U-joint is bad. If it's my transmission, I'll be torqued because I only have 85k. If you do a search, you will find some instructions about lowering the differential enough to slide the driveshaft out and set it on top of the lowered differential case.
 
Replace your Ujoints while you have it apart. They won't necessarily feel like they have play, but most every one I've taken apart shows to be grooved and pitted plus they are cheap. As for the output shaft, if there is any play in the bearings the whole tranny has to come out. Most likely you just need to replace the seal though. Use only a Ford OE seal if you don't want to do it again soon. Aftermarket seals are not as good. The tail housing bushing is a large brass bushing that is not replacable. I doubt it is bad.

Remember to mark your driveshaft to diff flange for reassembly.
 
Well, seals could just go bad because of dry rot, or foriegn object damage, sand, blah, blah, blah. I believe a worn tail cone bushing on automatics could allow the yoke to move excessively and wear the seal. The driveshaft end seal on my 95 Cougar was leaking. It was a bitch to remove, but it came out after quite a while of hammer/screwdriver blows to the metal retainer, but like I said, it was tough. Replacement wasn't a problem, just tap the new one in all around the edge. Getting it started was a bit of a problem, but once started, seating with the hammer was fine. Once installed, it didn't leak anymore, at least for 25K more miles, when the engine itself came apart.

You have the disassembly process down, but the exhaust comes off first, followed by unbolting of the driveshaft, then lowering of the tank, and sliding the shaft out the rear. Some will tell you that you don't need to drop the tank if you drop the IRS pumpkin instead. This is how I did it in my Cougar, but the shaft only slides out far enough to come out of the tranny before it hits something. It can be done, but the shaft is constantly in the way. If I did it again, I would drop the tank instead. Very important that you drain the tank as thoroughly as you can. It can be very difficult to wrestle with a tank that has even a couple of gallons of fuel in it. When I replace the clutch on my SC, the tank only had about 1/2 gallon in it and was very light. Didn't even need to support it with a jack, I could push it back into place with my hands.....

Good luck. If you don't have much experience working on cars, this would be a good "break in" job for you. This process has to be done frequently while working on our cars, so pay attention. If you live in the north, plan on many rusted bolts. I live in Alabama, so most of mine come off no problem. If you manage to get them off without breaking, make sure to reassemble with high-temp anti-seize to help in removal next time. If you keep the car long enough, there WILL be a next time!
 
I'm comfortable working on my car. It doesn't sound like it's gonna be difficult, but time consuming. All the rebuilding and mod work done to my car with the exception of the machine work on the heads and block, the exhaust welding, and installing the 355 into the pumpkin, I did at my house

I dropped by exhaust system and removed the pumpkin over the summer. So, I know how that goes. I'm glad I don't have to remove the differential for this job. This past summer I gave the race shop the pumpkin and they replace the gear with a 355. They gave it back to me and I reinstalled the pumpkin, hooked up the halfshafts and exhuast. It saved me a lot on labor costs.

While I'm down there, I'm gonna get an aluminum driveshaft. Hell, maybe I'll just get a whole new bulletproof tranny with all the trimmings :D I still have a deep tranny pan to put on I got for Christmas.

What kind of sound should I be hearing when I have the tranny in neutral and I freely rotate the driveshaft back and forth. I'm hear a clunk, loose, metallic sound. I don't know if that's normal in neutral. BTW, I am feel a pretty serious vibration in my car at about 65mph. I feel it in the steering wheel, in my accelerator pedal, when my right hand is resting on the the center console. I wonder if the tranny or d-shaft is causing it.?.!?

Thanks for the assistance guys. I definately helps when you talk to others about the problems!

Metalman
 
Metalman,
Any wobble in the crank pulley, I would guess that the harmonic balancer is about to go. I would go for a BHJ.

XR7 Dave,
Just so I have this straight, "probably" the u-joint is bad causing the end seal to leak? And thanks for the tip about the seal, I just bought one from Car Quest that was cheaper than the Ford one. Besides, Ford didn't have it in stock. It looks like I'll be returning some parts....DOH! And once I have the driveshaft removed, there should be no play in the tail shaft, correct?

Thanks a ton!

Mike
 
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