Transmission Front seal replacement

Hi,

I am just seeking a bit of advice...

I have a leaking front seal in the tranny on my 66. It's good when driving in town (a few drop) but after a good highway run it can create a 3 inch puddle under the bell housing. (I gather the gear oil get hot enough to flow better through the seal).

I check at a local transmission repair shop and they quoted me $600.00 part and labor not including the clutch. A tranny jack is about $150 for doing it myself. Now someone told me that they would NOT consider dropping the tranny without changing the clutch at the same time which "apparently" require the flywheel to be re-surface? Is that a good advice? My clutch is fine as far as I'm concern, it doesn't slip, grab etc... although I do have a faint intermittent ticking noise coming from the clutch or tranny?

The reason I'm asking for advice is that I feel I could handle pulling the tranny out and changing the seal but I'm no so sure about the clutch replacement. + if the flywheel need to be re-surface then I'll have to take that in to a shop anyway.

What do you think?

Lastly - I was wondering if the top bolt for the tranny can be accessible without pulling the floor pan?

Pierre

 

Should be a T86AA original unless the guts have been changed by the PO but I doubt. Everything thus far has been original and untouched. The tranny does not have a T90 case marking.

Pierre

 

If you have a buick v6, I would check my valve covers first. They leak from the rear run down the back of the block and bellhousing and appear to be leaking out the vent hole in the bellhousing.

 

I have the F134 and the cover leaks since I did the valves 2 week ago but not from the back - I just received my new cover gasket by mail today so will change that tonight.

That said, I'm 97% sure it is leaking gear oil, not engine oil - I have been collecting it for a few days in a plastic yogurt container and it's tick black and has a sulphur smell. I'll have a heavy duty mechanic neighbor confirm that before I pick up a wrench mind you - just in case.

 

The F134 only came with the T-90 or the T-98 4-speed. So you are almost 100% certain to have the T-90. I would look more closely for the identifying marks.

IIRC the T-90 can be upgraded with a sealed front bearing. Check out the instructions on the Novak site - http://www.novak-adapt.com/knowledge/t90_rebuild.htm

If I were sure that it's gear oil coming from the front of the transmission, I would not hesitate to pull it apart for inspection and repair. I have R&R'd a Jeep 3-speed in my driveway with just the tire-changing jack... so you don't need a lot of equipment. I expect your main problem will be the might-as-wells that come along with something like this.

 

The Novak instructions show a front seal, but isn't it just a thick piece of felt normally?

 

The Kaiser 66 came stock with a 3 speed T86AA which is almost the same as a T90 but weaker. I believe it is missing the cast "T90" letters on the side just like mine. Someone can correct me if I'm wrong. In any case, the seal in the front should be the same as a T90.


I know that I'll have to pull the tranny out to seal it... but would you always do the clutch at the same time "since its out" -- even if the clutch is working fine?? or should I just fix the seal and do the clutch when its needed? That makes the difference for me to do-it-myself or get a pro.

Also, do you have to surface the flywheel?

Thanks

 

My memory says you're wrong. AFAIK only the V6 Jeeps got the T-86, even in 1966. The F134 got the T-90 right up to the end. There is no way to bolt up a T-86 to a F134 without modifying the bell housing or transmission case - the T-86 bolt pattern is different from the T-90 bolt pattern. Not compatible with the F134.

 

Well if that's the case then I'm happy since the T90 is stronger - I'll double check on the side of the tranny on my Jeep - I was going by a document title "Specification - Commercial Vehicle" issued 4-15-66" Appendix page 13. I don't know if the doc is accurate mind you there is a lot of crap on the net.

In any case, sealing the case is the same.

 

I stand corrected - I had a look again, scrape some grind and look with a mirror and it says T90A on the side of the case as timgr said it should.

 

replacing the clutch while you have the tranny dropped anyway is just good insurance. especially if the clutch is more than a few years old and depending on how many miles are on it. the fly wheel may not need to be resurfaced, you'll have to take a good look at it to be sure.

 

Theoretically that should be true, but in practice I expect they will be the same.

The most important difference between the T-90 and T-86 is the case front. The T-86 case has a larger bolt pattern, same as the later T-14 and T-15. Internally, the case dimensions are the same.

The T-86 gears are different from the T-90 gears, in that the main shaft splines of the T-86 spiral, as compared to the straight splines of the T-90. The 1st and reverse gears of the T-86 are beveled, compared to the straight teeth of the T-90. Beveled gears are quieter than striaght cut gears, so the T-86 is a quieter version of the T-90.

Straight cut gears are stronger than beveled gears, but that should only be an issue if owners were routinely stripping the 1st or reverse gears. I gather that's not much of an issue with these transmissions. So the main issue with the T-86 should be the absence of replacement parts, not the strength of the transmission.

 

Few last thing...

1) Can I replace the front bearing with a sealed bearing without taking everything out of the tranny (should I? because I don't really like rebuilding things when its not needed).
2) Was the felt seal good enough to stop the oil from coming out - I have heard people greasing one side of the seal and then "pre-oiling" it (as per instruction in the manual) before installation?
3) Isn't there a oil return hole on the front of the case that sometime plug up? Would that cause (or help) the leakage?

The clutch is a bit of an issue for me since I question my ability to change it properly - Its working fine now but I don't have a clue as to the age. So I'm leaning toward changing the seal only and do the clutch when it is needed... hopefully by then I'll be retired and I have more experience wrenching on the Jeep.

The jeep mileage shows 46,100 miles on the clock but it could easily be 146,100 with a rebuilt already under its belt, or 46,100 original miles, in which case it had to be sitting somewhere for a very long time in a barn or driven without the speedometer attached or the speedo was replaced -- who knows. The only thing I know for sure is that the Jeep is in pretty good shape for a 66. It does show typical symptoms of not been driven a lot - leaky seals, dried up gaskets etc... The PO had it plated "historical" for 4 years which in my province restrict its use to going to car shows and parades only if they are officially approved. No Sunday ride after church with the wife are permitted.

Originally it was purchased new in NC - I have the gov inspection record dated April 14, 1966 and the original first 1000 mile inspection and oil change paper dated Aug 66 done at Bob Bass Inc. Raleigh NC. I don't know what happen to it afterward but it ended up in TN where it was imported to Canada from there. President red was the original color now its spruce tip green. The shape of the rear deck floor indicates that it was a working jeep and was likely carrying some heavy loads in its life. I'd like to know more of its history as I find that fascinating.

 

I can answer your first question as i just came in from doing just that...and i did it with the tranny in the jeep...but while the engine is out. A clam type bearing puller will grab the bearing in the snap ring groove and a puller against the end of the input shaft pulled it right off. the oil slinger will keep the shaft in place so the needle bearings did not fall out. Tapping the new sealed bearing back on was a bit more of a pain as care must be takennot to damage the seal on that side of the bearing. I silicones the bearing outter race to the case and filled the drain back hole with RTV and liberally greased the felt seal and put it back in place also. I guess time will tell how well it works with drying up the puddles on my shop floor where i park it at.

 

I recon that with a seal bearing you need to plug the oil return hole ( as per Novak's instruction) and with the open bearing you leave the hole open... correct?

Thank you all for helping me decide on this.

 

That is correct from all my research and is what i have now done to both of my jeeps.

 

The M38a1 i threaded the hole and screwed in a bolt and then cut the head off it flush. The one last night..cj3a i just cleaned it good with carb cleaner spray and filledit with rtv sealer along with the outside of the new sealed bearing. I debated about what to do with the old felt seal, but i went with greasing it up good and put it back in place where it was before reassembling the retainer.