New felt tranny felt rear oil seal leaking- suggestions?

['41 Fat Bottom Girl]

I installed new rear tranny oil seal when I had it out of the car... no -problems with original seal, but decided to replace it while I had it out. Checked for any noticeable bearing play on the main shaft in the process; all looked good. Ordered a new seal from Bernbaum. 

Shop manual didn't cover any seal prep, but thanx to forum recommendations, I soaked the felt in a heavy oil and blotted the excess before carefully installing (7/32" exposed) as per my shop manual. Filled with Redline MT90 90 weight oil.

Inspecting things after the first 90 miles on my rebuilt flat 6, it is slinging some oil...bummer, now also have oil on my new parking brake shoes...grrrrrrr! 

Any suggestions as to what is going wrong?

Are these felt seals typically problematic (I can't imagine why, they were used for many years)?  Should I research a similarly-sized double lip spring loaded seal instead?

Many thanx!!

[keithb7]

I am experiencing the exact same thing. The oil leak did get a little better at sealing after a while. Seems that maybe is softened up more in use? It still slings a bit, not as bad.  Next time my tranny is out I am thinking of matching up a modern seal to replace it. 

['41 Fat Bottom Girl]

    Yup, and this one sprayed ( I'm guessing) a good half-ounce of oil in the first 90 miles. More cleanup.

The felt seals seem to do a nice job polishing the shaft, so I am guessing it would be a good finish for a rotating shaft gland type seal- if one is available. I am going to remove the felt seal and check the measurements and do some research on availability of a modern single or double lip spring-backed seal.  

   If no prospects there, I will try to find an original N.O.S. felt seal. Maybe the original felt material sealed and wicked differently than that used in the after market knock-off parts?

   I will post what I find.

I gotta do something, the parking brake drum and shoe at the rear of the tranny are right in line of any drips coming back and get messed up fast. I am going to try salvaging my new parking brake shoe by rinsing it in  brake cleaner fluid. 

 

 

[Sniper]

The one spec'd for my 51 Cambridge is a modern type seal, it might work for you.  Spec's on the page linked below.

 

https://www.rockauto.com/en/moreinfo.php?pk=257487&cc=1349894&jsn=363

 

[plymouthcranbrook]

With the health annoyances I have had this summer I decided to have a local shop replace mine and so far(maybe 200 miles) doesn't seem to be leaking anymore at all.

[greg g]

Are you sure it's the felt leaking and not the gasket between the trans and bell housing? I thought the felt was more about keeping stuff out rather than keeping stuff in.

Edited September 14, 2020 by greg g

['41 Fat Bottom Girl]

Hi Greg G-

This is the felt seal at the rear end of the 3 speed transmission. Apparently it does keep dirt from getting to the adjacent bearing, but is also to prevent oil from leaking out.
FYI- the original felt seal was virtually leak free at 90K miles before I tore everything down, so maybe it is a felt material problem or dimensional issue with the replacement seal (?)

These felt rear seals were used for many years, so something is weird.

 

Sniper- thanx for the link, I will check it out. 

 

[Dartgame]

The original main seal should have been leather? Which you correctly soaked in oil. My guess is you need to install a speedy sleeve to get rid of the groove worn on the metal sealing surface of the drum.  Speedy sleeves are thin stainless sleeves which repair a worn surface thereby establishing a new wear surface for the seal. To do this you will need to yank out the parking brake drum install the speedy sleeve and reassemble, I'd install a modern style neoprene lip seal as well while its apart. This can all be done without pulling the trans out of the car....

[Dodgeb4ya]

The original seal was not just felt...but both felt and a leather.

Leather being the inner part oil seal.

The outer felt....being the dust seal.

I hope this is right?

[Plymouthy Adams]

I would think that overnight soaking of the combo felt and leather has the felt in saturation....it is only proper for this to be displaced on use....the continued movement will cause the oil in the felt to thin and continue to wick and be thrown off....odds are you can accelerate this wicking with paper towels pressed against the felt itself.  I would at least try this a few times before addressing another replacement.  We are not talking mass quantities here....

[keithb7]

By chance I happened to be under my 1938 car today. The rear leather tranny seal was originally leaking, as I mentioned above in post. #2. Today the situation looks good. I had degreased it a while ago. It's all dry back there still, as of today. I suspect the seal softened up over time. Break-in time has led to the desired results it seems.

[RobertKB]

2 hours ago, Dodgeb4ya said:

The original seal was not just felt...but both felt and a leather.

Leather being the inner part oil seal.

The outer felt....being the dust seal.

 

That's what I always assumed.

['41 Fat Bottom Girl]

You all may have put me on the right path here- my problem may be the Bernbaum replacement part (not the first time I have had problems with their parts- a lot were fine, but some not so good...).

From your descriptions and an enlarged sectional view of the transmission parts, I see there is no leather or rubber component in the Bernbaum seal- aside from the metal seal case, it is a fat cross-section of felt only. 

I have ordered a Chrysler NOS seal in the original box from another source that appears to be of the construction you guys have described.

When I pull the Bernbaum part, I will post a pic to show you what it looks like. With felt alone without some other wall barrier at the seal, I am wondering if the felt would just continue to get saturated and weep from capillary action...

Hot on the trail.

Thanx, all. I will be back with what I found.

['41 Fat Bottom Girl]

Well, I am eating crow pie on my recollection of the seal construction- got it out of the tranny this morning and it does indeed have an elastomer spring-backed lip seal beside the felt, and was correctly installed with lip seal side facing the inside, felt side out. Didn't remember it, it has been 11 months since I put it back together ( I thought it was short-term memory that goes first when you become an old fart?)

Another good lesson not to run my mouth until I have all the facts. At 71, you'd think I'd learned by now...So, in this instance, it may well not be the part- a sincere apology to Bernbaum.  

Will replace it with the NOS part when I receive it and see what happens. In the meantime, I will check the surface finish again and if I see any suspect area,  I will take care of that. If at all questionable, I will look into the speedy sleeve. Thanx, Dartgame.

Thanx all, I will post the resolution.

 

 

 

[Sniper]

Thanks for the update, too many times people don't follow up and the rest of use are guessing what happened.

['41 Fat Bottom Girl]

Alright! Good progress and ready to try the new rear tranny seal. Fresh oil going back in today.

-I polished the tranny seal mating surface on the parking brake drum and saw a small intermittent ring where the original seal lip had contacted. This minor pitting couldn't be detected with a finger nail, but it was there. Perhaps it was enough to affect a seal. So I installed an SKF Speedi-Sleeve.

-Installed a NOS rear seal, Victor P.N. 49318. I had some concern about aged rubber in the old part, but the seal seemed pliable. Oiled the felt lightly. Put some white grease on the seal and mating surface before assembling. 

My new parking brake pad is shot from the previous leak. Way too much oil soaked into the material. I replaced the pad but won't install the parking brake mechanism until I know I have successfully stopped the leak.

Here's hoping the Speedi-Sleeve did the trick!

Thanx

[DJK]

2 hours ago, '41 Fat Bottom Girl said:

Alright! Good progress and ready to try the new rear tranny seal. Fresh oil going back in today.

-I polished the tranny seal mating surface on the parking brake drum and saw a small intermittent ring where the original seal lip had contacted. This minor pitting couldn't be detected with a finger nail, but it was there. Perhaps it was enough to affect a seal. So I installed an SKF Speedi-Sleeve.

-Installed a NOS rear seal, Victor P.N. 49318. I had some concern about aged rubber in the old part, but the seal seemed pliable. Oiled the felt lightly. Put some white grease on the seal and mating surface before assembling. 

My new parking brake pad is shot from the previous leak. Way too much oil soaked into the material. I replaced the pad but won't install the parking brake mechanism until I know I have successfully stopped the leak.

Here's hoping the Speedi-Sleeve did the trick!

Thanx

Fingers crossed your leak is fixed! Do you have the part number for the speedi sleeve? Thanks

['41 Fat Bottom Girl]

You bet.

SKF 99156 Speedi-Sleeve

 

It fits a 1.560" Dia. to 1.565" Dia. shaft (the caliper measurement was 1.562" on the parking brake drum)

These sleeves are a terrific idea. Easy to install; I used a very light film of #2 Permatex on the shaft and it tapped right into place with the insertion cup they provide.

Back on the road tomorrow to test it all out.

 

 

[desoto1939]

I also order a trans tail shaft seal from Andy B and mine is a metal body that has neoprime seals, rubber There are three rubber rings to mine. Have not installed it but looking to do it over the winter when the car is down for any repairs.This was for my 39 Desoto so I would think that this would be used into the later cars.

 

rich hartung

[DJK]

1 hour ago, '41 Fat Bottom Girl said:

You bet.

SKF 99156 Speedi-Sleeve

 

It fits a 1.560" Dia. to 1.565" Dia. shaft (the caliper measurement was 1.562" on the parking brake drum)

These sleeves are a terrific idea. Easy to install; I used a very light film of #2 Permatex on the shaft and it tapped right into place with the insertion cup they provide.

Back on the road tomorrow to test it all out.

 

 

Thank you. After a failed AB pinion seal, I did the speedi sleeve and modern neoprene seal, no leak. If I could only stop the rear main seal leak!!!!!!!

['41 Fat Bottom Girl]

Woohooo! The Speedi-Sleeve and a new seal did the trick. Put 50 miles on it and not a drop of oil past the seal.

Thanx to all of you for the education.

[RobertKB]

Thanks for updating us. A lot of original posters don’t let the forum know, after getting a lot help, how things turned out.