1941 Dodge Fluid Drive Seal Leak.

[mike172]

Hey everyone. New to the forum. First 1941 rebuild here. Just finished a 1967 Big Block Corvette with my buddies. 

 

The Back Story:

 

In the middle of a power-train rebuild on our families 1941 Dodge Luxury Liner. Car has a 3 speed with the fluid drive.

 

We pulled the fluid drive out of the car. We've had the engine rebuilt. Also rebuilt the transmission our self. Everything was running smooth until the fluid drive unit. When we pulled out the fluid drive, it was still full of fluid. No leaks. We drained the old fluid, and used some de-greaser to clean her up. We filled up the fluid drive unit and let it sit ready for install and to test for leaks. So far so good.

 

The Problem:

 

About a week later, we stood up the fluid drive unit as if you would mount it in the car, spun it around by hand to check, and now it leaks like a dripping facet out the bottom. Not sure if we some how manged the seal by lifting it improperly. Hate to think these could be that fragile. I have never pulled one of these apart, but would love if anyone has a guide, advice or a recommended shop who can assist. I am located in southern California. Cant wait to get this baby sealed up and back in the car. If anyone knows a trans shop or some steps. We tried using a combination of bear pullers, you name it. Maybe we're going at it the wrong way and in over our heads.

 

I have on hand a fluid drive seal kit. Brand new that just came in. I can not remember the vendor I ordered it from.  

[Don Coatney]

How full did you fill it and what fluid did you use?

[Dodgeb4ya]

The fluid drive couplings are very fragile when not completely installed in the car with the transmission.

 

The bellows seal and graphite ring are very sensitive to out of plane movement when there is no transmission input shaft installed to keep the driven plate and clutch cover supported.

 

I would install the FD coupling back into the car and run it for a while to see if it seals up. If not probably a new bellows and graphite seal ring might be required.

 

Some proper tools are needed to do the work properly.

 

Changing the fluid can sometimes cause these units to leak. Seen it... done it. I won't do it anymore.

 

Bob

 

[mike172]

Thanks so much for the post! 

 

Yes it makes sense that the out of plane movement, lifting it by the wrong angle or force would have done that. I am assuming we did that as the unit did not start to leak out the bottom until it was about 9/10th full.

 

Is the fluid possibly incorrect?  We replaced the fluid with Universal Tractor Fluid 134. I was able to pick it up at the local NAPA. Branded as their 134 generic replacement. I can grab some photos when I am out in the shop.

 

I also have the new graphite seal ring you posted in the above photos. We had a bitch of a time getting the pressure plate surface disconnected using some 1 inch drive sockets. Still need to pull it off. Im wondering if we proceed further and try to replace the seals. 

[Dodgeb4ya]

Two choices go for it or not!

The driven plate is a six spline taper fit and really tight on the inner coupling splined shaft.

The bellows seal assembly is a copper fabbed assembly. The folds of copper in it can crack and also cause the leak if over flexed by rough handling of the driven clutch plate.

 The authority on replacement FD fluids is http://p15-d24.com/user/60-james-douglas/

[mike172]

In progress as we speak. The only confusion I have is the new kit included two rubber o-rings. Any idea where they go? They're obviously modern and not on the original setup

[Dodgeb4ya]

No rubber O-rings are used with the fluid drive bellows or grahite floating ring.

A repair kit was never sold to repair the FD coupling.... only seaparite pieces.

Sounds like a modern not so correct replacement sealing solution.

Qone large copper O-ring is used to seal the bellows to the coupling case.

[mike172]

I appreciate the fast response. We pulled apart the bellows even further and tried out the replacement parts.

 

You are right that the replacement kit I received which was supposed to be a "fluid drive seal kit" Contains many modern pieces.

The spring is large diameter.

The graphite seal is smaller diameter.

The bellows housing appears its redesign off the shelf part only uses one spring, You will also notice theres a shiny mirror polish on the graphite ring and its rough on one side.

 

Also the spring on the repair kit appears to only fit on the inside vs the original which slides on the outside of the bellows. Has anyone used this kit before? I will have to find the supplier or possibly best to find the original replacement seals for the bellows.

 

Should I even use this kit?? Doesnt look as well of engineered as the original. 

 

Edited March 1, 2015 by mike172

[Dodgeb4ya]

There are 3 types or styles of FD seals ...1941-42, 1946 to early 1950 and last the housing type seal assemblyused from late 1950 to 1954.

That kit you have is a late style 1950 to 1954 FD "housing" type seal. It replaced the bellows type fd seal assembly.

You can use it as a whole kit as long as all the parts are correct in your kit..The graphite ring should be hazy shiny if new and never used-not wear or pits.

 

I always install what was there so to speak to eliminate possibility of issues later on.

There is a Miller tool set that is used to install this newer style of housing seal assembly. You will notice the two notches in the graphite ring. The tool set centers and protects this delicate ring and also compresses the strong spring for proper safe installation.

 

A shop manual to install the housing type seal and special tools probably is required!

 

Some pics...

Bob

Edited March 1, 2015 by Dodgeb4ya

[Don Coatney]

Best trust what Bob says! He knows his stuff.

[mike172]

Now to find the tools! Probably impossible to find the miller ones. No listings on ebay. Are there any available?

 

If I can not find any miller tools for the Type 3 FD that we have, do you have a recommended retailer for the Type 1 (1941) Fluid Drive seal and gasket. I would love to put it back correctly and just return this Type 3 seal.

 

PS Thank you so much for your help Bob!

Edited March 2, 2015 by mike172

[Dodgeb4ya]

I don't know who to recommend for parts for the FD seals. I buy them off ebay when I see them.

I do have the Miller Fluid Drive Tool set C-885 I'd sell if you are interested.

PM me if interested.

Bob

[Erik E]

On 3/1/2015 at 5:22 PM, Dodgeb4ya said:

I don't know who to recommend for parts for the FD seals. I buy them off ebay when I see them.

I do have the Miller Fluid Drive Tool set C-885 I'd sell if you are interested.

PM me if interested.

Bob

I'm searching for this unicorn of a tool set if anybody has one they would like to sell. Desperate for a C885. Thanks in advance.