Gear Shaft Seal

Bruce Adams

Bruce Adams

Well-known member
Hi,
I have seen this "Gear Shaft Seal" in the catalogs. My ****** leaks a bit and I wonder whether anyone has tried this and what the results were. THANKS
 
I have used on and it stopped the leak out of the front of the transmission.

It is a little tricky to install but with a little patience, it can be done.

My experience,

Chris W.
 
There are three I think, one on the outside rear of the ****** near the universal and two that goe inside the case.

Which one are you talking about?
 
If you are referring to the one on the rear of the transmission, check the thickness of the shaft retaining plate on your car. The kit will only work on later style transmissions that had the 1/8" thick shaft retaining plate.

My '29 has a 1/4" thick plate and the kit won't work on it. (Sell it to you!)

I installed the front kit with the transmission in the car. Tedious, but it can be done.
 
It works almost too good. The back of my trans is so dry it is starting to Rust!!! :p:p

27777001475_b2228fbbd2.jpg
 
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There have been a number of seal modifications developed for the Model A transmission over the years. The first two are the most effective. replacement input and output bearings are available with seals on both sides. I prefer to remove the inboard seal on each bearing so that oil will flow to the elements. Some people leave both in place with the theory that the inboard seal will keep contaminants in the oil from reaching the elements. Whichever you subscribe to will prevent oil from passing through the bearing.

The second modification is the inclusion of an O-ring mod to the back end of the cluster shaft and the idle shaft. This will prevent oil from escaping out the back of the transmission housing due to a loose fit of the shafts in the casting. Most suppliers carry the modified shafts. They also carry a small casting that bolts up to the end of the two shafts to prevent an oil leak around the shafts. This is a very effective band aid until such time that the transmission is removed for overhaul and modified shafts can be installed.

The last two modifications were developed by the Mitchell overdrive company in order to eliminate oil leaks from their Model A synchromesh transmission. Their transmission uses a much lighter weight oil than a stock Model A transmission using 600W oil. These two modifications have found their way into the parts inventory of many of the suppliers and many owners think they need them in a standard transmission.

The first is a device that prevents oil from escaping into the bell housing past the two shifting rails in the transmission tower that protrude into the bell housing. Henry's original design thinking was that a small amount of 600W will get past the rails and run down to the base of the bell housing and saturate the felt pad that lubricates the ball on the front radius rod.

The second is a device that many suppliers do not carry. It replaces the odd-looking washer that is used with the bolt that attaches the U-joint to the rear of the main shaft. The replacement washer has a soft material that provides a better seal.

If you look at the back of a Model A transmission oil can pass through the flutes of the main shaft and through the inside diameter of the bearing. When you install the U-joint it butts up against this part of the bearing. Oil can still pass through the flutes in the U-joint. To prevent this the odd-looking washer with the little notch in it fits into a recess with the notch in one of the flutes. This dams the oil from passing through. It is a good idea to put a little sealer on the forward facing surface of the odd-looking washer when installing it.

Quite often oil leaks occur at the U-joint because someone has substituted an incorrect washer in place of the correct one.

Tom Endy
 
bunnyc said:
If you are referring to the one on the rear of the transmission, check the thickness of the shaft retaining plate on your car. The kit will only work on later style transmissions that had the 1/8" thick shaft retaining plate.

My '29 has a 1/4" thick plate and the kit won't work on it. (Sell it to you!)

I installed the front kit with the transmission in the car. Tedious, but it can be done.
Click to expand...

Can't you grind the plate down to 1/8"?
 
Chuck Sea/Tac said:
Can't you grind the plate down to 1/8"?
Click to expand...

The plate holds the two shafts in position. Reducing the plate thickness to 1/8" would probably allow the shafts to move inward 1/8".

Don't know this for sure and what this impacts gear wise. Afraid to try it.

Since the kit is aluminum, I thought about milling the slot for the plate 1/8" deeper. Modify the after-market part, not the Model A transmission. Haven't done this, just thinking about doing it.
 
bunnyc said:
The plate holds the two shafts in position. Reducing the plate thickness to 1/8" would probably allow the shafts to move inward 1/8".

Don't know this for sure and what this impacts gear wise. Afraid to try it.

Since the kit is aluminum, I thought about milling the slot for the plate 1/8" deeper. Modify the after-market part, not the Model A transmission. Haven't done this, just thinking about doing it.
Click to expand...

I agree, and would never modify an original part to fit an aftermarket part.
 
What is the "dam" made out of on the rear seal? Any help would be appreciated as mine is leaking quite bad at the rear seal (closest to the u-joint).
Kevin
 
Y-Blockhead said:
It works almost too good. The back of my trans is so dry it is starting to Rust!!! :p:p

27777001475_b2228fbbd2.jpg
Click to expand...
A friend cut the bottom off an oval PLASTIC bottle, filled it with RTV, cleaned the area with brake clean, "squished" it on & taped it until it cured. After painting it, it looked like "FACTORY"!
Chief always said, "The quickest way is the easiest & best way, IF it does the job PROPERLY"!
Bill W.
 
The plates I have seen are steel ... that is why his plate is rusted...

That is why I painted the ones I installed.
 
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