32 transmission with 39 gears

[Hoop]

Always seems like this seal goes in backwards ... but, there's a lot I don't know about seals.

[Hoop]

I guess I'll just have to keep wondering about that bearing retainer seal.

Standard seals are directional. They have an "air" side and an "oil" side. Special seals address this with reverse sealing or dual sealing.

What is 78-7052?

If a standard seal is installed in the front bearing retainer, it's going to be backwards with the sealing "oil" side toward the engine and the "air" side toward the oil in the transmission.

What if while rebuilding a transmission a barner goes to his local bearing dealer and buys a seal that fits without being concerned about direction. Will that be OK? Or, should he buy the seal from Mac ... which may be special in regards to direction ... Or, does it matter?

[rotorwrench]

I've never noticed any problems with leakage at the retainer stub on the Mercury car transmissions in the 8CM era (1949 thru early 1951). I guess they felt it wasn't all that necessary at the time. I'm sure they seep a bit but most old FoMoCo products do.

[Hoop]

Edit: I was just curious about the seal itself. (Obviously important re Mac's post #20.)

[rotorwrench]

The 8CM Mercury cars didn't use a seal. They went back to the spiral groove. I don't know why but they did it.

[my4dv8]

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Update.
Assembly of the 16/28 gear set of 39 to 48 years into a B4 transmission case went smoothly. Just removed front bearing from input shaft to aid assembly and clear the lower cluster gears. Pressed bearing back on afterwards.
Used new synchros etc. bearings etc.

One question as regards mainshaft endplay, we have the later 81A-7061 type main shaft.
I did notice approx .025 end play in the main shaft at the output end, with everything assembled and shifting smoothly. Can this be addressed with a shim between the end baffle and mainshaft bearing?
Or have i done something wrong? Nothing appeared worn enough to cause this.

[Mac VP]

First of all, you cannot check the endplay of the mainshaft unless the rear bearing retainer is installed with its gasket...... AND the universal joint is installed with its bolt and washer. The u-joint pulls the mainshaft back and up tight against the rear ball bearing. With the correct new snap ring on the rear bearing, there should be very minimal to no endplay present. It’s a bit awkward to test this with the u-joint installed but that’s the only way to check this.

[Tim Ayers]

Originally Posted by Mac VP

First of all, you cannot check the endplay of the mainshaft unless the rear bearing retainer is installed with its gasket...... AND the universal joint is installed with its bolt and washer. The u-joint pulls the mainshaft back and up tight against the rear ball bearing. With the correct new snap ring on the rear bearing, there should be very minimal to no endplay present. It’s a bit awkward to test this with the u-joint installed but that’s the only way to check this.

Ah, good to now. Thanks, Mac.

[my4dv8]

Well following Mac VP advise the rear carrier is bolted up snug sandwiching a Best gasket and the universal joint is tight using the correct washer etc. End play is difficult to measure as Mac said. But with out an accurate measurement it seems similar endplay in the main shaft as before with approx .025 between the input shaft and the main shaft when pulling the main backwards.
The 2 snaprings seem good at .075 thick.
What have I missed?

[Brian]

Does the endplay 'lessen' if you remove the Best gasket?

[Brian]

I have seen thin shims added to the snap ring area to take up play...as, when the universal joint is tightened up against the back of the bearing, there can be no movement of the mainshaft. However, if the entire bearing can float forward and backwards [which should be controlled by the .075 snapring], if you cut out and fit a thin shim there, you should be able to take up that movement.

[my4dv8]

Hi Brian, the bearing is snug with everything tight the bearing does not move, its the main shaft moving rearwards/or forwards, till the baffle contacts the transmission case.
The gasket does not affect endplay, originally i held the bearing in with a bolt and big washer and measured the play at .025.
Have I missed something ,or misinterpreting where the play is coming from. Its obvious play at the brass synchro cone at the synchro hub and where the rear baffle is .
Is it some wear I have missed,.
This is from a 39 transmission we drove for probably 17 years and the only known issue then was the jump out of 2nd thing. Now the gears are in a 32 B4 case.

[Brian]

Well Bryan, if the play is in the mainshaft, sounds like you'll need to add the .025 shim between say, the back of the bearing and the universal joint. Or, have you tried another universal? possibly the universal is pulling up as far as the bolt and washer can get it, but is it actually contacting the back of the bearing?

[Brian]

Is the B 7095 retainer washer flat? Possibly if distorted it would bottom out on end of mainshaft, and allow uni to float a bit? If as you say the bearing is snug and exhibits no end play, it must be the mainshaft. Mainshaft is 'secured' by that rear bearing. If the universal indeed abuts up to the rear bearing and forces the bearing up against the shoulder on the mainshaft, I cannot see how you could have any play? Or am I the one missing something?

[my4dv8]

Thanks Brian, found the B 7095 retaining washer was cupped a little.
Removed the rear bearing retainer gasket and replaced retainer only and found little difference in end play. After studying clearances between retainer and contact points I removed the rear retainer and held the bearing in with two bolts and big washers. Snugged up the UJ and bolt with no main retainer, the UJ seemed good ,and obviously pulled up to the mainshaft as play is down to a very imperceptible level now.
Ok so I am blaming the incorrect 21A rear retainer i have been using as a stop gap ( right or wrong??) as i do not have a correct b-5089 1932 type rear retainer , still 2 to 3 weeks away. Will post when it turns up.

[rotorwrench]

Here is a visual link for that rear mount retainer. https://www.fordbarn.com/forum/showthread.php?t=56099

It might give you an idea of any differences in the area that retains the rear main shaft bearing.

[Mac VP]

Maybe he could post a picture of the rear retainer he’s trying to use (both sides).
Something is not making sense.

[my4dv8]

As per Mac VP request , Something still does not seem right . This 21A retainer is only for mockup purposes till the correct B- 8509 one arrives.
i would have thought all retainers were the same as regards holding the bearing in.

[Brian]

So, from what you're saying, the play is caused by the bearing being able to move forward and aft when retained by the retainer. Cut a thin shim [.025?] with an od that will fit into the recess for the snapring in the rear bearing retainer, and an id that will go over the outside dia of bearing. In effect, you are simulating a thicker snapring. See if that eliminates the endplay...