Manual Trans Bearing Quandry...

[denmopar]

OK guys, I've been playing with my manual 3 speed trans from my '54 Plymouth.

The topic is the input shaft pinion bearing....

It would seem simple enough, but it has me puzzled.

The bearing I removed (as found) was open both sides....Likely replaced along the way at one time.

The replacement bearing from a big-name Mopar vendor arrived with a metal shield on the transmission INTERIOR side of the bearing...

Hmmm...Before installation, I did some pondering and wondered how, with that shield in the INSIDE, how was the bearing going to get lubrication(??)

Soooo- I peeled off the metal shield.

When I mentioned my actions to a well-known guru of these transmissions, he said to me (in effect):

"NO! You must have that shield in place or you're going to get oil on the clutch! (Now I know why there was good reason I had oil on the clutch when I bought the car.)

I asked:

The shield is on the inside!....How does the bearing get lubed with that shield in the way of the oil splash?

He answered:

"There is enough seepage through the shield to allow lubrication of the bearing."

OK- Off comes that $55 mistake and I order another bearing....Lesson learned, so I thought.....

The local shop machinist, while pressing on the new bearing, expressed some doubt about that shield being on the interior side of the housing. (As I had also thought...)

Now another parts guy online states the shield should be on the FLYWHEEL side of the bearing. (Side facing the front of trans.)

That shield facing the outer side makes mechanical sense to me, but I'm torn between my mechanical instincts and conflicting advice....

What say ye?

I'd really like to button this up for keeps.

Thanks-

Den-

[P15-D24]

Bearing should have cover/retainer with a path for lube to return to the tranny case. Item 21-09-29 in the attached picture. And it looks like in the picture the back is enclosed. 

[Greenbomb]

My 1953 OD transmission has a bearing that is shielded on the transmission interior side, like your original. I have a new bearing on order from NAPA, due here next week. I think there is plenty of lube available that the shield can be on the inside and it is still necessary to have a drain-back to the case from the front of the bearing. I will look at  the original non-OD stock transmission and see what that bearing is like.

[Dodgeb4ya]

Shield to the oil side of bearing. Info above is spot on.

[denmopar]

Thanks so much, guys!

I feel much better about it now and I'll proceed to assemble with glee......It just seems a bit odd to my perceptions, but that only means I still have more to learn. 

[1941Rick]

I hope I am reading this wrong......The shield is an oil seal. Why would you want to seal the oil from entering the bearing?

I have rebuilt mine and there is NO shield on either side. When the retainer is correctly installed there is a return hole for the oil to get back to the trany. I have never had a drop of oil enter the clutch housing. If you are hung up on the sheild, install it so the bearing is exposed to the oil in the case.

MHO

[Dodgeb4ya]

The shield goes to the inside.

[denmopar]

I hope I am reading this wrong......The shield is an oil seal.

Hi- The item is a "shield" -not a positive "oil seal."

I think it _limits_ the amount of lube getting to the front, since there is no positive "seal" to prevent any excess lube from spilling out the retainer.

I'm inclined to agree with the consensus of sage advice offered above.

[Don Coatney]

This link may clear things up a bit, or it might not. But it is good reading.

 

http://www.astbearings.com/bearing-closures.html

[Dodgeb4ya]

A Factory Ross Roy training film clip showing the input shaft bearing and metal "shield" that is not removable on the inside of bearing- the oil side.

Bob

[Greenbomb]

Just checked my original transmission and the shield on it is on the inside. I think we got a consensus.