Installed new layshaft bearing backward...

I just became aware that I installed the new layshaft bearing backwards in my recent tranny rebuild and I wanted everyone to be aware of the possibility and to avoid my error. I discovered this error while doing some reading about bearings/lubricants (more on the ATF/gear oil thing) just a few minutes ago.

The new AN bearing is a shielded bearing, as shown on the left in the pic below. The other side has no shield so that side looks like the (old) bearing on the left. I installed it so that the shield is facing to the outside of the case. The oem bearing has no shield on either side. My thinking was that there would be better lubrication flow with the shield to the outside and I "ASSumed" that the shield was just to aid in reducing oil leakage. But that was totally wrong thinking!

THe bearing should be installed so that the shield is facing the INSIDE of the case. The purpose of the shield is to keep debris out of the bearing. It doesn't hurt anything as far as actual function of the bearing is concerned but installing it as I did makes the shield useless. So do it right if you do it. No, I am not going to disassemble the box to "fix" it since at worst it is the same as the original bearing as far as debris contamination is concerned.

THis added a few minutes later: I originally had mistyped MAINSHAFT instead of Layshaft bearing in the heading/body; that explains the two following posts

I like your way better Mike. That shield might help marginally with leakage, I'd prefer the bearing getting a good supply of lube unimpeded by the shield, and being somewhat obsessive I change my gearbox lube pretty frequently and have never found much debris in there.

Thanks for the post MexicoMike. This is the type of information we need. I have a habit of printing treads like this and keeping them in a binder.

Taking the time to put photos in the post does two things. First, it illustrates much better than words, and second, it keeps Swooshdave from sending a post saying "pictures, pictures, we need pictures".

Leave it with shield against case open side exposed to fresh oil. There ain't much debrie in gear box and what there is settles to bottom and stays there unless crashing. Many applications are not blind seat like gear box but expose bearing to exterior stuff so shield is made to block it out and help keep oil in.

I agree here with hobot. That's the way I installed mine, and will do it again on my next gearbox rebuild ... about two months from now. (starting another project, this one with an 850 motor.) So as is, I think your layshaft gearbox bearing is installed the "correct" way ... IMO. Cheers.

MexicoMike said:

THis added a few minutes later: I originally had mistyped MAINSHAFT instead of Layshaft bearing in the heading/body; that explains the two following posts

Click to expand...

Nope, you're too kind. I think it said layshaft when I responded, but yes, I was thinking of the mainshaft.

I think my layshaft bearing was "sealed" on both sides but I'm not sure.

I still think your way is just fine, if not indeed preferable.