Stabilizing the pinion bearing cup A413!

[turbovanman²]

Have my trans apart, and apart from it being cracked, I've noticed the pinion bearing cup was spinning and basically wore out the bore. If you know these tranny's, they are basically held in place with a snap ring and bearing preload from the transfer gear. Sooooooooo, I was thinking after its assembled, just using a set screw to keep it from spinning and moving around? Thoughts? Options?

[shackwrrr]

Green loctite

[turbovanman²]

Then you can't remove it or you need force.

[zin]

And/Or Heat...

If the set screw were to engage a "dimple" in the bearing, it would help, but it seems like a band-aid, what is actually causing the thing to spin? Is is "wallowing" out the hole, or ?? If it is distorting the hole, the set screw will just postpone the inevitable... IMHO.

Mike

[turbovanman²]

Do you know what I am talking about? I'll have to take pics but as I said earlier, its simply an aluminum cup that sits in the bore and is simply held in place by a snap ring and bearing preload, so after some torque, it can start to spin in the bore, a really stupid design but I guess they didn't anticipate the abuse we give them,

[turbovanman²]

This is what I am dealing with-

[zin]

I see what you are saying now... I think I'd do both, a set screw and some kind of sealer, not necessarily locking compound, maybe a bit of that aerobic? The point of the sealer being to exclude oil from getting between the two pieces as the lube seems to have encouraged movement, but if oil can't get in and the cup isn't allowed to rotate (breaking the seal), it should be all good!

Of course my 1st inclination was to increase the pre-load to prevent spinning, but looking at it, I think that might create more problems (distortion) than it cures... In fact, I'd be curious if this "fix" might allow for lower pre-load? I know that would help parasitic losses and therefore increase mileage, but it's probably not worth the potential downside!

Mike

PS I'm guessing they didn't do a pressed-in cup in order to ease assembly... Otherwise the cup seems like a good candidate for a press-fit!

[turbovanman²]

You can't set the preload, its not adjustable unless you alter the shim up by the transfer gear. The groove on the retainer is for a rubber o-ring, I guess that was there fix, lol.

I am curious to hear of other idea's but I think after its assembled, a set screw should fit it.

[RoadWarrior222]

Cut keyways? Even if it's just drilling them half and half and hammering a brass peg in in 3 spots, with the snap ring over the top.

[turbovanman²]

Keyways might work but not sure how to machine a groove in the trans.

[RoadWarrior222]

Router bit on a dremel? could do it as weld nubs on the race, with the reliefs cut with a dremel or die grinder.... less small parts to come adrift and go careening round the trans... provided it can be done without distorting it... just thinking holes right through things might be stress risers or weak spots you don't want.

[black86glhs]

I think the keyway idea is better than the set screw. I can see the end of the set screw breaking off or it gouging the hell out of the cup and creating small metal particles.

[Reaper1]

A set screw will put a large load in a small area and could potentialy crack the part. Keyways seem to be a good option, but I'd be affraid of the stress risers in the case of the cut reliefs to make it work.

[zin]

If the set screw where more of a pin, that had a close fit, and the hole it went into were debured, the stress should be minimized. I agree, a simple set screw pushing on the part would concentrate the stress, and probably not be especially effective.

Mike

[turbovanman²]

Don't forget the bearing race is inside that cup, so the deflection would be at a minimum.

I think 2 set screws properly deburred and red loctite will stop it from spinning, but I'll use my buggered case to try different scenerio's.

[black86glhs]

Don't forget the bearing race is inside that cup, so the deflection would be at a minimum.

I think 2 set screws properly deburred and red loctite will stop it from spinning, but I'll use my buggered case to try different scenerio's.

Two might work.
The thing with a keyway is to do it with round stock so you don't have the sharp edges like with a square cut. Unless you can chamfer the corners and reduce the stress crack chances.

[RoadWarrior222]

That's what I was trying to say by drilling it in place at the join as the center.

[black86glhs]

That's what I was trying to say by drilling it in place at the join as the center.

Yep. That would be fine. Like the LS1 guys do on the crank pulley.

[turbovanman²]

Ok, figured out a fix, hope it works, fingers crossed.

I basically drilled down one side and fitted a small piece of dowel, then I put it together and went crap, what's going to stop the clip from rotating and uncovering it, then it falls out, so I removed it again and put a set screw in so now the clip can't rotate. I'll post pics later.

[turbovanman²]

Pics as promised-