AR60 Pinion Bushings vs Bearings vs Bushings Thread

[JeremyH]

Originally Posted by nigels_world

Why? Reading your thread it sounds like you plan to run it like this.

I do plan to run it like this. In fact, I'll put this thing back together tonight and give it a whirl after work tomorrow.

[Calderwood]

Originally Posted by JeremyH

I do plan to run it like this. In fact, I'll put this thing back together tonight and give it a whirl after work tomorrow.

I guess it's going over my head. Why won't we find out if it holds up then?

[JeremyH]

Originally Posted by nigels_world

I guess it's going over my head. Why won't we find out if it holds up then?

Only up to my joe schmoe powa.....not to "select few" powa!!

[Calderwood]

Originally Posted by JeremyH

Only up to my joe schmoe powa.....not to "select few" powa!!

I see said the blind man. Maybe you can send cephas one to test!

[ROWDY RACING]

Jeremy ran his wraith for 2 years on stock bearings with no issues. So if he puts these bearings in and they don't fail how would that make these bearings any better?

[ROWDY RACING]

Originally Posted by nigels_world

I see said the blind man. Maybe you can send cephas one to test!

You win!

[65BAJA]

I don't think that's going to work. The inner pinion bearing sees as much if not more radial load from the pinion head trying to crawl it's way up the ring gear as it does thrust load from the ring gear pushing the pinion head away. Running a thrust bearing only for the inner bearing will ware (radially) into the axle housing. If only we could get axle housing manufacturers to machine the inner bearing location for a 5x13x4mm inner bearing... A more HD inner bearing would last much longer.

[JeremyH]

Originally Posted by 65BAJA

Running a thrust bearing only for the inner bearing will ware (radially) into the axle housing.

More than a bushing? How so?

[65BAJA]

Because the bushing shouldn't spin in the housing. The inner race (the one against the pinion head) on the thrust bearing will. That inner race will be half way "in" the axle housing seat.

[JeremyH]

What makes you think that either side of the bearing will spin any more than a bushing will?

[rcmedic]

I run the same
Bearings as the day i put my truck together besides one tranny bearing. I run stupid power, and drive crazy. I'm still on stock ring and pinions cause i shimmer them just right to start with, and keep them bathed in grease. I get a new
Power plant today, so lets see how these bearings hold up. You can ask jeremy how i drive

[65BAJA]

Originally Posted by JeremyH

What makes you think that either side of the bearing will spin any more than a bushing will?

Unless the hole that the bushing is being installed into is already worn out a bushing isn't supposed to spin in it's seat. The pinion shaft is what spins inside the I.D. of the bushing.

The thrust bearing in post #150 has 3 pieces. An inner race (against the pinion head) that will spin when a rotating thrust load is applied to it. The ball and cage assembly (that spins at half the speed of the inner race). And the outer race that stays stationary against the mount surface (axle housing).

[JeremyH]

Originally Posted by 65BAJA

Unless the hole that the bushing is being installed into is already worn out a bushing isn't supposed to spin in it's seat. The pinion shaft is what spins inside the I.D. of the bushing.

The thrust bearing in post #150 has 3 pieces. An inner race (against the pinion head) that will spin when a rotating thrust load is applied to it. The ball and cage assembly (that spins at half the speed of the inner race). And the outer race that stays stationary against the mount surface (axle housing).

Yes, I understand just how bushings, regular bearings and these thrust bearings work. There is less friction between the race with the smaller ID and the housing than a bushing simply because of less surface area, but I still don't see that race spinning in the housing any easier than a bushing. I do see the pinion slipping where it contacts the race with the smaller ID.

Anytime you put a thrust load on an object, obviously there is the possibility for that object to spin, but I don't see how that will be any different with a bushing.

[65BAJA]

How tall (thick) is the thrust bearing? How deep is the seat it sits in? My thought was that if the seat is 4mm deep and the bearing is 4.5mm thick then the race that spinns with the pinion head would be, at least partially, sunk into the seat of the axle housing. This spinning race would ware the housing. The bushings even with thrust loads on them shouldn't spin in the seat.

[JeremyH]

It is 4.5mm tall. Not sure on the depth of the housing race.

Even if it's only partially inside the housing, it still shouldn't spin.

You could very well be right about this, I am just trying this to satisfy my own curiosity...

[JeremyH]

Baja, it seems that we were both wrong about how these bearings would operate in this application. I just tore apart the diff and inspected everything. The race with the smallest ID that I placed closest to the gears, spins freely in the housing....while the race closest to the second bearing sits still. Also, the outer race sits (what appears) flush with the lip of the housing. I am not sure if the stock housing is beveled slightly or not (this housing is fairly new), but it gives some room for that inner race.

Here are a few pics:



I marked a line on the inner race (closest to the pinion gears) and was hoping to see it move as I spin, but it did not.....not even when I pressed down on the pinion as hard as I could and spun it. Now, I know that me pressing on the pinion is nothing even close to the force that will be exerted when power is applied to the truck and it experiences torque changes, but my thinking was solidified when I saw this. I also spun the inner race around the pinion and pushed it up against the shoulder and I dont see them spinning as one. Even if they (inner race and pinion) do spin as one, the race should just spin on the bearings leaving that outer race to sit still.

I cant think of any way to test what happens in the diff without building it and running it. So I plan to place the mark on the race vertically, run it and then take it apart again to see if it has moved.

[Calderwood]

Originally Posted by JeremyH

Baja, it seems that we were both wrong about how these bearings would operate in this application. I just tore apart the diff and inspected everything. The race with the smallest ID that I placed closest to the gears, spins freely in the housing....while the race closest to the second bearing sits still. Also, the outer race sits (what appears) flush with the lip of the housing. I am not sure if the stock housing is beveled slightly or not (this housing is fairly new), but it gives some room for that inner race.

Here are a few pics:


I marked a line on the inner race (closest to the pinion gears) and was hoping to see it move as I spin, but it did not.....not even when I pressed down on the pinion as hard as I could and spun it. Now, I know that me pressing on the pinion is nothing even close to the force that will be exerted when power is applied to the truck and it experiences torque changes, but my thinking was solidified when I saw this. I also spun the inner race around the pinion and pushed it up against the shoulder and I dont see them spinning as one. Even if they (inner race and pinion) do spin as one, the race should just spin on the bearings leaving that outer race to sit still.

I cant think of any way to test what happens in the diff without building it and running it. So I plan to place the mark on the race vertically, run it and then take it apart again to see if it has moved.

I still think that the pinion is going to deflect since you are only supporting the side (radial) load with a single bearing that's pretty far from the point of force.

It's way cool that you are experimenting with it. I'm going to try some different setups out too. This will all result in good tech wether any of it works or not.

[JeremyH]

It's possible. But that thrust bearing is supporting the pinion as well, just not as much as a regular bearing (the race that sits still is only about 1/3 the width of a race on a regular bearing)...

[SkaldidDog]

Man I beat the crap out of mine and have only slightly bruised one pinion bearing (r). Front is original. Is is the Al axles keeping things aligned?

J

[JeremyH]

Joel,

yeah, same here. When I pulled out the stock bearing the other night, it was still in good shape. Not as smooth as a brand new bearing, but I wouldnt hesitate to put it back in there (in fact, I kept it to reuse ).