Rear Wheel Spindle Bearings Converted

[Guest Lenny]

I started to put bump stops on my rear suspension and when I jacked it up one of my rear wheel spindle bearings was loose. At about 12" out from the center of the tire, I could move the tire side to side about 1/4". So the project expanded. They use a double roll, I assume angular contact ball bearings built into one unit. The balls in one bearing are about 1" away from the balls in the other bearing. That's not much distance between them for support to keep the wheel from twisting sideways like when you skid. With my big tires and running it hard like I do, It's just not enough. So I am converting it to Timkin tapered roller bearings which will be farther apart and have about 2-1/2 times the load rating. I have to grind the spindle shaft .002" and slightly lengthen it by shortening the inner seal seat .071" and grind the spindle housing about .0025" larger so my new setup will work. Actually about 2 days worth of machining after I make special spacers etc.for the bearings to keep them properly spaced. Stock bearings were loose on the shafts and in the housings. The bearings inner race was actually spinning on the shaft and starting to wear it slightly. Mine will be press fit. When I do the bump stops, I'm also going to move the lower shock mounts about 3" closer to the wheel to reduce the twist forces in the swing arm. My reinforced swing arms don't really need it but It works out good with the bump stop bracket. Moving the shock lower mount closer to the wheel was sujested to me by Rocmoc at the Jamboree. It was good thinking, Thanks rocmoc. I'll do pics when I get done along with full specs should anywone else choose to make the change.

Lenny

[Guest Lenny]

Well, here is how I did the change to tapered roller bearings along with some pictures. The first pic shows where the inner race of the bearings were spinning on the axel.

ROLLER BEARING CONVERSION

Conversion per wheel uses Timken Tapered roller bearing:

Outer - #LM48510, 2.5625” OD

Inner - #LM48548, 1.375” ID

Seals can be replaced with seals that are the same size as the stock seals.

Due to different production runs of Joyner parts, there are some variations in part dimensions. As a result, based on the following, take measurements and evaluate if minor adjustments from those stated will be required.

The bearing shoulder, on the short axel that turns in the bearing with the CV joint bell on the other end, needs to be lengthened .071”. The shoulder O.D. also needs to be reduced by approximately .001”. This has to be done on a lathe with an O.D. grinding attachment. Lengthen the shoulder by extending it further on the shaft. This part can be machined using a good quality carbide tool. The shaft is hard and to get the O.D. accurate grinding is required. Grind the O.D. to be .0003” larger than the I.D. of the inner bearing. We are looking for a medium press fit.

The bearing outer housing will need to be bored a little larger. Bore it to be .0003” small than the O.D. of the outer bearing race.

The bearings are placed so that the inner bearing cones face each other. Picture a V with an upside down V directly below it. This provides the best angle of support for the wheel. These two (2) inner bearings require a .100” thick spacer in between them, thus, holding them apart .100”. The I.D. of this spacer should be 1.378” and the O.D. .280” larger.

The outer races are placed with their cones facing out to match the inner bearings. These races require a .120” spacer in between them holding them apart. This spacer will be 2.560” O.D. with the I.D. being .400” smaller.

Once these spacers for both inner and outer are done, they may need some adjusting. This adjusting is done by block sanding one or the other on a 180 grit wet sanding paper laid on a flat surface.

To get the spacing right, assemble the inner and outer bearing parts with the spacers in their proper place. This is just the bearings and the spacers, no axel or housing. Now squeeze the bearing assembly in a vise. This should put the bearings at their proper preload pressure against each other. Now rotate the two (2) outer races which should turn as one. They should rotate freely but with some firmness to them from the preload force. If they are too tight, then slightly sand the outer spacer until it feels right in the vise. If it’s too loose, sand the inner spacer until everything feels right.

Do a pre-assembly by pressing all parts together on the axel and in the housing. Now check for clearance between the CV belt and the bearing housing. When the axel nut is tightened, these parts may touch each other preventing rotation. If so, use a four (4) jaw chuck to chuck up the bearing housing to spin reasonably true and machine to relieve the interference area.

Now, being sure the outer races are all the way seated as far as they will go into the bearing housing, measure between the side of the 2nd outer race and the outer most edge of the retaining ring groove in the bearing housing. Now subtract from this dimension the thickness of the snap ring and make a spacer to take up the difference.

The last thing you are going to do is make sure the wheel mount plate that slides onto the axel spline before the nut goes on, is that the spline slides on nearly all the way. Also, check for clearance between the wheel plate and the side edge of the bearing housing. If there is a clearance problem, shim accordingly.

Do a good job of greasing up the bearings and do your final assembly. When putting the axel hex nut on, tighten it very tight and use a solid hardened pin in place of the cotter key. The cotter key can shear very easily and if the nut loosens, you’ll destroy the hub and probably the axel. I found a hairpin type retaining clip works great. It’s not so hard that I can’t bend it slightly on its extending end.

If this project is done correctly, which may require pressing the assembly together then dismantling it a few times, the final product will be far superior and take much more loading than the stock.

, , ,

Lenny

[ksimpsy]

That is great Lenny, I will be doing that this winter. Do you think there is a way to put in a grease fitting so a person could pump water or anything out of the hub after they have been in moist spots?

Once again great work and thanks for sharing the info with us

Kevin

[Guest Lenny]

That is great Lenny, I will be doing that this winter. Do you think there is a way to put in a grease fitting so a person could pump water or anything out of the hub after they have been in moist spots?

Once again great work and thanks for sharing the info with us

Kevin

I think you could put a grease fitting in ok. Just put it through the side of the bearing housing at a point that is between the two outter races. You would have to put a gap in the spacer between the races which shouldn't cause any problems. The fitting may be hard to access without some dismanteling. I didn't use one but I did use a marine grade grease which is very water resistant.

Lenny

[silverbullet]

Well, here is how I did the change to tapered roller bearings along with some pictures. The first pic shows where the inner race of the bearings were spinning on the axel.

ROLLER BEARING CONVERSION

Conversion per wheel uses Timken Tapered roller bearing:

Outer - #LM48510, 2.5625” OD

Inner - #LM48548, 1.375” ID

Seals can be replaced with seals that are the same size as the stock seals.

Due to different production runs of Joyner parts, there are some variations in part dimensions. As a result, based on the following, take measurements and evaluate if minor adjustments from those stated will be required.

The bearing shoulder, on the short axel that turns in the bearing with the CV joint bell on the other end, needs to be lengthened .071”. The shoulder O.D. also needs to be reduced by approximately .001”. This has to be done on a lathe with an O.D. grinding attachment. Lengthen the shoulder by extending it further on the shaft. This part can be machined using a good quality carbide tool. The shaft is hard and to get the O.D. accurate grinding is required. Grind the O.D. to be .0003” larger than the I.D. of the inner bearing. We are looking for a medium press fit.

The bearing outer housing will need to be bored a little larger. Bore it to be .0003” small than the O.D. of the outer bearing race.

The bearings are placed so that the inner bearing cones face each other. Picture a V with an upside down V directly below it. This provides the best angle of support for the wheel. These two (2) inner bearings require a .100” thick spacer in between them, thus, holding them apart .100”. The I.D. of this spacer should be 1.378” and the O.D. .280” larger.

The outer races are placed with their cones facing out to match the inner bearings. These races require a .120” spacer in between them holding them apart. This spacer will be 2.560” O.D. with the I.D. being .400” smaller.

Once these spacers for both inner and outer are done, they may need some adjusting. This adjusting is done by block sanding one or the other on a 180 grit wet sanding paper laid on a flat surface.

To get the spacing right, assemble the inner and outer bearing parts with the spacers in their proper place. This is just the bearings and the spacers, no axel or housing. Now squeeze the bearing assembly in a vise. This should put the bearings at their proper preload pressure against each other. Now rotate the two (2) outer races which should turn as one. They should rotate freely but with some firmness to them from the preload force. If they are too tight, then slightly sand the outer spacer until it feels right in the vise. If it’s too loose, sand the inner spacer until everything feels right.

Do a pre-assembly by pressing all parts together on the axel and in the housing. Now check for clearance between the CV belt and the bearing housing. When the axel nut is tightened, these parts may touch each other preventing rotation. If so, use a four (4) jaw chuck to chuck up the bearing housing to spin reasonably true and machine to relieve the interference area.

Now, being sure the outer races are all the way seated as far as they will go into the bearing housing, measure between the side of the 2nd outer race and the outer most edge of the retaining ring groove in the bearing housing. Now subtract from this dimension the thickness of the snap ring and make a spacer to take up the difference.

The last thing you are going to do is make sure the wheel mount plate that slides onto the axel spline before the nut goes on, is that the spline slides on nearly all the way. Also, check for clearance between the wheel plate and the side edge of the bearing housing. If there is a clearance problem, shim accordingly.

Do a good job of greasing up the bearings and do your final assembly. When putting the axel hex nut on, tighten it very tight and use a solid hardened pin in place of the cotter key. The cotter key can shear very easily and if the nut loosens, you’ll destroy the hub and probably the axel. I found a hairpin type retaining clip works great. It’s not so hard that I can’t bend it slightly on its extending end.

If this project is done correctly, which may require pressing the assembly together then dismantling it a few times, the final product will be far superior and take much more loading than the stock.

, , ,

Lenny

Silverbullet.You are to much.Thats in a good way. I would put a heat shield by your right rear shock.It gets real hot by header.Just a though.Good work!!!!