Front Wheel Bearings

[Matthew E. Herd]

Does anyone remember what the NAPA or other part numbers were for the tapered roller bearings that were direct-fit for the originals? Due to my racing, I think one of the two spherical thrust bearings on the front right side gave up (rumbling, esp. when braking and turning right, and it seems to be most prominent when I turn slightly to the right at high speeds). There isn't too much (but a little) wheel movement when I pull on it, but it's more than I think it should be. Any help would be appreciated, as I will otherwise have to pull the bearings out and measure them, then start calling bearing distributors. Either way, I'll make it happen!

 

[Bugeye58]

Matt, try Timken 07097/07024 for the inners, and Timken 05066/05185 for the outers.
Somewhat harder to find are 30205X inners, and 30303 outers. The 30205X has the correct radius to mate with the radius of the axle stub where it mates to the base.
Jeff

 

[Matthew E. Herd]

Jeff, I researched the 30205X and 30303's, but I didn't look into the other ones yet. I noticed that on timken.com, their automotive section specifically listed a note on conversion to tapered roller bearings and the appropriate part numbers. I'm going to call a few distributors I found online via a search and see what they offer. Naturally, I'll post results. However, the fronts seem significantly cheaper, even as non-standard items, ranging from 9.75 to about 11.50, from what I've briefly found online (per bearing ... 2 per side ...). The rears are also less than $12 each, and seem to be generally available, as Nial had previously mentioned. I happened to have recently bought rear bearings from moss ... perhaps not any more, depending on the results of my search.

 

[77MidgetMkIV]

Matthew,

How did you make out with your bearing relacement? I just tore down my front assemblies, and I am thinking of going to a tapered bearing. Were you able to get correct ones, and if so, from where? Also, I thought I remembered something that needed to be done about the tapered spacer when using tapered bearings. Anyone know?

thx

 

[Matthew E. Herd]

Hey, sorry it took me a while to get back to you about this. I used the bearings recommended on the Timken website (automotive section, refer to tapered bearing conversion ... it's an option under spridget). They were supplied via EB Atmus corp out of massachusetts, although I am sure they could be purchased about anywhere. They're metric bearings, as I understand it, and reasonably commonly available. The note on the timken website indicated that the washer on the end of the spindle, just before the castellated nut, should be shaved from 1/8th inch to 1/16th. It also said that should the assembly still be too long, you can mill a bearing surface (I'm not sure which one, as I was only 1/16th too long) to reduce the width.

However, instead of milling the washer, because I didn't have a mill handy, we simply cut the slots in the castellated nut 1/16th deeper (it has plenty of meat). This worked very well. I have some slop in the lower fulcrum pin on the passenger side, so I hear some noise over bumps on hard left turns (I'll get to that soon enough). I also discarded the spacers, as they're no longer necessary. The hub is stepped to accept the outer races, and the inner races are held in by the step on the inner face of the spindle and the washer/nut combination on the outside. If the spacers were retained, they'd either be too long, or if they were shortened to fit, they would do nothing or interfere with proper tightening of the spindle nut. In either case, they're no longer necessary due to the design of the tapered roller bearings. The transition is easy, with the primary trouble being the fact that the spindles needed a little sanding to get the inner bearing's inner race on smoothly. You'll need new nuts, cotter pins, and seals (2 each), and I believe that's about it. The cost for these items in nominal, and I got 2 complete sets of bearings for the rear (4 spherical ball bearings) as well as 4X each of the two types needed for the front (two complete sets) plus shipping for around $160. I figured it can't hurt to have plenty of bearings on hand, especially when racing.

 

[77MidgetMkIV]

Wow- that is the exact information I was looking for. Thanks: It was worth the wait! That gives me a lot to think about in terms of whether I do the conversion or not. I do not race, but am not tied to exact resto-type replacements either.

 

[Dave Russell]

Just a passing thought.
I believe that in the original design, the spacer was intended to be clamped between the inner & outer bearing races. With the spacer in compression, it adds to the effective diameter/rigidity of the somewhat small diameter spindle. Any adjustment that reduces compression on the spacer or eliminating the spacer will increase spindle flex & reduce the structural strength of the spindle. Maybe not a consideration for racing? By using precision shims with the spacer, a condition can be achieved where the spacer is in compression, the bearing fit is still correct, & a more rigid spindle is obtained.
D

 

[Bugeye58]

The kit that I got from Tom Colby at Speedwell Engineering a few years ago, came with the shims for exactly that purpose.
Jeff