tapered roller bearings

[kalist]

Can anyone tell me what the proper bearings are to convert from ball bearings to tapered roller bearings. I have found some postings on different forums that mention the timken 30205m and 30303 but there is also some concern that they don't mate properly to the spindle. Any help would be appreciated.

 

[Hap Waldrop]

Winners Circle, www.spridget.com has everything you need.

 

[tomshobby]

Spent a lot of time over about a year and a half measuring many axles, bearings and researching. Many others were also involved in the project.

I started with taper bearings that did not fit. And searched for bearings that did finally finding OEM bearings that do fit correctly. I did notice that the OEM ball bearings turn with much less resistance than roller bearings. I tried three different taper bearings.

It makes no difference to me what you use. The only thing I would suggest is that you check to make sure the bearings you use, ball or taper, fit on the stub axle correctly. If they don't and it were me, I would place a shim behind them. The page I posted has a couple photos showing how I measured behind a set of Timken bearings. And there are some diagrams of how and where to shim behind them.

https://smithtr6.com/bearings.htm

But do what you feel comfortable with, it is your car.

 

[Hap Waldrop]

all I can add is I seen guys go thru this for years withh tapered bearings, and I always got the ones that came from WC and they are in Timken boxes, but WC has good prcing on them, better than my local bearing house, and they are what myself and almost every SCCA abd vintage race cars uses in their race cars, and have for decades, because no one hardley races a Spridget on the stock wheel bearings, and we use special double bearing hubs for the rear as well, and even though I and buddy did make a small CNC batch of DB hubs, over the years most of DB hubs came from WC as well. Rob and Dave at WC have supported Spridget race and performance items for year, stuff no one else had, they are good guys, give them and call, listen to what they tell you and you'll have no issues. WC has slipped thru the cracks with alot of non racer or newer Spridget owner because they are old school, their website is non very interactive, but these guys know this stuff like the back of their hands, so it still pays to call them upo and talk to them. Here's short list of the unique WC products I used over the years.

Really trick wet oil sump pans
Heim adjustable front and rear sway bar kits
Tapered wheel bearing kits
reworked spindles that hold up under racing
Double bearing rear hubs
Panhard bars kit
Nice headers
rear race axles that hold up and seal
Fidanza fylwheels set for 7.25" race clutches
Roller bearing set up for those race clutches

I could go on and on how many times these guys have had the right part for the Spridget crowd, and they are great guys, give them a call, they been at this for decades.

Oh and I'll put to like this, I've never had a Spridget that didn't have tapered front bearings, and they all cames from WC, and I trusted them with my life while running a 125 mph with them at the races, so I trust these guys as well as do hundreds of other Spridget racers around the country and world. While tapered bearing might seem like a new idea to most, some of us have been doing this for many, many years.

Oh and it would be worth your wild to check the radius right in front of where your hub seal goes on the stub axle portion of the spindle, I seen more cracks in this area on front hubs, than I seen good uncracked stock hubs, I will not eve buy used fornt hubs anymore because of this, so find someone who will crack check them for you. This is a big weak point on Spridgets, especially early cars.

 

[Spridget64SC]

Second to Hap's recommendation to give Rob and Dave a call.

From a purely technical perspective, Here is what I can provide. Timken bearings are quality bearings. There are two inner bearing and two outer bearing sets that can be used. The complete and fully detailed technical difference between them is best left to close examination of the Timken bearing catalog. But, summarizing it here, what you need to know is this:

There is a radiused area on the stub axle that needs to be accounted for with the inner roller bearing (cone). There are differences in the two inner bearings. Most of the time either will work.

07097/07205 Inner pair, r=.060"
30205/30205 Inner pair, r=.040"

The bigger radius on the cone can account for a larger radius on the spindle. Especially important if using the modified racing stub axles. These sometimes come with a larger radius than stock.

The other thing to know is that there is also a difference in the "T" distance. This is helpful when using the bigger Spitfire disk and MGB calipers for racing purposes. The 30205 pair will offset the disk/adapter further out from the stub axle body a bit further, like about 0.049". This helps with disk to steering arm interference. Now, this upsets the disk center in the caliper as well. But using the MGB calipers also upsets the disk center. So, machining of the caliper ears is necessary to center the MGB brake pads on the disk.

Turning attention to the outer bearing, these two bearing offerings will pose some unique situations of their own. Because the inner bearings can kick the whole disk/hub assembly outward. This causes the spindle nut to become too thick and the cotter pin might not have enough hole to pass through. I'll thin the nut own enough in the lathe to all the properly sized pin to pass through.

Also, the Timken 30303 bearing set seems to be discontinued in their latest internet catalog. Here are the two outer bearing sets that fit.

05066/05185 Cone/Cup
30303/30303 Cone/Cup pair.

Racers will typically "Zero Pre-load" the tapered bearings in the front hubs. This means using shims of various thicknesses to take out the compression of the tapered bearings until the bearings run free. This actually loads the spindle itself and changes the stresses.

Check the centering of the brake disk in the caliper and check the front toe-in after changing from drums to disks.

HTH,
Mike Miller

 

[kalist]

Thanks for all of the input. I just ordered a set from winners circle. Less than 150 and I cam be confident that I am getting the correct setup. Many things on cars are options but braking and steering are necessities.

 

[markberry]

I don't have my timken tapered bearings' part #'s in front of me at the moment, but I was wondering if there's a short answer "fix" for the inner bearing being held back from seating all the way on the spindle as a result of the radius area discussed earlier? I bought my setup from speedwell engineering a few years back but I don't remember that issue being adressed in the kit instructions. Also, is there a good place to pick up more of those shims needed to preload the bearings?
thanks
Mark

 

[Spridget64SC]

Yes, It's very shade tree, but you can add some radius by grinding. The radius concern is usually only an issue with the aftermarket race modification spindle. These may have a bit more radius than the 0.040" of the 30205 set or the 0.060" of the 07097/07205 pair.

On the shims, check out a good "Old" bearing distributor. Or, if you have plenty of old style steering racks that are damaged, the shims for the "rack" tensioner can be used. You can also cut your own. There may be a machine shop locally that can do this too. We made a bunch back in the 70's when a bunch of us Charlotte, NC area Spridget racers were building cars. Some of the valve spring balance shims (0.015") might work too for the rough adjustment. Take the spacer cone in from the front and get some from a machine shop.

HTH
Mike Miller

 

[markberry]

Yes, It's very shade tree, but you can add some radius by grinding. The radius concern is usually only an issue with the aftermarket race modification spindle. These may have a bit more radius than the 0.040" of the 30205 set or the 0.060" of the 07097/07205 pair.

On the shims, check out a good "Old" bearing distributor. Or, if you have plenty of old style steering racks that are damaged, the shims for the "rack" tensioner can be used. You can also cut your own. There may be a machine shop locally that can do this too. We made a bunch back in the 70's when a bunch of us Charlotte, NC area Spridget racers were building cars. Some of the valve spring balance shims (0.015") might work too for the rough adjustment. Take the spacer cone in from the front and get some from a machine shop.

HTH
Mike Miller

thanks Mike

 

[ChrisS]

I ordered my shim stock from mcmaster carr when I did it. I think it is clear, but in case it is not, if you don't shim the distance piece between the roller bearing and torque the nut to the proper amount you are not getting the benefit if the increased section modulus. You'll need to play with the shim size to get the end play correct but once you set it you are set for the life of the bearings.

 

[tomshobby]

McMaster-Carr has shims.

 

[tomshobby]

Mike, do you have a drawing of the 07205. I would like to compare it to the dimensions found while researching this.

Thanks,
Tom

 

[Spridget64SC]

I took my copy of the Timken bearing catalog back home. The information should be available on-line. If not, then I will bring it back in and provide the information. If I remember correctly, the main difference between the 07205 cup and the 30205 cup is a small radius difference where it seats in the hub and a slight height difference.

McMaster-Carr has a nice shim selection. Their offerings should work for setting up the front bearings as well as helping the crush-sleeve adjustment in the diffs.

Have a great, safe and Joyous Christmas! And, spend some time in the shop getting your hands dirty. I plan to! Carb sets and engines. They are on my list of things to work on over the days off from the normal day job.

Mike

 

[tomshobby]

I took my copy of the Timken bearing catalog back home. The information should be available on-line. If not, then I will bring it back in and provide the information. If I remember correctly, the main difference between the 07205 cup and the 30205 cup is a small radius difference where it seats in the hub and a slight height difference.

McMaster-Carr has a nice shim selection. Their offerings should work for setting up the front bearings as well as helping the crush-sleeve adjustment in the diffs.

Have a great, safe and Joyous Christmas! And, spend some time in the shop getting your hands dirty. I plan to! Carb sets and engines. They are on my list of things to work on over the days off from the normal day job.

Mike

I tried to find it on the Timken site and had no luck, will try again.

Thanks for the information Mike, working on this I have made it a priority to stay open to all points of view to find the best solutions possible and better understand the set up. My interest is and has been to find the best solution for all of us with street cars. I don't care where the answers come from or who gets credit.

 

[Spridget64SC]

Tom:
Are you looking for the technical drawing information for the 07205 Cup used with the 07097 tapered roller cone? Or, are you looking for the Inner race ID information on the 7205 ball bearing? I think I have both at home.

I took a look at your link and fully understand the issues you are addressing. Thinking back on what I did with my SCCA FP/HP racer and the stub axle spindles, I think I actually increased the radius a bit on my 30205 cones via the shade tree method I discribed above. That was over nine years ago and I've slept a few times since. But I've seen the situation you described and portrayed in the CAD illustrations. I may have also picked through my good stub axles and chose the ones which yielded compatiable radii.

I've gone through dozens and dozens of stub axles over the years of SCCA racing and I agree that you will find different radius' on them. Even among the same part numbers.

Will advise of either information and will check what may be available on the web. I've found some sites that are better than others.

Mike Miller

 

[tomshobby]

Actually both drawings would be great. I am not only checking against the stub measurements I have but also comparing the drawings for each bearing against others I have of the same bearings.

I have found stubs with 1mm through nearly 2.5mm radii. The 2.5mm was the only one over 2mm and there were only a couple at 1mm.

Mike, for guys like you and me this is not such a problem. I am really trying to help the folks that are not as familiar with bearings and how they fit.

If this was just for myself I could have fit bearings by several methods and been on my way within a few days at most of realizing the fit problem.

I appreciate your help.
Tom

 

[aeronca65t]

Great discussion and I have enjoyed reading it.

I have raced mostly on the old-style ball bearings on my front hubs for years. Including all of this year. Never had a failure to date. Admittidly, I'm running modest 185/60 Toyo 888s. On the other hand, I realize that the rollers are better and I'd like to fit them to the new car that I'm building.

A few questions:

One of my reasons for sticking to the ball bearings is due to the fact that I can easily retain the distance piece (spacer) between them.....adding a greater section thickness to the front spindles. With the ball bearings, the front spindle nut is torqued up to a moderate level so the spacer would be in compression (so that it could do some good).

But with the rollers, I have generally understood that the spindle nut is tightened up to the point where there is no clearance and then backed off to the first point where a cotter pin can be fit. This means the spacer is not really under compression. Or are you guys leaving out the spacer? I guess I'm not fully understanding this point.

I'll be going through my spares and crack testing a bunch of used spindles. I'm concerned that some of the new,replacement spindles may be built in countries with less-exact quality standards....so I'll stick with used British stuff.

 

[tomshobby]

OEM bearings are still being made. The only thing is that they are about twice what other bearings cost. But they fit the way they should.

That said roller bearings can be made to fit too. And they can be used with the spacer between the bearings and the nut torqued the same way as for ball bearings. It just takes some test fitting of shims to provide .002" to .003" more spacing from 0" contact. Not hard to do just takes some patience.

There is a drawing on the link I posted above that shows some idea of how much extra spacing would be needed. Just remember that it is only an estimation and the test fitting will be required to determine the amount needed.

It took a year and a half of searching and making inquiries until I found this source for the OEM bearings. And they are not cheap. But they are the correct bearings for our cars.

I purchased them and am very happy with them. They roll so much better than the taper bearings I first tried.

Hi Tom,

2 pieces R&M 3MJT17 at 55.00 each.

There is NO Sales Tax to be applied to this sale.

Bearings ( 2 x 34LJT25 and 2 x 3MJT17 ) at 200.00 GB Pounds toal.

Insured Airmail is 25.00 GB Pounds.

Total transaction value 225.00 GB Pounds.

Visa payment is fine - please include the following details :

1. Start Date if shown

2. Expiry Date

3. Last 3 Security Digits on the back of the card.

4. 16 digit number across the face of the card.

Regards

Graham Naughton
Director


Email bearinginfo@gmail.com
Tel 0044 1132 631919
Fax 0044 1132 631913

 

[aeronca65t]

Yes, I've read your article and seen some of the postings on mgexperience (and other places) related to this. And I've read some of Norm Kerr's comments too.

I guess the questions that still remains to me is this:

<span style="font-style: italic">1-If you are allowing the spacer to have 0.002" of play, doesn't this negate its stiffening effect? (since it's just sitting in there "loose").

2-Or should we use the roller bearings and leave the spacer "tight" and torque up the stub axle nut to the same 25-65 foot lbs of torque as the ball bearings? (but then, isn't this "incorrect" for roller bearings.....they're not supposed to be torqued tightly)

3-Or leave the spacer out and use the tapered roller bearings, "backing off" the cotter pin hole after tightening all the slack out of the assembly? (like we used to do with old, rwd American cars)</span>

I've read Bill Young's comments that he does not use the spacer with the tapered rollers.

These guy (below) insist on using the spacer (but it's not clear to me if they torque the stub axle nut up tightly).

https://www.speedwellengineering.com/suspension/tapered-front-wheel-bearing-conversion/

Here's a comment (below) promoting the use of standard ball bearings even for racing.

https://www.spriteparts.com.au/tech/gillspeed_files/6.pdf

This article (below) says that tapered bearings can be used with or without the spacer.

https://www.mgcars.org.uk/mgcc/midgetreg/Frontwheelbearings.shtml

As you know, the "new" bearings aren't really bad. They're just the wrong specs.

I know (thanks to you) that Koyo makes a "big radius" inner bearing that may work. Or maybe I'll spring for extra money and get the correct RHP bearing that you've mentioned above. Or I maybe I'll just shim out a good set of ball bearings (to clear the inner radius on the stub axle), trim the axle nut slightly and accept the slight offset (spacing out the caliper a similar amount). I'm also tempted by the Speedwell set above. Or Winner's Circle. Lots of choices.

Thanks for your work on this!

 

[tomshobby]

1,2- The shimming process for the spacer would leave the .002" play in the bearings after the nut is torqued against the spacer. This would give the benefit of the spacer and still have the proper clearance for the bearings.

3- Yes, I believe Bill is still adjusting his taper bearings the way you describe and not using a spacer. I consulted with Bill early on with this project to get a good understanding of his point of view which was helpful.

Sad to say KOYO told me they no longer make that bearing. I liked it because it was a more robust bearing. The problem with it was that at least with my car this bearing caused the rotors to rub on the calipers. True the mounting ears could be machined down but I didn't feel comfortable doing that for at least a couple reasons. I was going to machine the step in the hub so the bearing could fit deeper.

Remember, I began this project to find bearings that fit correctly without machining or shimming. And if possible to find off the shelf and readily available replacements in case of failure while on the road. The resulting solution may be suitable for racing but that is not a concern according to the stated purpose.

I contacted at least 150 bearing manufacturers and suppliers before I finally found the bearings that fit with no alterations.