TR2/3/3A Brake Problems - Possible Solution

[mastaphixa]

The 1960 TR3A I have been working on exhibited excessive brake pedal travel after negotiating a corner. Much has been documented on this issue in several posts on this and other forums. The basic problem is caused by front stub axle flex which results in the brake pads being pushed back into the caliper during cornering. I know hard cornering in competition has brought this to light and is a known characteristic of the car. I can only surmise the 195/65/R15 tires might contribute to this behavior even when not cornering aggressively. I eliminated the usual suspects by making sure my rear brakes were properly adjusted and the front wheel bearings did not exhibit excessive play to no avail.
Pursuant to correcting this problem I ordered the Upgraded Aluminum Hub and Stub Axle Kit (661-318) from Moss. This is a new offering from MOSS so I was prepared to work through whatever issues I might encounter. No instructions come in this kit. The axle swap was a non issue and I was impressed with the additional material the upgraded axles had. The hubs presented several problems.
First, the studs installed in the hub are for steel wheels not wires, so if you are installing this kit on a wire wheel car be sure to get the correct studs for them. Second the dust/grease cap will not work with wire wheels as they will not fit under the splined extension. Moss pn 662-060 grease caps did work nicely. Third, after installing the hub on the axle, I found there was interference between the inside face of the hub and the upright. This may have been something totally unique to the car I was working on or not, but I was able to fix that problem by installing a .025” shim between the inner bearing of the hub and the upright. I modified a 1 ½ “x 1” x .025” stainless shim (obtained from Amazon) pn B006UHDJO by turning the outside diameter down to approximately 1.32” so it would fit inside the inner grease seal.
After these issues were dealt with, I can report the car no longer requires a second pump of the brake pedal when applying the brakes after cornering.
I contacted Moss to advise them of all of these issues and they were very responsive and interested in my experience. They’re feeling was that at the price they were selling the kit at, these issues should not be present and I agree.
One additional piece of information to pass along. The inner grease seals are provided in the kit, but no part number is given. They are a metric seal 35x49x6mm. SKF carries them under part number 562578. The bearings/races provided in the kit I received were in a box with Timken part number SET1202.

Steve Baker

 

[TR3driver]

FWIW, TRF offers a spindle spacer kit that was developed by a long-time TR4 racer, and works quite well even with the stock hub. The only downside is that the bearing clearance gets set with shims rather than the nut position.

 

[DavidApp]

Hello Randall

Does that spacer kit from TRF require the up rated spindles or will it work with the factory spindles?

David

 

[Snowkilts]

Moss also sells the upgraded axle with the spacer kit. P/N 661-293. I installed this (with the stock hub) last year. I think it's the exact kit I got from Tony Drews ("Uncle Jacks Racing") for about $200 bucks less than what Moss sells it for.

http://www.tonydrews.com/Jack_Parts.htm

Edit: I bought it from Tony, not Moss. What I got looks exactly like what is in the Moss picture.

 

[TR3driver]

The spacer kit will work with the stock axles; although the upgraded axles are recommended for best effect. TRF P/N HP660 for just the spacer kits; HP661 for spacers and axles.
http://trf.zeni.net/TR6-TR250GB/191.php?s_wt=1920&s_ht=1200
(Although listed for TR6, the same parts fit TR3 from TS13046 (front disc brakes) onward, TR4, TR5, etc.)

PS, My apologies to Steve for hijacking his thread.

 

[mastaphixa]

Randall,
No worries! I think what attracted me to try the Moss axle hub kit was not having to fool with shims, which I ended up fooling with anyway! It sure is nice to have the brake pedal where it should be all the time. There's usually several ways to skin a cat.
Steve