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MG TD TF 1500 - Pedal shaft replacement TD-LHD

Good day to all,

I am in the middle of restoring the brake box and all of it's assorted parts. I have a question about the pedal shaft. What is the new diameter of the shaft? From Jeffrey Delk's article, it appears to be something over .740". The pedal shaft I removed from the car is clean with a little minor scoring. It's diameter ranges from .741" to .738. Is this within acceptable limits once I replace the bushings? I plan to modify the shaft with the extra holes and machined grooves. I am wondering if this variance of .003" is a deal breaker.

Thanks for your help,

Jim
JV Smith

Jim, a number of years ago I attacked the pedal box issue. The shaft had the expected wear on it in the area adjacent to the crank. Must admit that I didn't measure it. The price of a new one was frightening. I ended up mixing up a batch of J-B Weld to cover the worn area and used a new bushing to bring it to size (then removed the bushing while the J-B set up). Then added the holes and grooves. Came out fine. Bud
Bud Krueger

Sounds good Bud,
Based on some other posts, I am beginning to think JB weld is a miracle cure-all. I will go ahead and order the bushings and see what everything looks like at that point. If someone has the diameter of a new pedal shaft, that would tell me how far off I am and also the bushing to shaft tolerances.

Thanks,

Jim TD17744
JV Smith

Jim

This web site will provide applicable info:

https://www.cobanengineering.com/Tolerances/ANSIRunningSlidingFits.asp


Graeme
G Evans

Shaft assembly is a crudely and poorly designed feature of our cars. There should be minimal to no lateral/up and down movement in the shaft when inserted into the frame bushings. The brake pedal should have no more than 1/4" or so lateral movement at the top when assembled with a new bushing. Be aware some replacement shafts have the arm angled out too far so they foul the box cover, and the new spacer washers are too think, so after all assembled the snap ring groove is inside the bushing. The original pedal shafts I have seen (with one exception on a 17,000 mile TF have been badly worn, so likely yours has been replaced. George
George Butz III

Thanks George,
I will check the lateral movement when I install the new bearings. The 1/4" lateral movement gives me a benchmark. The shaft came out of the car, so fouling the box cover shouldn't be a problem. Hopefully I can use the spacers that came off the shaft and eliminate the new spacer thickness issue. It looks like there may be some trial fitting in my future.
Jim TD27744
JV Smith

This thread was discussed between 10/10/2020 and 11/10/2020

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