TC Clutch Throw Out Bearing

[reed714]

INSTALLING A BALL BEARING CLUTCH THROW OUT BEARING IN AN MGTC


The original carbon type rubbing surface used to disengage the clutch dry disk from the engine is not an especially elaborate design. The carbon surface is meant to slide over the flat portion of the pressure plate when the clutch pedal is activated and to transmit pressure sufficient to disengage the clutch dry disk from the engine. The carbon surface will wear rapidly if any roughness is present on the face of the pressure plate disk.

This procedure details how to modify the original carbon type release bearing and install a ball bearing in its place.

Press the original carbon disk out of the release bearing carrier and with a belt sander, sand the four mounting tabs off of a Timken 614110 clutch release bearing. Sand the bell at the bottom of the 2.25” flange and sand a small bevel in the open end. Reassemble the bearing using the wafer spring and bearing body and press the assembly, using a large socket, into the original MGTC throw out bearing mount. Install the modified bearing assembly using the original mounting wires. Adjust the clutch pedal to release the clutch disk when the pedal is about 2-3” from the floor.

Reed Dickinson
TC/EXU7385
XPAG7436

[Steve Simmons]

Reed, have you been running this configuration? How many miles do you have on it so far?

[reed714]

I got the engine back in the car last week and so far I have put on 30+ miles. More miles will prove the modification and I will report again at 100 miles.

Reed

[Gene Gillam]

Any photos of the process/finished product?

[reed714]

Sorry, no pictures, I just wanted to get the rebuilt engine back in the car.

[Duncan M]

wonder how long it would stay together? 60 years?

[Steve Simmons]

I don't know about the TC specifically, but I've heard that roller bearings aren't always a good idea for cars with clutch forks that travel in a short arc. Reason being, as the arm arcs, it introduces a side load on the bearing. I have no personal experience with roller bearings in MGs, that's just what I've heard from others.

[stephen stierman]

Had plenty of old cars with the carbon bearing, never had a problem, they seem to wear a good long time.

[Gene Gillam]

For a short period of time I used a "very" lightweight racing clutch and flywheel with a roller bearing on my TC. I didn't care for the feel of the entire setup so swapped back to a normal clutch/flywheel/carbon bearing. I do know that a number of the MG Vintage Race group use the roller bearing but they're purpose built for the application. I am interested in Reed's version...I looked up the part number on the internet and can see how it would work.

[Steve Simmons]

Then again, race cars probably don't use a throwout bearing for very long before replacing. THe engines get torn down quite often.