MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Starter ring gear too small

Hi All:
I have a very original 65 MGB GT (54,000 miles) and have pulled the engine to replace seals etc. The new ring gear (10.5 inches) that I bought will not fit the flywheel - its inner diameter is 20 thou less than the original. Has anyone else had this problem with current suppliers?
Godspeed in Safety Fast
Jc
John Crawley

John,

I've not done one, but typically they are put on hot. Is heating it not enough to gain the 0.020 that you need to fit it?

Charley
C R Huff

The ring gear must be heated and and it will drop on when hot enough. The best way to judge the heat is when it will just melt resin core solder. Still a black heat. Denis
D M Hill

Yep
I smear them with oil and when the oil is hot enough to cook dry the temp is just right
Pop it on and lightly tap into position with a hammer and punch until it sets-shrinks
If it has leeds on the teeth make sure you've got the ring the right way round as it's a one way trip
willy
William Revit

Stick the ring gear in the oven under the grill on highest setting and put the flywheel in the freezer.

After half an hour or so the gear will drop straight on the flywheel, give it a spin to settle it and leave alone for a while till cool.
Chris at Octarine Services

Hi All:
Guess I should have been more specific as to what I had done. I had my son take the ring gear to his workplace to install the ring gear; he wrenches in a shop that races in the CASCAR circuit. They baked the ring gear to the correct temperature, deep-froze the flywheel and it would not come close to fitting. They then checked the tolerance; the new ring was a full 20 thou more in depth, from the bottom of the teeth to the inner diameter of the ring, than the old ring that was removed with heat and then allowed to cool before measuring. They said that it would have to be molten before it would fit. I just wondered if this was a common problem.
Anyway, my supplier has ordered a new one so I'll know in a couple of weeks when it arrives, I'll keep you informed . . . and in the meanwhile, the restored and new parts for my '66 MGB GT, "Earl Grey", keep piling up on the garage floor but there is an end in sight. Hope I get to try him out before the snow hits.

Godspeed in Safety Fast
Jc


John Crawley

This thread was discussed between 14/10/2017 and 15/10/2017

MG MGB Technical index

This thread is from the archives. Join the live MG MGB Technical BBS now