MG-Cars.info

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

Recommendations

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 - Quick Question

can I replace the five main bearings without removing the engine?
Peter Murray

Peter,

I am not absolutly sure, but I think something is in the way of removing the rear cap while the engine is in the car. Might be something in the way of the front cap too. No problem with the middle three.

Hopfully someone will come along who is more sure than I.

Charley
C R Huff

thanks C R
Peter Murray

Peter,
You can not change the mains with the engine out but you can change the big ends.

HTH

R
Roger

Correction to Roger's post - you cannot change the mains with the engine *in*, you *have* to take the engine out. You can change the big-ends in or out.
Paul Hunt

With some engines, you can replace all of the mains, the thrust bearings, and the big end rod bearings with the engine in place. I have done it on a large inline 6-cylinder engine.

The issue is if interference exists with the front and rear cap, and I would have to be looking at one to know if it can be done in a B.

I believe the front plate of the engine bolts to the front cap, but I think that could be overcome. I don't know if the back plate / gasket / and seal interfere with removing the rear main cap.

The mains and thrust bearings can be replaced with the engine installed for any caps that can be removed. I have a B engine partially disassembled, but it is not here for me to look at. I may get a chance to look at it this weekend.

Charley
C R Huff

Remember that you have a locating dowel pin in each main bearing. It is located in the block section. This means that the crankshaft would have to be lowered sufficiently to clear this dowel.
Sandy
SANDY SANDERS

Sandy,

Do you mean there are dowel pins for the mains or for the thrust? If there are dowels for the mains, it has escaped my memory. I thought I remembered a tang at the end of each bearing shell. Maybe the 3-main engines had dowels? I never had one of those apart.

Charley
C R Huff

This thread was discussed between 18/08/2009 and 20/08/2009

MG MGB Technical index

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