MG-Cars.net

Welcome to our resource for MG 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 MGA - Transmisssion check out

Is there any good way to check out an MGA transmission without installing it in the car? I have a 'spare' transmission that came with my car from the PO. I know the transmission in the car has a bad 2nd gear synchro. I would like to evaluate the 'spare' transmission to see if it would be any better than what I already have installed.

Any recomendations?

Rick
rpb bunch

Hi Rick. Spin the input shaft and when doing so, shift through all the gears. Wwatch the output shaft to see that it spins (quietly) in all 4 gears. Listen for excessive nose as the gears spin. Wiggle the input shaft to see how much play is in the input shaft bearing. There should be a bit of play, but lots of wobble indicates a worn input shaft bearing. Then about all you can do is open the tranny and have a look inside. If oil is still in the box, is there lots of gold coloured particles floating around? If so, the synchros are probably quite worn. Is the oil clean or black and gritty? Dirty oil can damage bearings and bushings. Drain the oil then check for any chipped, broken, or badly worn gear teeth. Check the sludge at the bottom of the box for broken teeth or metal chunks. You can slide the hubs back and forth and check the brass synchro rings. Ideally the three ears on each synchro ring should have a largely the unworn triangular shape. Any wear in the brass ears is obvious. Really badly worn synchro rings will be worn away to almost nothing. You can also check the laygear for excessive play. Move the laygear back and forth with a lever to check for excessive end play. Try moving the laygear sideways to see if there is excessive slop in the laygear bearings or layshaft. You can actually remove the layshaft without dismantling the transmission. If you hold the transmission on it's end, and remove the front cover, the layshaft can be pulled straight out. You have to be very careful not to tilt the tranny, or the shaft may not go back in. Wear on the layshaft is also obvious, and any wear that you can see or feel is probably excessive, in which case the layshaft should be replaced Check the large rubber and metal mount at the bottom of the tranny. If the rubber is oil soaked or rotted, the bushing will need to be replaced. Check the carbon clutch release bearing for wear. Also check the clutch release fork bolt and bushing for wear. These items are often neglected, and are usually badly worn. these checks are only a very rough indication of the transmission's condition. Hope this helps, Glenn
Glenn Hedrich

Over here the going rate to pull down a transmission and replace oil seals, gaskets and brass synchros is around $450 for an MGA.
Mike
Mike Ellsmore

Glenn...very helpful post...Thanks! I will comb through it this upcoming weekend. Any work that I do/have done will be this winter anyway. I just need to know what parts and resources that I may have available.

Maybe I can get my local club to design a Tech Day around transmission R/R!

Cheers,

Rick
rpb bunch

The wonderful thing about this website is info like yours above Glenn!!

I have a Twin Cam gearbox to check, so will follow your suggestions.

Thanks a lot, mate. Barry
BM Gannon

This thread was discussed on 10/08/2009

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.