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 - Pinion shaft binding

I'm posting this on the MGB section, but my car is a 59 MGA. Since they are similar, I thought more people would look and comment on the MGB than the MGAs.
Anyway, I was replacing the pinion seal in my diff and had the pinion bearing out as well for inspection. While waiting to replace the parts, I had to lower the car to the floor to make room for my wife's car and move it forwards, not realizing I shouldn't do that. I had been turning the pinion shaft while both wheels were off the ground and there was no problem, but when I tried rolling the car, the pinion shaft rotated and is now at an angle in the housing and wedged to the side of the housing. It will not turn and turning the wheels by hand have no effect on the pinion shaft.
What have I done? Sounds like I have the pinion gear and the other gears wedged. Does this call for taking the diff a part, or is there something else I can try?
If pictures help, I can add those.
Thanks,
C
C Crews

I take it the bearings are still out. I'd try reversing what you did that jammed it, although once the car was rolling there is a fair bit of inertia there to jam things pretty tight. I.e. it might need a fair bit of effort to unjam it, and either can cause damage.

I take it you have the banjo axle, the diff assembly on those can be unbolted complete and looked at on the bench, easier to deal with than the later Salisbury axle.
PaulH Solihull

Paul,
It's the standard MGA diff that has the removable nose. I've been sitting on this for weeks now because I can't use my right arm, but when my arm gets better I want to know how to fix the diff. I've been mentally taking it apart as a form of rehab.
I do know that when this first happened, I tried pushing the car back the other direction and due to the diff, the wheels were locked and wouldn't undue what I just did. Spinning each wheel off the ground does nothing.
When I get better I'll pull the axles and take off the nose and see what happened.

C Crews

When you attempted to roll the car back, the pinion gear became dislodged from the ring gear, pulling it rearward. It's now jammed against the differential cage. You should be able to "massage" it free by gently moving it back and forth, as well as up and down, while pulling it forward. RAY
rjm RAY

Ray,
I'm going to try that when my injury heals. Should I try it with the car on the ground, or try moving the wheels with them off the ground, with help of course?
Your suggestion makes me feel like I have some hope rather than taking everything apart.
C
C Crews

Hi, C,

I agree with Ray, the pinion has moved back a little. I would suggest you jack the back wheels off the ground to let them turn if necessary. I would then bolt the flange back on the end of the shaft to help you gently pull it back into place.

Did you push it far or hard to get your other car in? If not, you may be lucky!

Mike
Mike Standring

Agree. Wheels off the ground. RAY
rjm RAY

Mike and Ray,
Right now I am able to look over the opening of the battery tray and see that the flange will not go back on the shaft because the shaft is against the nose piece where the oil seal fits, so I can't pull it forward with the flange bolted back on. I might be able to put the nut back on the pinion shaft and pull carefully with something.
I've injured my neck and can't work on the car, but I will do as you say when I get better.
Thanks so much!
C Crews

I hope that you get well soon. RAY
rjm RAY

This thread was discussed between 28/01/2013 and 02/02/2013

MG MGB Technical index

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