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 - Overdrive clicking noise on deceleration

The overdrive box in my BGT is making a click when I let off the accelerator. I believe the click is the sound of slack being taken up. I can’t hear it on acceleration, only on deceleration, but that may be due to greater exhaust sound on acceleration.

The sound is similar to that made by having too much gear lash in a rear axel, but it is a much lighter weight sound than that made by a rear end. There is no such sound when the car is not in overdrive, so I think that rules out anything like the rear axel or drive shaft.

This gearbox has an unknown history prior to my putting it in 10 or 12k miles ago. It did make the sound at the time I put it in, but I believe it is getting more pronounced. It is a 4-syncro with the dip stick, and if I remember correctly, it is a black tag box.

So, does this symptom sound familiar to anyone?

Thanks,
Charley
C R Huff

In overdrive the drive is going through the planet gears, so it sounds like there could be a bit of play in those. What oil are you using? Should be engine oil of whatever grade is correct for local climate, 20W50 in most cases.
Paul Hunt

Paul,

I'm using Castrol 20W50 engine oil. It is early spring in Kentucky so freezing temps are pretty much a thing of the past now.

Thanks,
Charley

PS, Sorry if this post shows up twice. The screen went blank after my previous attempt.
C R Huff

OK, just live with it then. Consider it 'character', after 30-odd years they are all different, and they were never flaky like some marques.
Paul Hunt

Excellent, Paul. I can live with that. Character it is.

Thanks,
Charley
C R Huff

I had something similar, I got a good deal on a virtually new gearbox and overdrive so had them put in - but it is still the same !! I have pumped the UJ's on the propshaft with grease and checked for anything knocking together but no result so far, my back axle has quite a bit of play in it so I will do the axle de-clonk and see if it makes any difference.
It's not causing a problem - I would just like to find out what it is !
Chris
Chris Cordingley

This thread was discussed between 19/03/2009 and 21/03/2009

MG MGB Technical index

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