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MG Midget and Sprite Technical - Clunky Back End

Okay so I have a clunky back end. This manifests itself if the right foot is put down too heavily or lifted off quickly with a single clunk.

If you're gentle then it's barely noticeable.

I'm reckoning it's either the hub splines, there's about 2mm of play on the nearside rear at the rim or the diff, I can turn the rear wheel a tiny amount before the prp shaft starts to turn, but I'm new to this so could be very wrong.

I've had a good broggle underneath and everything else appears to be tight.

Does anyone have any thoughts, suggestions as to how to proceed.

Thanks

Ian
I Ball

Wire wheels? If the splines are worn you can get a noise like two empty coconut shells banging together. Although I only heard them when starting off or reversing.
Just a thought.
Col.
c pearce

Or universal joints on the propshaft
Gary & Gaps

empty coconut shells eh? isn't that the sound of horse power...

I'll get my coat.

Malcolm "almost too ashamed to put my name to that joke" Le Chevalier
M Le Chevalier

"Wire wheels? If the splines are worn you can get a noise like two empty coconut shells banging together. Although I only heard them when starting off or reversing."

I like the coconut shell analogy Col, that about sums it up.

I'm thinking it's the splines, it looks like I may be having some new hubs on the wheels and some new axle splines.

I think I'll swap the spare wheel in to see if there's any difference.

I Ball

It could be a few things to narrow this down is easy. check the backlash in the diff with the handbrake on if there is too much play before it engages the drives shafts then this is your problem. If this is ok then I would think it is caused by the play on the wire wheel and splines.
C Carter

Agree it sounds like wheels, but it is certainly worth checking the diff as above as any backlash there is usually from worn thrusts which are cheap and easy to fix.

A simple check for diff wear is to jack up one side and rotate the wheel back & forward with the car in gear (as it sounds like you have done). Under these cirumstances the wire wheel should not move on its hub so shouldn't add to the backlash. Total backlash for all the transmission is usually less than about 15mm at the outside edge of the tyre. If significantly more, then investigate spider gears and their thrusts. Oversize thrusts are available if the diff cage is worn.
Paul Walbran

Having had another look, my prognosis is worn splines. I'm going to pop into the local guru's workshop tomorrow for 10 mins, so that he can cast an eye/ear over it.

Ian
I Ball

I would be 99% certain it is worn splines.

Sometimes it is possible to swap wheels around to confirm this or indeed determine if it is the wheel or the hub. Most of the ones I have sorted have been on the wheel and normally you can see the difference against a new spline and you can generally feel the peak of the splines does become sharper.
Robert (Bob) Midget Turbo

Conformed today that it's the splines on the wheel hubs, actually it's the wear on the inner mating surface which is causing most of the problem.

So I'm looking at a pair of rears to begin with.

At least I've learned how to fit and tighten wire wheels properly so that future wear is minimised.

Ian
I Ball

This thread was discussed between 27/06/2011 and 01/07/2011

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