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MG Midget and Sprite Technical - Salisbury LSD

Hi there,

I am investigating the possibility of going down the Frontline fine-spline halfshaft route and have just discovered that I will need to buy their LSD as well.
A friend has indicated that he would be interested in my existing Salisbury LSD if I am going to sell it complete with diff casing crown wheel, pinion etc.
What would be a fair price to ask for the complete unit?
I would be grateful for your opinions.

Regards

Robert
w r holmes

Hi Robert just a thought if the main thing your looking for is stronger half shafts and you already have the lsd what about asking some of the half shaft specialist if they can make some stronger half shafts for your axle ? as i said just a thought ?? :-)
Darren 2 litre frogeye

Nothing wrong with Peter Mays competition half shafts and they will fit straight into your Diff. Why buy frontline...?

Mark.
Mark T. Boldry

maybe not a strange idea to machine the shaft down.....

the theory is that with machining the complete shaft down to the inner level of the splines you spread the torque

Shafts usualy break at the transition remove the differance in strength there and the load will spread.
Onno Könemann

I agree with ONNO.
The taper or slimmed down section of the shaft is nothing new.. I was an Outboard Marine Dealer for many years. The company was haveing drive shaft troubles with their outboards, It was splined on both ends and approximately 5/8" diameter.It would break at the lower end near the splines. They machined the center poition down to about 7/16" and eliminated all further shaft failures.
I have had two MG failures and both axles broke at the inner end right adjacent to the splines. One I was able to fish out but the other one was stuck in the spider gear. Had to take it apart to remove it.
Sandy Sanders
conrad sanders

Hi all,

Thank you for your replies.

When I bought the car 5 years ago there were 2 competition halfshafts with a big nut on the end fitted but standard splines. There were two the same in the box of spares that came with the car and according to the previous owner these had recently been changed so the ones in the car had done one event. I assumed that these came from Frontline. I lent the car to a friend of mine to compete in a rally and one broke on the first autotest halfway down the splines. Once the broken bit was extricated I fitted one of the spares.
I used the car once after that in a night rally/trial and then for various reasons the car was put away until last month when it was MOT'd and prepared for an event.
When the halfshafts were taken out both were twisted - one at almost 45 degrees so I tried to buy replacements and when they came they had no nut on the end.
I will not bore you with the end of the story - suffice to say halfshafts and bits of diffs have been winging their way back and forward across the Irish Sea for the last month and purchase of the fine spline diff is the latest attempt to ensure my MK 1 midget has a strong back axle without changing the axle to a Ford Anglia one.
Unfortunately the only halfshafts that appear to stand up to autotesting are the fine spline ones but they are not cheap(especially if a new diff is required) so selling the Salisbury to help with the costs was the reason for my original question.

Regards

Robert
w r holmes

Hi

The idea of turning the shaft to a smaller dia to 'protect' transitions from eg. plain to splined parts of the shaft can work well. The idea is the 'turned down' part of the shaft has less torsional strength and so will twist more than the rest of the shaft when loaded. It therefore tends to absorb the rapid changes (incl reversals) of torque, e.g. when a wheel spins and then grabs and releases again).

The important thing is to ensure the transition to the smaller radius is done as smoothly as possible; even peen the surface to keep the stress raisers to a minimum.

Any one remember torsion-bar suspension? A coil spring BTW is only a torsion bar coiled to fit into a smaller space.

A
Anthony Cutler

Mark, i have destroyed a Peter May competiton 1/2 shaft with just my humble 1500 engine...(and 3.5 years of use and abuse) :)

Robert, i have the Frontline set up(finespline-lsd-double bearings) because i now have a 135bhp(@flywheel) Kseries engine and after 3 years everything is still okay...knock on wood. :)
With my rather standard 1500 engine and 3.9diff i already had 3 shafts break on me and was gutted about it so went for the best thing available at that time(and still is?).

Sorry, i cant help you on the value of a Sal.lsd.
Arie de Best

Anthony & Arie,

Thank you for your replies. Over the years many things have been tried to provide a reliable back axle and either the Ford Anglia or more recently the Frontline fine spline conversion are the only viable options.

Has anyone on this board bought or sold a Salisbury LSD to give me an idea of a fair price to ask?

Regards

Robert
w r holmes

This thread was discussed between 09/02/2009 and 13/02/2009

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.