Is it possible to fit a limited slip differential to the Mk 1 axle?

To add a little extra width to the rear axle, I've bought a set of Mk 2 wheels which will provide a modest additional 1/2 " either side, and I found a couple of wheel spacers that I bought for a BMW many years ago and suprise suprise the wheel stud spacings and centre spigot match exactly!

These are 15mm in width so I could in reality increase the width of the rear track by just over an inch on eitherside (2" in total) This would enable me to retain the original axle and the spats (may need to ease them out a little) which would be pleasing, the only question is whether I could find some longer wheel studs by 1/2" over standard - would appreciate any thoughts on this approach?

Thanks in advance...

 

A limited-slip differential (Thornton Powr-Lok) was available as an option for 3.4-litre Mk1 models. Someone more au fait with the model would have to advise you as to whether this meant a new axle casing was required.

 

I believe that all 3.4 Mk1s had Salisbury 4HA axles and can be fitted with the Thornton LSD. However, is it worth the effort? I'm not going to offer an opinion - it's better for you to do your own research as some people like Powr-Loks and others think they are a detriment. Instead, here are a few questions:

Are you going to be doing the sort of driving that requires an LSD?
Would it be easier to find a complete second hand axle than convert what you have?
Given the cost and effort (even of an axle swap), would a modern Torsen/Quaife torque biasing differential be a better choice?

 

The Powr-Lok works extremely well on S Types & especially on wet roads. I suspect, however, that the IRS is playing a bigger part in this than one might imagine.

 

Glyn, Your S is a beautiful car.

My Daimler has a Powr-Lok. I rarely notice its presence. Sometimes, pulling out quickly from a tight T-junction, I feel it lock, encouraging the car to go straight on instead of turn. It's not a severe effect, but sufficient for me to be aware of it.

My Mk2 doesn't have one. I recall wishing it had on only one occasion. That was when I stopped on snow with one rear wheel over a sunken drain cover. Careful application of the normally not very effective handbrake got the car moving.

Given unlimited funds and a magic wand, I'd go for a Quaife/equivalent or an electronically controlled diff.

 

Thanks Peter. Yes I find it unobtrusive. I run mine on an 85W-140 LS product even though it's not called for.

Of course many things are possible if one has unlimited funds to throw at the issue.

 

Thank you gents for your considered opinions.

I'm speaking to a couple of companies about installing an LSD from a Mk 2 axle to the Mk 1 as this will give me the later option to with a wider axle should this be necessary. And will I hope shine some further expertise on the matter. However, part of the appeal for the Mk 1 is its quirky styling and the Citroen DS seems to have this narrow rear track, but confidence on the road is extremely important so I guess I'm tippy toeing toward how these diverse situations can be accommodated.

I did a couple of maths on the track width to allow me some head space on the subject. Out of interest the Mk 1 front axle 5/8" wider than the mk 2 - therefore with my fitting the Mk 2 axle this will give me a slightly narrower front track = to 4' 7"

The standard rear track on the mk 1 is 4' 2 3/8" wide! the standard rear track on the Mk2 is 4' 5 3/4" wide.

If I were to fit the Mk 2 wheel (5J as opposed to 4.5j on the mk 1) this plus a 1/2" spacer would provide a rear track width of 4' 4 3/8" and this would enable the rear spats to remain fitted. This is effectively increasing the rear track by 2"....

I'm presently of a mind to fit the car up as standard (but with the Mk 2 wheels as this modification would be very subtle) and see how it performs, then add the spacers if found wanting and also see if the LSD is a requirement. (My style of driving is to accelerate out of the apex as early as possible so it may be of help for this installation)....

 

You must do what makes you happy. It's your car. Remember the Citroen DS was Front Wheel Drive. Quite a different proposition.

BTW ~ there is nothing wrong with hubcentric spacers. If Porshe can do it on their cars so can you. Even the Panamera comes with spacer options.