CV Driveshaft Conversion

[andyelan]

Hi Everyone

Just fitted a pair of the Mick Miller CV jointed driveshafts to the back of my Plus 2S 130/5 and taken it out for it?s first drive. What an excellent modification / upgrade this is. Even though I consider myself a very smooth driver, gear changing and driveability are now just so much better and I no longer feel I?m treading on eggs every time I let the clutch in. I really can?t see any downside to this conversion.

Fitting the shafts was straightforward enough although, if doing it with the car up on axial stands as I was, it?s quite physically demanding particularly if you?re not used to doing manual work. Worst part of job in my case was cutting the anti-flail pin off the existing diff and stub shaft spiders, what a bitch of a job that was.

All done now though and I don?t think I?ll ever be reverting to rubber donuts, and all this coming from ?Mr Originality Is Best? himself

Regards
Andy

[Jason1]

Hi Andy

Cutting the pins off was easy for me, you should of used:

http://cgi.ebay.co.uk/Dremel-SC406-Spee ... 1521wt_982

Don't you just love smart alec's that tell you these things after the event

I found the worse bit having to open up the bolt holes, it would have been a nightmare without the Dremel, it has to be one of my favourite tools. I tried a cordless one for awhile but the battery was pants so swapped it back at B&Q for the Pro Dremel which is the business.

Jason

[AussieJohn]

Went the other way regarding the holes and turned the shoulder on the studs down by 8 thou [ or at least a kind mate did it for me ] Good riddance to donuts!!!

[mcclelland]

Hi all,
I'm also thinking of going down the CV driveshaft route shortly and would be interested to know has anyone fitted the CV conversion offered by Kelvedon motors and is there any difference / preference to the one offered by Mick Miller ?
Many thanks, regards George...

[andyelan]

Hi George

I had a look at both the Mick Miller and the Kelvedon Motors drive shafts and to me they looked almost identical, they were both near enough the same price too. I chose to buy from Sue Miller simply because I'd had more dealings with her and my impression was that they were the ones in more common use. It was a farly arbitrary decision though as I don't think there's really much to choose between them

Regards
Andy

[peterako]

I seem to remember hearing that Susan also supplies the Mick Miller CV's to other vendors for resale.....

I have my Mick Miller CV's in my +2 for years and (it must be close to) 20,000 miles and can safely say they are well worth every penny!

I'm a VERY happy trooper

My +2 is a daily driver and apart from not having to worry about a Donut going, they have really made my car much more driveable.

Peter

[Jeff@Jae]

The best CV conversion axles come equipped with the inboard drive shafts ( diff output stub axles) as they are a failure prone part even with original Rotoflex couplings. CV conversions are certainly the way to go especially since current Rotoflex are not nearly as reliable as the original Dunlop made devices. After all, a Rotoflex coupling is simply a rubber CV joint.

[andyelan]

Hi there Jeff

Although there are plenty of more elaborate CV driveshafts kits available, I find that generally the best solutions are a compromise between function, cost, availability and ease of fitting.

As I was fitting the driveshfts in situe, I did not want to be laid on my back messing with diff to replace the output shafts, also, my car is a late model so it has much stronger shafts fitted as standard. The best solution for me was therefore the type which bolt stright on with minimum other alterations. My feeling is that if I am unlucky enough to break an output shaft, which I doubt will actually happen, then replacement ones are available with flanges to suit the cv shafts I have and that will be the time to replace them.

Perhaps if I were working with a bare chassis or has access to a four post hoist I might have made a different choice but I'm always wary of over complicating things just to solve problems which in actual fact might not really exist.

Regards
Andy

[adigra]

I have the Mick Miller ones as well. Haven't had the time to fit them yet though, but am really happy to read that others are happy with theirs.

Adi

[Jas]

Hi

I also have the Mick Miller CV's fitted this winter, but have noticed that they have quite a lot of radial play in them, can be rotated back and forth with out the axle turning. They also make a "clonking" noise when going on and of the throttle we moving slowly i first gear.
Has anybody else experienced this?

[peterako]

Clonking noise.....

No, not from my CV's....

But, soon after fitting the CV's I DID have a clonking noise.....which turned out to be a broken diff mount!

This wasn't (noticably) clonking with the Donuts....but on inspection seemd to have been broken for quite some time.

Peter

[types26/36]

a lot of radial play in them, can be rotated back and forth with out the axle turning. They also make a "clonking" noise when going on and of the throttle we moving slowly i first gear.

That doesn't sound right to me, I've had quite a lot of experience with CV joints (not specifically on Lotus although I have CV's on one Elan) and the only time I had play & clonks as you describe is when the cage in the CV has been broken, have you checked that the bolts into the adapters are tight? the propshaft UJ's and the diff mounts as Peter says?

[andyelan]

Hi Jas

There will be a tiny bit of backlash in CV joints but this is not normally noticable when new as they're packed with grease. What can be quite susprising however is the amout of backlash there is in the differential, are you sure it's not this that you can feel. Also do be aware that it often quite remarkable how easy it is to detect even the tinyest amount of movement in things just by feel, things can seem much worse than thay really are.

The fact you can hear clonking noises when driving however doesn't seem right so this does need checking out.

One suggestion I'd offer is that when fault finding it's often all to easy to start second guessing yourself. If I were looking for this clonk, I'd begin with the assumption that as the CV driveshats were new and purchased from a reputable dealer, they're almost certanly going to be ok. What I believe can happen is that when changing to cv joints, faults become apparant which weren't noticed previosly because the rubber donuts kept all the suspension/drives shaft bits under tension. When I fitted my driveshafts I discovered that I had a worn wheel bearing which I'd never noticed before.

Andy

[types26/36]

There will be a tiny bit of backlash in CV joints but this is not normally noticable Andy

Andy, I cannot agree with you there, while there is a certain amount of backlash in the gearbox, the diff, the output shaft splines, even in the splines on the intermediate shafts ( that the CV's are on) etc. all of which add up and can make a clonk.
IMHO if there is any movement in the actual CV joint then there is something worn, either in the tracks of the inner or outer cones, the balls or the cage.
The CV joints are precision made to high tolerances and any play will usually result in a knocking (as in worn CV's on front wheel drive cars) although the rear CV's do not have the angler movement of FWD cars.
One thing we do agree on though is that if Jas has a clonking which sounds quite loud then it needs investigating particularly as he specified the CV's as " they have quite a lot of radial play in them, can be rotated back and forth with out the axle turning"

[kstrutt11]

I have had the Spyder type with one do-nut and one Cv joint for some years now, the do-nuts certainly seem to last longer with the substantual centre bearing and the driveability is improved.

On the subject of clonk I have found the outer bolts (ones which go through disk, stub axle and joint flange) need regular checking as they do seem to work loose, possibly due to heat cycling from the brakes?
Also a broken diff mounting was more apparant with the new shafts, in my case one leg had fatigued off which can not be seen normally, to check lever the diff up and see if the mount case moves relative to the chassis

With solid shafts I imagine all lash in the driveline would become more apparant, If it is the diff or gearbox it is usually worse when hot and the oil thins out. (assuming they are full !)

Kevin