CV Driveshaft Conversion

[RotoFlexible]

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?

You can get this clonk if the forward ends of the diff torque rods (where they bolt to the chassis) are loose or worn. I rectified such a noise earlier this year by simply tightening a loose nut on one side. Worn or perished bushings at the other end of the torque rods can also cause this noise.

[Jas]

Thanks for all the comments, but it is not the bushings, joints, bearings or any of that.
The play in the CV is felt when one hand is holding the body of the CV and the other the axle, no other parts are involved. I should probably have mentioned it to the supplier as they have done so from new, but wanted to get out and drive in the spring weather.
I just wanted to hear if it was a lone case or if any other had had the same experience.

[AussieJohn]

Hi Jannik, I have Sue miller's cv's and have also noticed this play which is definately in the cv's. Mine has done about 2,000 miles over 3 years. The play doesn't appear to cause any problems as the backlash in the diff is more than the cv. I am still very happy with the conversion, cheers, John.

[gino1]

Hi jannick,
Sounds as if you have a broken diff bolt.
Happened to me twice. You will be able to see from inside the boot by turning and lifting the bolt head if it's broken.
I solved the problem by purchasing a larger diff bolt kit from Pat Thomas but it would mean you would need to enlargen the hole in the diff lug slightly.
Never broken again though

Gino
Milano
italy

[alaric]

Hi. I think the backlash in the CV joint may increase if it's flexed significantly, as when the car's jacked up for example. Thinking about the geometry of the internals, you've got a bunch of large ball bearings that sit in grooves in the outer body of the joint, and are captive in a set of cups on the end of the shaft that's flexing relative to the outer body. So, the clearances of the bearings in the grooves should increase as the joint flexes - at least some of them anyway.

Sean.

[andyelan]

Hi Jas

To answer your question and repeat what I've already said. Doing the same as you, ie holding the driveshaft and rotating the CV joint, Yes I too can feel some movement and this was the case out of the box.

Irrespective of how we speculate here therefore, either this is normal or we've both been sold 4off faulty bearings each. My feeling is that, as these are common off the shelf GKN components made by the hundreds of thousands, it's most likley this is normal. I think it's the case that we often look a bit too deeply into things.

I dont like to fact you're getting clonking noises though. In spite of what I've said above there are no clonks on my car, at least not from the cv joints

Regards
Andy

[terryp]

I think it may be that one man's clonk isn't another man's clonk........

My Susan Miller shafts do have movement but I don't really think it would be possible not to have any movement. I've done about 1000 miles on them and are very pleased. I did replace the diff mounts on installation and recently the gearbox mounting.

Terry

[ceejay]

Hi all.

I have been following this thread with a bit of interest.
Clonks or clunks... (take your pick) are pretty normal with
CVs that have seen a fairly high mileage... but when new,
they are generally tight as a drum... in fact some are far
too tight to run in the elan drive line, we dismantle every CV
that passes through our workshop during manufacture of the
drive shafts, and if required, we carry out a small amount
of corrective work to optimise them for best performance
& operation.

Just be aware that not all CVs are created equal, there
are some very cheap and nasty units for sale out there
that are less than half the cost of genuine GKN Lobro CVs.
(You get what you pay for)

These dirt cheap CVs do in fact clunk from new, they
also rattle and have rotational movement forward
and back when held in the hand... These Cvs made
in the Who Flung Dung Factory do not compare to
the GKN product.

A good set of used GKNs are a better choice (As long
as they are not pitted or spalled) than the dirt cheap
new items.

The most noticeable time you will hear the clonks or
clunks is the moment when you back off on the loud
pedal, and again when you accelerate.

The noise you hear should only be very slight, very loose
or worn CVs will emit a very loud noise and will even make
a grinding kind of noise. If the CVs making the loud noise
are new, then you may have some faulty items... it might
be time to ask for replacements.

Hope this helps.

Col
www.elantrikbits.com
Australia.
We only use GKN Lobro CVs

[512BB]

Oh dear, now that has set the cat amongst the proverbial pidgeons! For my part, I will NEVER go over to CVs, love donuts, and always will. So you can stop sending me buying reminders Col, even if yours dont clonk! IF CABC had wanted an Elan to have CVs, he would put them on. I think they were about in the 60s/70s.

Leslie

[terryp]

I think its merely a case of longevity.
If Do-nuts were produced better as they were , we would all still have them. Also if we were all doing 25000 miles a year then changing the Do-nuts every couple of years wouldn't be a big deal , but when you are only doing 3 to 10000 miles a year as most of us do then changing the do-nuts every couple of years doesn't really make sense.
The CV solution is a fit and forget (well apart from the odd nut tighten).
I had a Ginetta G15 for 17 years with donuts , and became quite quick at changing them but was always amazed at the shape they seemed to go through and how quick they began to crack even with using Lotus components. It may have had something to do with the 110bhp Imp engine I had

I for one are very glad my Lotus now has CV joints!

Terry
PS perhaps its time for a Poll?

[mikealdren]

Leslie,
I agree that donuts are fine and they are an integral part of the character of the original cars but their lifespan isn't great - we expect parts to last much longer than they did in the 1960s.

Yes, CV joints were around in the 1960s but IIRC they weren't too good. They were also only used on low power/torque cars and their lifespan wasn't great either.

I'm sure that CABC would use CV joints if he were around now,

Mike

[512BB]

Terry, Mike,

Hear what you say, but sounds like there's a whole lot of klonkin goin on. Now that DOESNT sound like longevity to me. If that was me, and paid my 500 quid, Id be worried, and miffed.

Leslie

[ceejay]

Old Chappers was not into spending money where he could save a
quid or two on the production line... rubber donuts were cheaper
by the dozen at the time so they were an obvious choice.

High quality CVs will cover very high Kms of 60,000 + before they'll
require replacement... as long as they have been serviced (Lubricated)
correctly... and with on board lubrication (Only on our design) it's not
a problem.

Obviously, it is freedom of choice what you use in the elan driveline,
but for 100% reliability on a long road trip I'll take the CVs every
time thank you very much.
Col.

[terryp]

whole lot of klonkin goin on

Leslie
Isn't that a song?

Terry

[nebogipfel]

Oh dear, now that has set the cat amongst the proverbial pidgeons! For my part, I will NEVER go over to CVs, love donuts, and always will. So you can stop sending me buying reminders Col, even if yours dont clonk! IF CABC had wanted an Elan to have CVs, he would put them on. I think they were about in the 60s/70s.

Leslie

Hi Leslie,

You'll change your mind when you get slapped in the bum by a flailing drive shaft