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CV joints - how tight?

PostPosted: Tue Jan 25, 2011 2:20 pm
by steve.thomas
Hi all,
I fitted the Sue Miller CV conversion to my Plus 2 over Christmas, but now have a slight ticking / knocking noise from the rear drive that wasn't there before. The fitting instructions recommend using a long spanner while someone applies the brakes, but did not give a torque setting. I've only been able to get an open ended spanner on the nuts and have tightened as much as I could, although I only needed to apply the handbrake to stop the shaft from turning (my handbrake is actually quite good !). This makes me think they may not be tight enough. so my questions are:
1. How tight do they need to be and should I be using an extension on the spanner (I'm concerned I'll either round off the nuts or strip the thread) ?
2. What improvisations have others used to get the necessary tightness ?

Thanks for any help / advice
Steve.

Re: CV joints - how tight?

PostPosted: Tue Jan 25, 2011 4:00 pm
by cal44
Steve,

Not having done this I don't have an answer.......BUT.

Using brakes as the hold back to tighten bolts on the drive train? hmmmmm.....
No torque values for the bolts?
In my mind if there is non consistent torque then how would one know if the everything is even throughout the process?
Just a thought

Re: CV joints - how tight?

PostPosted: Tue Jan 25, 2011 5:11 pm
by quaybook
Hi Steve
I fitted Sue Miller's CV shafts on my Elan (not a Plus 2 though). I could only get an open ended on them like you and tightened them as much as my feeble old arms could manage and I've had no problems. However, Sue's instructions say you should retighten the nuts after so many miles ( 100 or 200 I think) and that was most certainly necessary. After 100 miles mine definately needed tightening, but i've checked regularly since and they've always been fine. I think the shake proof washers she provides collapse under initial useage, which causes the torque to relax in the early stages.
A ticking noise sounds to me like it could be a faulty CV. I believe Sue's CV are very reliable but a rogue can always occur. My worry with the shafts has been excess articulation on full suspension droop, so I've fitted webbing droop limiters.

Vernon

Re: CV joints - how tight?

PostPosted: Tue Jan 25, 2011 5:24 pm
by bcmc33
Steve,

Check how close the outboard nuts are to the hub casting. I had to grind some clearance on one area on both sides, and I also turned a millimetre off the nuts just to make sure there was a reasonable clearance.

Re: CV joints - how tight?

PostPosted: Tue Jan 25, 2011 5:41 pm
by leifanten
I have the RD Enterprise CV joints on my +2. I also run a race car (VW 16V gti 1988) that uses the same (I believe the Lotus kits are using VW joints) and have had the CV joints off more times that I would like to count. Generally I tighten them #well# but not too hard - these are 8mm bolts, so go to hard and they will strip. I never used a torque wrench and never had any problem with them coming loose. I would estimate 35-40ft/lb or there abouts. Having someone on the brakes that prevents the shaft from turning helps a lot.

Re: CV joints - how tight?

PostPosted: Tue Jan 25, 2011 6:02 pm
by andyelan
Hi Steve

I assume its the 3 off 7/16 UNF nuts you're talking about. If so these are the same as those which hold the rotoflex joint in place, so I'd tighten them up to the same ie 35-40 lbs ft ( that's lbs ft by the way not lbs/ft ). That's not an excessivly high torque and should easily be achieved with a good hard tug on a normal open ended spanner ( spanners are actually designed so that they are the correct length to apply approximatly the correct torque when used by an average adult male ). Do not use an extension or you'll over stress the nuts. The 8mm cap screws which hold the cv joints to the aluminium carrier should be tightened to 22 lbs ft

One thing I did when I fitted the driveshafts was to discard the star washers. I don't believe they're necessary when using nyloc nut and they can make tightening the nuts correctly difficult.

As far as the ticking noise goes I'd check other area such as wheel bearings. This is what I found when I fitted the CV driveshafts. I hadn't noticed it before as the tension of the rotoflexes had been masking the play

Regards
Andy

Re: CV joints - how tight?

PostPosted: Tue Jan 25, 2011 6:15 pm
by leifanten
Andy, that is indeed lb ft :D
I had forgotten about that aluminum carrier that sits between the joint and the drive shaft on the Lotus mod. On my VW the 8mm bolts go into a steel flange, and hence the higher torque on those. I recall now that I used loctite on the 8mm bolts on the Lotus since I was worried about torquing too hard into the aluminium flange.

cheers

Re: CV joints - how tight?

PostPosted: Tue Jan 25, 2011 6:26 pm
by andyelan
Hi Everyone

Leif, I too used a little loctite "Nutloc" on the 8mm cap screws when I replaced them. Sue Miller says this isn't necessary but I can't see it doing any harm. Don't use the really strong stuff though or you'll never get the screws out again

Regards
Andy

Re: CV joints - how tight?

PostPosted: Tue Jan 25, 2011 8:29 pm
by Foxie
steve.thomas wrote:Hi all,
I fitted the Sue Miller CV conversion to my Plus 2 over Christmas, but now have a slight ticking / knocking noise from the rear drive that wasn't there before. Thanks for any help / advice
Steve.


May not be your problem, but here is a possibility:

I had a ticking noise start from a well run-in set of CV joints, when setting off on a continental trip. I feared for the worst and ordered a new set. When I removed the original CVs (having survived the trip), they were more or less perfect, but it could be seen that the balls were now running in a slightly different track, caused by a ride height change I had made, combined with full tank/boot/ + loaded back seat + heavy passenger :oops:

Re: CV joints - how tight?

PostPosted: Tue Jan 25, 2011 9:12 pm
by bcmc33
andyelan wrote:Hi Everyone

Leif, I too used a little loctite "Nutloc" on the 8mm cap screws when I replaced them. Sue Miller says this isn't necessary but I can't see it doing any harm. Don't use the really strong stuff though or you'll never get the screws out again

Regards
Andy

I always use Loctite on these type of fasteners.

Warning - don't put too much Loctite on the thread as it has the habit of extruding into spaces you don't reaaly want it to go. Please don't ask how I know. :oops:

Re: CV joints - how tight?

PostPosted: Tue Jan 25, 2011 9:51 pm
by andyelan
Hi Again Everyone

One thing to be aware of is that on standard commercial grade CV joins the tracks for the balls are not particulally well finnished off. While I've never noticed a problem with this, I suppose it might cause some noise untill the joints are fully run in

If you buy GKN Motosport CV joints then the tracks are polished and finished to a much higher standard, but then you're talking over ?100 each per joint. Personally for normal road use I would say standard joint are perfectly accecptable.

Regards
Andy

Re: CV joints - how tight?

PostPosted: Wed Jan 26, 2011 9:31 am
by peterako
Another thought Steve.....

I fitted Mick Miller CVs many years ago.

Very soon after I fitted them I too noticed a ticking/clicking from the rear of the car.

I too suspecvted the CV's, and spoke to Sue, who was very helpful (as always).

But...in the end it turned out to be a broken Diff mount.

Changed that (actually both mounts and and tie rod mounts :) ) and ticking/clicking gone.

As to tightening the CV shafts to the hubs etc.

I/we just used a normal spanner and tightented them to 'bloody tight' :)

One of the best changes I've made to my +2.

Best of luck,
Peter

Re: CV joints - how tight?

PostPosted: Wed Jan 26, 2011 11:56 am
by terryp
peterako wrote:
I/we just used a normal spanner and tightented them to 'bloody tight' :)



Funny I did mine to "F tight" torque and they have never come loose!

I'll be listening for a clicking noise now..........

Re: CV joints - how tight?

PostPosted: Wed Jan 26, 2011 12:03 pm
by bcmc33
terryp wrote:Funny I did mine to "F tight" torque and they have never come loose!

French tight? - now that's a new one for me :)

Re: CV joints - how tight?

PostPosted: Wed Jan 26, 2011 12:11 pm
by bcmc33
Steve,

Just a thought - with the wheels jacked off the ground, can you hear or feel the ticking when turning the wheels by hand?
I have been known to spend an inordinate amount of time chasing a rolling click on a neighbour's car that turned out to be a granite chip stuck in the tyre tread. :oops: