Discussion
I’ve just bought a 71 Elan Sprint and considering changing to solid drive. I’ve had two Elans and an Elan+2 in the past and managed to do many miles on doughnuts without any problems.
Anyone got any comments on the pluses or minuses of solid drive couplings? I like the occasional spirited drive but I’m too old to be doing any fast road or track driving.
Anyone got any comments on the pluses or minuses of solid drive couplings? I like the occasional spirited drive but I’m too old to be doing any fast road or track driving.
I changed my S3 a few years ago using Sue Miller's kit. Like yourself I've done a lot of miles on the rubber doughnuts with no problems but when the last set started to fail I decided to go the CV route. The reasoning was simply the number of tales about poor quality replacements and I didn't want to find that 2yrs down the line the ones I'd bought were failing.
Personally I like them, I can't say it's made a massive difference to the way I drive or made the car harsher. One thing that was noted was that on the 2 seat Elan there's a potential problem if you ever get the suspension in full droop and for that reason the recommendation is to restrict suspension travel.
I didn't bother for the first few years but when I changed springs/dampers I fitted reduced travel dampers at the rear. Something to bear in mind if you're driving fast over humped back bridges
Personally I like them, I can't say it's made a massive difference to the way I drive or made the car harsher. One thing that was noted was that on the 2 seat Elan there's a potential problem if you ever get the suspension in full droop and for that reason the recommendation is to restrict suspension travel.
I didn't bother for the first few years but when I changed springs/dampers I fitted reduced travel dampers at the rear. Something to bear in mind if you're driving fast over humped back bridges
I believe that all strut inserts supplied for Elan and Plus 2's are now reduced travel as standard (by about 30mm) to overcome the over articulaton issue on full droop which I think is only really an issue on the Elan.
The CV's work very well in my experience and bearing in mind the replacement cost of good qualiy rotoflex couplings they're something of a no brainer in my view.
The CV's work very well in my experience and bearing in mind the replacement cost of good qualiy rotoflex couplings they're something of a no brainer in my view.
UnluckyTimmeh said:
You’ve just got to be careful if ever driving really hard as I’ve known these to break the output shafts of the rear diff.
Apparently you can get half and half shafts? So a doughnut on the inside and conventional cv on the outer. Can’t say I’ve ever seen any though.
Spyder do them, in fact it's their only offering.Apparently you can get half and half shafts? So a doughnut on the inside and conventional cv on the outer. Can’t say I’ve ever seen any though.
The early diff output shafts were certainly prone to failure as they have a waisted shank. After around 1968 (circa) the shafts were made thicker with a constant shaft diameter and are much stronger and therefore less prone to breakage. TBH I have never known shafts to break as a direct result of fitting CV driveshafts but it certainly would be a heightened risk with the earlier diff outputs.
Tony Thompson does billet outputs for racing use and billet hub shafts (these too can break with much more worrying consequences) - both pretty much essential for race use.
UnluckyTimmeh said:
You’ve just got to be careful if ever driving really hard as I’ve known these to break the output shafts of the rear diff.
They can also cause (or contribute to) fatigue cracking of the chassis around the diff upper mounts - hidden under the boot floor - and diff. torque rod, mounts, if you do a lot of mileage.UnluckyTimmeh said:
You’ve just got to be careful if ever driving really hard as I’ve known these to break the output shafts of the rear diff.
Apparently you can get half and half shafts? So a doughnut on the inside and conventional cv on the outer. Can’t say I’ve ever seen any though.
We have Spyder half’s’half units fitted to our car (despite me inadvertently saying Vegantune in the video Apparently you can get half and half shafts? So a doughnut on the inside and conventional cv on the outer. Can’t say I’ve ever seen any though.
)https://youtu.be/qCPOm0-NtA0
Believe they were fitted in the early 80s, possibly late 70s and haven’t caused any diff issues. The donuts are perished and need replaced, but the car hasn’t moved in 20 years so possibly to be expected.
They are still susceptible to damage on the donuts from full suspension droop when jacking. I understand it’s recommended to jack from the bearing housing / wishbone end using a plate, but you’ll need a mighty low slung jack to get under there!
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