Driveshaft conversion

[alan.barker]

Correct BUT that still leaves the Diff Output Shafts which are the next weak point.
Also a question of weight.
The ex Mick Miller CVs are heavy.
Personal choice and depends how deep your pockets are.
Alan

[alanr]

Converting to CV's it seems to me is becoming increasingly less attractive due to the overall cost of the conversion and also the added weight issue!
Most owners of these cars nowadays don't do great annual mileages therefore it seems to me that sticking with Donuts and doing regular condition checks just may be a more realistic and sensible solution.

Alan.

[William2]

Personally I wouldn't touch doughnuts as it is a fact that the type of rubber used is nowhere near as good as the original and to me the beauty of solid shafts is that they are fit and forget.

[alanr]

I know that is what people have said for some time now regarding Donuts but is that really an up to date fact or just a bit of a myth from maybe a bad batch of Donuts produced some years ago?
My +2 is still on Donuts which look perfectly ok at the moment although I am hoping to do a couple of thousand miles in it this coming year so a little unsure presently on which way to jump on this one.

Alan

[alan.barker]

+1 they say the modern Doughnuts are not soo good BUT WHERE IS THE PROOF.
Been running Doughnuts for 45 + Years NO PROBLEM.
Alan

[TBG]

I ran doughnuts for years and had endless delamination problems. CV conversion has - a. sorted it and b. made the car so much more user friendly. D

[Donels]

Doughnuts are used on many historic race cars where the stresses are arguably higher than road cars. Yes they probably get a quick visual check before every race, but there is someone supplying the market with a suitably strong part. It would be good to know what the race experience is and who supplies the market. Anyone know a historic racer or Classic Team Lotus?

[rgh0]

I had the good quality OEM donuts fail 3 times during sprint and race meetings during the early 80's in my Elan and Plus 2 despite close regular inspection. After the third failure I changed to CVs and this has been fit and forget ever since then. I worked with Col Croucher on these Cv's design back then and what we did has evolved to be the excellent product he sells now. If you have a post 1970 car you should have the stronger diff output shafts already which are fine with Cvs. If you have the weaker output shafts in pre 1970 cars then they have probably broken and been replaced already or will fail soon regardless of whether you have donuts or Cv's

cheers
Rohan

[512BB]

' If you have the weaker output shafts in pre 1970 cars then they have probably broken and been replaced already or will fail soon regardless of whether you have donuts or Cv's'

You have written this before Rohan and I do not agree with you. On 2 of my cars, I still run the original waisted output shafts and there is absolutely nothing wrong with them, and it is a myth that they will break any time soon. I have no plans to swap them, despite having several pairs of the stronger type on the shelf.

Indeed, I remember in my 20s, I used to perform standing starts at the top of a hill using the same waisted shafts that that same car wears today!

It should be noted that the waisted output shafts ran right into Sprint production and my research, observations and car ownership tell me that they were only changed after about mid to late 1972. I also believe that breakages were mainly confined to +2s, as they are much heavier than an Elan.

Any part of an Elan can fail at any time, if that part has been abused, and I have abused some, to no avail. I think we will have to agree to disagree on this one R.

Best

Leslie

[rgh0]

' If you have the weaker output shafts in pre 1970 cars then they have probably broken and been replaced already or will fail soon regardless of whether you have donuts or Cv's'

You have written this before Rohan and I do not agree with you. On 2 of my cars, I still run the original waisted output shafts and there is absolutely nothing wrong with them, and it is a myth that they will break any time soon. I have no plans to swap them, despite having several pairs of the stronger type on the shelf.

Indeed, I remember in my 20s, I used to perform standing starts at the top of a hill using the same waisted shafts that that same car wears today!

It should be noted that the waisted output shafts ran right into Sprint production and my research, observations and car ownership tell me that they were only changed after about mid to late 1972. I also believe that breakages were mainly confined to +2s, as they are much heavier than an Elan.

Any part of an Elan can fail at any time, if that part has been abused, and I have abused some, to no avail. I think we will have to agree to disagree on this one R.

Best

Leslie

Hi Leslie

Your experience with the early waisted shafts appears to be much better than mine as every set of early shafts from both Elans and Plus 2 I have seen removed from cars in the last 30 years has a twist in the splines if examined closely and will sooner or later break at that point where the splines exits the diff or where the splines run into the waisted shaft. My understanding is that the stronger shafts without the waisting and using better steel were introduced with the stiffer "sprint" style donuts with the metal interleaves around 1970. Though with anything Lotus ... anything is possible to have actually occurred from time to time so you cant be absolute on anything

cheers
Rohan

[RichardHawkins]

Gentlemen,

I have only taken one diff apart, 1968 S4, one shaft had broken and been replaced by the later design, but some of the broken parts were still in the diff, the other shaft of the earlier design was twisted.

Hope this helps,

Richard Hawkins

[MenBret]

Hello
Can you on please tell me what brand / origin is this U joint ?
Thanks in advance!
Vincent

[berni29]

Hi

I have a very nice set of UJ driveshafts (and a propshaft) made by Bailey Morris Ltd on my plus 2. Not sure what they cost, but it may be worth checking them out.

All the best

Berni

[Andy8421]

Hello
Can you on please tell me what brand / origin is this U joint ?
Thanks in advance!
Vincent

A number of suppliers sell them:

https://paulmattysportscars.co.uk/product/driveshaft-conversion-kit-elan-2/

I am not the biggest fan of this arrangement as the sliding splines in the centre of the shaft lock up under load. Unfortunately it is the only design permitted in period racing - but in a race car suspension travel is limited, so perhaps it isn't such a big deal. CVs plunge, so it isn't a problem on CV conversions.

I can't find the link now, but someone posted a picture of a 26/R UJ driveshaft that had been supplied by the factory with ball-splines to avoid the lockup problem.