Doughnuts

PostPost by: jimj » Mon Nov 20, 2017 11:51 am

JonB`s search for a +2 recently brought up the issue of doughnuts. Mindful that mine hadn`t been professionally inspected since the MOT in May, I`ve checked them over this morning, and they`re fine.
It`s a Sprint in original spec. and almost too good to use, I`ve only done 3000 miles in the 4 years I`ve had it which is a bit sad but we have the S3. Being virtually mint I want to keep it to original, factory spec.
The S3 we use a lot, especially on competitive rallies, so with the inevitable rough treatment the drive train has TTR shafts and Miller CV joints which are fine, if a little harsh. I do prefer the more refined drive with doughnuts, though, and this set seem durable enough. Maybe because the car is so nice I drive it a bit more "respectfully" and this aids longevity.
Jim
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PostPost by: JonB » Mon Nov 20, 2017 3:28 pm

Hi Jim

My +2 has terrible wind up that makes it very hard to drive smoothly. Not helped by the throttle cable which I discovered was fitted wrongly (and when I refitted it I was rewarded by it snapping! Replacement on order :roll: ).

I've looked around and everyone seems to recommend fitting the Sue Miller halfshafts. I spoke to her this morning to ask for a catalogue. We discussed the shafts - they're expensive, something like ?500+VAT as she doesn't make them in-house any more. I have also read about the Spyder "half dougnut" shafts but I am a bit wary of them as I would rather not have 'nuts on my car. The thought of them failing on the motorway or during hard acceleration gives me the shivers! I have not drawn any conclusions though, because there is so much debate; but I will have to do something.

My car vibrates horribly at 80mph and I fear it's the 'nuts. I had a look and they are on their last legs. I got a spare set with the car, used but in good shape. Wondering whether to sell them on, go for the SM shafts and keep the old shafts in case I ever sell the car to someone who values originality over safety and / or convenience. Of course there are other issues that might make it vibrate and I read about them too - propshaft balance, loose bolts on the diff flange, play in front bearings / steering (both of which I have), etc.

Much to learn here!

Cheers
JonB
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PostPost by: MarkDa » Mon Nov 20, 2017 3:58 pm

The Spyder shafts incorporate a very substantial fail safe at the donut end.
So if despite regular inspection the rubber let's go completely it will be contained.
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PostPost by: ericbushby » Mon Nov 20, 2017 4:04 pm

Hi Jonb,
I have just fitted cv shafts on my Elan Series 3.
I hear what Jim says above but I much prefer the car as it is now. My doughnuts were still in good condition but I did not like the wind up. It made it difficult to accelerate away smoothly. I had to wait until it got going a bit before I could give it more power. It now pulls away smoothly from rest as you would expect from a modern car.
So take your pick.
I believe that Sue miller shafts are made by Kelvedon Lotus, but they are the same price anyway.
Eric in Burnley
1967 S3SE DHC
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PostPost by: JonB » Tue Nov 21, 2017 5:09 pm

OK.. after nipping the front bearings up a bit and taking it for a test drive (couldn't quite get to 80) I think - think - the vibration has gone (or reduced). I've got the new throttle cable and fitted it (5 minute job, amazing for a classic car) and it's much smoother. I can now manage the throttle with more precision and the doughnut windup is easier to control (but not entirely gone). It could be down to tired 'nuts; I expect they flex more when they are at end of life.

I think this has bought some more time. Clearly, I will have to do a full-on back end overhaul at some point (diff seals, CV joints, bushes, shock absorbers), but for now I will concentrate on the smaller jobs, like the interior and electrics.
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PostPost by: MarkDa » Tue Nov 21, 2017 5:30 pm

Hi JonB
This may be a daft question but you do have the stiffer reinforced donuts rather cheap plain ones?
When it comes to need driveshafts ?600 sounds a lot but 4 new donuts are ?360 or so, with replacement more often.
People do say that modern ones aren't as long lasting either.
So going solid isn't that much more expensive and providing you do exercise some restraint you needn't overstress the diff output shafts.
Mark
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PostPost by: JonB » Wed Nov 22, 2017 7:10 am

Hi Mark

I'm not sure what's on the car (will look next time I'm underneath it), but I have a spare used set that look like this:

https://i.ebayimg.com/00/s/NTc2WDEwMjQ= ... 0/$_86.JPG

That is, with the additional plate between the bolt holes, and they seem to be in good condition.

Do they have less windup than the non interleaved ones? Maybe I should fit them and try them out. I was thinking of selling them to help fund a set of Sue's shafts. The other consideration is the time it takes to do - I have much to do under the rear of the car and would like to get it all done in one go. Diff seals, bushes, shock absorbers, halfshafts.

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JonB
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PostPost by: jimj » Wed Nov 22, 2017 8:56 am

Jon, while you`re doing that work at the rear, changing the doughnuts will only add a few minutes to the whole job. The big advantage to CVs is you can almost fit and forget and, over time, will be the cheaper option.
I`ve never quite got this wind up experience, either now or back in the 60s/70s. Are other people clumsy with their clutch control?
Last year a pal, a good smooth driver, drove both our Elans back to back, having never driven an Elan before. The S3 with CVs, higher diff, and 5 speed Voight box has a much lighter clutch, easier to drive I`d say, but he preferred the standard spec. Sprint. He didn`t experience any wind up.
Jim
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PostPost by: theelanman » Wed Nov 22, 2017 9:34 am

jimj wrote:The S3 with CVs, higher diff, and 5 speed Voight box


as your local FIVA inspector I think I need to reinspect this car......... :lol:
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PostPost by: Orsom Weels » Wed Nov 22, 2017 11:59 am

jimj wrote:I`ve never quite got this wind up experience, either now or back in the 60s/70s. Are other people clumsy with their clutch control?
Last year a pal, a good smooth driver, drove both our Elans back to back, having never driven an Elan before. The S3 with CVs, higher diff, and 5 speed Voight box has a much lighter clutch, easier to drive I`d say, but he preferred the standard spec. Sprint. He didn`t experience any wind up.
Jim


In my experience, there's a big difference in wind up between an Elan & a +2. The clutch always seems to be much heavier on the +2, I suspect something to do with different pedal box arrangements, & in conjunction with the extra weight of the +2 it is difficult to avoid wind up all together, after 30+ years of driving them, I can just about eliminate it, but still get caught out once in a while. With the lighter Elan. it's much less of a problem.
There's also the quality problem of new Rotoflexes, we put a new set on my friends series 3 while restoring it & they fell apart in a few months while we were finishing the rest of the car, before it had even got on the road. They came from Sue Miller, who replaced them without question, & the replacements have now done a couple of summers & still look fine. Seems to be a lottery. The set on my +2 were from Lotus themselves & were fitted during it's restoration in the late eighties/early nineties. They have done over 35,000 miles & show no signs of deterioration at all, so good second hand ones may possibly be better than a new set.
I think the CV conversion is in some ways more suited to the +2 as there's no issues of the joints locking up on full suspension drop, as there is on the Elan, & given the cost of Rotoflex couplings now, I've more or less made the decision that when they do need replacing, I'll go down the CV route, although I do have some reservations about loosing the cushioning effect in the drive line.

Regards, Tim
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PostPost by: john.p.clegg » Wed Nov 22, 2017 12:23 pm

Tim
I found the Kangarooing much worse in reverse , since fitting the Performance Unlimited type U/Js fifteen years ago it has been even more of a joy to drive.

John :wink:
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PostPost by: Grizzly » Wed Nov 22, 2017 4:19 pm

I agree with Tim, i nearly kept my 2 seaters rotoflex's as it drove alright (not too much wind up at all) gave it some character. My +2 needed a bit of a driving style change to be able to drive smoothly but it can be done..... i found when the rotoflex's on my +2 where getting old low speed cruising was surprisingly difficult especially in traffic.

But all that said i have had one that looked to be ok on my +2 fail on me smashing the caliper off the hub, so even when they appear to be good i can never fully trust them....

Not sure i would call CV joints fit and forget, i know a few people that have done decent distances on them and because they do articulate quite a long way the Boots tend to fail quite quickly (can kill the joint in exactly the same way it does on a modern car). Just to add because of the articulation good quality joints are important or they tend to be noisy.

Don't forget to fit the Diff brace, the Rotoflex's absorbed shocks very well but once you take them out of the equation the rather delicate diff ears have a habit of snapping off.
Chris
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PostPost by: jk952 » Wed Nov 22, 2017 9:09 pm

...not to mention firm/fresh diff torque rod rubbers and ensure tightened up...
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