Drive shaft up grade

[LotusNorth]

What experience is there out there? I want to replace the rotoflex couplings as am always worried one day the shaft will come through the floor and they are a pain to replace on a regular basis.

I have tried the universal joint replacement and found that a little agricultural noticing the joints rotate.

I have tried a UK supplied CV joint replacement after a few miles and 12 months the four boots were cracking, grease escaped from behind the joint on to my rear disc, and I had vibration on the over-run at speed, they were fitted with Chinese CVs and probably boots!

I have been looking at an Australian from either Croucher Engineering and Lotus Marques they both look the same and read very professional promising GKN Lobro CV Joints and Lotus Marques they both look to have common source. Has anyone fitted them and what experience?

Thanks,
Alan

[alan]

i suggest you look at past posts, there's lots of info

[Plus 2]

Alan, (OP)

For sure the quality of rubber parts in the aftermarket appear exceptionally bad across all car marques and is a regular complaint on several classic car forums I support. The common factor appears Made in China, PROC or Indonesia and it was one of the factors that I decided to fit my CV's through concerns of the quality of recently produced foreign donuts.

I was fortunate I bought my Mick Miller CV joints over 10 years ago and only got round to fitting them a couple of weeks ago and they were fine. I have checked them after 100 miles and all is good.

I found absolutely no benefit in the ride quality though which was what I was trying to ascertain together with any issues in long service, however strangely I thought I had some slight diff whine on overun which appeared immediately after I changed the diff nose seal 20 years ago. This has disappeared. I did fit new bearings though at the same time as the CV's and overhauled the brakes but I was pretty sure the whine was the diff just on overun. Anyway it has gone.

When the CV's were fitted on full droop I could not easily turn the wheels. Jacked up half an inch they were easy to turn so I suspect the driveshafts on the +2 are right on the limits if no other mods are done.

There are quite a few old posts on the CV shafts but I found none that were actually addressing my question and mainly answered fit issues and problems and what I wanted was a discussion on issues longer term that may have come to light after years in service.

45 years working on Lotus and owning 17 Elans I have somewhat fitted quite a few diffs, donuts, rear wheel bearings and rear shocks.........probably like you it is not fitting help, service or maintenance you seek but information on the products you are no doubt seeking.

Hope someone can give you the actual links or answer your questions on the information you have asked if it exists direct and you don't get the flurry of gear crunchers that just say search GOOGLE or search the library, as you will have a lot of reading to do no doubt.

I have backed onto your post just in case any additional information provided while the post is in the discussion section does prove useful. Sorry I can't help with the products from the companies you quote but again please follow up what you decide and again in service information issues.

Regards

Steve

[LotusNorth]

Hi Steve,

Thanks for the very full reply, it is good to hear that the CV conversion on your car runs well, I suspect yours has GKN CV joints.

I was just wondering if anyone has imported these drive shafts from Australia.

Alan

[roblotus79]

Having recently gone through this and remembering a lot of the thread information associated, it seems to me that the ones supplied by Elantrickbits in Australia might be worth considering. I seem to remember that they do not require droop limiters etc.

I have a Plus 2 and installed the ones supplied by RD Enterprises in the states. They work well and come in a kit with new differential output shafts as well. I have not had them long enough to help you with a long term assessment. However, my local Lotus guru who recommended them has run them for years on his Elan including lots of racing and has never had a failure problem regarding boots etc. He has also never had any problems, that are discussed exhaustively, with respect to driveline shock in the diff etc. It is his contention that anything like that might actually show up at the weakest link the system, the clutch and pressure plate.

Hope it helps.

[Plus 2]

Having recently gone through this and remembering a lot of the thread information associated, it seems to me that the ones supplied by Elantrickbits in Australia might be worth considering. I seem to remember that they do not require droop limiters etc.

I have a Plus 2 and installed the ones supplied by RD Enterprises in the states. They work well and come in a kit with new differential output shafts as well. I have not had them long enough to help you with a long term assessment. However, my local Lotus guru who recommended them has run them for years on his Elan including lots of racing and has never had a failure problem regarding boots etc. He has also never had any problems, that are discussed exhaustively, with respect to driveline shock in the diff etc. It is his contention that anything like that might actually show up at the weakest link the system, the clutch and pressure plate.

Hope it helps.

Rob/Alan,

That really is useful information and exactly the sort of information I was looking for when I put my post up
originally.

When I bought my Mick Miller driveshafts I actually spoke to Mick at the time (RIP MM). I am sure he said the CV's were VW so if they used GKN that I don't know.

In fact I had no idea actually what is inside. When I was fitting them I did pick up some 'trials and tribulations' from others that had experienced difficulties and others that had fitted them in 30 minutes.

Mine took 3 days but as always other jobs get done along the way. Brakes, bearings and a bit of bicycle frame painting.

At first as most issues I read seemed to be tightness and having to remove the hub from the lower frame I first thought mine must have been supplied wrong and maybe the Elan ones opposed to the +2 as there was at least a 5mm gap and the shafts just slipped easily into place.

As they were tightened up each side the gap closed up and all was well.

Although it was about 12 years ago I replaced the donuts they were perfect when I removed them as only done around 5000 miles so I will probably just sell these on now as the Cv shafts are proving fine. Hopefully I don't ever expect at my age and slow driving either to be ever suffering full droop when in motion so if an issue just on the limits of travel I doubt to be affected

Still looking forward to info/issues on any other makes though.

Regards

Steve

[AHM]

Welcome Alan,

You don't say if you are talking Elan or Plus 2 - This is one area where it makes a difference.

As Alan mentions there is quite extensive discussion from all angles (pun intended!) in the archive.

I don't have experience of the Oz driveshafts but they do look like the best engineered ones.

You may get more replies if you have other specific questions.

[rgh0]

Hi Alan
If you have a Plus 2 I would just buy a new set of GKN Lobro CV joints and give it another try. If you have an Elan you may need some form of droop limit to stop the CVs binding on full droop but this should not be needed on a Plus 2. I have run CV,s on my cars for round 30 years with no problems. The Col Croucher kits are certainly very well made in my opinion. Col originally used to supply Lotus Marques but I don't think he does anymore and they get them made elsewhere.

cheers
Rohan

[bengalcharlie]

installed a US made set many years ago supplied by Ray from RD enterprises and I am very happy with them. I particularly liked that fact that the diff output shaft is integrated with the inboard CV joint. They are a piece of art, just beautifully made!
Not trying to cause offence but I have far better experiences with USA made products than UK made stuff.
Do not know where you are located, that might make a difference in your decision making as well.
cheers robin

[Plus 2]

Not trying to cause offence but I have far better experiences with USA made products than UK made stuff.
cheers robin

But we all still love these old British handmade cars, back then when made with virtually ALL British parts.

Regards

[stugilmour]

Have also used the RD supplied shafts for several years and about 15K miles. Work very well. No issues on my car at full droop; the integration of the inboard CV with the replacement diff output shafts presumably makes the shaft a bit longer and reduces angle at full droop. Note the output shafts in my car did show signs of distortion, and were supposedly the stock higher strength ones, so replacement shafts were a bonus in my case.

I did have a boot failure as well, but figured it was caused by miss-handling during a diff repair job. The RD units use VW CV's that are easily sourced locally; I cannot recall the exact call up but a VW independent matched up to them easily. There are two VW CV sizes that are similar (Bug and Van) with different bolt patterns, which caused an issue when I initially tried to get new boots on-line without an exact call-up.

I think Col's units are terrific as well, and would probably be my choice for an Elan. IIRC he modifies the CV to lighten it and get around locking issues at full droop. Col posts here and can provide you with details. Only issue I suppose with purchasing from a different continent is the shipping cost; the units are very heavy.

Agree with Rohan that I would try to source a good quality replacement CV & boot and give the units another try.

HTH

Stu

[elanner]

My two seater S4 Elan has Col's (Elantrikbits) driveshafts fitted and they do not need droop limiters. Of course I can't be sure that it has the standard amount of droop, whatever that is. But it's on standard springs and standard looking struts. It certainly droops a good bit, to the point that it's hard to imagine anything else would droop more.

Great product. Fit and forget. Mine were $1,708 which included shipping to the US, back in early 2012. I see that they are now $1,545 including shipping, presumably due to exchange rate changes. Win some, lose some.

Nick

[LotusNorth]

Thanks guys for all your information and experience looks like I need VW CVs for my Plus2 next to decide where from.

Alan

[Sea Ranch]

I don't think Mark (memini55) will mind if I offer that he has at least 2 cars with Elan Trik Bits cv halfshafts installed (a baby elan and a plus 2, I believe). He could offer another impression of Col's units in use.

Regards,

Randy

[ceejay]

Hi Guys.

Thanks for the kind words re the elantrikbits CVDS.

Yes, we ONLY use GKN Lobro CVS, we checked out the Chinese CV's
years ago, and I'm afraid they are only good for the rubbish bin, sure, they
are dirt cheap at less than half the cost of GKN, if you see a CVDS
conversion that is dirt-cheap... you wont have to look far to find the reason why.
The CV's are common to the VW beetle (Vee Dub) as we call them out here in Australia,

Hopefully, GKN will never stop producing these CVs, if they do, we are
all in the poo, but I cant see that happening any time soon.

Pleased to say our CV Conversion does not require droop limit cables
or straps, providing your elan rear suspension strut inserts have not been
molested, IE, are still standard length.

My S2 elan has always had CVDS, I have never driven it with donuts,
so if you notice some variations with vibes & noises after changing from
rotoflex to CVs, it is probably a normal thing.

To help reduce diff noises migrating into the chassis, make sure that the
upper diff mounts are actually isolating the diff, and make sure that
the torque arm bushes are in excellent condition, and be sure to check
that the steel cup washers either side of the torque rod bushes are not
touching the web casting gussets on the alloy housing, I had this problem
recently, and after replacing the bushings, and grinding some small clearance
scallops in the washers near the alloy strengthening webs, the diff noise
level was significantly less.

I have three diffs that I use, IE, 3.55, 3.9, 4.2, they all have their own peculiar
sounds at certain speeds.

The GKN CV's should see 60-80 thousand K's of life, keep them lubed with
correct CV grease and they will last, (That is why grease nipples are inserted into
each adapter plate).

We used to supply Lotus Marques (elanfactory), same thing, several years
ago, that arrangement no longer exists, the particular design of adapter plate
is our design, I still have the original hand drawings, anything else is a copy
of my design and intellectual property.

We have supplied countless CVDS conversions to elan and elan plus 2
customers both here in OZ, and all over the world, unfortunately as with all
exports, the recipient will be asked to pay customs duty, we have no control
over that, the airfreight cost is always an issue, as is fluctuating currency
exchange rates, it's a crazy world out there, and sometimes it is difficult to
keep track of.

If you still have questions, then please PM me, or contact through the
web form at www.elantrikbits.com
We post new articles at the blog from time to time.
http://elantrikbits.com/lotus-elan-blog/

Regards
Col Croucher.
Australia.