To Rotoflex or not to Rotoflex

[Matt Elan]

After reviewing all the posts and otehr threads (and other boards etc) I came to the conclusion that double CV's were the way to go for fit and forget. Mick Miller Lotus are having a new batch of CV joints for Plus 2s made and should be in stock soon; I've got my name down for a set....

[holywood3645]

Gearbox, Do you have any pictures of the finished items you made from the VW items?
Can you provide any pictures of the modifications you made to the shafts to fit the 2 seater elan application.

Thanks

James

[gearbox]

Gearbox, Do you have any pictures of the finished items you made from the VW items?
Can you provide any pictures of the modifications you made to the shafts to fit the 2 seater elan application.

Thanks

James

Hi James, The process is fairly simple, find yourself a set of used OEM VW Bug shafts from a late 60's early 70's vintage. The difference is that the OEM shafts had circlips holding the CV's on to the shafts. The Bug never really needed these so all the new versions do not have this feature.

I found a pair on ebay for $60.00 that were pretty dirty and greasy, but the shafts were in great condition.

The worst part of doing this job was disassembling the shafts, amazing how much grime and dirt accumulates over decades, plus the CV grease didn't help either.

The next step was to cut the shafts to size. I am using a pair of diff output shafts with CV cups and on the outboard side I have 1/2 inch thick aluminum adaptors, so I needed to have the shafts to be exactly 12" in length end to end. The shafts are hardened steel, so the surface of the shafts are incrediably hard. I used a die grinder to cut the shaft in half, and then trimed them to size, 6 inches, on the lathe. I also wanted to make a sleeve to ensure that the both halves would be concentric when welded together. Since the shafts are metric and all I had were SAE drill bits, I decided to mill down the shafts to 15/16", or 0.9375", by two inches on both shafts to accept the 4" sleeve.

I went a bit overboard with the sleeves, but I wanted to make sure it will hold. I used a 4" long 1.375" diameter steel rod. Drilled a 15/16" hole for a friction fit for the shafts, drilled and countsunk 6 holes for plug or rose welds. I also milled down a relief for the CV boots to lock into on both sides.

I Tig welded both ends of the sleeve to the shafts and weled up the 6 plug holes to the shaft. Pretty much bullet proof at this point, but I am told that you can also use 1/8" tubing with a 1" I.D., or butt weld the shafts together. I've seen a Formula B car with butt weled shafts and after years it has not yet broken. But I didn't trust my welding skills so went with some extra insurance.

The finished shafts. A bit of paint and they look brand new.

I opted for a new set of GNK Lobro CV joints and they came with new boots and bolts. Apparently there are alot of cheaper aftermarket CV kits out there, but for $262.00 for 4 complete sets of OEM CV's, why not.

!BkdghLQ!2k~$(KGrHqEH-EMEs8kiCZUgBL(nf3Q-7g~~_1.jpg (22.69 KiB) Viewed 1554 times

Top picture is the Diff output shaft I bought on ebay and the guy also had the outboard adaptors. However, you can just make two adaptor plates for both sides for 1/2" thick aluminum, but these wrere nicely made, and for $388 shipped, it wasn't a bad deal.

I have this entire step by step project on my site at http://thelolaregistry.com/Projects/LOT ... ersion.htm so you can check it out. Let me know if you need any help, Allan

[Jaybee]

Sue Miller cv conversion no drop limiters etc fit and forget . To many people on here that comment about things that they haven't done themselves and just make things up. Seats spring to mind I've just replaced mine in the forums every body's talking about what might fit but no one seems to have actually changed them! .john..........

[AHM]

To many people on here that comment about things that they haven't done themselves and just make things up.

If you read this thread you will see that your comments are out of place.

If you read some recent history you will see that they are rather awkward.

Most people on here are knowledgeable and helpful.

[vernon.taylor]

Salut

To many people on here that comment about things that they haven't done themselves and just make things up.

If you read this thread you will see that your comments are out of place.

If you read some recent history you will see that they are rather awkward.

Most people on here are knowledgeable and helpful.

I'm afraid I have to agree, too. This forum is very frindly, helpful, informative, knowledgable and probably constitutes the most complete resource for Lotus Elan and Plus 2 cars on this planet.

Please share, don't flame

@+

Vernon

[Jaybee]

You are correct in some of your comments but sorry I stand by my findings and only comment on the things I have done ,by that I mean facts not guess work and assumption . Sorry it would appear I'm a boat rocker and not a lamb agreeing with others for the sake of it.

[AHM]

Rock the boat? Hardly!

Do you want to tell us something about driveshafts?

[Mazzini]

Rock the boat? Hardly!

Do you want to tell us something about driveshafts?

Plus one to that.

I'm running US CV's driveshafts on the S3 and am just about to fit a set to the S2, I can post photos if anybody is interested, they come complete with diff output shafts. Bought from Jeff at JAE whom I can't recommend highly enough.

[Spyder fan]

Rock the boat? Hardly!

Do you want to tell us something about driveshafts?

Plus one to that.

I'm running US CV's driveshafts on the S3 and am just about to fit a set to the S2, I can post photos if anybody is interested, they come complete with diff output shafts. Bought from Jeff at JAE whom I can't recommend highly enough.

Do I need a comfortable chair, a bowl of popcorn and a few tins of Stella?

Regards

[StressCraxx]

Or, to rotoflex or to guibo?

Yes, I'm dragging this out from the dusty archives for those who do not want to convert to CV joints. This conversion is cost effective, actually cheaper than rotoflex by a wide margin.

Here is quote from a vintage racing thread (RMVR).

"We are using these on the west coast for Formula Ford and Formula B (Lotus Twincam 200HP) cars. After multiple failures on new metalastic couplings, the vintage prep shops have adopted the "Guibo" couplings used on Volvo and BMW for halfshafts.

Just went through this exercise again, so posting links to suppliers:

Donuts: Volvo driveshaft guibo from FCP Euro, Febi/Bilstein P/N 1220843, $44.89 each, (2) https://www.fcpeuro.com/products/volvo- ... em-1220843

Spacers: 7/16" bore, 7/16" wide shaft collars from Fastenal, SKU # 33373, $1.07 each (6)https://www.fastenal.com/products/details/33373

Shims (to reduce 12mm sleeves in the donuts to ~7/16"): 15/32" OD, .015" wall brass tubing, Specialty Metals #138, Thompson's Hobbies and Crafts, 1585 Wadsworth in Lakewood, ~$3.80/ft; also available at Ace Hardware stores. Need (12) pieces cut to 1.2" length, so buy 12" two sticks."
Original post: https://www.tapatalk.com/groups/rmvr/rubber-axle-donuts-t3945.html

John Anderson Racing in Sonoma uses specially fabricated spacers that spread the tension and torsion loads. I will see if I can get the info and cost.

All of the above is provided at your own risk.

Regards,
Dan Wise