Rotoflex Couplings

Date: Sun, 20 Sep 1998 19:01:47 +0100 (WET DST)
From: Hawes
Subject: Rotoflex Couplings

Speaking of rotoflex couplings. I want to fit a new set to my son's stiletto. How should I go about it? Do I have to rotate the wheel to enable each bolt to be removed without snagging on the transaxle, or will they all be able to be extracted with any trouble. Do I need to clamp the old ones before removal? Can I do the work with the rear wheels on ramps or axle stands? Any advice would be helpful?

Roger Hawes

Date: Mon, 21 Sep 1998 07:57:05 +0100 (WET DST)
From: Gary and Carol Henderson
Subject: RE: Rotoflex Couplings

Hi
  1. Use stands - don't jack it up.
  2. remove the four smallish bolts that hold the rear engine-mount. Then you can shove the engine/trans sideways to help squeeze the monsters into place.
  3. Make the clamps - you might need them, even though new one scome banded. DON'T cut the bands until installed!
  4. Next time I do it, I'm going to make a plate with 6 taper-pins on the correct pitch-circle, so that I can ensure the holes in the coupling really will align with the flanges!
  5. Use Loctite on the bolt threads & antiseize on the shanks.

Good luck

GaryH

Date: Mon, 21 Sep 1998 09:13:18 +0100 (WET DST)
From: hawes
Subject: RE: Rotoflex Couplings

Thanks Gary, does that mean that I won't have to rotatate each coupling to get the bolts out because looking at them it seems that some will foul the transaxle when they are pushed through ?

Date: Mon, 21 Sep 1998 10:39:09 +0100 (WET DST)
From: Graham Miller
Subject: RE: Rotoflex Couplings

Last time I undid a set of Rotoflexes, I remember having to rotate the wheel to get the bolt to free. You can, as I recall remove all the nuts to leave everything free, then rotate and wiggle the bolts out. I used two ring spanners most of the time, although it might be possible to get a rachet in there, I can't quite remember. I do remember that it's quite handy in that a ring spanner will jam against the transaxle if you put it on the back, leaving you free to work on the front. Obviously, jack it up, and then use axle stands, you will be seriously under the car, so you want it properly supported. You might want to put the stands on the body as opposed to the swing arm in case you want to move the wheel up and down... when I did it I was replacing rear springs.

Good luck!

Graham

Date: Mon, 21 Sep 1998 11:44:16 +0100 (WET DST)
From: Mark Norman
Subject: RE: Rotoflex Couplings

Get the new ones from a good supplier (Speedy Spares, Impetus, Malc Anderson etc). A couple of years ago I bought two sets cheap from a local store that had had them on the shelf for ages and was selling them off.
Each set lasted about 6 months! - the rubber came away from the metal segments. Not fun to have to replace them that often!

Mark.

Date: Mon, 21 Sep 1998 12:26:17 +0100 (WET DST)
From: Simon Trickett
Subject: RE: Rotoflex Couplings

If you want new ones the cheapest place in the country is Christopher Neil Sports Cars.

They are a Lotus Garage in Cheshire, they supply most of the Imp Specialists !!

Comp rotoflex's are £30 each.

I can give you they number if you want.

They also do 2 different types of Bolt at a good price. It is advisable to change the bolts when you replace the rotoflexes.

I have large Allen bolts and nyloc they never come loose.

Simon

Date: Mon, 21 Sep 1998 13:29:38 +0100 (WET DST)
From: Hassall
Subject: Rotoflex Couplings

Hi all

Not trying to be disresprectful to the traditionalists out there but the doughnuts are a pretty bad way of transmitting power to the wheels.

UJ's aren't constant velocity and so these accelerations must be taken up by the doughnuts.
Power is absorbed as they flex to accomodate the camber and lateral movement of the wheel. (ok so this is probably small).

Why not weld in another UJ? I have seen this done on a race Imp with sliding splines and all. Don't know where the part came from but it reputedly worked ok.

Other interesting features on this car were

With the car were interesting manifold adaptions for the standard imp.
a Griffiths Super Speed with twin 1¼? SU, the other was an Lynx for Twin webers/dellortoes (for use with the standard exhaust!). Presume these were period items out of the UK? ( on the car was twin del 40's with a l o n g exhaust that went Behind the transmission!

This car is for sale by the way- in Chch, NZ. The guy was knocked off his motor cycle by some drunken driver and now has a epilepsy condition. This prevents him from driving /racing.

Has anyone done any analysis of the optimum exhaust/inlet manifold lengths for the Imp? Know of any good literature on the subject?

Cheers

Matt

Date: Mon, 21 Sep 1998 14:12:18 +0100 (WET DST)
From: Simon Trickett
Subject: RE: Rotoflex Couplings

UJ's are constant velocity for small angles but not at extreme angles.
They are ok on the imp as the movement is very small. CV joints were develop for these stupid front drive/front engined Euroboxes were the angle of the driveshaft joints is very extreme at times.

See yer

Si

Date: Mon, 21 Sep 1998 15:13:32 +0100 (WET DST)
From: Gary and Carol Henderson
Subject: RE: Rotoflex Couplings

Hi again

Yes, you do need to rotate things - awkward on ramps. And sorry, I was forgetting from my Mk1 perspective (with rear jack-points on the body crossmember) that later cars jacked on the trailing-arms. Jacking from here, plus of course chassis-stands for security, will keep the axles near-enough in line. This is one of the few times that a pit would be great! You'll find them such reluctant b....s that you'll wonder how they ever could fail!

Good luck

GaryH

Date: Mon, 21 Sep 1998 22:45:36 +0100 (WET DST)
From: Nickcleak@aol.com
Subject: Re: Rotoflex Couplings

> Why not weld in another UJ?

well because there will be nothing to absorb driveline shock and the transaxle casing will split open !!

Peter Harper's rallycross Imp of the Late 60's had solid driveshafts , but maybe he had a conventional type of sprung clutch plate ..
Due to the Imps great traction , the damage is done if the wheel looses traction over sat a manhole cover or a mud patch especially when going uphill under full power , then digs in when grip is found , more important on a modified engine of course ..

not so important in a front wheel drive car of course as the wheel just spins away to itself ..
Anyway the competition type rotoflexes seem to last well ,, i have had mine on for well over 60000 miles .still ok ..although there are normal hairline cracks ..

nick ..

Date: Mon, 21 Sep 1998 18:45:31 +0100 (WET DST)
From: Henk Hol
Subject: RE: Rotoflex Couplings

>If you want new ones the cheapest place in the country is Christopher
>Neil Sports Cars.
>
>I can give you their number if you want.

Please give the adress and telephone/fax number.
Thanks, Henk Hol

Date: Mon, 21 Sep 1998 18:55:11 +0100 (WET DST)
From: Simon Trickett
Subject: RE: Rotoflex Couplings

Good supply of Rotoflex couplings (comp) plus bolts.

Christopher Neil Sports Cars
Middlewich Rd
Northwich Cheshire CW 9 7BN
Tel 01606 41481 or 0044 1606 41481

please mention my name, ta

Simon Trickett

Date: Mon, 21 Sep 1998 21:22:46 +0100 (WET DST)
From: rienk steenhuis
Subject: Re: Rotoflex Couplings

hello roger

>Speaking of rotoflex couplings. I want to fit a new set to my son's
>stiletto. How should I go about it? Do I have to rotate the wheel to enable
>each bolt to be removed without snagging on the transaxle, or will they all

yes. the wheel at the side you're working on must rotate. also the long bosses must go to the flanges. and the bolt is put through from the side of the short boss. whatever you do make sure the car is properly supported as some force and gentle ;-)) persuasion is likely to be involved.

rienk

Date: Mon, 21 Sep 1998 22:26:13 +0100 (WET DST)
From: hawes
Subject: RE: Rotoflex Couplings

I bought mine from Speedy Spares #13 + pp & VAT each

Roger H

Date: Mon, 21 Sep 1998 22:26:20 +0100 (WET DST)
From: hawes
Subject: RE: Rotoflex Couplings

Thanks rienk, nice and clear.

Roger

Date: Mon, 21 Sep 1998 22:26:20 +0100 (WET DST)
From: hawes
Subject: RE: Rotoflex Couplings

Thanks Gary for the words of encouragement! As I don't have to replace them just yet I may delay it a bit whilst I carry on the research. I'm concerned to replace them because on one side packing washers are installed for some reason that I can't make out (but perhaps don't want to find out !!).

Date: Tue, 22 Sep 1998 19:43:28 +0100 (WET DST)
From: Nickcleak@aol.com
Subject: Re: Rotoflex Couplings

< I bought mine from Speedy Spares #13 + pp & VAT each

how long did they last ? are they the dreaded SUK type ?
the comp ones last much longer than std types
nick ...

Date: Tue, 22 Sep 1998 01:28:57 +0100 (WET DST)
From: Gary Henderson
Subject: Re: Rotoflex Couplings

Hi Nick & all

The Fiat 600 (actually 767cc by 1964) had a strange coupling - like a pair of square threadless nuts running in a slot in the diff drive - inside amongst the oil, with a big rubber boot outside. The other end of the simple swing-axle included a big rubber coupling (not a U-J of any kind - a concentric toothed-sleeve pair with rubber in between.)

Question re the comp. Rotoflexes - are these still the preference, with a bog-standard engine and suspension, and skinny shafts?

Cheers

GaryH

Date: Tue, 22 Sep 1998 21:02:55 +0100 (WET DST)
From: D.K. Pitts
Subject: Re: Rotoflex Couplings

Hi All!
A guy here in the US has couplings in 'Quinton Hazel' (sp?) boxes.
Is anyone familiar? Would these be any good?
Darryl

Date: Wed, 23 Sep 1998 00:35:05 +0100 (WET DST)
From: Gary Henderson
Subject: Re: Rotoflex Couplings

Hi Darryl
The last 'genuine' ones I ever got new via Todd/Mitsubishi NZ were in Q-H boxes and were genuine Rotoflex. Mind you, the no-good redesigned waterpump was Q-H also!

A very l-o-n-g time in the boxes doesn't help.

Cheers

GaryH

Date: Wed, 23 Sep 1998 03:12:10 +0100 (WET DST)
From: Paul Greville
Subject: Re: Rotoflex Couplings

Hi Darryl,

If they are cheap enough, appear in good condition and are only intended for use on a standard vehicle why not give them a try.

Regards,
Paul Greville