Rotoflex Coupling Supplier or CV conversion

[Ingieuk]

Hi,

What is the latest on getting hold of quality rotoflex doughtnuts? I have just found a large split in one section on my car, looks to be nearly all the way through.

Rimmers sell them for £50 each, James Paddock for £35, Canley's for £40. One company I found in a forum search seemed to have re-manufactured originals http://race.parts/Catalogue/Drivetrain/Rubber-Drive-Donuts/Heavy-Duty-Rubber-Drive-Donuts at £113 each. Does anyone have experience or guidance on which to choose? Is more expensive better? I'll be steering clear of the £30 for a pair ebay jobs for sure.

I'd contemplate a CV conversion also if it's reasonably fool proof. I need to do some more research on the Nick Jones conversion, there is also the Rimmers one and TSSC seem to have one too. £500-700 seems a lot to spend vs a £100 doughnut. Easy to say until a cheapo doughnut fails and strands me maybe...

Thanks,

Rich

[Nigel Clark]

Not the answer you want perhaps, but I've given up on rotoflex couplings. After a very old pair on my GT6 started to crack I replaced them with genuine Metalastic.  These lasted 3 years and about 10,000 miles before fine cracks began to appear.

Not wishing to repeat the cost and hassle of regular rotoflex renewals, I've fitted CV shafts from Classic Driving Development,  which are excellent and well worth the money in my opinion. 

Nigel

[Clive]

Yes, the price difference is significant. But then again so is the effort to replace a donut. 

I have the jones/bowler conversion, that has the huge advantage of a modern bearing in the upright so no faffing with shims. Downside is it needs the upright machining. But today finding the correct Rover 100 driveshafts is a mission, as are the Volvo CV joints. The other conversions seem to work well, though you are left with the shimming. But bearings should last for a very long time.

Another advantage of the CV conversion is that working on the rear shafts is soooo much easier as no tension from teh donut. You can also use the std shock absorber position and normal spitfire shocks.

 

[Gary Flinn]

This is from an old thread about Rotoflex couplings:- 

"When I was struggling to find genuine Metalastic donuts about ten years ago  - for a reasonable price - I found some in stock at Bailey Morris Propshafts, in Cambridge ? They were new manufacture by Trelleborg, who have bought the rights to the Metalastic brand and are made to the same standard. Trelleborg make a lot of different size donuts as they are commonly used in propshaft couplings. Might be worth a try...

Gav"

I've no idea if Trelleberg still make the Rotoflex coupling to original Specification, I do remember them being near on £200 Each though!

Some of the reproduction Couplings last longer than others, not sure if the ones with the letters G&M are long lasting or not?

One things for sure it is a time consuming and often unpleasant job to replace them and I can see why the CV conversions are very popular.

I was lucky that when I rebuilt my rear Rotoflex suspension, genuine Metalastic couplings where still available from James Paddocks, I reckon I paid £45 each for genuine ones in the Unipart Boxes, they are still on the car to the best of my knowledge 12 years and around 15,000 miles after fitting?

PS - You may get lucky and find genuine ones on E-Bay?      

 

 

 

[Ingieuk]

Thanks all. 

The CV conversion seems the long term solution for sure, but having just overhauled the gearbox, the brakes and now this finding £650 is an ask. 

I think my route will be to replace like for like and look to do the CV conversion in 2000miles time (about 18 months). At least I'll be back on the road. 

I guess the question is what's the best of a bad bunch? I wonder if those sold by rimmers/Canley/james paddock are all the same item from the same manufacturer just at slightly different prices. 

1 hour ago, Gary Flinn said:

This is from an old thread about Rotoflex couplings:- 

"When I was struggling to find genuine Metalastic donuts about ten years ago  - for a reasonable price - I found some in stock at Bailey Morris Propshafts, in Cambridge ? They were new manufacture by Trelleborg, who have bought the rights to the Metalastic brand and are made to the same standard. Trelleborg make a lot of different size donuts as they are commonly used in propshaft couplings. Might be worth a try...

Gav"

I've no idea if Trelleberg still make the Rotoflex coupling to original Specification, I do remember them being near on £200 Each though!

Some of the reproduction Couplings last longer than others, not sure if the ones with the letters G&M are long lasting or not?

One things for sure it is a time consuming and often unpleasant job to replace them and I can see why the CV conversions are very popular.

I was lucky that when I rebuilt my rear Rotoflex suspension, genuine Metalastic couplings where still available from James Paddocks, I reckon I paid £45 each for genuine ones in the Unipart Boxes, they are still on the car to the best of my knowledge 12 years and around 15,000 miles after fitting?

PS - You may get lucky and find genuine ones on E-Bay?      

 

 

 

Funnily enough I found that thread earlier today and emailed them for a price. Might not like the reply if they are £200 a piece though! 

I'll look for any with g&m on them. A couple of older threads mention getting decent ones from a supplier shortened to "QH" - any idea who that might be? 

[Steve P]

QH would be Quinton Hazell.Not the same company or parts as back in the day i don`t think.

I have the Jones/Bowler conversion on my Vitesse and,i am about to change my Herald to the other CV conversion available,the shimming is going to be a ball ache as i don`t have the tools or facilities to do it.

Fit and forget once done and peace of mind for me as i snapped a driveshaft when it was live axle.

Steve

[KevinR]

The genuine Metalastic couplings (manufactured by Trellebourg) that were available from Bailey Morris were £75 each, whilst at the same time the large Triumph trader near Lincoln was advertising "OEM" couplings at £200 each.

I was informed by someone in the trade that knew more than they were prepared to reveal that the ones from Lincoln were NOT Metalastic couplings by  Trellebourg, but were made by the same company that supplied Unipart, so a little bit of a stretch on the term OEM.

Minor cracking on the coupling is not a problem - they remain serviceable even with large splits in the rubber, and the genuine ones last an awful lot longer than any of the reproduction aftermarket ones.

 

[Ingieuk]

Thanks for the info, I'll see if I hear back. In the meantime I've found some lotus suppliers selling ones they claim are higher quality, £80 plus vat. 

 

The current ones are as per the photos below. The splits are not all the way through. I'm wondering if they have sufficient integrity to manage a couple of runs out (locally!!) to check my brake and gearbox rebuild before I tackle the rear? 

 

[NonMember]

Hmm... Well, the ones I replaced in 1994 were worse than that and hadn't caused any obvious symptoms. The ones I fitted had to be replaced again a few years back, so they lasted over 20 years.

[Gary Flinn]

2 hours ago, Ingieuk said:

Thanks for the info, I'll see if I hear back. In the meantime I've found some lotus suppliers selling ones they claim are higher quality, £80 plus vat. 

 

The current ones are as per the photos below. The splits are not all the way through. I'm wondering if they have sufficient integrity to manage a couple of runs out (locally!!) to check my brake and gearbox rebuild before I tackle the rear? 

 

They don't look good at all!

I personally wouldn't risk driving the car with the Rotoflex couplings in that condition, if one lets go it can be nasty, ruin your drive shafts and you may end up spinning off the road?

I have seen genuine ones for sale at Car shows and Auto-jumbles for reasonable prices, trouble is no Car shows at the moment although Auto-jumbles may be starting up soon now the restrictions on Outdoor markets have been lifted?

Remember, keep an eye out on E-Bay they do come up occasionally, although be prepared to pay a premium.   

[Colin Lindsay]

37 minutes ago, Gary Flinn said:

They don't look good at all!

I personally wouldn't risk driving the car with the Rotoflex couplings in that condition, if one lets go it can be nasty, ruin your drive shafts and you may end up spinning off the road?

I'll agree with that. Don't chance those, even for a short trip. When they go, they really go, and having had two halfshafts snap over the years (non-roto GT6) the amount of damage caused, and the resulting bother and cost of repairs is far more than replacement doughnuts would have been. The halfshafts both snapped at relatively slow speed; I'd worry that those doughnuts would continue until they get too much force, maybe cornering at speed, and off you go through the hedge. I paid £1300 in bodywork alone, plus the cost of replacement halfshaft assemblies and original panels, for the repairs to my current GT6 and although it's a swing-spring model that's twice the cost, at least, of a CV conversion.

Even the cheaper doughnuts, expecting to have to replace them after only a year or two, would be better than risking those. 

[Peter Truman]

I have QH ones purchased around 1983 by the FI Law in the UK and fitted around 10years ago only recent road service tho' they appear to be OK, no cracks yet.

 I fitted them without removing the outer axle and upright. I undid the compression band sprung the donut over the two spiders, then I'd made a new heavier compression band (hexagon in two halves) and screwed/clamped it back into shape and fitted the 6 bolts, unconventional but I'd do it again I kept the crude home made clamp in case!

[Ingieuk]

1 hour ago, NonMember said:

Hmm... Well, the ones I replaced in 1994 were worse than that and hadn't caused any obvious symptoms. The ones I fitted had to be replaced again a few years back, so they lasted over 20 years.

I've had no symptoms, I just happened to be under the car checking if I needed to replace brake lines or wheel cylinders whilst I was on with the front calipers and noticed. 

Interestingly it's only the RHS one, the LHS looks in good nick. They are metalastik ones as it happens.

Sounds like it's not worth the risk at all, I will heed the advice! 

There is an ebay seller selling a pair of QH (unipart?) ones for £58. Think they may be worth a punt. 

[Peter Truman]

why did Triumph put both the driver and driven fingers on the same side of the donut surely one on each side would have been OK I think the Imp is like that? It would have been peesy easy to replace!

[Paul H]

Are doughnuts part of MOT testing ?

Paul 

[Ingieuk]

8 minutes ago, Paul H said:

Are doughnuts part of MOT testing ?

Paul 

Not sure. CV boots are so I'd guess so?

57 minutes ago, Peter Truman said:

I have QH ones purchased around 1983 by the FI Law in the UK and fitted around 10years ago only recent road service tho' they appear to be OK, no cracks yet.

 I fitted them without removing the outer axle and upright. I undid the compression band sprung the donut over the two spiders, then I'd made a new heavier compression band (hexagon in two halves) and screwed/clamped it back into shape and fitted the 6 bolts, unconventional but I'd do it again I kept the crude home made clamp in case!

I like the alternative way of doing things! 

I have a polybush kit so whilst in I might as well do the wishbone bushes etc. Is it worth new wheel bearings (timken if I can find them), hub oil seals, and renew UJs whilst it's in bits? No signs of deterioration to date. 

[Paul H]

2 minutes ago, Ingieuk said:

Not sure. CV boots are so I'd guess so?

I like the alternative way of doing things! 

I have a polybush kit so whilst in I might as well do the wishbone bushes etc. Is it worth new wheel bearings (timken if I can find them), hub oil seals, and renew UJs whilst it's in bits? No signs of deterioration to date. 

If you change wheel bearings ( I purchased mine from Canleys as well as doughnuts ) you will need to reshim , make sure you gave a good selection of shims to hand . Canleys have a good write up on reshimming . If you can find it I’ll dig out a copy

Paul 

[NonMember]

49 minutes ago, Ingieuk said:

I've had no symptoms, I just happened to be under the car checking if I needed to replace brake lines or wheel cylinders whilst I was on with the front calipers and noticed.

I only noticed mine because the car failed the MOT on rust around the rear damper mountings (GT6, so on the wheel arch) and I decided to refurbish the rear axle while I was converting to shorter dampers. I'm a bit surprised the MOT man didn't object to the rotoflexes - it was my current MOT man who pointed out the need to replace them the second time.

[Ingieuk]

6 minutes ago, Paul H said:

If you change wheel bearings ( I purchased mine from Canleys as well as doughnuts ) you will need to reshim , make sure you gave a good selection of shims to hand . Canleys have a good write up on reshimming . If you can find it I’ll dig out a copy

Paul 

The shimming aspect does concern me slightly. The 'if it ain't broke...' philosophy might be prudent for the UJ and wheel bearings for now. Unless that seems short sighted?

[Paul H]

3 hours ago, Ingieuk said:

The shimming aspect does concern me slightly. The 'if it ain't broke...' philosophy might be prudent for the UJ and wheel bearings for now. Unless that seems short sighted?

Only you can make that decision !!!!

Paul 

[Nick Jones]

If the wheel bearings turn smoothly and quietly with just the merest hint of play then you can probably assume they are ok.  Also possible to dismantle (carefully noting and keeping the shims and spacers) wash out the bearings and check their condition and, hopefully just reassemble with fresh grease.  Much easier than the gearbox work you've just done!

MoT man should pick up shot rotos.  They certainly wake you up if they do let go whilst driving.  My spring bears the scars to this day.  If you can get hold of the proper ones (Metalastik now Trelleborg - not sure whether the  recently produced Trelleborg ones are the equals of the originals) they usually last very well.  The pattern versions..... much more variable.  It was the failure of a pair of new (less than 1 year) rotos that drove me to do the CV conversion.

Cars which have suffered coupling failures may have visible damage to the driveshaft ears, usually on the outer section.  Quite major distortion sometimes.

[Karl R GT6]

On 30/06/2020 at 10:48, Paul H said:

Are doughnuts part of MOT testing ?

Yes.  At my MoT this year the tester checked them over carefully. 

[Ingieuk]

On 30/06/2020 at 22:44, Nick Jones said:

If the wheel bearings turn smoothly and quietly with just the merest hint of play then you can probably assume they are ok.  Also possible to dismantle (carefully noting and keeping the shims and spacers) wash out the bearings and check their condition and, hopefully just reassemble with fresh grease.  Much easier than the gearbox work you've just done!

MoT man should pick up shot rotos.  They certainly wake you up if they do let go whilst driving.  My spring bears the scars to this day.  If you can get hold of the proper ones (Metalastik now Trelleborg - not sure whether the  recently produced Trelleborg ones are the equals of the originals) they usually last very well.  The pattern versions..... much more variable.  It was the failure of a pair of new (less than 1 year) rotos that drove me to do the CV conversion.

Cars which have suffered coupling failures may have visible damage to the driveshaft ears, usually on the outer section.  Quite major distortion sometimes.

Thanks Nick, good to know the gearbox work will have been trickier. I just hope everything comes apart without too much persuasion! 

Any tips for loosening off the rotoflex bolts? Is it best done with the drive shafts on the car? (bit worried about applying force when connected to the diff). I wonder if heat might be required, they look well rusted in. 

Also is it a requirement to put new bolts in when the coupling is changed? Happy to do so but the workshop manual is vague. 

[Nigel Clark]

Yes, driveshafts on the car. Soak the bolts repeatedly with penetrating oil then lock the brakes by tightening the adjusters. Loosen the Rotoflex bolts with a ring spanner and Weetabix. Lots of Weetabix!

There's no need to replace the bolts.

Nigel

[Colin Lindsay]

59 minutes ago, Ingieuk said:

Any tips for loosening off the rotoflex bolts? Is it best done with the drive shafts on the car? (bit worried about applying force when connected to the diff). I wonder if heat might be required, they look well rusted in. 

I've never owner a rotoflex Triumph but I reckon it may be easier to get better leverage with the shafts still on the car; if the diff can cope with the rigours of driving it should cope with the force of a socket wrench or big spanner. It may be easier to dismantle and renovate the assembly off the car but for loosening prior to dismantling I'd start with them on the vehicle.