Thought this might be interesting

[pfenlon]

http://pantera.infopop.cc/eve/forums/a/tpc/f/9550045562/m/4561020956

[RogerH]

Hi Pete,

very interesting. The angles were rather extreme but show the problem well.

 

And that is why CV joints appeared.

 

Roger

[Lebro]

Like

 

Bob.

[mike3739]

Interesting thanks for posting.

 

Cheers

 

Mike

[john.r.davies]

A lovely demonstration!

 

Don't know about TR propshafts, but on a small chassis the flanges either end have bolt holes in offset pairs.

This limits the possible positions to two at each end, and four overall. Is this what they meant by phasing?

The demo gita bit skimpy at that point.

 

John

[Peter Cobbold]

Thanks Pete, a video worth a thousand words.

Peter

[Waldi]

The ingoing shaft (in our hobby the differential output shaft drive flange) and the outgoing shaft (where the wheel is bolted on) are more or less parallel axis, so if the couplings are "in phase", which cannot go wrong during assembly because the splines can only be assembled in one way, it is not that bad during normal straight ahead driving.

[Peter Cobbold]

I read somewhere that UJs should not be run 'straight', they need about three degrees ( IIRC) to work correctly. Which is roughly what TR6 prop shaft supplies. Dont know why, perhaps it ensures the rollers rotate......

Peter

[ChrisR-4A]

The ingoing shaft (in our hobby the differential output shaft drive flange) and the outgoing shaft (where the wheel is bolted on) are more or less parallel axis, so if the couplings are "in phase", which cannot go wrong during assembly because the splines can only be assembled in one way, it is not that bad during normal straight ahead driving.

Hi Waldi, after putting up with the inherent problems and deficienties of UJs for nearly 20 years I no longer wanted to settle for "not that bad" and recently upgraded to CV driveshafts.

I would never go back to UJs now as the difference is a revelation.

Chris

[Stag powered]

Interesting video, I knew why input and output angles had to be the same but I have never seen it so simply demonstrated.

 

When I first had my TR it had a persistent vibration at certain speeds that I didn't get to the bottom of for years. Eventually the propshaft munched one of its joints and on removing it for joint replacement I realised that the front and rear yokes were one spline out of phase.

 

I don't know if the joints had been replaced before, I didn't bother changing them when I rebuilt the car as they had no play in them and they lasted until several years later.

 

Having replaced both joints I reassembled the shaft so it was phased correctly and the annoying vibration had disappeared!

 

Neil

[pfenlon]

Long ago I bought a written off police TR4A from Evans's scrap yard in Manchester.

 

I bought a new unused Bodyshell from the lake district, and set to.

 

months later I had a car which was wonderful and had a vibration, being unskilled in the nuances of car mechanics it took time to find.

 

The prop was fine but the diff flange had become distorted in the write off, a new flange cured the problem.

[Charlie D]

Interesting,

 

I wonder where cars like the Herald, Spitfire and VW Beetle fit into all this with their rear “Swing axle”. Only one UJ (at the diff), so there is no way to balance anything out with a second UJ. With cornering and going over bumps the angle must be constantly changing.

 

Was the design done on the cheap? The later Vitesse had double joints, but the original cars went for many many years with the single joint setup.

 

Charlie.

[MostEasterlySteve]

Interesting,

 

I wonder where cars like the Herald, Spitfire and VW Beetle fit into all this with their rear “Swing axle”. Only one UJ (at the diff), so there is no way to balance anything out with a second UJ. With cornering and going over bumps the angle must be constantly changing.

 

Was the design done on the cheap? The later Vitesse had double joints, but the original cars went for many many years with the single joint setup.

 

Charlie.

 

I've no doubt the design was done on the cheap but in my opinion the later swing axle Spitfires, known as 'swing spring' due to a small but ingenious change to the central leaf spring mounting, are by far the best handling Triumph sports cars - far more chuckable and forgiving than an IRS TR. The reversed rear wishbone set-up (Rotoflex) was, again in my opinion, a dreadful lash-up. Initially successful in terms of curing jack-up oversteer, but horrifying in terms of later maintenance issues with the Rotoflex itself a silent but deadly weak point that could let go utterly without warning.

 

I have replaced the half shafts on my TR6 with Limora CV types and it is an utterly transforming thing to do to the car. Spline lock is not quirky or endearing, it is a horribly unsettling thing, especially on long sweeping bends. That hip-wriggle is a very undesirable characteristic!

[Waldi]

Hi Waldi, after putting up with the inherent problems and deficienties of UJs for nearly 20 years I no longer wanted to settle for "not that bad" and recently upgraded to CV driveshafts.

I would never go back to UJs now as the difference is a revelation.

Chris

[Waldi]

Chris,

Thanks.

And what a great forum!

I am currently replacing the UJ's on my TR6, as part of a full restauration.

I notice no visible wear (by the eye) on the splines, but they have some play. The amount of play is hard to quantify ("limited") and I will install them with new UJ's and see how they behave. I fully agree the CV joints are technically preferred over UJ's but in my case it is a matter of where to spend my money.

My old UJ's had markings (indents) on some of the journals and some play so things will improve.

Wishdom comes with age and I'm only 54, so maybe in the future I will upgrade to CV joints:)

Regards,

Waldi

[Motorsport Mickey]

Hi Waldi,

 

I can understand that any judgement of whether to change from UJs to CV driveshafts is a choice that can be influenced by perceived benefits that can only be measured after having committed and bought the CV driveshafts, this may come with advanced age and wisdom. However I'd suggest that a decision of changing at least your rear hubs alone and making them a safer alternative to the 40+ year old originals or even worse reconditioned hubs that have been exposed to enormous forces to change the rear wheel bearings (see the photos in the other thread "Rear drive halfshafts") is worthy of wisdom that should prevail even at your "tender" age you currently enjoy.

 

Mick Richards

Edited November 26, 2016 by Motorsport Mickey

[Peter Cobbold]

Chris,

Thanks.

And what a great forum!

I am currently replacing the UJ's on my TR6, as part of a full restauration.

I notice no visible wear (by the eye) on the splines, but they have some play. The amount of play is hard to quantify ("limited") and I will install them with new UJ's and see how they behave. I fully agree the CV joints are technically preferred over UJ's but in my case it is a matter of where to spend my money.

My old UJ's had markings (indents) on some of the journals and some play so things will improve.

Wishdom comes with age and I'm only 54, so maybe in the future I will upgrade to CV joints:)

Regards,

Waldi

I use molygrease on the splines, applied by toothbrush and liberally coated. Despite the extra torque form supercharging the splines slide fine, no sign of locking coming out of bends.

Peter

[Waldi]

Mick,

Thanks. I have read the posts on failed rear hubs and also front stubaxles.

It is one of those safety related decisions one has to make during the work.

My existing rear hubs exibit no play, and feel smooth. I am not planning to recondition them myself, although I did that with a previous TR6 some 25 years ago, no forum then to make me aware of such issues!

I am not planning on racing, uprated springs/dampers, but new rear hubs may be a sensible investment.

I will put them on my list to be ordered, i will not even source reconditioned hubs.

Thanks for pushing me in the eight direction.

 

Peter,

Thanks, Mo2S is what I use for the splines too.

 

After all I learnt on this forum, it is time I subscribe for a membership, although of less benefit for a Dutch guy, but I don't want to go double-Dutch.