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Rear drive shafts & wheel bearings rotoflex


Mat
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Hi

My rotoflex rubber couplings were very worn and had big splits, so I decided to replace them along with the UJs while I was at it. I'm sure you will agree:

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So I ordered off e bay a pair of second hand drive shafts one was fine the other one had the hub nut threads badly cross threaded, so they both had to go back. 

So I got hold of new rotoflex couplings (QH not too bad quality as far as I know?) a spring lifter & a Triumph hub puller. Then last Thursday I started with the NS as that coupling looked worse. Everything came apart easily (about 1 1/2 hours)I replaced the coupling and the UJ. Now to putting it all back together, what a nightmare! trying to line up the rear suspension for the bolts, even with the correct tools! (any advice of the order to put things back together will be most welcome as I need to do the other side, plus the N/S will probably need to come apart again!) I did it in the end with about 3 jacks in various different places. Hours later I finally managed to get it back together, only to find that even tho the threads looked ok, the old or new hub nut would not go on!!

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So all day Friday I was looking for a 5/8 UNF thread cutting die to see if I could do it that way (without having to take it all apart again!) but I could not find one. So I rang a local Triumph (second hand) parts supplier to see if he had a outer half shaft, yes he did! Actually he had 2, but one of them had bad hub nut threads (I see a pattern emerging! Must be a weak point on them?) 

So on Saturday apart it all came again, with a ratchet strap I managed to get the coupling off and back on the other shaft. (one of the threads for the coupling mount was not very good, so I had to use a long suspension bolt and nut) Got it all back together and on the road.

I did notice that when I pushed the hub on as far as it would go, and torquing the hub nut up correctly, the hub seemed to fit a little further out than before. I Presumed if I put the bearing shims back as they were they would be fine. When I drive it it seems smoother on moving off, but above 50 mph there is some vibration from the rear end (I presume that will be the nut and bolt?) and some wheel bearing noise (that was always there a little sometimes, but now a bit worse)

I Know people are going to say "welcome to the joys of Rotoflex!!"

So now onto my questions before I take the other side apart:

1) I've been thinking of maybe getting a CV conversion, Are they a lot better? are they as easy to fit as said? should they outlive the car? Where will I get things like replacement cv boots from in a few years time? Are there any downsides to the CV conversion?  So overall is it worth doing?

2) Are shimming the rear bearings a mythical secret special  tool act that you need to take to a "Rotoflex specialist" (whoever they are) As Jigsaw, Rimmers and others sites suggest? If no How do I do It?

3) Can the vertical link, bearings, driveshaft and hub be put together off the car, then attached to the car

Many Thanks

Matt

 

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I will jump to the last bit. I had a rotoflex GT6 25 years ago, and it wasn't easy then....(though proper couplings were easily available, even Unipart boxed ones)However, like many things I have forgotten the details of setting it up. 

Anyway, when I built my current spitfire, I wanted CV Rotoflex as it is (arguably) the best suspension setup. I went down the "Nick Jones" route which is a bit DIY. (it uses an adaptor on the diff output flange, then a Volvo Lobro joint, Rover100 driveshaft and mgf/R100 outer CV) and the most wonderful part of all is that the rear uprights are machined to accept the R100/MGF bearing. No setting up at all, just torque it up. 

I know a chap who has fitted several CV conversions for people, the TSSC one and the original Canley ones. So much easier to fit once the bearings are set up, and really it is a no-brainer if the car gets used much as the non-genuine rotoflexes are never going to last too long.....

 

Re vibration, was it there before? Usual cause is propshaft, it can make the car feel like it is about to fall apart yet can look OK.

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Hi Mat. I have a mk2 Vitesse and have changed the rotoflexes , ujs and bearings plus plybushes. It was a very difficult job and speaking to Canleys they describe the job as a design fault . On Canleys site they have an article for adding the shims https://www.canleyclassics.com/technical-archive/rear-end-noises. Basically it’s fitting the shims without grease initially 

I will check my files , photos and let you know the tools I used to refit plus how I refitted

Back soon

Paul 

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1 hour ago, clive said:

 

Re vibration, was it there before? Usual cause is propshaft, it can make the car feel like it is about to fall apart yet can look OK.

Hi, thanks for the info, no there was no vibration there before, so I think this must have something to do with the driveshaft, bearing or hub.

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11 hours ago, Mat said:

 I did it in the end with about 3 jacks in various different places.

That works! I once refitted the springs on a Series 3 Landrover, the owner couldn't do it and to me it was just a bigger version of a Triumph, so I had no bother.

Re the vibration - I'm thinking out loud here but is it possible it was there before, just muted by the old rubber of the rotoflex couplings? Unless the shafts aren't assembled accurately and are vibrating due to misalignment, then as Clive says suspect the driveshaft.

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Refitting rotoflex drive shaft 

Using the spring lifter I raised this to maximum level .

Fitted the main chassis link & forward outrigger link .  The rotoflex banding was left intact though not sure if this improved fitting .  The Chassis link and outrigger link bolts were loose fitted until the top bolt was in place .

This leaves the top bolt to drive in - This is the most difficult part - There are many offered solutions but this worked for me and whilst one side took several hours to line up the second side took about 1.5 hrs . Using a scissor jack raise the brake drum to start the alignment , you may need blocks under the jack . Because of the "twist" the top bolt wont go in and as a persuader I used a modified crow bar - originally a 24" roughneck from Toolstation  Using a hacksaw cut the crow bar approx 6.5" from the pointed end . The will leave a shortened crow bar for leverage and a pointed alignment tool which is the most important item 
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With leverage together with the scissor jack it should be possible to start the bolt travel though problems arise aligning the full bolt travel - Here's a cheat solution purchase a new top bolt  10cms longer , and grind the extra length to a taper , this will greatly assist the bolt travel - Once the bolt has started using either a longer tapered bolt or original use a combination of jack, mini crow bar and pointed aligning tool . I managed one side with an original bolt and the other side resorted to a longer tapered bolt . Other tools i used were a spotlight and small mirror as its then  possible to check the hole alignment progress.

As you can see its not one tool but a combi of many to get the bolt through. Access isnt great so cutting the crow bar to my spec is important . I did have access to bigger crow bars but these proved ineffective due to the width of my garage and wheel arch clearance 

Heres a pic of the tapered top bolt in situ 

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Hope this helps 

Paul 

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Hi Paul

Thanks for the information, very similar way to how I did it but with 3 jacks In the various places, and thanks for the tip on the tapered bolt, i can see that working well.

Does anyone know if the driveshaft vertical link, bearings and the hub can be fitted off the car, then placed on as one unit? (What I'm thinking is taking it all off, taking them parts to a garage/engineering place to be assembled then refitting to the car, i don't really want the whole car, in a garage for weeks & here in Cornwall there are no real Triumph specialist)

Thanks

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2 hours ago, Colin Lindsay said:

..... Unless the shafts aren't assembled accurately and are vibrating due to misalignment.

I am thinking more along these lines, the (slightly smaller) nut and bolt, plus possibly a little in/out movement at that join, plus I've only replaced one side for now.

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19 minutes ago, Mat said:

Hi Paul

Thanks for the information, very similar way to how I did it but with 3 jacks In the various places, and thanks for the tip on the tapered bolt, i can see that working well.

Does anyone know if the driveshaft vertical link, bearings and the hub can be fitted off the car, then placed on as one unit? (What I'm thinking is taking it all off, taking them parts to a garage/engineering place to be assembled then refitting to the car, i don't really want the whole car, in a garage for weeks & here in Cornwall there are no real Triumph specialist)

Thanks

Hi Mat , thats how I did it , replaced UJs, Rotoflex, Bearings, re shimmed, Trunnions, Blue Polybush - all on the bench, reassembled and added back in one unit initially bolting the UJ Yoke to the Diff .

Paul 

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22 minutes ago, Paul H said:

Hi Mat , thats how I did it , replaced UJs, Rotoflex, Bearings, re shimmed, Trunnions, Blue Polybush - all on the bench, reassembled and added back in one unit initially bolting the UJ Yoke to the Diff .

Paul 

Thanks, that's good to hear!! Do the polybushes make a big difference? never driven a classic car with them fitted.

Now on to keep rotoflex (main problem I've found is 50 year old threads! as been mentioned before on here, none of these cars were supposed to last 50 years, when built) I only do about 2k - 3k miles a year. I made an enquiry about the hub nut threads on these these last week, still no reply so I'll take it they are no good, even tho they are fitted with nuts in the photo  Or go to the brand new CV joint drive shaft and hopefully do it once and forget about it! (famous last words!!) Is it worth the £600 or so?

matt

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11 minutes ago, Mat said:

Thanks, that's good to hear!! Do the polybushes make a big difference? never driven a classic car with them fitted.

Now on to keep rotoflex (main problem I've found is 50 year old threads! as been mentioned before on here, none of these cars were supposed to last 50 years, when built) I only do about 2k - 3k miles a year. Or go to CV joint and hopefully do it once, and forget about it! (famous last words!!)

matt

Polybushes will last longer and seems the best way to go - Ive just fitted polybushes to the Steering rack - just changed 1 for the time being as need to raise the engine to get the other side - the change with just 1 was very noticeable and significant improvement . RE rotoflexes - since replacement ive done 2500 miles and so far so good - ill address the CV upgrade if issues occur 

Paul 

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if you x ref the rota flex  good quality ones with CV conversion theres not a great differential.

one  advantage of CV is you dont have to fight the doughnut into submission when refitting the shafts , and they should last longer than some nasty repro versions on sale,  think Firstline are  sourcing good rubbers  

had an idea club shub sourced some but cant find them in the  2018 brohure 

pete

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10 hours ago, trigolf said:

Rotoflex Bearing end float setting is also described in Technical Archive , Rear End Noises , Note 4 ,on Canley Classics website. It's essentially the same technique that Andy Cook uses, apart from Andy double checks end float with a dial gauge.

 

Gav

Thanks for the info, I've read that archive (and printed it off) as I have not got the courier that old.

9 hours ago, Pete Lewis said:

rotaflex coupling  to spider  is 1/2"unf  

long bolt 144588

short bolt  141850

Pete

Thanks for that, very useful, I have now ordered an 1/2 UNF tap, to clean the threads.

Matt

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