Prop shaft frustration continues unabated!

[RichardS]

I've been trying to sort out the vibration on my GT6 as per my previous thread which I ended with the decision that I was going to replace the UJ's and get the prop balanced. However, things have not gone to plan, as is sadly becoming the norm for me with this car.

Anyway, all opinions as to what is going on are welcome.

I bought two of the more expensive UJ's from Rimmers, the ones without the grease nipple, as the ones already fitted were without nipples and were full of grease when I dismantled them.

I started the fitting the first UJ at the gearbox end of the prop shaft. I removed the short sliding section to make it easier to manipulate. I pressed the the first axis into the flanged section and that was fine. It centralised OK and the two circlips fitted fine and the joint was smooth and notch free. However, with the second axis into the prop shaft stub, it soon became clear that if I tried to press both bearing cups in far enough the fit the circlips, the bearings would be absolutely rigid. In fact, it is not even possible to press the last bearing cup in enough to get any of the circlip slot visible as the assembly is already totally rigid.

I've played around with it a bit this afternoon and if I press both sides until there is about half the circlip slot visible on each side then the bearing rotates correctly. This is good in that at least the spider is central in all planes but, of course, it is useless as I can't install either of the circlips.

Has anyone else experienced this issue?

Many thanks

Richard

[Pete Lewis]

yes you have a needle dropped out and is jammed under the cap 

only solution is to remove all and re load the needles , if  you attempt force you can crack the cup  

its not an uncommon problem fitting UJs   

Pete

 

[RichardS]

53 minutes ago, Pete Lewis said:

yes you have a needle dropped out and is jammed under the cap 

only solution is to remove all and re load the needles , if  you attempt force you can crack the cup  

its not an uncommon problem fitting UJs   

Pete

 

I specifically tried to avoid this by making sure that the spider was able to move freely from one side to the other as I pressed in the second cap. However, your suggestion does fit the symptoms and the misalignment sounds about right so thank you for that suggestion. I will reassemble it again and post the result on here.

Richard

[RichardS]

38 minutes ago, Mathew said:

What pete said is correct but also check the distance between yokes . Why, because i "f ed" up the other day and squeezed the yokes on the prop! Got out of it with a bit of threaded bar ,nuts and washers! It was only a little bit and the threaded bar was enough to clear it 🙏. 

That was what I thought might be the problem although I did not knowingly squeeze the yokes and they do appear to be aligned correctly. If there were no more likely explanations I was going to try forcing open them open a bit. However, I suspect that Pete has hit the nail on the head but we'll soon find out.

Many thanks for the suggestion.

Richard

[Pete Lewis]

and when its all together   do really   make sure the circlip is fully FULLY   engaged  

there are a good few Tee shirts to find it pops out 150 yds from home    and thats very noisy 

its useful to try and compare with vernier or simple calipers the width between the circlip legs  so you know they are all the same 

any being closer are suspect 

if you end up with end float canley sell thicker circlips 

if its a prop and you have split the telescope  do make sure you align the yokes on refit   any out of phase will make classic vibrations 

Pete

 

[Colin Lindsay]

13 hours ago, Mathew said:

I was in a bit of a rush and using a press, so did not notice until assembly! Hopefully its just as pete said as that can easily happen.  I was about .5mm out from getting the last circlip in!

Hope you didn't press it TOO much... one end goes in, the other... out. Sort of.  Running a small wire brush, like a flat Dremel head, in round the slot makes sure the circlip can seat properly.

 

[RichardS]

22 hours ago, Pete Lewis said:

yes you have a needle dropped out and is jammed under the cap 

only solution is to remove all and re load the needles , if  you attempt force you can crack the cup  

its not an uncommon problem fitting UJs   

Pete

 

You were spot on Pete. 😊

When I looked really closely at the assembly I could see that although the two caps were centred halfway across the circlip groove, the actual spider was fractionally off to one side so it was obvious which cap needed to come off. Anyway, off it came and one needle was sitting across the bottom of the cap. I was being so careful not to dislodge any of the needles but was obviously only 75% successful with my first UJ rebuild!

Let's hope that I can hit the elusive 100% with the other end!

The clips all pinged into place with a click and the joint is notch-free compared to the old one which seemed to have a preferred central position.

Many thanks for steering me in the right direction and saving me a lot of time.

Richard

[Pete Lewis]

youre not the first and wont be the last  this can happen  even when you know its can 

some thick grease helps 

Pete

[Pete Lewis]

24 minutes ago, Mathew said:

who you calling thick!

only the grease.......... but you can include  all of us that have done the same  over the  years   ha !!

Pete

[dougbgt6]

I can top that! Long ago I did my first UJ and the same thing. I took it apart again, a roller had popped out. I thought "This shouldn't happen, there's something wrong with the new bearing!"  So went and bought another one. 

Doug

[Colin Lindsay]

8 minutes ago, dougbgt6 said:

I can top that! Long ago I did my first UJ and the same thing. I took it apart again, a roller had popped out. I thought "This shouldn't happen, there's something wrong with the new bearing!"  So went and bought another one. 

Doug

Wait until you fit four UJs then when cleaning up find a roller bearing on the floor...

[RichardS]

34 minutes ago, Colin Lindsay said:

Wait until you fit four UJs then when cleaning up find a roller bearing on the floor...

I reckon that would put me off car maintenance for life! ☹

The most annoying thing with the UJ's, apart from user error issues, is that fact then the cap does not press out fully but you have to grip it to pull it out the final third. Why is it not designed so that the cap presses completely out of the sleeve? It would surely make the whole job much easier.

Richard

[Peter Truman]

Is it the American UJ's, also fitted to some Holden's here, where the UJ Yoke splits and there is a bolted on retaining clamp to hold the bearings, would make the reco so much easier.

Yes I've failed miserably at fitting the bearing caps too, and yes Colin I've found one on the floor afterwards BUT was it from the old or new UJ that is the question, and there's only one way to be sure BU*G*R!

[Wagger]

Fret not. One roller less it better than one too many. The gap will 'Average out' around the assembly. You are brave doing a prop shaft. Mine always went 'Out of balance' afterwards. I always replace props now and confine fitting uj's the the drive shafts only.

[Peter Truman]

The Spit prop wouldn’t balance, so with the daughter being an aero space Eng and a vibration analysis expert and once she started on primary, secondary, and Xth order vibration, Sympathetic vibrations I got Hardy Spicer here to make a new one, finally success at last all smooth, but at a high cost, the advantage was I didn’t have to pretend I understood!

[Pete Lewis]

balance on a prop is more critical as its going round like 4 times faster than a drive shaft and has a lot more length/mass to dissipate   out of  balance energy 

Pete

 

[trigolf]

I've never really understood why Triumph props are such a bugger to balance. The amount of times I've had prop specialist's balance it - then put on the car and it's crap. I'm too nervous about crawling underneath with a flailing prop! 😕

[johny]

I wonder if the sliding joint doesnt help. Everything can be perfectly balanced but if the joint allows excessive radial movement between the two parts its never going to be vibration free. This might not show up on the balancing machine but once the prop is exposed to the movements and forces on the car its another matter....

[Pete Lewis]

its probably due to the trans and diff all being chassis mounted  its easy to transmit vibes into the body rather than having a live axle  well decoupled from the body4

Pete

[Nick Jones]

23 minutes ago, Pete Lewis said:

its probably due to the trans and diff all being chassis mounted  its easy to transmit vibes into the body rather than having a live axle  well decoupled from the body4

Mostly this, plus the diff is a small mass, flexibly mounted whereas a live axle is a much bigger mass and considerably damped by being pressed firmly on the road via nice squashy tyres.

Nick

[Peter Truman]

The daughters Mk2 Spit was Aus CKD assembled by AMI (Aust Motor Industries), and I think I read somewhere that prop shafts were locally sourced to meet the 20-25% local content to get import tax credits.

The propshaft that was replaced with a new Hardy Spicer sliding joint unit was also sliding jointed BUT the joint didn't employ splines but 4 V shaped grooves @ 90 degrees around the splined assembly & which had 9 or 10 cylindrical bearings in each V say 3/16in dia by 3/16in long with each cylindrical bearing placed in the opposite direction to the next, this assembly had 2 retaining sleeves and was then slid into similar V shaped slides in the female  or outer part of the sliding joint.

I've always put the sliding joint at the diff end, somewhere I think I read in the thread a recommendation to put it at the gearbox end, and I've read elsewhere similar, is there a right and wrong way?   

[RichardS]

4 minutes ago, Peter Truman said:

The daughters Mk2 Spit was Aus CKD assembled by AMI (Aust Motor Industries), and I think I read somewhere that prop shafts were locally sourced to meet the 20-25% local content to get import tax credits.

The propshaft that was replaced with a new Hardy Spicer sliding joint unit was also sliding jointed BUT the joint didn't employ splines but 4 V shaped grooves @ 90 degrees around the splined assembly & which had 9 or 10 cylindrical bearings in each V say 3/16in dia by 3/16in long with each cylindrical bearing placed in the opposite direction to the next, this assembly had 2 retaining sleeves and was then slid into similar V shaped slides in the female  or outer part of the sliding joint.

I've always put the sliding joint at the diff end, somewhere I think I read in the thread a recommendation to put it at the gearbox end, and I've read elsewhere similar, is there a right and wrong way?   

The telescopic prop shafts that I've seen on other cars seem to have the sliding section at the gearbox end like the Triumph, although I've no idea whether it makes any difference.

[DanMi]

I really couldn't be bothered trying to recon a propshaft, with the cost of 2 quality UJs plus balancing, cleaning and paint, along with getting it to the balancers plus time and a new guaranteed one at about £160 (Canleys)

[RichardS]

On 15/11/2021 at 10:01, Pete Lewis said:

and when its all together   do really   make sure the circlip is fully FULLY   engaged  

there are a good few Tee shirts to find it pops out 150 yds from home    and thats very noisy 

its useful to try and compare with vernier or simple calipers the width between the circlip legs  so you know they are all the same 

any being closer are suspect 

if you end up with end float canley sell thicker circlips 

if its a prop and you have split the telescope  do make sure you align the yokes on refit   any out of phase will make classic vibrations 

Pete

 

I've now installed the UJ bearings at the diff end and managed to do that without user error. However, I cannot assemble the splined end symmetrical with the fixed/diff end. There is a minimum error of about 10 degrees. Is this a significant misalignment? 

Richard

[Nick Jones]

2 hours ago, RichardS said:

Is this a significant misalignment? 

I would say so yes. If that’s how it was before (sounds like you think it is), that’s likely the real reason for your rumble.

Nick