Which UJ?

[AlanT]

Hi Experts.

Is there a way to tell if a dud UJ is on the prop or a driveshaft? I can hear a slight rhythmic tap that goes with speed. Not sure if to ignore for now.

Clearer now I’ve swapped to stock exhaust!

Thanks

Alan

[Clive]

Have a look at the end of thd uj cups, there may well be a shiny witness mark where ot has been moving g.

Prime especially is driveshafts as they need to have the ujs tight, props not.

Every driveshaft I have fitted needed at least 2 oversize circlips.  These can be fitted on the car, pop a circlip out, knock the cup in with a hammer/drift (Ali bar is ideal) and fit an oversize clip. Rotate 90 degrees, repeat. And keep doing that to see if you can get 4 oversize clips in.

[AlanT]

Thanks Clive. There’s no ‘clunk’ going into drive so seems more likely a driveshaft.

The niggles post resto continue! 

[Wagger]

I jacked each rear wheel up separately and ran the engine with 3rd gear engaged for a very short time. The left one gave regular clicking, but the right one was smooth. I changed the u/j on the left one and it cured it. Make sure the clips go back in properly and that there is no endfloat.

[Pete Lewis]

and to add props run at engine revs  drive shafts about 4 times slower so the frequency of knock is quite different 

props  va varoom    drive shafts  whir whir 

as props self centre you get vibrations at higher speeds maybe 50mph 

drive shaft uj takes a lot of load and runs at wheel rotation so you find this at low speeds sometimes affected by cornering 

Pete

[AlanT]

1 hour ago, Wagger said:

I jacked each rear wheel up separately and ran the engine with 3rd gear engaged for a very short time. The left one gave regular clicking, but the right one was smooth. I changed the u/j on the left one and it cured it. Make sure the clips go back in properly and that there is no endfloat.

Doesn’t it ‘drive off’ if one wheel is on the ground? 

[johny]

No need a limited slip diff for that. Even so not sure if i like the idea very much😳

[AlanT]

Me neither @johny Not after 5 years of resto. Think I’ll inspect the ‘long form’ way! 

[Pete Lewis]

spinning   one wheel  with on on the deck is a good way of wrecking the differential gears they should only turn slowly on corners 

and will be noisy as  they are poorly matched  spur gear teeth you are now whizzing round   

this is not a advisable way to treat a diff 

pete

 

[Peter Truman]

I know the LSD in my Dolly Sprint takes a little abuse to get it to work correctly after a period of layup or controlled driving! Get on a backroad revs up drop the clutch then test by dropping the left wheel onto the soft edge.

The Sprint is a Leyland Aus special, one of 49 produced with LSD for the mid 70's Bathurst 1000 Mountain car race homologation  of the Sprint. It hasn't been out for a month due to rebuilt carb issues so today a good run is proposed down the Peninsula pickup the daughter then up Arthurs Seat an old public road hill climb event lots of hairpins! What I don't test she will, but poor syncro on third will catch her out always does, never mastered double de-clutching! 

[Wagger]

On 13/04/2022 at 19:38, AlanT said:

Doesn’t it ‘drive off’ if one wheel is on the ground? 

No, the diff slips but do not use too much wellie. Do not do it if you have a limited slip diff. AND do not apply te handbrake. Chock the front wheels and declutch if anything becomes worrying.

[Wagger]

In my post I stated that I did this for a very short time. Five seconds per side at 1000rpm. Hardly likely to damage a diff in that time. Wheelspin with one wheel in the mud or snow is far worse than that as it is under load.

I would not suggest doing it for more than five seconds.

[Pete Lewis]

thats good  

Pete

[Wagger]

I spent weeks trying to isolate which shaft was clicking last August. Having someone in the back whilst driving was  not good enough, nor a mate watching and listening with both wheels off the deck.

So I resorted to the 'Desperate measure' as described using 3rd gear at a fast idle (1000rpm). Engaged clutch gently. Right side no noise. Left side, immediate clicking withing 5 seconds so declutched and switched off as soon as I heard it.

You can spend for ever chasing these noises and dropping a shaft to replace the u/j's is not a trivial job. Separating the hub with the churchill puller makes handling easier, but may take longer. Removing the whole assembly on a mk1 is too heavy for me now.

You can change all of he u/j's and still have noises due to brakes binding for part of a revolution and trunnion wear. Running on a rolling road might help if you are brave enough to watch and listen from below.

Hope that you find the cause and cure it. So far no problems with any u/j's or diff on my car after doing both shafts and Trunnions.

Sorry if I worried you guys. I should have explained the process at the start. Dealing with two brother's medical problems distracted me.

[Pete Lewis]

its easter have a day off  

good you understand the limitations of whats inside a differential   many dont  have a clue  

whats next   Ha   

ive been helping a spitty with a drive line rattle , UJ failed  new one slack the yoke was spread, then output shaft is wagging around  

new bearing but the crownwheel bearing is shot  so bit by bit he is getting there but identifying can be a bit tortured 

Pete

[Wagger]

I am taking Pete's advice. Lovely spell of weather, so walking through Bluebells, Celandines and Wood Anenomes. Ignoring wooden enemies.

Meeting friends for lunch tomorrow. May take the Vitesse out to The Six Bells at Chiddingly on Monday. Usually something entertaining to see there.

Enjoy this weather guys. Not many Easters are this good.

[AlanT]

Hi Everyone,

One of my new driveshaft UJs was ‘tapping’ very slightly so I put in a thicker circlip. I’ve now got a regular squeaking of the ‘bearing noise’ variety. Wondering if it’s possible to have these too tight (was tricky to get as the driveshaft was fitted when I swapped circlips.

Of course it’s possible that something else is on the way out.

thanks

[johny]

I suppose its possible. How tight did you have to get it to install the thicker circlip and being new it must be well greased?

[AlanT]

2 minutes ago, johny said:

I suppose its possible. How tight did you have to get it to install the thicker circlip and being new it must be well greased?

Hi @johny I tapped it home (using an old wheel nut) before pushing in the clip. 

[johny]

That shouldnt be the problem then - might be if youd squeezed it with a vice or something to get the circlip in... I take it no signs a cup is turning in the yoke although cant see any reason why it should?  

[AlanT]

No sign of it moving. 

[Pete Lewis]

most uj creak or click  a squeak/squeal sound like elsewhere 

is the hub allowing the drum to kiss the brake shoes ??

fitting circlipson car is unlikely to cause any grief and you cant over tighten when lying on your back with a pair of circlip pliers in hand 

and giving the cap a light whacking to maake sure the clip is seated    look for another suspect 

back plate fouling ???  shoe contact ???   oil seal ???   dust flinger contact ???

Pete

 

[AlanT]

Think I’ve found the issue. Front left wheel bearing once it gets warm. Employed the far better ears of my 18 year old son who confirmed it’s not coming from the back! 
Nice simple fix. Perfect.

 

[johny]

Do you think its dry or needs replacing?

[AlanT]

9 hours ago, johny said:

Do you think its dry or needs replacing?

I’m going to change it @johnyto be on the safe side. It’s one of the few things not changed since buying the car as a wreck that had stood for 20 years.