Page 1 of 2

Differentail clonk

Posted: Sat Oct 08, 2016 9:58 pm
by herald1360
Hi all
Got a clonking diff when pulling away.
I can feel a fair bit of play on the back wheels when jacked up off the ground. The diff otherwise runs quietly.
Is this a diy fix ?
Any advice gratfully received

Paul Barlow

Re: Differentail clonk

Posted: Sun Oct 09, 2016 3:27 am
by tony
Check u/j's and drive shaft/axle bolts before getting too worried.

Re: Differentail clonk

Posted: Sun Oct 09, 2016 8:48 am
by pete lewis
if all shafts are sound then drive line play is normally just the float on the sun and planet gears in the diff , these have a good clearance and can give good amount of prop rotation to wind up the drive shafts its not a problem certainly not crown wheel related , the spherical thrusts can wear ( not a normal)you can get nearly 1/4 turn of the prop in some cases .

think you will find many of these cars suffer with a clonk /clang theres many sline drive components with varied clearance from diff quill shaft through to drive shafts

they can all contribiute


Re: Differentail clonk

Posted: Tue Oct 11, 2016 11:39 am
by Mike Stevens
I agree with Pete, if the play is in the diff, the most likely cause is worn thrust washers on the sun and planet gears.

However, if the rest of the diff is OK (no whines, smooth operation etc.) it's worth changing them. CW sells the thrusts, one of which is a fixed size and the other selective. The selective ones have their size stamped on them so you can just replace like-for-like! I have done this on an old diff as an experiment and it is not difficult, the hardest bit being getting the diff out from and back into the car.

So, this may be a way forward for you!

Good luck.


Re: Differential clonk

Posted: Wed Oct 26, 2016 7:24 pm
by herald1360
Hi all
I have now dismantled the rear drive train

I have found the following expensive issues!!

Both propshaft UJs rough, sliding joint has play (will get new one made)
both drive shafts, ujs cups are spinning in the yokes and flanges. Pity, as these are Datsun linear bearing driveshafts
Diff Play in sun gear/inner axleshaft splines

Has anyone fitted or experience of the rilsan coated driveshafts?
Recommeded suppliers? as there is quite a price variation (I don't want anything made from balsa wood!)
Can the diff problem be adjusted?


Re: Differential clonk

Posted: Thu Oct 27, 2016 12:59 am
by TedTaylor
herald1360 wrote:sliding joint has play (will get new one made)
Recommeded suppliers?
Getting a sliding joint made ............ :shock:

Chris Witor is my choice (and probably many/most others) of you want quality. He is near Cheddar not THAT far from Exeter for a trip up to see him but check his website for times and cost of parts.


Re: Differentail clonk

Posted: Thu Oct 27, 2016 11:45 am
by Mike Stevens
Remember that these are the same parts as used on the Stag and new (OEM) drive shafts seem to be available as well as more modern CV types. There are a lot of Stag specialists around who have these parts.

The play in the diff (sun/planet gear thrusts) is not difficult to fix. The parts are available from Chris and getting it all apart is a bit of a fiddle but perfectly do-able without any special tools. I have done it on one diff which now has very little play.


Re: Differentail clonk

Posted: Thu Oct 27, 2016 7:08 pm
by herald1360
Getting a complete new prop made, including sliding joint by Dave Mac

Re: Differentail clonk

Posted: Sat Oct 29, 2016 10:31 pm
by david_lall
I had some rear end noises which rapidly became worse.

Last weekend, indeed with a little help fro Mike Stevens :-) , fitted a recon diff with new Cw & P from T.D. Fitchett (off the shelf, and the cheapest around using Timken bearings) and also CV driveshaft assemblies from CDD

The transformation is absolutely staggering - had I known, I would certainly have ditched the Triumph splines years ago!

Re: Differentail clonk

Posted: Sat Oct 29, 2016 11:15 pm
by Mike Stevens
No problem David. Glad you got it sorted OK!