Clunk on over-run - TR4A

[Yorkie1952]

Hello, I've had this annoying clunk from the rear end on the over-run ever since I've had the car, over 3 years now, and I'm trying to tie down its source.

Originally I thought it was hub spline wear on the wire wheels but I replaced these some time ago. There is now 2mm play at the rims which I would have thought is OK. I can't feel any play in the half shaft UJs. (its an IRS)

However, there seems to be a lot of backlash in the diff. With one back wheel off the ground and the car in gear, I get about 25mm of play at the wheel rim before the prop shaft moves. So my question is, is this normal or excessive? The diff was a recon unit from Rimmers about 10k miles ago. Thanks, Brian.

[Pete Lewis]

that free movement is the play/backlash in the planet diff gears , not the crownwheel and pinion  its quite normal as these gears transmit all the load but as the dont rotate much they have no cleaver meshing  as a crown wheel does .

 

this can give upto 1/8 turn on the prop or even more,  its normal.

 

Pete

[AndyTV8]

As Pete says, the driveline play doesn't sound excessive.... Coming back to the problem, it could be worn splines on the IRS driveshafts themselves - if they are worn and you are going down the replacement path it is worth considering some of the alternatives (need fairly deep pockets though!) with CV joints and ball bearing sliding shafts.

I changed to a Datsun120-based conversion on my old Stag and the difference was significant.

 

Are the trailing arm bushes in good order? If not Polys will tighten things up nicely.

 

...... Andy

[Pete Lewis]

yes got to do the rear end on my 2000, def has the exit roundabout twitch and rear wheel steering due to  soggy bushes ,  due for a strip after duxford

and if the shaft splines are how i think maybe a set of CV from club shop is on the horizon   can i have some for christmas ???

 

Pete

[AidanT]

Hi. As you are talking about rear Bush replacement I was considering this as a winter job. Not done anything like this but understand a lot of grunt is required. Can you recommend the tools needed to take this on please.

 

Thx

[Pete Lewis]

strong tea bags and a good whisky

 

pete

[AndyTV8]

Hi. As you are talking about rear Bush replacement I was considering this as a winter job. Not done anything like this but understand a lot of grunt is required. Can you recommend the tools needed to take this on please.

 

Thx

 

most say it is a devil of a job to remove them, but on a couple i have done i just used some threaded bar, hefty washers and some tubing to 'wind' the old ones out and the new ones in, it wasn't so bad.

 

If anyone is interested i have got a set of new Blue SuperFlex IRS trailing arm bushes & inserts which I won't need - my 4 is live axle - £40 plus the postage if they are of use?

 

cheers, Andy

[AndyTV8]

strong tea bags and a good whisky

 

pete

 

excellent advice, regardless of the job

[Pete Lewis]

Andy Ive got the bushes already, and tea and tipple and a selection of tube socket and threaded bar to drag them wonky rubber out and blue back in

Its what I find on the shaft splines thats unkown

 

pete

[AndyTV8]

I was very lucky to get hold of a set of Datsun converted driveshafts for a very good price complete with good hubs, the prices seem to have gone up recently... I know of a couple of folk who have fitted some greasing nipples to the driveshafts which at least make regular lub'ing less of a chore.

Ball-bearing/CV shafts get rid of two problems in one hit, but they do require some penny-saving!

 

Why not do the trailing arms Polys first and see if they improve things enough to not need to do the driveshafts immediately.... The shafts can be easily swapped at a later date without disturbing much if things are stil too twitchy.

 

..... Andy

[Pete Lewis]

Hi Andy, yes there,s a plan in place, get the knees to work , get the back supple, make the tea

add the scotch !!!

It will be a careful look see , not going to jump into deep pocket sydrome

mine has the greaser but was off road for 20 years after a resto, so who knows

I knew the bushes were soggy when I bought her last year but concentrated on doing the front first with added p stg,

the backs not looking difficult but she still wanders and has excess rear toe,

have blue poly to fit, re track and pull the shafts

Big box of tea bags ready

 

pete

[AndyTV8]

good plan Pete,  enjoy the tea & scotch breaks  

[Yorkie1952]

^{Thanks for the advice chaps - guess I need to take a closer look at the shafts and bushes. Is it possible to check spline wear without removing the shafts?}

[Pete Lewis]

Dont think so, just dont force old rusty small nuts on the bearing housing or seems you can strip them easy and redrilling realy needs a jig to ensure alignment

 

many seem to use cv grease or moly types to grease them after a good clean and fettle

 

pete

[Yorkie1952]

An update (obviously I took a long time getting around to sorting this :-) I've since moved and the owner of my local garage is well up on classics so I got him to have a look. He had it up on the lift with another chap slipping the clutch in gear with the brakes hard on. He diagnosed play in the drive shaft splines as suspected.

After doing some research on the other TR forums I got some new shafts from Proptech in Hartlebury. They have splines coated with some sort of plastic, sealed and greasable, and GKN heavy duty UJs (I had to fettle the stub axle yokes somewhat to get the spiders in). So a bit of an upgrade, and not much more ££ than standard ones. The CV type shafts are about 4 times the price! I wouldn't think justifiable unless you have a highly tuned car and do lots of miles?

 

I also replaced that little spring at the bottom of the gearstick, so now I have a much less clunky and buzzy machine!

 

Brian.

[Pete Lewis]

Club shop sell them with a Rilsan coating,

supposed to cure any frictional sticking

 

 

And a good spline clean up and blue poly in the trailing arms and the 2000 goes where you point her now no exit or driveline twitch

 

pete