Knocking shafts!

[Guest Simon Bolton]

Hi all I am now back on the road after a fair bit of work and am delighted except for a couple of niggles which have both been touched on recently.The first is knocking in the half shafts-These are both new exchange units from Rimmers and still I get some knocking at take off and some gear changes- everything is tight(I 've been under the car whilst on the hoist at my garage)and I assumed that this was just the 'Triumph' way---Am I wrong? Also there is no (and never was) vacuum hose on the distributor .I have electronic ignition(lumination) and apart from occasional pinking the motor is running really well.I don't know enough to DIY this so should I take myself off to a tuning specialist and if so who (I live near Moreton in Marsh). I would really appreciate any comments Many thanks Simon

[Richard Crawley]

Simon

If it's a PI there is no vacuum hose, it uses just the dizzy mechanical advance, the dizzy vacuum thingy should be blanked off with a small rubber cap. Re knocking drive shafts on take off; this shouldn't happen with recon units otherwise they can hardly be considered recon; what exactly was reconed? Re the motor; if it's running well, I would be inclined to leave it alone. You should perhaps retard the ignition a little if it's pinking badly but I would avoid allowing anyone other than a specialist to fiddle with it; if they don't understand this old motor, they can do more harm than good!

[Kiwifrog]

Simon,

 

are you sure the knocking is from the drive shafts ? There are a number of places that could also cause a simular noise, prop shaft for one, diff mounting brackets or if you have wire wheels worn splines on the adapters.

 

Cheers

 

Alan

[modelbuilder]

Simon,

 

are you sure the knocking is from the drive shafts ? There are a number of places that could also cause a simular noise, prop shaft for one, diff mounting brackets or if you have wire wheels worn splines on the adapters.

 

Cheers

 

Alan

 

Hi, I too have a hollow clonk from the rear end of my 6, unless I am ultra careful with the clutch. This is my 7th IRS car and I have had it, from memory, on most of them. My current car is supposedly fitted with " new driveshafts " and a recoditioned diff and it still persists. The sound is like a hollow clang rather than a dull clonk. Everything is tight and the diff mounts are strengthened and sound. My wire wheels are new as are the splines. The UJs are also new. There appears little or no play in the prop.

On one of my previous 6s ripped the mounts and after they were repaired, I fitted a Rimmers recon diff and Revington uprated shafts, and guess what, it still clonked.

I have a suspicion that mine could be a rear hub unit as in this case it sounds as if it's coming from the nearside. (On the other one, it was the offside).

Has anyone had a hub problem that fitted our descriptions ??

 

Regards, Rodney.

Edited May 5, 2007 by modelbuilder

[marks]

Hi

 

I too have the clonk on take up if I let the clutch out too quickly. I have checked the uj's etc. Although I havent pulled them down. The diff mtgs look fine. But I have a lot of play in the diff. I can rotate the prop shaft back and forwards I guess about 5 - 10 deg. Could this be where the noise is coming from.

 

Mark

[Guest Simon Bolton]

Hi all Many thanks for comments.I think I will heed advice and leave well alone for the moment .Till the next time Simon

[Les Pettitt]

Hi Simon

Are you absolutely sure you have checked the diff mounting rubbers thoroughly? I spent 18 years with an annoying clunk. I had the diff rebuilt - no difference. I replaced all the uj's but still had that damned clunk. Eventually turned out to be that the metal insert in one of the diff mountings was no longer bonded to the rubber. Just a thought.

Regards

Les

[Guest Simon Bolton]

Hi Simon

Are you absolutely sure you have checked the diff mounting rubbers thoroughly? I spent 18 years with an annoying clunk. I had the diff rebuilt - no difference. I replaced all the uj's but still had that damned clunk. Eventually turned out to be that the metal insert in one of the diff mountings was no longer bonded to the rubber. Just a thought.

Regards

Les

Hi Les Thanks for reply I shall check these over the weekend

[Guest Simon Bolton]

Hi Les Thanks for reply I shall check these over the weekend

Me again. Rather glib to say I will check them(makes it sound as if I know what am I am doing !).Which ones am I checking ,is it a difficult job and should I have replacements at hand?I took this project on three quarters finished and the previous said that they were new .To be honest I have to take that with a pinch of salt 'cos I have had to 'redo' quite a lot. Starting to ramble-look forward to any help Simon

[dykins]

Simon,

 

if you are suffering from "knocking shafts", might I suggest a visit to your doctor?

 

Regards

 

Peter

[Les Pettitt]

Hi Simon

You are really testing my memory now. I think it is only the rear pair of diff mounts that have the metal tube bonded into them. It was certainly a rear mount that gave me my problems. We discovered my problem by accident as the car was being reversed slowly off a pair a ramps having just replaced all the uj's. You could see the diff move when the drive was taken up. I had not noticed there was anything wrong with the mountings when I reused them after getting the diff rebuilt but then again I wasn't looking for a problem in the mountings. I would hope you could tell whether they are the culprits without having to remove them from the car.

Good luck

Regards

Les

[Guest P Cobbold]

Here's another source of a knock, audible during inital take-up of drive from a standstill. The pressed steel frame that is bolted to the nose of the diff and which supports the two front rubber mountings can fracture. Mine went on the offside leaving the diff hanging from three rubber mountings. Can be welded up easily, but diff. needs to be dropped.

Peter

[marks]

Hi Guys

 

Just returning to this thread, Iknow it was a while ago but would be interested if any of the "faults" were substansiated. I have always had the elusive "hollow clonk" on changing gear. Not when pulling away or in reverse but when chaging from 1 > 2 or 2>3. I can eliminate it if I "pause" during the gear change. Ive had a REALLY good look underneath this time starting from the front. The prop shaft, u/js are all in good condition no play at all. The diff mounts have been reinforced but not boxed in, however I can see no cracks or signs of movement.

 

The plate bolted to the front of the diff at some time must have fractured because there is evidence of a weld, but looks good.

 

The mounts are rubber "metalastic" brand and "look" in good condition. One question I have regarding these is that on the rear mounts refering to a previous thread the central steel tube detaches from the rubber. I took of one of the large steel washers and the steel tube was protruding 2-3 mm when I put the washer back the tube obviously moves back through the rubber.?? The metal tube must pull up tight on the underside of the mount, so is it bonded to the rubber or floats in and out???

 

One thing I did find and havent got the car off ther ramps yet to try, is the nuts on the bolts securing the mount for the back end of the gearbox onto the cross member were loose.

 

Could this allow suficient movement on the gearbox to transmit through to the rear and produce the clonk?

 

Lastly if all these ideas prove unfounded I am thinking (by reading through the threads" it may be the thrust washers on the diff. I know nothing about this so it will be a new learning curve.

 

Mark

[stuart]

Hi Guys

 

Just returning to this thread, Iknow it was a while ago but would be interested if any of the "faults" were substansiated. I have always had the elusive "hollow clonk" on changing gear. Not when pulling away or in reverse but when chaging from 1 > 2 or 2>3. I can eliminate it if I "pause" during the gear change. Ive had a REALLY good look underneath this time starting from the front. The prop shaft, u/js are all in good condition no play at all. The diff mounts have been reinforced but not boxed in, however I can see no cracks or signs of movement.

 

The plate bolted to the front of the diff at some time must have fractured because there is evidence of a weld, but looks good.

 

The mounts are rubber "metalastic" brand and "look" in good condition. One question I have regarding these is that on the rear mounts refering to a previous thread the central steel tube detaches from the rubber. I took of one of the large steel washers and the steel tube was protruding 2-3 mm when I put the washer back the tube obviously moves back through the rubber.?? The metal tube must pull up tight on the underside of the mount, so is it bonded to the rubber or floats in and out???

 

One thing I did find and havent got the car off ther ramps yet to try, is the nuts on the bolts securing the mount for the back end of the gearbox onto the cross member were loose.

 

Could this allow suficient movement on the gearbox to transmit through to the rear and produce the clonk?

 

Lastly if all these ideas prove unfounded I am thinking (by reading through the threads" it may be the thrust washers on the diff. I know nothing about this so it will be a new learning curve.

 

Mark

Mark if the tubes move in the Metalastic bushes then you will get a clonk as the tube should be bonded to the bush and if not the diff can move up and down. This wont help the mounting brackets either as the weight of the diff even moving only a couple of mm up and down constantly will flex them enough to crack eventually, loose gearbox mounting nuts wont help either.

Stuart.

[marks]

Mark if the tubes move in the Metalastic bushes then you will get a clonk as the tube should be bonded to the bush and if not the diff can move up and down. This wont help the mounting brackets either as the weight of the diff even moving only a couple of mm up and down constantly will flex them enough to crack eventually, loose gearbox mounting nuts wont help either.

Stuart.

 

 

Thanks Stuart

 

Ive ordered news ones.

 

Mark

[Tinman]

Hi all,

My 6 has developed a clonk or a loud click when I change gear, dip the clutch or as soon as I lift mt foot off the throttle.

I do not suspect the diff mounts as I replaced them over the winter.

any further ideas or advice would be good and hopefully save me time and effort before I start ripping the back end down

 

Tin

[smizgals]

Mark if the tubes move in the Metalastic bushes then you will get a clonk as the tube should be bonded to the bush and if not the diff can move up and down. This wont help the mounting brackets either as the weight of the diff even moving only a couple of mm up and down constantly will flex them enough to crack eventually, loose gearbox mounting nuts wont help either.

Stuart.

 

Stuart,

 

The polyurethan ones, not cheap, I installed came with the tubes to be inserted on installation.

Would they have the same effect? Or does the stiffness of these prevent up and down movement?

 

Stan

[stuart]

Stuart,

 

The polyurethan ones, not cheap, I installed came with the tubes to be inserted on installation.

Would they have the same effect? Or does the stiffness of these prevent up and down movement?

 

Stan

Stan I think thats the general idea as they are much stiffer and have hardly any compression although i would check that when installed the tube is not longer than the compressed bushes otherwise there will still be up and down movement.

Stuart.

[88V8]

Hi all,

My 6 has developed a clonk or a loud click when I change gear, dip the clutch or as soon as I lift mt foot off the throttle.

 

Click? Drive shaft. If not vibrating, probably splines.

One of mine clicks if I'm a bit lead-footed. Although it doesn't clonk, so if yours clonks it might be something else.

 

Are the rear damper mounting bolts tight?

 

Btw, I have a couple of low-mileage recon drive shafts I bought from Spiro, but I'm thinking of going to the Goodparts uprated shaft/hubs so Spiro's might be available if you decide that new ones are what's required.

 

Then again, if you have wire wheels, the hubs & centres could be worn or they could just be a bit loose, or the adaptor nuts (whatever they are ) may be loose, Stuart said elsewhere.

 

Ivor

Edited August 17, 2008 by 88V8

[Richard Crawley]

Hi all,

My 6 has developed a clonk or a loud click when I change gear, dip the clutch or as soon as I lift mt foot off the throttle.

I do not suspect the diff mounts as I replaced them over the winter.

any further ideas or advice would be good and hopefully save me time and effort before I start ripping the back end down

 

Tin

Hi Tin. It's really not a good idea to hijack someone else’s thread, particularly a live one, it causes confusion & can be upsetting for the OP; start your own thread & you will get a better response.

[marks]

still waiting for the rear mounts to arrive, but whilst waiting decided to take one off and inspect further. It "looked" fine from the outside but when clamped in the vice and with a screwdriver up the tube the rubber could be seen to come away from the metal when twisted. Im so looking forward to fitting the new ones and HOPEFULLY get a drive without the clonk. Will report back when fitted.

 

Mark

[Tinman]

Hi Tin. It's really not a good idea to hijack someone else’s thread, particularly a live one, it causes confusion & can be upsetting for the OP; start your own thread & you will get a better response.

 

Richard,

well I'm so sorry you feel I was "highjacking a thread"

As I have a similar problem I intended to add useful contributions as well as hopefully gain useful information. When I have found the problem with my own car even if it means a total strip, insection and rebuild of the back end I will be very happy to post my finding and experience to help anyone who cares to read it.

Simon apologies if you feel I have highjacked your thread,

watch this space I hope to have sorted my clonking by the weekend

regards

Tin

[Richard Crawley]

Hey Tin.

Sorry but you didn't contribute to the topic, you just asked more questions so that's hijacking! Don’t go all “hurt” on me, it’s just a bit of friendly advice about forum etiquette & simple good manners; would you go into your local & start drinking someone else’s pint! Most forums have this as a base rule & a few I’m on would have blasted you all to hell & back for it but the Register Forum (& I think myself!) is one of the more user friendly; & long may it remain so.

 

Also consider this; regular contributors like myself post many times every day, several times a day to many different questions & may have problems trying to remember specific individuals. If two folks start posting questions (not contributions) on the same thread it gets very confusing. Don’t take it personally it’s just advice & if you post in your own right, even on a very similar topic, you will always get a better response.

 

Do post on your weekend's outcome.

[Alec Pringle]

Crikey Richard,

 

be damned to hijacking, it's just chewing the fat in the same vein. Similar sort of problems, similar sort of discussion.

 

If we start getting hung up on etiquette and manners . . . it's a nattering session, not a schoolroom !

 

Cheers,

 

Alec