diff knock and whine

[P500KO]

Gradually getting thro all my "RAF" fund so could do with a bit of help in keeping some of it in it!!
Having gradually taken my griff further on, ie rebuilt engine new clutch etc"i am now at the diff...it has a really annoying whine and a clunk if you dont get the gear change perfect! ok ok i must do better ...do i go down the Quaife route or just try and get it rebuilt? I dont at this time think I will track it as I am not a good enough driver but it needs sorting...also just got the four poster lift from Fred so no excuse for getting it out, 7 days delivered and the best value i could find IMHO...

[BliarOut]

Check the input shaft nut is done up tight before you go too far. If it's loose you'll get excessive backlash which can cause whine and clunking. It may not be this, but it's cheap and you can do it en route to getting the diff out.

[sjwb]

Point of order:
It is the pinion not input shaft, but other wise well spotted.
However do NOT just tighten the nut, if that is the issue.
Renew the nut and accurately tighten to the recommended torque and or angular displacement.

Bad news; it could of course be a sign of a pinion bearing collapsing. Hope not.

[Bodmin]

sjwb said:

Point of order:
It is the pinion not input shaft, but other wise well spotted.
However do NOT just tighten the nut, if that is the issue.
Renew the nut and accurately tighten to the recommended torque and or angular displacement.

Bad news; it could of course be a sign of a pinion bearing collapsing. Hope not.

I have never seen any recommended torque setting for the pinion nut. The pinion preload is set by a collapsable spacer in front of the nut so, in theory,it cannot be overtightened. Strangely the nut, considering the speed at which it can rotate, does not appear to have any form of locking device i.e. split pin/lock tab

As I have commented before on these forums, I suspect there have been a lot of diffs condemned for clunking etc by dealers & indies alike when in fact all that was required was the nut to be re-tightened. In fact the first 'clunking' diff that I looked at for a friend had been diagnosed by a main dealer as needing replacement, £1000+, was in fact a loose pinion nut

Bodders

[P500KO]

Thanks for the info people, will check it out before I spend.
I have ordered Steve Heaths new edition book,on back order though do you know if its covered in there?

[P500KO]

Bodmin said:

sjwb said:

Point of order:
It is the pinion not input shaft, but other wise well spotted.
However do NOT just tighten the nut, if that is the issue.
Renew the nut and accurately tighten to the recommended torque and or angular displacement.

Bad news; it could of course be a sign of a pinion bearing collapsing. Hope not.

The wine and slight clunk have not got any worse in 2.5k miles, would you summise that if a bearing was collapsing that it would have got worse in that time?
Will still check the nut anyway...thanks

[tbdgriff500]

hi Bodders long time no see, hope you are well!
i have a diff from a 30,000 mile crashed griff if anyone is interested,
gathering dust at the moment! small donation to my racing fund will secure.
pm me if interested or i will stick it in the classifieds if i ever get round to it.
regards
tim.

[Bodmin]

tbdgriff500 said:

hi Bodders long time no see, hope you are well!
i have a diff from a 30,000 mile crashed griff if anyone is interested,
gathering dust at the moment! small donation to my racing fund will secure.
pm me if interested or i will stick it in the classifieds if i ever get round to it.
regards
tim.

Tim....hows the trophy cabinet coming along

Bet you can't wait to get out in the Tuscan racer

Bodders

[Bodmin]

P500KO said:

Bodmin said:

sjwb said:

Point of order:
It is the pinion not input shaft, but other wise well spotted.
However do NOT just tighten the nut, if that is the issue.
Renew the nut and accurately tighten to the recommended torque and or angular displacement.

Bad news; it could of course be a sign of a pinion bearing collapsing. Hope not.

The wine and slight clunk have not got any worse in 2.5k miles, would you summise that if a bearing was collapsing that it would have got worse in that time?
Will still check the nut anyway...thanks

Strange things bearings....some are noisy for a short period then break up & yet others can go on for years 'whining' away before anything happens....bit like women

Once you have released the prop flange & can get at the pinion shaft you should be able to check for any side to side movement on the bearing...at least this check can be done without having to remove the diff

Bodders

[hiltonig]

BliarOut said:

Check the input shaft nut is done up tight before you go too far. If it's loose you'll get excessive backlash which can cause whine and clunking. It may not be this, but it's cheap and you can do it en route to getting the diff out.

Where is this nut ??, is it the nut on the flange into the diff ???

[P500KO]

Quinny said:

Ignore the tape.... I was taking a measurement for someone doing a bit of a project

great pic
Will deffo be checking this out before spending....if it is loose will need to find out if there is ant torque settings or if to just change and retighten...real useful information guys....

[Belchy]

Hi

Not sure if your talking about a GKN diff or not but I found this link on here before when searching. I think its off griff pages;

http://www.maserati-alfieri.co.uk/alfieri155-3.htm...

page 3-19 may help for clunking pinion nut torque stuff?

Also a different spec of oil may help to quieten a small whine.I have just changed the oil in mine and it definately quieter now!

hope link works and you get rid of clunking/whining,

Belchy.

[P500KO]

tbdgriff500 said:

hi Bodders long time no see, hope you are well!
i have a diff from a 30,000 mile crashed griff if anyone is interested,
gathering dust at the moment! small donation to my racing fund will secure.
pm me if interested or i will stick it in the classifieds if i ever get round to it.
regards
tim.

Tim,
Sent pm, did you get it?

Clive

[Simon Says]

Quinny said:

Unfortunatly, I don't think there is a torque value for this nut It seems that it's tightened against a crushable washer, and backlash measurements are taken..

I wish I hadn't undone mine But I was convinced my issue was internal... Then when I found the bracket loose at the back, I though Mmmm, maybe its not an internal problem after all...

All Im going to do for now is tighten it to the previous mark on the threads (The shaft has a mark where the nut was) and hope for the best....



Don't forget to check the mounts, both sides and especially the rear.... Also the bushes

Just tighten till you feel resistance Quinny then a fraction more about 30 degrees(but no more)Ford rear axles have the collapsible spacers fitted to later cars i.e Capri,s etc and i have changed pinion weeping hardened seals this way and have never had problems with over pre-loading the bearing or leaving with excess float causing noise due to poor pinion & crownwheel alignment or bearing failure due to over tightening,just use a few drops of thread lock on the nut with your background and savvi you can do this with total piece of mind you cannot keep repeating this exercise though for every time you remove the nut by re tightening you are effectively collapsing the spacer a fraction no matter how small this is the case because otherwise you will not be suitably clamping the inner bearing races together and will suffer fretting between the bearings and pinion shaft

Edited by Simon Says on Friday 22 January 21:37

[Simon Says]

Quinny said:

Cheers mate.... That was pretty much the plan, just tighten down and then a final nip...

To be honest its all I can do.

If I do have any trouble with the diff later on, I won't be doing it again, I'll just send it off to someone who know what they're doing, or look out for a SH one from a known source..

I think I should be ok, but I wish I'd found out the diff was loose before I whizzed that damn nut off

Hi mate,i reckon you will be just fine and already had the solution/right idea i picked up a GKN a while back for silly money is currently stripped and filed under jobs to do,just needs a set of pinion bearings but will get the lot

Edited by Simon Says on Friday 22 January 21:54

[sjwb]

Sorry didn't realize that it was a collapsible spacer, as against shims.
The correct way is to renew the spacer, nut and seal and set the preload in the recommended manner; which usually requires stripping the FDU.
However, if you are going down the route of 'giving it a nip' then protect the future by at least renewing the nut. They should never be reused.
Assuming that the bearings are OK, the preload has been lost because of slop on the splines caused by fretting as a result of torque reversals on the pinion flange. In the past I have seen an application of Loctite 601 Retainer on the splines to effect a temporary cure.
Regarding a torque setting; there will be in the manufacturer's data a minimum torque value for instances when the nut is renewed.

Edited by sjwb on Friday 22 January 22:12

[dnb]

The collapsible spacers are nasty things. Mine collapsed further and almost clobbered the diff.
It's now rebuilt using shims and this seems a lot better.

[haircutmike]

Clive.

If you have any play at all in the diff mount you will have an almighty clonking.

This mount has to be torqued to about 56 ft lbs, I took drastic action and all clonking solved!



As to the whine, mine has a minor whine that hasn't changed for 3 years, maybe tadts!

[Simon Says]

haircutmike said:

Clive.

If you have any play at all in the diff mount you will have an almighty clonking.

This mount has to be torqued to about 56 ft lbs, I took drastic action and all clonking solved!



As to the whine, mine has a minor whine that hasn't changed for 3 years, maybe tadts!

It was daft of TVR not to fit sprung washers on those Allen bolts really i like the access hole Haircut

Edited by Simon Says on Saturday 23 January 10:37

[haircutmike]

Holes cut in two minutes with a hole cutter on a cordless.

Holes covered with an ally plate siliconed and pop rivited in place!

I will be taking it off again soon to renew the diff bushes when I install a ramp, (courtesy of the local tyre shop who are upgrading!).

P.