Oh dear - thup thup thump from rear !

[matt brighton]

Hi

1982 - 1.6d na devon - 130,000m

What do you think - has this happened to you ?

Flippin great (and I mean very loud .....and vibrates) "thump thump thump" from the rear end on over-run (in OR out of gear) -the noise stops when under accelleration.

Very loud and almost makes the van shudder with each thump.

The thumps are speed related - they slow as I come to a stop in gear or coasting. Sounds like a blacksmith is whacking the engine with a club hammer.

Not looked properly yet but drive shafts dont seem to have excessive play on them - I have just reached under and tried to rotate by hand.

This happened on friday - the day after my other car (my pipe n slippers Rover 75) was in the garage for a gearbox repair which has cost me £500 I didnt budget for

We are due to go on our 1st camp of the year in may to IOW and cornwall.

Guessing a cv joint / driveshaft / wheel bearing ?

Im getting a day off work next week to get the wheels off the ground and investigate -

please - any advice/tips / diagnosis tips very welcome from you lovely people would be welcome,

Regards


Matt - brighton

[Plasticman]

Methinks youve answered your own question there Matt Its rotational and speed related therefore driveshafts>>>outward.. it will most lightly be a well unhappy cv joint or just as likely a loose one, no need to take a day off work, light evenings jack a corner up and have a propper look see.
mike

[Fin]

Yeh sounds like you've got it with CV's
I can never figure out how to find out which one is doing the knocking - do any mechanics have any tips?

It's well worth upgrading them - I think you can get Porsche ones that fit - the stock ones seem to give up all the time

[AdrianC]

Really quick & easy one to check - swap the rear tyres to the front, and have a damn good look at 'em as you do so. It may well be that a tyre's started to delaminate.

[Plasticman]

the stock ones seem to give up all the time

Are you buying cheapo's?
mike

[Plasticman]

Oh heck Adrian, that reminds me of the cheapo old days with remoulds but still valid and worth checking, I think were all agreed that it must be ..................rotationaly related.
M

[Fin]

the stock ones seem to give up all the time

Are you buying cheapo's?
mike

Yeh I think so - ebay tastic
Although it could be my 10in wide rear wheels causing stress

[Plasticman]

Your first paragraph is more likely
mike

[matt brighton]

Hi All

All fixed...

To my shame and embarassment it was loose wheel nuts !!!!

Cheap fix - but a bit of a scary reminder for me to check and re-check those routine weekly/monthly safety checks .

I think I last had that wheel of may 2010 - I "always" do wheel nuts up to the correct torque - maybe this time i didnt

What with camping season comint up - When was the last time you checked yours.....

Thanks for all replies

Matt - brighton

[CovKid]

Yep, in my experience worn CV joints only really make a noise under power or when cornering.

[fodtommo]

I know this is obvious... but...

Noise under deceleration is nearly always something loose between gear box and wheels, id dissapears under acceleration as rotational torque 'locks' it.

I have on more than one occasion known this to be loose wheel nuts... I have done it once myself after a late night garage session, nipped the nuts up lower the jack then have a tin of beer and promptly forget you didnt tighten them (you only do it once)

I have diagnosed it on a couple other cars too, it will take a good few miles for them to undo to the point where the noise starts.

Worth checking...

My golden rule now ids if the hubcaps are off check the wheelnuts... wont work for you smart chaps with alloy wheels though

[fodtommo]

Ooops - I should read the whole thread before posting...

[matt brighton]

thanks fodtommo

I hesitated to confess to this - - very embarassing - but I thought if it means others might check thiers then its worth it.

And yes - you would only do it once - and hope that you find out the "easy" way - like I did...

Regards

Matt - brighton