Driveshaft\diff Failure And Diagnosis

[BuD 0]

Hi all.

 

My problem first started to show up as a slight knock which occurred when i progressivly broke to a standstill. As the front of the car dips a knock can be heard. This has now developed into a stronger knock or short series of knocks and now it does it when i accelerate when pulling away or from crawling along seemingly linked to the front of the car lifting during acceleration. It also does it as i go over a bump particularly if the wheel is turned altho this isnt needed and the direction of turn makes no difference.

 

The knock does not occur everytime altho it is more often than not now. If i brake smoothly it just gives one firm knock whereas if i modulate the pedal slightly i can produce 2 or 3 in quick succesion.

 

The sound seems to come from lowish on the drivers side but these things are difficult to pinpoint from the cabin. The knock produces a small vibration which can be felt through wheel and pedals.

 

It does it with or without the engine on and with the clutch in or out.

 

Obviously there is no noise when the vehicle is not in motion and it doesnt do it when the car is stationary driven against the hand brake and not allowed to move.

 

The balljoints, wishbone bushes and drop links are all fine and i have swapped them out with good items to confirm this. The top mounts and struts are newish and i am sure these arent to blame. there is no play in the road wheels during the wiggle test and there is no clicking on either side lock and no vibration. The car drives fine. All SF and GB bolts are tight as well as all the front suspension bolts.

 

When i spin the o\s road wheel when the car is jacked up i get a light clicking from the inner CV joint which turns into a creaking type noise as the wheel is span faster. I can feel the a slight vibration in the driveshaft every click. I can hear a click also from the n/s shaft but no where near as loud and zero vibration.

 

When starting to rotate either road wheel i get a clack type noise from the GB\diff. Furthermore as i leave a wheel spinng to come to rest i sometimes get a clack as the wheel is spinning. when i jsut jack up one side of the car and put it in gear i get about 25 degrees of movement and clacks from the box at the start of movement.

 

The o/s DS is only about 5000 miles old but has been on and off a few times now.

 

As i understand it the outer cv joint is the one that typically fails as it is the one that is worked at most varied angles and exhibits clicking on lock. What does a failed inner joint behave like and how can it be diagnosed?? (A key question!)

 

I know all BE boxes have a clack noise when a wheel is span when the car is jacked up but the noise when the wheel is spinning is worrying!

 

So what do you think then guys do i get a new DS or save for a gearbox rebuild or is there something have missed

 

Sorry for long post but I am a desperate man and need some good advice!

Edited July 19, 2006 by BuD

[Simes 248 2 Cars]

Try a 2nd hand drive shaft first - that would be cheaper than going for the gearbox rebuild.

[boombang 2]

How are you engine mounts? Is this on the 306?

 

We've had this problem on 3 306's when the exhaust isn't sitting perfectly - they were all aftermarket exhausts.

 

The exhaust bangs off the subframe and makes a noise that sounds like a less ticky driveshaft.

 

It was noted that the engine flaps about like a big heavy flappy thing so we changed the mounts only to find a brand new set of Pug mounts were softer than the 50k Pug mounts we took off.

 

Exhaust was changed for a Peugeot OE exhaust and solved it.

 

I guess though that its less likely to do this out of gear but if a mount has gone and downpipe to subframe gap is tiny is may still do it.

Edited July 20, 2006 by boombang

[BuD 0]

Cheers for the replies guys.

 

Yeah this is on the 306.

 

Newish bottom mount (3k) and brand new GB box mount, the top mount looks fine and the buffers are positioned to allow minimum movement. Can pull and push on the standard exhaust and am unable to produce a knock - good suggestion tho.

 

Anyone with anything to add? What symptoms for failing diff? What symptoms for inner joint DS failure.

Edited July 20, 2006 by BuD