Knocking on acceleration and deceleration

[Marvin]

@PeteZ3 I had a similar problem with my1998 with the M44 & 5 speed. Turned out to be the carrier bearing assembly. It helps carry the drive shaft. The sound was coming from the center of the console.
Marvin

 

[dva99999]

I had this and after changing the diff mount which can be done on the car it has removed it completely.
The clunk is there on the drive taking up the slack the thud is the diff moving under load it is more of a gently engagement now removing the thud

Aah......!

 

[Antm72]

That may be the culprit !

 

[PeteZ3]

What was the latest on this....seems to have come to a halt. My car has the same clunk issue like a little nudge in the back.

Also for those of us not technical what are 'cush' drives?

...and a propshaft 'donut' coupling?

hi, sorry not been on here in a while, basically what i have done is change the diff mount baring, this has reduced the clunk to some extent but it is still there. I know that it is slack in the drive train. but i just can't find out where. what i plan on doing is: jack up the left or right rear of the car and engage 1st with the engine off and vigorously move the wheel by hand, with somebody under the car to locate where the sound is coming from.

people have thrown so many diagnosis's at it, it is just getting to be a bit of a nightmare. on the other hand, the car is fine and i drive it everyday. i do what to sort it out though and i will. its just finding the time to do it!

 

[PeteZ3]

oh and i used the same powerflex pictured in the thread

 

[Lee]

Pete I will put money on it being the pinion bearing in the diff. I bet its lost its pre load.

Lee

 

[PeteZ3]

Pete I will put money on it being the pinion bearing in the diff. I bet its lost its pre load.

Lee

so the symptoms of a pinion bearing loosing its pre load are exactly as i have described? are there any other side effects of it? i want to be certain that it is this before stripping the thing down.

also, how can i test that it is this?

 

[Lee]

so the symptoms of a pinion bearing loosing its pre load are exactly as i have described? are there any other side effects of it? i want to be certain that it is this before stripping the thing down.

also, how can i test that it is this?

Lay under the rear, leave the car in neutral rotate the prop shaft left/right, You will hear the clonking on the front of the diff.

Lee

 

[PeteZ3]

Lay under the rear, leave the car in neutral rotate the prop shaft left/right, You will hear the clonking on the front of the diff.

Lee

okay, thanks lee, ill do this and get back to you weather is crap at the min, so it will have to wait for now!

 

[t-tony]

That's what is also known as " back lash " which you can also " feel " by jacking up one rear wheel and rotating the free wheel backwards and forwards before taking up the drive. As Lee says you will hear the clang inside the nose of the ditt.

Tony.

 

[PeteZ3]

okay, how easy is it to replace the pinion? compared to replacing the diff mount baring which i have done.

 

[Lee]

okay, how easy is it to replace the pinion? compared to replacing the diff mount baring which i have done.

You don't replace it as such. There's a bearing inside with a torqued load. When this load is released it allows movement (backlash). I tried searching high and low for the torque figure but couldn't find anything, I ended up removing the diff and letting a specialist do it for me.

 

[PeteZ3]

You don't replace it as such. There's a bearing inside with a torqued load. When this load is released it allows movement (backlash). I tried searching high and low for the torque figure but couldn't find anything, I ended up removing the diff and letting a specialist do it for me.

wow, okay, sounds expensive

I love my zed but i just cant see myself plowing money into it

 

[Lee]

wow, okay, sounds expensive

I love my zed but i just cant see myself plowing money into it

Na not hugely costly, just shy of £200. My dad's clunks and has done the 5 years we've owned it.

Lee

 

[t-tony]

It's far better to have a slight backlash than a whining/howling diff as that means there is too much pre-load on the bearings and will give premature wear on the diff gears. If it's not excessive, personally I would live with it. I had a Ford Consul years ago which had backlash in the diff and it still had when I sold it.

Tony.

 

[PeteZ3]

It's far better to have a slight backlash than a whining/howling diff as that means there is too much pre-load on the bearings and will give premature wear on the diff gears. If it's not excessive, personally I would live with it. I had a Ford Consul years ago which had backlash in the diff and it still had when I sold it.

Tony.

The thing is Tony I think I have quite a lot of backlash, so I do want to get it sorted as it sometimes distracts me from the feel of the car. Anyway, I'll test this as it really does sound like this is what's wrong with mY zed.

I'm working all weekend so it will have to wait until next weekend unfortunately!

 

[PeteZ3]

I really appreciate the help guys, I feel as though I'm getting somewhere with it now

 

[Lee]

Your welcome mate, It's why we are all here

 

[dva99999]

Well I took mine out today....I couldn't hear the noise. But that maybe due to the fact that it was sunny, the top was down, and my driving was spirited!

Perhaps that's all one can do.

 

[PeteZ3]

View: https://www.youtube.com/watch?v=Vw7Zbp1rfGI


New youtube video and i think he has hit the nail on the head.... my zed has a new drive shaft (before i bought it) and this is the one. he made the perfect impression of my clunk time to get it sorted me thinks