Odd noises, really quite worried!

[alexlocke]

Evening all!

Right, I'll try to explain this as clearly as I can.

This morning whilst driving to work, I noticed that when I accelerated, the car would lurch and make a sort of bang from the rear, usually more than once, in a sort of bouncing motion, for example it would go CLUNK...clunk...clunk (perhaps 3 or four times, getting quieter and less violent each time). Also if I took my foot off the throttle, it would do the same, much more noticeably in the lower more responsive gears. Usually cars do this a bit, i guess its just a bit of play in the transmission somewhere, but through the day it got quite bad. Also, as this problem got worse, I noticed that when in a fairly responsive gear, when I let the throttle off, after the clunk has happened, there is a strange noise. I'm not quite sure how to describe it; it's a mix between a grinding, a humming, and a vibration. Other than the clunks, there are no vibrations or shakes that can be felt.

I jacked the back up and had a quick look under the car, but I honestly don't know what I'm looking for. I tried to have a feel of the torque tube, but it felt like it was encased in a larger solid tube, of which didn't feel at all loose. I also gave the wheels a wobble, there was a bit of play if i rotated them before any resistance was met, but the bearings seem ok. I also gave the drive shafts a wobble, and whilst they moved a bit length-ways, there was no other play in them.

Any advice would be greatly appreciated, as at the moment I've got a horrible thought that my gearbox/diff is going to spread itself all over the road in the morning.

Thanks, Alex.

 

[mike220]

Clutch centre beginning to marmalise itself ? Or driveshaft rubbers disintegrating ?

What model have you got Alex ? Could have help to diagnose

My thought's lie with the clutch initially, unless you can tell the noise is coming from the back of the car ?

Mike

 

[alexlocke]

Sorry Mike, I should have said, its a 1989 2.7 manual. I cant be 100% sure that it's coming from the rear, but it really does sound that way! I understand clutch kits are pretty expensive, I don't suppose one from another, cheaper car fits does it? Would the clutch failure cause the noise that occurs on a trailing throttle? Also, I forgot to mention, the trailing throttle noise does stop after a few seconds, as if something is vibrating after the throttle has been released, but then settles.

Hope this info helps!

Alex

 

[peanut]

+1 clutch centre I'm afraid[]

 

[pauljmcnulty]

I understand clutch kits are pretty expensive, I don't suppose one from another, cheaper car fits does it?

Clutch itself isn't expensive, it's a huge labour charge though. I'd agree it's the first place to look.

When was the last documented clutch change?

 

[alexlocke]

I would have to check the service history, but unfortunately I think it is probably long overdue a clutch, and its likely that I have the rubber centre type I suppose! The cheapest I can find a kit for is around the £500 mark, anyone know of a cheaper source? Also, too it for another blast tonight, and found when shifting enthusiastically from 1st to 2nd, there is a fairly loud squeak for a split second, sounded almost like a dog bark! Would the clutch centre failure cause the noise that happens when I release the throttle?

Your suggestion really does sound like the most likely issue. Thanks a lot for all input, it's greatly appreciated!

Alex

 

[peanut]

its not just the clutch plate that is expensive its the clutch cover and thrust bearing you need to buy with it . Its a big job and expensive so you would be ill-advised not to replace the plate cover and bearing at the same time whilst you are there.
There are several ways to do it and some garages opt to remove the engine rather than mess about removing the torque tube and dropping the gearbox.
You are probably looking at about £850 lab and materials which is why I never tire of saying don't drop the clutch on 944's and do a racing start the standard clutch is not designed for that.
Not that you have of course []

 

[peanut]

If you drive it gently you might get a few hundred miles out of it whilst you save up and book it in. If its a rubber centre clutch plate that is breaking up its basically in 'limp home' mode at the moment. Every time you dump the clutch on spirited changes you are doing more damage and risking complete failure.

One test you could try to confirm it is to drive the car down a straight road at a steady speed say 40mph and see what happens. If the clutch has gone the car will buck and stall as the gap in the clutch is taken up in the transmission.

 

[mike220]

Whereabouts are you located Alex ? Yeah it's sounding more and more like the clutch as I first thought.

Mike

 

[zcacogp]

If it's the original clutch, and over about 100k miles (although take that last one with a pinch of salt), then it's suspicious. There is a small inspection port on the back of the clutch bellhousing which you can remove; you can't see anything much through it, but if the clutch is completely kippered then you may find bits of rubber (old clutch centre) in there. These rubbing against something else would also explain the squeak. You can also measure the clearance in there to tell how worn the clutch plate is (although the symptoms you describe aren't of a worn clutch, they are of a failed clutch centre.)

If it is the clutch centre then it will remain drivable, but get nastier and nastier to drive.

The only garunteed way to diagnose the clutch is to remove it. Which is a big job (but not at all hard - well within the scope of a good DIY'er). Given this fact, you may want to inspect everything else carefully before diving on in. Or spend 1/2 hrs labour at your local indie getting it diagnosed (they may not charge for this if they later do the clutch work for you.)


Oli.

 

[peanut]

ORIGINAL: zcacogp


Which is a big job (but not at all hard - well within the scope of a good DIY'er).
Oli.

are we talking about the same car Oli ? []

 

[mike220]

Sure - I'd do my own haha. It's just a long job, not particularly difficult............

 

[zcacogp]

ORIGINAL: peanut
are we talking about the same car Oli ? []

I think so. >ChecksForumNameToMakeSureI'mNotTalkingRubbishAsUsual<

No part of changing the clutch on a 944 is difficult. (OK, getting the gearbox back on is a prize fiddle and having small, triple-jointed fingers would help with doing the gearbox mount nuts up, but I suspect you can take the rear cross-member off instead which would alleviate this step.) If you can unbolt the driveshafts you are more than capable of changing the clutch.

It's just that it is a long job, with lots of stages, and it takes a lot of work. A weekend, with a good friend to help, and you'll have time for a visit to the pub on Saturday night and probably be done by Sunday lunchtime. (With the clutch, that is. Not done at the pub [].)


Oli.

 

[peanut]

you've actually done a clutch Oli ? wow I'm impressed. [] .........(puts Oli back on Christmas list )

I used to do all my own work once upon a time but when I saw the mess the garage got into doing my clutch I'm glad I let them do it.[]

 

[Mike_Pollock]

I've changed the gearbox in mine in a (longish) morning, I would try the clutch. As Oli says I think its lots of straightforward bits.
Mike

 

[Diver944]

Oli is 100% correct (as always [] ), a clutch change is well within the DIYers realm as it's just a very long list of things to unbolt/disconnect and then put back together again. I helped Tony F do his last year and armed with the guide on Clarks Garage it was very straight forward.

By help, I mean I made the teas and ate the chocolate biscuits whilst he unbolted mechanical things from underneath his car [&:]

 

[sulzeruk]

It takes about an hour of faffing to drop the gearbox on these cars I have found. The top 2 bolts are always a pain to get off, I just drop the gearbox support off as it is best to get in and clean up the mountings and give the crossmember a grit blast and paint. Just what I am doing at the moment on an S2 apart from everything else!
Alasdair

 

[peanut]

ORIGINAL: Diver944

a clutch change is well within the DIYers realm
I made the teas and ate the chocolate biscuits whilst he unbolted mechanical things from underneath his car [&:]

you'll know all about how its done then []..making the tea I mean[]

 

[zcacogp]

Alasdair, When you talk about the gearbox support, I presume you are referring to the lump of angle iron which runs from one side of the car to the other, and has a single bolt on each side? I looked long and hard at that when taking the 'box off mine and thought it would be an easier route than undoing the gearbox mount bolts, but decided to slavishly follow the instructions instead. Sounds like I took the harder route.

ORIGINAL: peanut
(puts Oli back on Christmas list )

I don't think I want to be on your Christmas list if you're being like that about it. >sulks<

And it's not Christmas either. (Although it is my birthday tomorrow, and if you send me a nice present I may forgive you!) []


Oli.

 

[sulzeruk]

If you put a transmission stand under the gearbox ans get the 2 bolts holding the crossmember out, it makes it a lot easier getting the 2 bolts out above the box,
Alasdair