Another noise to identify

[scotty2]

Suggestions welcome:

My 89 SE has just been put back together after having the manifold changed and complete belt / hose /tank change.

It started first time and all seemed well until a noise (akin to a rumbling bearing or water pump) developed a few minutes after starting. The water pump and tensioner are new and when the car was put back on the ramp it was found to be coming from the gearbox (new clutch also fitted).


Does anyone have experience of a noise developing after an oil change on the gearbox?

Thoughts so far:
Change for a SAE90 oil to see if something has been disturbed.

Clutch operation does not seem to affect the noise.

HELP!

[zhastaph]

A simple way to rule the gearbox out of the equation is stick it into gear, press the clutch and listen then, in this configuration there will no parts moving at all in the box.

Assuming it's not the box, clutch release bearing or the bearing on the end of the crank mayb?

[deecee]

Got Oil?

[Autocross7]

Not a practice I would do often, but...
just pulling off the line, slowly release your clutch and feel for a slight vibration... do this in just socks for better feel.

Sorry I cannot describe this better... but before I started doing my own work due to getting discusted with shop work and prices... I had a clutch done and the dip wads at the shop did not replace the hard steel spiggot on the end of my drive shaft... I noticed a noise similar to what you described and after about a week or more I started feeling this slight vibration in the clutch when released slowly... was an easy fix... I did it myself. Shop simply said "well, it must have fallen off"...??? Yea... me too if I'd have believed that one!


Good luck...
Drive topless!!!
Cameron

[cnh1990]

almost sounds like the release bearing like someoen mentioned before.

[Scotty2]

What effect would attempting to "pop" out the driveshafts without removing the cotter pins. Could that damage anything to give the noise. I would have thought it would only be evident when moving?

Will check the clutch in / out noise change again if there is one.

[scotty2]

Checked again with the garage working on the car:

Noise does not change with clutch operation.
Noise seems to be from rear of gearbox?

Noise is present when car stationary and engine running.

Any clues?

[Dr.Hess]

Lemme take a guess:

Car stationary, in gear, clutch released (pedal to floor) - Noise.

Car stationary, in neutral, clutch engaged (pedal up) - Noise.

Car stationary, in neutral, clutch released (pedal to floor) - Noise.

Noise is all the time, regardless of clutch state or gear.

Are we correct so far? If those are the symptoms, I am going to take a SWAG and say that either something on the clutch or release bearing is hitting something on the bell housing, or something around the crankshaft isn't right. I would say that the gearbox is not the source of the problem here, as the noise happens regardless of the state of the box turning or not. I would also say that the box is coming out one way or the other, at the shop's expense, as it appears that they screwed it up.

Dr.Hess

[timrdlotus]

The only thing moving in the gear box when the car is stationary is the input shaft. If you step on the clutch and the noise disappears then it's the input shaft bearing or retainer. HOWEVER, you got the noise with or without the clutch pressed in correct? That eliminates the gearbox.

If the throw out bearing was bad, the noise would change either stop or get louder. So if the noise doesn't change then you can eliminate the throw out bearing and the clutch assembly.

So that leads us to what is turning when the car is not moving. ENGINE. Noise has a way of transmiting it self. I would use a mechanic's stethscope and see exactly where it's coming from.

But I would definately rule out the transmission. Just my 2 cents.

[cross-eyed-twit]

you're not into research and development at Lotus are you Tim?



Dom

[timrdlotus]

No, just a former repair shop owner. I owned a transmission and a muffler exhaust shop. I sold both and got back my weekends. After the raping from the ex and attorneys, I bought some boyhood toys (930 turbo, 90 esprit se, 70 camaro z-28) and just tinker around with them.

[kylie]

If it was a release bearing would it make more of a whirring sound that could be different to a rattling sound, esp when clutch is depressed?

[scotty2]

Garage are going to pull the box to investigate.
Current thoughts are spiggot bush.

[Dr.Hess]

If it was the spiggot bushing, which your car does not have, by the way (it's a bearing), the noise would go away when you put the transmission in neutral and had the clutch engaged (pedal out), or were moving in gear.

But, we'll see now.

Dr.Hess