Gear box noise?

[Grizzly]

Hi all.

I have just been looking at old posts that relate to a problem a mate is having with his fd and was wondering is anyone else had the same problem in the past?

Basically on idle the gear box makes what can be only described as a loud rattle (its only on idle not when rev\'d) and its more notchy that usual when changing gear (is you try to change fast it crunches slightly), i had a look at it (changed the oil, checked for bits in the old oil) i am 80% sure its the gear box as the noise comes from the box rather than the bell housing (thought it may have been the clutch) thing is the guys gear box was rebuilt about 30-40k ago for syncro problems which tends to imply the Bearings weren\'t changed?.

After doing some reading up i am fairly sure its the lay bearings that are on the way out but would this sound about right? The car has been stood for quite a while so would it get better if used or would you say its rebuild time?

[rx-dave]

Lay shaft bearings would be correct in my experience, i\'d just buy a decent used box as it easier / cheaper.
Dave.

[SiH]

Yup, sounds like input/layshaft bearing. Does it disappear when you put the clutch down?

[Grizzly]

Yep, noise goes when the clutch is down.

Cheers for that guys, didn\'t want to go swapping boxes etc and finding it was just the idle was too low or some thing daft like that (not that it is)

[SiH]

Yeah, sounds like the input/layshaft. My old S14a did exactly the same PITA, but was like it for 25k on that box! My FD is the same too, rumbles and whines. It\'ll die soon, but I\'ll cross that bridge when i come to it!

[Grizzly]

Can you tell if a box is bad when there out of the car? i am looking at a few second hand boxes but there all out and i would have to buy and fit to find out if there good or not??

[Sicknote]

Could also be the clutch release bearing.

[MaLicE]

Yeah, sounds like the input/layshaft. My old S14a did exactly the same PITA, but was like it for 25k on that box! My FD is the same too, rumbles and whines. It\'ll die soon, but I\'ll cross that bridge when i come to it!

gotta get the rex back on the road first lol, i think soon is a exageration lol

[Grizzly]

Could also be the clutch release bearing.

Isn\'t that the other way round though? would make the noise when the clutch is down? This is making a noise when the clutch is up.

[MaLicE]

isnt that on a push type clutch that would happen, seeing as rx7\'s are special needs and being a pull type isnt the bearing engaged when the clutch has no pressure on it?

[Grizzly]

But surly there wouldn\'t be load on the bearing when the clutch is not pushed down???wouldn\'t you expect the noise to get louder when there is load on the clutch?

[SiH]

Isn\'t that the other way round though? would make the noise when the clutch is down? This is making a noise when the clutch is up.

That was my understanding too - But Sicknote is a lot more knowledgeable than I

I understood it to be noise when clutch is up, even in neautral, but goes when clutch depressed = noisy when there\'s drive to box = input shaft issue.
Noise when clutch depressed, goes away when clutch released = clutch release bearing.

And Malice - yer ded :p