Hi All,
I have a Type 9 gearbox bolted behind a 2ltr Zetec in my Fury, and mostly it works very well. There are a couple of problems though...
1. There is a loud rattle that occurs when the throttle is closed and the engine rpm is dropping down between 4000 & 3500 rpm. i.e Lift off
throttle at 5500, and the rattle starts when it has dropped to 4000 and stops once it gets below 3500.
2. The second problem is that if I am traveling at speed >65 mph and I dip the clutch I get a similar but much quieter rattle from the gearbox as
the revs drop.
I am supposed to be taking the car abroad at the end of this week and am slightly concerned that the gearbox is about to expire. Any suggestions as to
what the problem might be?
Cheers
Jonathan
[Edited on 15/7/07 by brycheiniog]
does the rattle hapen if u put ur foot on the clutch and rev the engine? it does sound like a clutch relese bearing to me!
That's the thought that went through my mind - but it still means an engine-out job - not a good thing when you're off in 1 week!
(1) Something is hitting the chassis or tunnel somewhere -- when viewed from the front the engine trys to rotate clockwise under overrun/engine
braking conditions.
First suspect would be the speedo cable.
(2) Is more difficult to diagnose but is highly unlikely to be the clutch release bearing, clutch release bearing problems tend to be heard when the
car is stationary and clutch is slightly pressed.
Look for one first
PS dipping the clutch at 60+ mph is'nt a good idea except when changing gear as I have known clutch driven plates to fly apart under these
conditions.
Sounds like release bearing, had it happen on my old XR4x4 with type 9 in it.
1 week, that's ages, its a two evening job on your own or one evening with two of you.
Britishtrident, driven plate breaking up at 60 mph, must have been one hell of a 5hit clutch, what about changing gear at 140mph if 60 mph is too much
for a clutch dip!!!!!!!!!
I would have thought that the speed of the car has nothing to do with a clutch plate breaking up and more to do with engine rpm. I have had one go when I missed a gearchange, and that was an AP jobbie.
My 'diagnosis' is based on the theory of 'try the easy bits first'! The clutch release bearing is something that can fail,
causing unexpected noise. It can also cause noise when it's loose on its support.
Saying that, following on from britishtrident's comments, I would also look closely at engine and gearbox mounts. If one or more of those start
to go, you can get unexpected buzzes, rattles and knocks when you go on and off power.
DJ
Thanks for the suggestions all. It should be fairly easy to remove the speedo cable so I shall try that first.
The CRB is only 1500 miles old, so I would be surprised if it was that. What I noticed today was that if I knock it into neutral at 70 I also get the
strange rattle as the revs drop down to idle. Make of that what you will 
.
Cheers
Jonathan
Ok a bit more investigation today.
I took a friend for a ride to see what he made of the noise and it almost totally stopped occurring whilst he was in the car. Once he got out it
started happening again..
The few times the noise happened when he was in the car was when we went over big bumps in the road.. This all fitted quite nicely with the
"something rubbing" theory. However when I put it up on stands there does not appear to have been any untoward contact between the drive
train and the chassis 
.
I was wondering if the diff or prop could be to blame, but the diff was rebuilt 2500 miles ago and runs very quietly, and the prop is not much older
and does not seem to have any play in the UJs.
Jonathan
quote:
Originally posted by gazza285
I would have thought that the speed of the car has nothing to do with a clutch plate breaking up and more to do with engine rpm. I have had one go when I missed a gearchange, and that was an AP jobbie.
quote:
Originally posted by brycheiniog
The few times the noise happened when he was in the car was when we went over big bumps in the road.. This all fitted quite nicely with the "something rubbing" theory. However when I put it up on stands there does not appear to have been any untoward contact between the drive train and the chassis
The gearbox mount looks ok, but one of the engine mounts has a small crack in it...
I think I am going to fix that then take it for a drive with the tunnel top off and see if I can see anything bad happening...
Jonathan