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Whoops Think I have Just Blown Up My Gearbox

OK I have had the diff cover off and to be honest everything in the diff looks really good. All the gears are clean and crisp and I can't see any signs of damage. There was a fair bit of swarf on the diff magnets, which I think should be normal and one really tiny piece of metal that I couldn't identify as gear teeth or anything. So where do I go from here? Do I strip the rest of the gearbox looking for the problem? But what would affect drive in all gears? Do I just take a punt and get a new box. Or do I start looking elsewhere? Could it be the clutch? Why would it manifest itself in such a way? Answers on a self addressed postcard please to confused in Stamford. One final thought could it be the torque tube at the clutch end? Are the splines stripped on the tube or the clutch plate? Has this ever been known to happen?
 
It affects the car regardless of gear selected so it definitely could be the clutch or the torque tube. The one thing it doesn't sound like is the gearbox itself (and the diff now eliminated).
 
I agree with what you are saying about the torque tube. It is just so much work just to check it!! Probably the easiest part of the job is removing the transaxle. I just can't think of any other part of the gearbox that would affect all gears apart from the diff or the final drives.
 
I'd still be looking at the clutch, affects drive in all gears.
(I assume the propshaft/gearbox input connector was ok)
 
The plot thickens! No worries about the help, came away with a belly full of lasagne so I was well chuffed! [:D]
 
ORIGINAL: robwright
So where do I go from here? Do I strip the rest of the gearbox looking for the problem? Do I just take a punt and get a new box. Or do I start looking elsewhere? Could it be the clutch?
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If you had jacked the drive wheel and done the checks I suggested before ploughing in and removing the diff you might have had an answer . Now your only option is to strip everything because you cannot manualy rotate the entire transmission anymore.
Suggest you start by checking the rear wheel bearings and cv joints and work your way along the transmission to the clutch so you can eliminate everything.You might be best off puting the diff back in to aid checking the rest as suggested.
good luck[;)]
 
ORIGINAL: peanut

If you had jacked the drive wheel and done the checks I suggested before ploughing in and removing the diff you might have had an answer . Now your only option is to strip everything because you cannot manualy rotate the entire transmission anymore.
Suggest you start by checking the rear wheel bearings and cv joints and work your way along the transmission to the clutch so you can eliminate everything.You might be best off puting the diff back in to aid checking the rest as suggested.
good luck[;)]
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Peanut of course I rotated the drive train whilst the car was on jacks mate.  It would have been foolish not to.  But as stated in the OP the problem only manifested at over 2000 RPM.  With all the best will in the world though there is no way I could rotate it with enough speed or enough load to recreate the fault.  I am just looking at every option I can before stripping further.  If it were to be clutch or torque tube related then the transaxle has to come out anyway. And yes my next step is to pull the driveshafts off completely and service all of the CV joints.  It would be silly not to whilst I am at it anyway [:)]
 

Hmmm,

Is the car still on the original clutch Rob?

I think the factory items had a large rubber doughnut damper(instead of the more conventional springs). These have been known to perish and break up. Perhaps they have some kind of fail-safe 'get you home' dog drive arangement and that is the noise you are hearing under load...
 
Jonny the answer to that one would be I simply don't know. There is no evidence in what history I have of the clutch being changed but that is not to say that it hasn't been. The car was 138k up when I got it and is now at 161k. I think the transaxle has been off before at some point so maybe it has. If it is still the original clutch then it is or maybe was doing extremely well for the mileage. I am almost 90% confident the transaxle is OK so now I have to methodically work backwards staring with a complete tear down of the driveshafts and all the CV joints. The only place to go after that is to drop the torque tube off the clutch and if I haven't found it by then the process of elimination tells me that there msut be a problem somewhere else on the gearbox. Now the only thing I can think that it could be if that were the case would be the input shaft.
 
Rob

as you know i have two ramps, loads of spare torque tubes, three very good clutches etc so if you need help i am only down the road.

ps i have a dolly that you can use to transport the car if need be.

Elliot
 
ot thanks for the offer mate. You are a star. I am going to do a few more investigations during the week and see where I can go from there. If the clutch has to come out I may well just take you up on that offer though [:)] Not so sure about the torque tube but the turbo definitely has a different clutch to standard 944 if I am not mistaken though?
 
ORIGINAL: robwright



Peanut of course I rotated the drive train whilst the car was on jacks mate. It would have been foolish not to. But as stated in the OP the problem only manifested at over 2000 RPM.
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sorry I thought that you said you had to abandon the car because it lost all drive ?


If the drive is completly lost in all gears there is a very limited number of things it could be.

As Johny says it is highly likely to be the clutch centre breaking up if you have one of the rubber do-nut types.( However you would probably had had some warning of this beforehand)

You would have been able to check the clutch when the diff was in but you can't now ! your only option now is to either pull everything to pieces hoping you find the fault sooner than later or.. put the diff back and do the tests I suggested to pinpoint or eliminate the clutch. From what you've said my first checks would be the cv's and the clutch

I wish you luck . I know how frustrating these things can be but sounds like you have plenty of get-up-and-go .
Mine got-up-and-went a long ago lol
 
ORIGINAL: barks944

I don't think the turbo's had the donut rubber centred clutch, at least mine didn't anyway....
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I seem to remember reading the same somewhere else too.

I think Rob would have had quite a bit of warning first if it was the rubber centred clutch. Mine see-sawed like a drunk kangeroo for months before it finally failed due to the extreme lash in the transmission but there were no graunchy noises at all.

My money is on the drive cv . I think that would fail before the first motion shaft ,axle spline or torque tube .
 
( However you would probably had had some warning of this beforehand)
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I don't think the turbo's had the donut rubber centred clutch, at least mine didn't anyway....
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All very fair points.

Discreetly slides his chips over to the square marked 'mullered CV joint' .... [&o]
 
Starting to think that too..................

At least you can tidy up in about the bits you have off if so! Every cloud!!

Stuart
 
Was thinking CV joint from the start, the LSD might have allowed some drive if onwe side failed - however expected you to find that when in the gearbox area, If its clutch, isn't there an inspection hole in the clutch area? worth having a nose in there for swarf / springs etc I would have thought.
Tony
 
I've had both clutches and CV joints let go in the past... (and diffs, and gearboxes thinking about it)... So... These are only my experiences, but might point to where I think the problem is...

CV joint - pulled away, went ZZZZzzzz... no drive, ball bearings on the floor.
Gear box, popping and banging, big hole in the back of the box, oil on the floor. So I tried to see if it would limp home as box was dead anyway! Trouble sellecting/loosing gears one by one (and then some came back) until there was only one gear left in the box (it got me home) that was in a 944, I had several gearboxes in another old car that let me down, and did pretty much the same thing.
Diff. Big bang, no drive, pool of oil - wasn't a 944.
Clutch. Noise lie you say, clutch went to the floor, coasted to the side of the road with no drive. lifted the clutch, and it seemed to work, with nasty vibration over a certain speed.

So... my money would be on the clutch - as Tony says, there is an inspection window... but... check all sides of it - mine looked fine on one side, but had broken up on the other (sounds bonkers I know). Sorry... thinking about it - you might not be able to see any of it, becase the clutch cover plate hides it... I'll just say my money (an old 1/2penny - cars will make a liar of you every time...) is on the clutch.
 
ORIGINAL: 944Turbo

If its clutch, isn't there an inspection hole in the clutch area? worth having a nose in there for swarf / springs etc I would have thought.
Tony
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Tony true there is an inspection window that should actually be fitted with a dust cover but never is. The best and only use I ever found for it was gauging clutch wear by the position of the slave cylinder piston. I had a look in there but couldn't see anything. In fact it's really hard to see anything on a turbo because of the crossover pipe heatshield being in the way. Drive shafts are off anyway and wrapped up safely in my boot ready to be stripped and cleaned at work tomorrow. Haven't had a great look at them but outwardly they both look OK.
 
At least it is not the diff Rob, your car will be in brilliant mechanical fettle when all sorted, is there nothing you havn't taken apart yet !

Fettle= Health, in Cumbrian [;)]
 
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