Just changed clutch on son's Fabia 2 1.4 16V, and tested while car still on stands so could engage gears. The gearbox was perfect before but clutch had worn down to rivets.

 

If clutch is disengaged the engine idles normally and no strange noises, if any gear engaged then there's a dreadful 'bag of spanners' noise from clutch/gearbox.

 

So dropped gearbox again to investigate. Getting good at this as only took about two hours to remove. What's very odd now is that the gearbox seems incapable of being in neutral. The selection shaft is in neutral (can move up or down), but if I turn output flange by hand the input shaft spins! There is no position where this doesn't happen, even if I engage the 'neutral lock' used for adjusting the shift mechanism.I can select gears as normal when I pop the selector arm on when the output and input shafts turn together as expected, but easier/harder depending on selected gear.

 

Before I removed gearbox, the wheels didn't turn with box in neutral and shafts attached.

 

I was going to take off the clutch assembly from engine thinking maybe I got something wrong there, but I'm now worried it's a gearbox fault but can't think of anything that happened when removing box originally and reinstalling it that could have  caused such a failure. I know it's impossible to know what's going on without taking gearbox apart but are there any gearbox gurus here who have an idea based on description? It's maddening as thought job was done! 

Edited 5 March, 20233 yr by Stratfordade

1 hour ago, Stratfordade said:

If clutch is disengaged the engine idles normally and no strange noises, if any gear engaged then there's a dreadful 'bag of spanners' noise from clutch/gearbox.

Did either or both  of the driveshafts & wheels turn when you did this?

 

Running the transmission with the wheels off the ground especially in higher gears at low revs will result in a lot of backlash noise.

Edited 5 March, 20233 yr by J.R.

One driveshaft on RHS was definitely turning when in gear. Must admit didn't look LHS as was so concerned by the racket! I'm surprised that it would be normal to have a noise like this (very loud irregular rattling) with wheels off ground but if so then I've just condemned myself to another gearbox install needlessly! 

Reset the gear linkage and all will be well.

22 minutes ago, sepulchrave said:

Reset the gear linkage and all will be well.

Do you mean adjusting the cable lengths using the index hole under gearstick? I did this after installing the gear box and after that the shift worked very precisely through all gears. Do you have another procedure in mind? Thanks for any advice.

Well the good news is that I didn't do anything wrong fitting the new clutch. The bad news is that the catastrophic noise wasn't a worn/disintegrated clutch, but the input shaft bearing eating itself! Did an autopsy this evening and found these fragments behind the fifth gear cover at rear of case, and a sludgy metallic mess at bottom of cover. I'd realised it was a bad gearbox when turning shaft after I got it back off car and hearing ball bearings rattling around! I've already found a good used gearbox to install instead — I don't have a press to install a new bearing and in any case would never be confident that all metal bits removed. The 'new' gearbox feels silky smooth by contrast.

Wow, that looks pretty catastrophic! Out of curiosity, how many miles did the gearbox that failed have on it?

 

106K so it’s beyond its service life. I completely disassembled the box yesterday and the input  bearing ball bearings are anything but ball-shaped! Rest of ‘box including diff is in lovely condition. For several thousand miles before complete failure there’s been a light rattling noise in neutral that stops when clutch disengaged. Now I know why.

Edited 12 March, 20233 yr by Stratfordade

4 hours ago, Stratfordade said:

106K so it’s beyond its service life. I completely disassembled the box yesterday and the input  bearing ball bearings are anything but ball-shaped! Rest of ‘box including diff is in lovely condition. For several thousand miles before complete failure there’s been a light rattling noise in neutral that stops when clutch disengaged. Now I know why.

That bearing really is the definition of knackered, think that bearing is often the one that lets go in these gearboxes. I'd better let my brother know to take it easy then, he has the same engine and gearbox as in his mk2 fabia and its now past 100k miles with a fair few being quite hard (fully loaded and/or towing a trailer). I changed the gearbox oil at 80k miles to try and prevent a premature failure but I don't think it helps the bearing you show has failed as its a sealed one. However from what I understand, bearing lifetimes can vary dramatically between supposedly identical units so I guess its a roll of the dice, could last another 50k for all I know.

 

 

 

 

Yes was fortunate to find replacement gearbox from Fabia BXW scrapped at 32K. Having taken it all apart last night I wouldn't fancy my chance of reassembling without error. If I didn't need car off my drive I could have also just given existing gearbox to transmission specialist to fix. As I said everything else looked in fine condition.

5 hours ago, Stratfordade said:

For several thousand miles before complete failure there’s been a light rattling noise in neutral that stops when clutch disengaged. Now I know why.

 

This is not meant to be confrontational but you should have mentioned that when you created the thread, you made it sound like the problem occurred after and as a result of the clutch change.

 

On 05/03/2023 at 18:44, Stratfordade said:

The gearbox was perfect before but clutch had worn down to rivets.

 

Its possible that the wobbly bearing was not particularly apparent in service before because the shaft was aligned and located within the crankshaft spigot bearing, on reassembly the drooping shaft would not have slid smoothly through the clutch splines and crank spigot bearing, tightening up the bolts may have pushed a displaced ball against the bearing carrier and broken it.

 

Did you encounter resistance when aligning and bolting up the bellhousing?

 

Did you check for smooth running on the input shaft when the gearbox was removed and also the crankshaft spigot bearing?

 

Once the cage has broken up on a roller bearing disintegration follows rapidly.

 

I'm pleased you were able to find the fault and replace the gearbox.

Edited 12 March, 20233 yr by J.R.

6 hours ago, J.R. said:

 

This is not meant to be confrontational but you should have mentioned that when you created the thread, you made it sound like the problem occurred after and as a result of the clutch change.

 

 

That’s a fair point. My son drove home complaining of clutch slip and it was slipping disastrously. I had put that rattle down in past  to clutch plate or gearbox but leapt to wrong conclusion about clutch as it was slipping so badly. Was very frustrated to have awful noise when engaging gear after replacing clutch and installing the ‘bad’ box - gearbox install no fun with FWD. when I first posted I thought I may have done something wrong - it was only later that I went into garage and realised on rotating gearbox that that was issue all along. Was so p***ed off after dropping gearbox again that I didn’t go in garage for a couple of days and discover it was nothing to do with clutch! My mistake, but if you don’t attempt DIY tasks you don’t learn! I’ve just installed the ‘new’ gearbox and well on way to buttoning the Fabia up.

Edited 12 March, 20233 yr by Stratfordade

I think we've been here before @J.R. but I don't think there is a bearing between crank and input shaft on the 02T.

6 hours ago, J.R. said:

Its possible that the wobbly bearing was not particularly apparent in service before because the shaft was aligned and located within the crankshaft spigot bearing, on reassembly the drooping shaft would not have slid smoothly through the clutch splines and crank spigot bearing, tightening up the bolts may have pushed a displaced ball against the bearing carrier and broken it.

 

Did you encounter resistance when aligning and bolting up the bellhousing?

 

Did you check for smooth running on the input shaft when the gearbox was removed and also the crankshaft spigot bearing?

 

Once the cage has broken up on a roller bearing disintegration follows rapidly.

 

I'm pleased you were able to find the fault and replace the gearbox.

No resistance bolting up bellhousing. My fault I didn’t check gearbox for smooth running when it was removed. Schoolboy error but was just blinkered about clutch problem. It’s always bitten a bit high so was aware it was worn. Seeing a shiny rivet on old clutch plate reinforced my wrong assumption about worn clutch.

No spigot bearing means the input shaft has bearings at each end which is good engineering practice, on reflection all modern FWD East West gearboxes are probably like that, my probably incorrect comment would be a hang up from RWD North South gearboxes, I have rebuilt probably 10 of them to every FWD one.

 

I can now see in my minds eye a short stub shaft ending at the splines, I need to keep my hand in because my memory is letting me down, it was only a year since I removed my transmission to change the DMF and clutch.

 

Strafordade.

 

Pretty much all I have learned  in life has been through mistakes, my Grandfather once said "the man who never made a mistake never made anything!" and I have taken that a little too much to heart!

 

Did I check my gearbox input shaft bearing and non existant spigot bearing when I removed my transmission last year? - I very much doubt it!

I am lucky to have a Wing Man in Pete to correct my J.R.'isms and to do it in such a polite manner, I am inspired to follow his example.