General Gear box noise

[blackmagic11]

Hi all.

Basically, the stilo 1.6 has started making a noise from the gearbox.
Surprisingly or not after the Mrs borrowed it to go leicester last Saturday. Sunday I went up to Rutland to see the vulcan flyby and noticed a ticking noise that increases and decreases with engine speed but only under load in all gears. If I'm cruising on mway, I.e. Not loading it to much, it's there but not bad.
The only way I can describe it is like the sound of a sewing machine.
I changed oil , checked and it did have alot of fine grains of magnetic metal, so not alloy or phosphur bronze from synchros. Im guessing a bearings failed somewhere inside and will want replacing.
Which other gearboxes will fit the 1.6 stilo? it helps broaden my search.
Any intellectual help appreciated so please dont say scrap it as I cant afford another car and why should I when everything else is OK.

Cheers

 

[alexGS]

First off, consider checking the driveshafts for free play/looseness - try to move the shaft up and down and rotate to check for free movement - compare one driveshaft against the other. If the inner joint (tripode universal) is worn, it can make a sound like you're describing. Outer CVs are a less likely but still possible cause. Driving in a tight right-turning circle makes a clicking/cracking/knocking noise if the left hand outer CV is worn out. And vice versa. Looking for a rubber boot that's been split for a while is another handy check but I guess you probably know this!

If it is the gearbox, then assuming the synchromesh and gear selection is satisfactory, my suggestion (hopefully an intelligent one) is to get the gearbox fixed - as in, have the bearing replaced. Once you've gone to the trouble of removing the gearbox, it doesn't take much more to drop it off to a specialist workshop and have them open it up, find the faulty bearing and replace it. No need to do all the bearings as they won't all be failing, though of course you would want them checked.

I think you'd need to act quickly on this because if bearings are loose for a while, gears will be damaged. Since you don't have a whining/grating noise yet, I reckon you'll get to it in time if you get onto it soon. The fine grain debris you describe is probably not from your bearing and is just typical gearbox wear of the synchros and gears.

It is possible to do the job yourself, and you shouldn't have to completely strip the gear sets, but there can be difficult tasks such as how to remove a bearing that's pressed hard against a gear, with no space to use a puller tool etc. It can be challenging first time around!

Sometimes FIAT use custom-sized bearings in their gearboxes, but an industrial supplier such as SKF can usually order the correct bearing even if it has to come from overseas. I rebuilt a 1988 Croma gearbox once and the input shaft bearing had to come from France. 19.5mm ID I think it was, something weird like that. Anyway, to get the bearing off the shaft, I carefully whacked the outer race with a sledgehammer to crack it - had to do the same to the inner race - then, to fit the new bearing, I left the shaft in the freezer for a few hours and heated the bearing gently in an oven. Then the bearing slides on easily without a giant press tool being needed. Unconventional but effective...

Finding a replacement gearbox from another car works out well when the gearbox you're replacing is completely trashed and the cars are fairly new. I suggest the '96-'01 Bravo/Brava 1.6 may have a similar gearbox - you'd need to check the gear linkage and whether you need a speedo sender or not (I expect the Stilo gets the speed from the ABS). But these cars are getting old now and there's a high chance you'd be taking on a similar problem - something you only find out after all the work removing and refitting the gearbox.

That's why I suggest fixing the particular fault with yours. Along the way, you'll probably find it a good idea to replace the clutch as well. It's worth it for a car you know and trust. I presume you haven't had/got the throttle/ECU problem to deal with - seems to plague all 1.6 Stilos that I've seen!

-Alex

 

[blackmagic11]

Changed gear box and noise is gone, now airbag fault...............