I am trying to narrow down what could be up with my Punto gearbox before I go spending any money on any bearings.
Its a 1997 Mk1 5 speed manual. Its done 140k. It was secondhand to replaced my old box that had lost reverse gear so we swapped them and fitted a new clutch kit.

The symptoms of the 2nd hand gearbox are as follows;-

Whines in all the gears under part or full throttle (cruising/accelerating)
The noise stops as soon as you back off the throttle.

No clutch problems. No release bearing noises. No selection problems. No jumpoing out of any gears. It works fine but its just the noise that is irritating especially on a long motorway run (keep any suggestions of turning up the radio to yourself, please). Fresh oil in there.

My view is that the differential is fine - if the car continued to whine when in gear but off the gas, this would point to diff bearings - is that correct?

That said should I just have all the bearings replaced including the diff?

Just wondering also what peoples experiences are of gearboxes after a rebuild - are they ever right again - can you realistically refurb a gearbox to give a nice quiet drive?

Another box time
I'd suggest you find a recon box

Why?
I've had loads of 2nd mk2 boxes on the mk2, and always they've had problems....

Ziggy

I agree with Ziggy, you'll rip your hair out trying to do it at home so much better to get a recon with a warranty.

Chances are it is the diff. Box is old, and has probably been run on low oil at some point.

Never done it, but it may be possible to fit the diff from the old box.

Otherwise, recon, or get your box rebuilt.

Unfortunately the gearboxes are not well documented -- all there is seems to be in Polish!

it looks possible to change a diff in situ on the mk2
obviously driveshafts out
oh dear that bearing went ping though

only problem with recon gearboxes as mentioned by joni and his panda are that most of em have a wash and brush up and hope they dont come back
any old established proper gearbox reconner would strip your box down and advise you,they are about ask in the trade for a recommendation as we all have our favourites

Yeah, ditto ask your local garage who they use, they will only use a bad one once!

sounds like diff

didnt want to slap in another unknown box or a so called "recon" not at £500+ on a 17 years old Punto so ive taken a cheap spare box with the internals from my original box to DMD Transmissions in Bilston near Wolverhampton. i got their name after thinking of buying one of their repair kits on ebay and noticed they also do rebuilds and thats all they do apparently.

ive said my old box whined and to make me up a sound gearbox from the parts handed over with a full compliment of new bearing and seals.

Like you say you only use a bad place once and so I will report back shortly.
dropped the box off on Tuesday and it may be ready to collect tomorrow or Monday.

obviously their name will be mud if its a bad job. i will be back !

Collected the rebuilt box last Friday.

It is being fitted tomorrow so will post the results tomorrow night or Thursday.
It should be handy for people to know if a remaufacturer is good or bad and if the box proves to be good I will recommend them to anybody looking for a repair in the West Midlands.

I paid £225 plus VAT for the box to be stripped rebuilt using new bearings and seals reassembled and given a quick black paint blow over. Comes with 12 months warranty although I dont know if its worth anything.......

Rebuilt gearbox fitted yesterday - not taken it on a run but Ive still got a whine. its not terrible but its there - better than the last gearbox although I havent been on a fast road or motorway to listen to it cruising. If I can do a steady 80 or so and not have the box whining away then I will be happy to run it to the ground.

I'm disappointed but not going to table any accusations at the place that did the rebuild. I just have to assume they renewed all the bearings. I reckon it must be wear in the actual gears so that when they are meshed there is some slack that only a full on gears and all rebuild would ever solve and thats £500-600+ territory so Id be daft spending that sort of money.
The new box will stay on now until the Spring at least. Ive got another spare box but as with the last two boxes I dont know the history or wear rates or mileages etc. Still I think on a car of this age its probably best now to just take punts of secondhand boxes as they come up sale, then try them and see if they are quieter. Knowing my luck I will find a really quiet gearbox but has other issues such as crunching gears or worn syncros.

Just wondering if its worth trying a different spec of gearoil to help quieten it down? Any recommendations? Its got the standard synthetic 75w/90 in at the minute.

just run it as you say
i had one last week gave a bit of a whine dead on 60mph in top gear
sold it to a learner driver so that wont be in 5th for ages
result