Technical gearbox troubles

[Pugglt Auld Jock]

Some of the older VAG boxes used to slacken their crown wheel retaining rivets which then machined their way through the casing. So you thought all you had was a leaking 1st motion shaft seal and when you took the box out and cleaned it up you found the box was most likely scrap. A nasty shock and could be easily missed if it was only just starting to break through.

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If it is it's no repairable at a reasonable cost

I fitted a £60 1.2 fiat 500

 

[Pugglt Auld Jock]

I fitted a fiat 1.2 500 gearbox, around 52 mph at 2000 RPM in fifth, so not a million miles out

Owner got rid of the car after the gearbox became noisy, following a clutch change, payed £300 for a 2010

Input bearing cage had failed,, dropped it's ball bearings into the gearbox, took some teeth out before one existing through the differential

I paid £60 for the gearbox £40 for the clutch, the oil was annoying there's no cheap alternatives, just under £10 per litre and you need two bottles, fitted a new input bearing and seals at the same time

Comes to around £150 to fix in the end

Still a cheap car though.

 

[dagdromer]

Sourced a gearbox local to me for a reasonable price. Since the oil drain (and refill) it completely lost fifth gear you cant select it with or without the engine running. and in 1 to 4 it grinds like crazy so i think the box is beyond repair. I will take it apart just for pictures

Now I want to order a new clutch but there are loads of options in diameters. I see 180, 185, 190 and even 200mm. Last time I did a panda I bought a blueprint 185mm. Anybody knows when which clutch was fitted? It needs to go on a 2004 1.2 no ac.

 

[jrkitching]

Sourced a gearbox local to me for a reasonable price.

Good news - I think that's the easiest way forward.

I've done the same thing myself on an old Nissan Micra which would otherwise have been scrapped. I was given the car, and the replacement 'box cost me £50. The 'box looked scruffy but worked just fine.

Another £10 for a set of pads (they were down to the metal), and I had a decent car which then sailed through its MOT.

 

[koalar]

Sourced a gearbox local to me for a reasonable price. Since the oil drain (and refill) it completely lost fifth gear you cant select it with or without the engine running. and in 1 to 4 it grinds like crazy so i think the box is beyond repair. I will take it apart just for pictures

Now I want to order a new clutch but there are loads of options in diameters. I see 180, 185, 190 and even 200mm. Last time I did a panda I bought a blueprint 185mm. Anybody knows when which clutch was fitted? It needs to go on a 2004 1.2 no ac.

2004 1.2 base models 2WD 180mm

 

[koalar]

If you spend some time stripping the old gearbox down you will recoup some of the cost

Aluminium case
Brass syncro rings
Steel gear


Not easy some of the bits are very tight unless you have a press

I kept the shafts and put them on a bonfire to aneal them, and use the for making tooling on my lathe

Not sure how much I got back as I lumped it in with some other bits

 

[Pugglt Auld Jock]

If you spend some time stripping the old gearbox down you will recoup some of the cost

Aluminium case
Brass syncro rings
Steel gear


Not easy some of the bits are very tight unless you have a press

I kept the shafts and put them on a bonfire to aneal them, and use the for making tooling on my lathe

Not sure how much I got back as I lumped it in with some other bits

I collect all my old metal bits and pieces and sort into type - Ally, copper, steel, etc and once a year (it'll not be so often now I'm old and decrepit) and take it to the scrappie. Surprising sometimes what it fetches. Worth inquiring about prices before you go though as it jumps up and down by quite a bit sometimes. I'm often sorely tempted to challenge people I see at the council recycling simply giving away this "valuable" stuff.

 

[dagdromer]

I'm waiting on the new clutch to arrive but the old gearbox is out. I drained the oil again and while it only drove for like 5 mile it was filled with metal flakes and again a chunk of gear.

When you spin the input shaft without an gear selected the gearbox spins without any problems. When you select 3th or 4th you can turn the shaft but it binds up. If you put force on it you can push it over the hard spot but it does not feel good.

 

[Pugglt Auld Jock]

I'm waiting on the new clutch to arrive but the old gearbox is out. I drained the oil again and while it only drove for like 5 mile it was filled with metal flakes and again a chunk of gear.

When you spin the input shaft without an gear selected the gearbox spins without any problems. When you select 3th or 4th you can turn the shaft but it binds up. If you put force on it you can push it over the hard spot but it does not feel good.

Not worth the effort of a strip down unless just for your own interest. With all the metal chips/filings almost certainly now dispersed into every nook and cranny of the gearbox and the very obvious damage to at least one of the gear sets you'd have a difficult and major clean up job to be sure every last bit of "glitter" was removed and then source and buy the gears and a complete gearbox over haul kit, maybe even a synchro or two as well? Leave behind just one wee bit if metal debris and you risk undoing all your work.

I was faced with the same situation when our Ibiza lunched it's final drive. We were away on holiday at the other end of the country at the time but luckily, as we were at my wife's sister, I knew the local SEAT garage. They drained the oil for me and it was full of "glitter". Their opinion was the same as mine - not worth trying to rebuild. I think, from the noise it was making, that it had run a crownwheel bearing and that started about 150 miles back up the motorway, but the cost of the strip down - not enough clearance to drop the final drive casing on it's own so the box had to come out anyway - only to perhaps find other damage as well, and the fact we needed to be able to drive home at the end of the holiday a week later, made a new box a "no brainer". VAG gave us 30% off the price of the factory replacement box - couldn't find a rebuilt box anywhere - and the garage matched it with the same discount on labour. The bill was still pretty steep but, on a six year old car, I thought they were being pretty good about it.

 

[DaveMcT]

500 has a tall 5th gear which over works the engine on the slightest hill. Use if it’s all you can get but I wouldn’t want one.

 

[Pugglt Auld Jock]

500 has a tall 5th gear which over works the engine on the slightest hill. Use if it’s all you can get but I wouldn’t want one.

Becky's fifth is pretty high (2010 1.2 eco dynamic) as she's very much a town car we almost never use it and, on the infrequent occasion we do vernture out onto the country roads, it's quite stiff to engage. Goes in fine, just stiff to select due to lack of use I guess?

She won't climb the long hill on the A68 where it leaves the A702 ring road and climbs steadily for over a mile heading south towards Pathhead in 5th gear - mind you the new Scala isn't too keen either. It will go up it in 6th but the throttle is pretty much to the floor to accomplish it. with this being a small turboe'd engine I prefer to leave her in 5th where, although the revs are higher, the engine is less heavily loaded. I notice the oil temp rises less ascending the hill in 5th than if you flog it in 6th, I would guess this is due to heat transfer from the turbo working in 6th with the throttle on the floor.

While we're on the general subject of gearboxes. I was thinking about the advice I was given by our instructor all those years ago in college. Which was - as long as conditions allow and engine revs permit (ie don't slog it at very low revs) it's "kindest" to the gearbox to drive in top gear when possible - advice I've followed most of my life and benefited from seldom having gearbox problems. Of course we questioned him in detail about this statement and it all made sense back then but maybe not so much now? His contention was that, thinking about your average RWD gearbox - thinking stuff like Ford (maybe Anglia or Cortina) BMC (A30/35, Oxford/Cambridge/MGB/and many more even the Mini/1100/etc) and many others - the gearbox transferred drive from the 1st motion (input) shaft into the Layshaft and then back up into the main (output) shaft. the 1st motion shaft took drive from the clutch and was in line with the main shaft, most had a small needle roller bearing into which the spigot on the main shaft was located. So, the 1st motion shaft and main shaft ran in line. When first, second or third gear was selected (talking 4 speed boxes back in those days), the drive forces were being transmitted from the 1st motion shaft into the layshaft and back into whichever gear was selected on the main shaft. The resultant forces, apart from causing the shafts to rotate of course, were also trying to force the layshaft and main shafts away from each other. This was further problematic because the 1st motion and main shafts were not one solid shaft, being split where the main shaft and !st motion shaft were joined with that wee needle bearing, so the centreline from front to rear of the box would be trying to assume a "banana" shape and the needle bearing was the weak point. Surprisingly perhaps, it was usually the layshft bearings which packed in first (it wasn't unusual to hear this on the boxes used behind the A series engines and also the small Fords, manifesting itself as a noisy first gear in particular) When you stripped them down it was often the actual solid central layshaft itself, not the bearing needles, which had failed (poor hardening/materials?) In top gear the 1st motion shaft and main shaft would be locked together by the synchro striker ring so, although the layshaft and 1st, 2nd and 3rd gears were still rotating no forces were being fed through them Hence his contention that you were best to drive around in top whenever acceptable to do so as the drive forces were being transmitted in a straight line through the 1st motion shaft into the main shaft and on out to the prop shaft. Made a lot of sense to me. I suspect though that modern manual 2 shaft gearboxes don't have any of these problems as both shafts are now solid with much more substantial bearings so don't suffer the problems I've mentioned above? If true, then it doesn't make any difference to the box and it's bearings whichever gear you select.

 

[koalar]

500 has a tall 5th gear which over works the engine on the slightest hill. Use if it’s all you can get but I wouldn’t want one.

???????

There the same box with the same ratios

It's what I fitted to mine

With the same engine, same weight ISH car, same rolling radius

Panda eco is slightly different

 

[dagdromer]

I took the bad gearbox apart and I can only say that an replacement box was the right decision. It seems that the bearing on the input shaft shat itself causing a lot of play on the shaft which resulted into severe rubbing on the casing and finally stripping the gears. There was material everywhere. Even the roller bearings on the diff felt like there was fine sand on them.

 

[Pugglt Auld Jock]

I took the bad gearbox apart and I can only say that an replacement box was the right decision. It seems that the bearing on the input shaft shat itself causing a lot of play on the shaft which resulted into severe rubbing on the casing and finally stripping the gears. There was material everywhere. Even the roller bearings on the diff felt like there was fine sand on them.

Salutory lesson to one and all. If your gearbox gets noisy do something about it NOW. by the time things start breaking up it'll be too late. You may renew just the faulty bearing and think all is good only to have it all come back to bite you later once the wee bits and pieces have been circulating round the box for a while.