Gearbox project for next year maybe

[Jaba]

The gearbox on my GTi has an oil leak from the top gear selector shaft. This may be due to wear or o-ring failure. This car also has a very stiff clutch. Its always been that way despite a cable swap and lubing the cable and everything else.

What I want to do is fit a 16v TD type of clutch to it and fit a new seal in the selector. I have always found the TD clutch with the pull lever release much lighter and smoother. This involves installing a clutch release cross shaft. I have a good TD donor gearbox so it seems to me (at the moment) that all I have to do is remove the bell housings and swap them over and while doing this dismantle the selector forks and shafts to put good bits in the GTi box.

What I dont know is what happens when you unbolt and take off the bell housing. Do the gearbox internals just stay safely in place or does some sort of mayhem occur with springs, balls, shims, spacers and any other bits making their escape ?

Anyone done this and have any useful advice to offer please ?

[Kitch]

Would it be easier to fit a complete 16v gearbox with a TD 5th gear cog? Spirited sprinting ratios with a relaxed cruising gear!

[Jaba]

Would it be easier to fit a complete 16v gearbox with a TD 5th gear cog? Spirited sprinting ratios with a relaxed cruising gear!

Possibly Rich but I dont have a 16v box and have 2 TD boxes. I did the 5th gear mod 10 or 12 years ago, the 8v box needs a 5th gear from a 19 or 16 petrol not the TD. I have done this mod on every petrol injection car that I have owned. So I already enjoy a nice quiet engine at motorway speeds, which is just as well as I spend a lot of time on them when I am away.

This is just a sort of dream of mine at the moment, the oil leak is not bad, I get a bit of a stink of hot exhaust burning oil on the alpine passes occasionally and the stiff clutch is still usable even by wife.

[Kevin B]

If your careful you should be able to relace the worn selector shaft seal without stripping the g/box, as it is possible to prise out the old seal as it has a raised flange (which it is possible to get a screwdriver blade behind), once free of the housing, just slide it of the selector shaft and over the ball end. Replace ment is just as easy, but be carful not to damage the lip seal or spring ring when sliding the new seal over the selector shaft.

Later BE3 gearboxes already have provision for the cross shaft clutch arrangement, just remove those two plastic blanking bungs that are already there. You will however also have to remove the steel ball which the clutch arm pivots on to make this modification work, because from memory it clashes with the cross shaft.

[mds141]

If you do change the clutch, make sure you get a Valeo one. Malcom Lockwood is your best bet.

[Kitch]

If you do change the clutch, make sure you get a Valeo one. Malcom Lockwood is your best bet.

To counter that I had a Valeo clutch fail on the 16v a few years ago and replaced it with an LUK one which I've had no issues with.

[Jaba]

If your careful you should be able to relace the worn selector shaft seal without stripping the g/box, as it is possible to prise out the old seal as it has a raised flange (which it is possible to get a screwdriver blade behind), once free of the housing, just slide it of the selector shaft and over the ball end. Replace ment is just as easy, but be carful not to damage the lip seal or spring ring when sliding the new seal over the selector shaft.

Later BE3 gearboxes already have provision for the cross shaft clutch arrangement, just remove those two plastic blanking bungs that are already there. You will however also have to remove the steel ball which the clutch arm pivots on to make this modification work, because from memory it clashes with the cross shaft.

Thanks Kevin, this is the joy of this forum. I am forever learning new stuff about the BX. I have never looked at the gearbox apart from playing with the 5th gear end and did not realise that the selector seal was so easy to get at. But are you sure that is the one I want to change - the one on the top of the box with a cranked lever pinned to it.I imagined that it has some sort of internal oring seal. The easier one you describe is on the other selector shaft as far as I can tell from the parts breakdown.
I did of course know that the cross shaft could be installed but it looks difficult/impossible to extract the securing pin for the actuating lever to reuse it in another box and I dont really want to start buying new parts when I have donor parts available. I will have a proper look when I have got the engine swap done on my Hurricane.

I went into Motor Parts Direct in Didcot the other day for a few bits. There was a new, friendly guy on the counter who told me he used to work in Newbury and spoke of a guy down there who was a BX collector who came in quite often.
Anyone you know ??

[Kevin B]

Thanks Kevin, this is the joy of this forum. I am forever learning new stuff about the BX. I have never looked at the gearbox apart from playing with the 5th gear end and did not realise that the selector seal was so easy to get at. But are you sure that is the one I want to change - the one on the top of the box with a cranked lever pinned to it.I imagined that it has some sort of internal oring seal. The easier one you describe is on the other selector shaft as far as I can tell from the parts breakdown.

There are two selector shafts on the BE3 gearbox. As I did not read your post in more detail, I assumed that you need to change the oil seal on the lower selector shaft, as it is the the more likely of the two too leak, as it is positioned lower than the other shaft.

The selector shaft on the top of the gearbox has a lever pinned to the shaft with a roll pin. It has an 'O ring' retained by a washer and spring positioned under this lever. Replacement of the 'O ring' will require you to partially strip the g/box. This is because when you want to reassemble the lever to the shaft, you have no way of holding the shaft in the correct position whilst you refit the lever and drive in the roll pin. As it will be pushed into the gearbox as you try and refit the lever.

IMHO the biggest weakness on these BE3 gearboxes is how the 5th gear cluster is attached to the lay and mainshafts, ie a fine pitch trapeziodal spline, which is prone to wear. This most noticible on the mainshaft spline, and seems to effect the TD, Gti, and 16v models (possibly due to the higher torque produced by the engine).

I did of course know that the cross shaft could be installed but it looks difficult/impossible to extract the securing pin for the actuating lever to reuse it in another box and I dont really want to start buying new parts when I have donor parts available. I will have a proper look when I have got the engine swap done on my Hurricane.

The ball (which the clutch arm pivots on) is held into the Aluminium via a straight cut knurl on the steel shaft of the ball, some time ago I made a tool which enabled me to lever the ball out of the housing.

I went into Motor Parts Direct in Didcot the other day for a few bits. There was a new, friendly guy on the counter who told me he used to work in Newbury and spoke of a guy down there who was a BX collector who came in quite often.
Anyone you know ??

Aye that would be me, and the friendly guy is Jason Calder, it was a shame he moved on as he is very knowledgable chap. I used to get a good deal from him on parts, please give him my regards when you see him next.