13 replies to this topic

[somecrapname]

So I just broke down about an hour ago and got towed home, and I believe I may need a new/recon gearbox. Can anyone suggest the cause (and solution?) here:

Engine runs fine (carb'd 1380cc, recently tuned on a rolling road. Thanks Rob!), but I can't select any gears. If I put the stick to 2nd and turn over the ignition/starter there is no "jerk" (for want of a better word) so I assume there is no longer a connection between the block and the box.

When the engine is running and in gear there is a grinding noise coming from the engine/box as I let the clutch out, but no movement.

I don't have time until the weekend to pull the engine so I can't physically see the problem, but if anyone can suggest what to look for at least I'll have a head start come Friday.

I assume the simplest solution is to swap the entire box, and I have an old 998 in the shed, assuming both engines are a similar age is there any difference between a 998cc gearbox and that from a 1275 (which is what I think the engine was to start with). Or would I be better off getting a recon? Any suggestions who/where from in the Lancashire area?

(I'm searching atm but without any keywords other than gearbox is ****** I'm a bit lost)

Thanks!

Edited by somecrapname, 23 October 2012 - 11:17 AM.

[Cooperman]

It's difficult to diagnose a complete loss of drive without seeing and inspecting the car.
It could be any of the following, plus possibly something I've missed:

Clutch centre plate sheared around the friction pad area
Failure of transfer gear or gearbox input gear
Broken gear selector part(s)
Sheared diff pin
Broken planet wheel
Snapped drive shaft
Broken CV joint

One of the problems with modified engines is that they do put additional load on the gearbox and when fitting an up-rated engine it is essential to overhaul the gearbox. With a 1380 engine a X-pin diff is best.

[Ethel]

Is it all gears, particularly including 4th?

Jack it up and turn the roadwheels, does the opposite wheels rotate in the opposite direction?

[somecrapname]

Cooperman - that list just made me put my head in my hands, but thanks for the info! Hopefully I'll get a better idea of what's gone wrong when I get a look inside, I'm assuming things like broken planet wheel/sheared diff pin are obvious to see? I don't have much (any) experience with this so I'm just taking it off and handing it to someone, but it's nice to know what they might charge for.

Is it all gears, particularly including 4th?

Jack it up and turn the roadwheels, does the opposite wheels rotate in the opposite direction?

all gears inc. reverse.

I'll try spinning the wheels next time I'm with the car.

Edited by somecrapname, 23 October 2012 - 11:42 AM.

[The Principal]

what happened prior to breaking down? was there a bang or worrying noise, wonder if the idler bearing has failed and your drop gears have moved?

[Cooperman]

what happened prior to breaking down? was there a bang or worrying noise, wonder if the idler bearing has failed and your drop gears have moved?

That is on my list above. I call it the transfer gear.

[The Principal]

what happened prior to breaking down? was there a bang or worrying noise, wonder if the idler bearing has failed and your drop gears have moved?

That is on my list above. I call it the transfer gear.

in that case snap - I knackered a standard 998 idler bearing years ago through abuse lots of aluminum swarf from memory

[Cooperman]

I had one go in a rally 'S', but I drove it 30 miles and it was very noisy. Then I fitted straight cut transfer gears - big mistake!

[Tahiti Joe]

I had one go in a rally 'S', but I drove it 30 miles and it was very noisy. Then I fitted straight cut transfer gears - big mistake!

Bet that made it much quieter....

[Cooperman]

I had one go in a rally 'S', but I drove it 30 miles and it was very noisy. Then I fitted straight cut transfer gears - big mistake!

Bet that made it much quieter....

[somecrapname]

what happened prior to breaking down? was there a bang or worrying noise, wonder if the idler bearing has failed and your drop gears have moved?

That is on my list above. I call it the transfer gear.

No unusual noise really, I'd been cruisng on the motorway and luckily just came off a junction when I lost all power. The only noise was the grinding/rubbing (not loud) that came when I let the clutch out.

Check both driveshafts are located properly, pushed in to the diff casing all the way.......

I've managed to get some time and was taking things apart when (I'm quite mad about this) the castle nut was OFF the end of the shaft, when I removed the wheel the nut and retaining ring(?) fell out - there was no split pin! I'm going to be having words with the garage where I took it for MOT as they had to do some work before it passed.

I have just refit the nut (and as a guess the shaft wasn't in place) and shaft and see what happens, unfortunatly I have already drained the oil, water, removed the rad and carb and other bits and bobs. Kicking myself for not starting at the wheels.

I have just refit the castle nut, the shaft was too far to the 'inside' (no thread protruding). When moving a wheel the opposite side also rotates in the opposite direction, this also happened when the nut was off. The pistons don't move when the wheels are rotating.

Edited by somecrapname, 24 October 2012 - 02:24 PM.

[Yoda]

Before you refit the nut, pop the drive shaft out and check the splines in the hub, its quite likely that they have stripped and you will need to replace it. dont just fit a nut and hope for the best!

[somecrapname]

Before you refit the nut, pop the drive shaft out and check the splines in the hub, its quite likely that they have stripped and you will need to replace it. dont just fit a nut and hope for the best!

good call!

[Cooperman]

Well, at least you know what the problem is and how to resolve it.