Sprint Clutch/Gearbox Grinding

[benbabik]

Hello everyone,

I'm having a progressively worsening problem with the Sprint whereby it doesn't go into reverse without crunching when hot. When I first got it, the overdrive wouldn't work, and all the changes were stiff but after a run about it all loosened up. Now it's tighter when it's hot. I've gotten so paranoid that when I when it's hot and I want reverse I'm stopping the engine to select it.

I drained the box and filled it again this evening, there weren't any bits to speak of in the oil, though it hasn't made a notable difference. There was some wear in the holes on the clutch pedal to cylinder push rod, and clevis pin, less than an inch at the end of the pedal, but having fitted a through bolt temporarily, that's been taken up. I've heard the rubber section of the hose may soften and expand when warm but I'm sceptical replacing it with copper will be enough to cure this. Fastenings at each cylinder have been checked and all looks ship shape.

One other thing I have noticed, but wasn't sure if this was normal, is that there is a definite whirr sound when depressing the clutch. The revs drop a little, but to the best of my scant knowledge that always happens, right?

[esxefi]

clutch could be dragging when pressed and not letting the layshaft stop/slow down.

how high is the biting point when slowly raising the pedal in a gear with engine running?

sometimes it works to quickly engage a forward gear while stationary before selecting reverse to stop the layshaft spinning.

[Toledo Man]

Another problem with the Sprint clutch is the cross shaft. You will need to get under the car and have a helper operate the clutch while you check it. This can break and repairing it means that the box has to come out. I'm not sure it can be done in situ even if you remove the tunnel.

It would be best to check the hydraulics first. It can be a pig of a job to get all the air out. The bleed nipple on the slave cylinder should be at the top. Also, a pressure or vacuum bleeding kit should get any air out. I always found the clutch hydraulics easier to work on with the tunnel off. You could fit a copper pipe but it will need a coil putting in to allow for some movement as copper pipes can fracture without the coil in it. My Dolomite 1300 had a copper pipe for the clutch and I had no problems with it. Another alternative would be to fit a braided hose.

[benbabik]

esxefi wrote:

clutch could be dragging when pressed and not letting the layshaft stop/slow down.

how high is the biting point when slowly raising the pedal in a gear with engine running?

sometimes it works to quickly engage a forward gear while stationary before selecting reverse to stop the layshaft spinning.

Thanks for that! I've been ferrying people to and from work night outs tonight and putting it to second and then reverse definitely takes the crunch out of it. The car is becoming a sod to get into first though. This has been particularly apparent this evening.

The biting point is low. That is, close to the floor. It won't shift out of gear without putting it down as far as it will go. Even then it's sometimes only coming out with a yank. The fluid level is fine and pumping it doesn't appear to make a difference.

I've chatted to Sam Clayton about it (we work at the same place) and one of the things we talked about was crankshaft end float. Can I replace it without an engine out in the sprint?

[esxefi]

just echoing Toledo mans' post.

I had the weld around the bell crank arm on the cross shaft shear(quite common) as it is only welded on one side from the factory and is not really strong enough,this can be checked from underneath the car. if the arm is hitting the bell housing then something is wrong.

I would think you would need a fair bit of crank end float for the clutch to be that bad.

[Toledo Man]

I doubt that it would be crankshaft endfloat. I know the OHV engines are bad for it but the slant 4 is a different beast.

Sort the hydraulics first and then check the cross shaft. The gearbox can be removed leaving the engine in situ if you take the tunnel out. It might be possible to remove the gearbox from underneath by lowering the rear end of the front subframe but I've never done it that way.

[benbabik]

Thanks guys.

I've got a braided clutch hose and slave cylinder on their way. I know I said already I wasn't losing fluid, but the seal/cover that sits on the end of the slave has largely disintegrated so I think a renewal is a reasonable idea.