Can't engage reverse gear on Caterham 6-speed gearbox

[colinh2]

Hi,

Sometime during the winter I found I couldn't engage reverse gear. A bit later I managed it a few times, but since then it won't engage any more. I can't push the gearknob down to get to the left of first gear.

I've just checked the gearbox oil level and it was OK. All the other gears are OK, although to be honest, not as smooth as on the VWs, Audis, Porsches and BMW I've had...


Any ideas?

[V7SLR]

Firstly check your LH engine mount to make sure it is intact and bolted up properly, they can fail.

Secondly what gearbox oil are you using?

[DCL]

Remove the gear stick by undoing the the 3 bolts that hold it in, then clean and lubricate the spherical bearing. The gear stick slides through the bearing against a spring. It'll be that which is seized. It can be totally dismantlement but lubrication is probably all that is needed.

[downsman]

As quick fix you can run some oil down the gear lever and it might free the up and down movement of the steel shaft through the ball and allow you to select reverse. I used a small tube to do this and it worked well.

For a long term fix, buy a Rover SD1 steering rack gaiter, remove and clean the gear lever mechanism and fit the (cut down) gaiter over the lever and base with cable ties. It stops water pooling in the unit causing corrosion and if you have used grease it stops grit sticking to it.

[colinh2]

Hi all,

thanks for all the advice.

The engine mounts look OK :-) I don't know what gear oil is in there now—I bought it used from Caterham. I suppose they serviced it first, but that wouldn't necessarily have included a gearbox oil change, would it? I bought one litre of oil from Caterham, but that's not enough for a full oil change.

Anyway, yes, the gear stick and spring etc was all pretty rusty—so that'll be the problem.

I've WD-40'd and run some gear oil down the gearstick, but that hasn't quite done it. So I'd like to do the full removal/cleaning. But getting the tunnel cover off isn't as easy as I'd thought it would be.

I undid the fan/heater air vents (under the dash) and then removed the entire fan/heater assembly (in the engine bay) for good measure :-) But there's still the wiring loom preventing the tunnel cover sliding into the gap where the heater/radiator/vents used to be. At the other end there are the seats (which don't move, because they're rusted/seized too :-(

Any tips on removing the tunnel cover?

[DCL]

If you will slacken the handbrake adjuster to allow the handle to move as vertical as it can go, you should be able to slide the gaiter off. Then loosen or remove at least one seat and lift it up at the back and slide it out.

[Tango7]

To remove the tunnel cover normally I'd remove one or both seats. There might be a couple of self tappers at the very edge of the cover to hold it down too. Unscrew the little grub screw on the back of the 6speed gear knob. You will have to slacken the had brake cable right off by accessing the area above the diff and winding the two plastic nuts along the handbrake cable towards the rear of the car. this will allow the handbrake lever to stand nearly vertical and then you can remove the tunnel cover...

[colinh2]

Great! Thanks guys. And rapid response time too. This site is brilliant!

[downsman]

Last time, I was fed up with adjusting the handbrake cable, so I pulled it on as hard as I could and cut the stitching on the gaiter to get the tunnel cover off.
I fitted a couple of press studs to the gaiter that don't really notice as they are under the lever, so I now have a slightly quicker to remove cover.

Still needed to remove both seats though as Tillets are a very tight fit

[colinh2]

Well, I managed to undo the three bolts and remove the gear stick and the spherical bearing etc. I undid and cleaned the spring ok, but unfortunately the stick is completely seized within the sphere.

I used Liqui Moly Rust remover spray. Is there anything else I can try?

[downsman]

Give it a good soak with plusgas or WD40, then tap it with a mallet. If you can get to the corroded part of the shaft a little fine wet and dry should clean it up. Good luck

[colinh2]

I did the soaking and bashing with a mallet. No luck. I've ordered a new gearlever from Caterham...

Hmmm, just out of interest: when I removed the old gearlever the bottom part (everything "inside" the gear box) was covered in grease/slime. Not oil. Do I need to use any particular grease, or should I strip/clean the gearbox?

[DCL]

Yes, that bit is not open to the oil and is lubricated with a Moly type grease. Check it is still lubricated and, if need be, add a little more.

[colinh2]

Great. Thanks!