Occasional 5th gear selection problem

[ditechspain]

Over the winter break the 130 5 Speed box has developed an intermittent 5th gear selection problem. Sometimes it starts off not changing into 5th at all, but eventually starts to work fine for a period. Then the change becomes progressively more awkward. Then it won't go in at all for a period, usually a few miles during which the cabin air turns blue, before selecting again. It can repeat the sequence indefinitely without getting bored.

Sometimes it starts out working before refusing to cooperate.

It's almost as if something is gradually moving into, across and out of a tolerance range, before moving back into tolerance. Reverse selection has never been brilliant but isn't ever impossible. The other 4 gears behave fairly normally.

I've widened the console aperture to make sure it's not binding, and there is no sign of the console moving while changing gear. I replaced the fairly stiff top rubber gaiter with a leather one which lightened up the change considerably.

It used to lock in a gear occasionally and refuse to come out, but, touch wood, not for months.

Any suggestions as to simple solutions or a gearbox specialist somewhere near Southampton?

[gjz30075]

"...cabin air turns blue" ??? Does it have an odor?

[john.p.clegg]

Sounds like the synchromesh...The name Boulton rings a bell but not sure where he is located.

John

[ditechspain]

Would that be Graham Boulton, of Dereham in Norfolk? He seems to come up on a couple of sites as a guru to keep in the contacts page. I'm beginning to think we might be headed there if I can't solve it before the winter semi-layup. i get the impression he isn't e-mailable.

[mbell]

Can you expand on what happen when you try to select a 5th? Just won't go in? grating noise with clutch down, grating noise as you bring the clutch out?

Have you tried double de-clutching?

[ditechspain]

No noise, just simply won't go in.I don't think it gets anywhere actually engaging. The lever simply won't move forward the right amount.It never has, I think, gone in with that nice sense of latching into gear, it's always been, I think, as if it's just wedged in. But I had an Imp that did that for 100,000 miles from new so that shouldn't necessarily be a problem. We usually have four or five tries, including taking it up the rev range a bit because it may be a bit worse at lower revs. Then we give up, leave it for a few miles, and then it usually goes in. I've never driven another one, so I don't know if the total absence of any sense there is a gate you're moving the lever around is normal.

[ditechspain]

For anyone facing a similar problem in all or any of the gears, I think the problem has been solved, fingers crossed, relatively inexpensively.

I've replaced the gear lever with a newer one which Graham Boulton was kind enough to do his mod on. Not a Lotus one (rare and very expensive as far as I can make out), but an RWD Escort/Capri 4 speed one which is much cheaper and more widely available on ebay and is what Lotus sourced in the first place. I think they're from 1600cc or less and 2 litres may have used a different box. Make sure it curves back, otherwise it will probably foul the dash and will certainly trap your fingers in 1st, 3rd and 5th.

The rubber spring was not in good nick on the original but the real problem appears to have been the black nylon bush that the lever pivots on. This should basically not allow the lever any side to side movement. In our case there was at lest a 1/4" of space between the bush and the lever and a fair amount between the bush and the cup it moved in. It was so degraded I thought it was sponge rubber rather than shiny hard black nylon/plastic. Another layer of plastic/nylon bearing was missing entirely.

As far as I can make out, the effect of all this free play/lost movement was that the movement at the top of the lever wasn't mirrored at the bottom so the selector wasn't always being moved enough to select 5th or reverse effectively. It also meant changes to the other gears were hideously imprecise.

it doesn't feel like the same gearbox now. It feels like a proper one.

My thanks to Graham Boulton for the mod to the lever and for his advice and John Clegg for his advice, pictures and explanation of how the selector mechanism works, I pestered both as I was too embarrassed to reveal my total lack of knowledge to just one person. They both agreed fortunately.