CRUNCHY REVERSE

[50nny 0]

Hello, guys. I'm new to LEF. I have a 2001 Esprit V8 which has a crunchy reverse as soon as the engine reaches normal temp. Can anyone share an advice or two to remedy this symptom?

[DanR 61]

Whatever you do don't force and bang it into reverse. That crunch is the cross shaft finger picking both the reverse and second rods at the same time. Crunching it is a good way to ruin second.

Have it, as well as your hydraulics, inspected and adjusted by somebody experienced with the mechanism, master/slave/line and their foibles.

===========================

I'm thinking of doing an internal modification to my cross shaft and selector rods. If successful I'll let you know. If not....

Edited October 22, 2008 by DanR

[rogerch 63 3 Vehicles]

My money is on a marginally dragging clutch, so like Dan says, have it checked. You mention when hot, so, I'm not sure what type of hydraulic hose you have, the early ones had plastic which expanded under heat, causing a dragging clutch. Most people have gone to braided hose, which fixed the problem. It may be just a simple adjustment.

Roger

[lotus4s 24 1 Vehicles]

The V8's all had braided clutch lines.

Usually when the UN1 gearbox grinds into reverse it's because the clutch isn't fully disengaging the input shaft and there is no synchro on reverse. As Dan said, check the hydraulics. Does it help if you shift to first gear and then try to go to reverse?

[dave excell 51]

I have that problem on my V8. Having fitted a new clutch, I found it dragged from the start. On strip down it was found that the outer diameter of the friction plates were just picking up on the inner stainless tags on the cage. Removing a small amount from the outer edge of the friction plates cured this for about 5000 miles, perfect. However now I am getting the same symptoms when hot but its OK when cold. I have yet to get round to striping it again so if you get there first please let me know. It will be mid November before I get round to do my own.

Have fun

Dave Ex

[Iconic Ride 267]

Jim is "spot on" on this, Sonny. The selection of a forward gear, usually first, prior to selecting reverse has prevented "crunching" on nearly every vehicle I've ever owned. It's become a lifelong habit pattern for me. Not sure of the specific reason why, but it seems to "line things up" somehow. If this does not help, then (as mentioned above) adjustment of the linkages and/or a check of the hydraulics would seem to be in order.

Best of luck,

John

[73JPS 0 1 Vehicles]

I am also having the crunchy reverse problem, and I have not noted if it happens when the car is cold or not: I usually only have to select reverse in warm engine conditions. I will say that selecting first and then reverse does not help this problem at all on my car, although I do agree it has always seemed to do the trick on any other car I have driven.

Also, according to "Lotus Esprit: The Official Story", the V8 gearbox does feature a synchromesh for reverse.

[DanR 61]

I'm convinced the crunching is due to the cross shaft not being fully shifted to the correct position for the reverse selector rod. Consequently both the reverse and first/second selector rod are being moved simultaneously and with second being next to reverse one has to give. Might explain why so many seconds lose their dogs.

The case worsens when things are hot and expanded etc due to the fine tolerances on the translators, rod ends and all. Selecting first before reverse can give the mechanism a "little" nudge and work but in those cases where it doesn't the tolerances are out too far for the nudge.

I've felt the change in a Renault Alpine which is like the proverbial hot knife in butter. Perfect and yet they're the same box. The linkage is so much simpler and more direct in the Alpine. I've changed parts and got my change as smooth, precise and light as I think I can but still not as good as the Alpine. I think I can improve it but need to take the end housing off first.

For those with problems I'd suggest checking and adjusting the cables, translators and hydraulics. And change with sympatico, that is no speed shifts, shortened gearsticks, holding the side instead of the top of the knob in the palm of your hand, double de-clutch (at least on the upshift), etc.

Edited October 23, 2008 by DanR

[nodemgr 1]

I've felt the change in a Renault Alpine which is like the proverbial hot knife in butter. Perfect and yet they're the same box. The linkage is so much simpler and more direct in the Alpine. I've changed parts and got my change as smooth, precise and light as I think I can but still not as good as the Alpine. I think I can improve it but need to take the end housing off first.

For those with problems I'd suggest checking and adjusting the cables, translators and hydraulics. And change with sympatico, that is no speed shifts, shortened gearsticks, holding the side instead of the top of the knob in the palm of your hand, double de-clutch (at least on the upshift), etc.

Do you have a pic/drawing of the alpine gearchange?

What parts did you change in your gear change?

[westhamtim 7]

I have that problem on my V8. Having fitted a new clutch, I found it dragged from the start. On strip down it was found that the outer diameter of the friction plates were just picking up on the inner stainless tags on the cage. Removing a small amount from the outer edge of the friction plates cured this for about 5000 miles, perfect. However now I am getting the same symptoms when hot but its OK when cold. I have yet to get round to striping it again so if you get there first please let me know. It will be mid November before I get round to do my own.

Have fun

Dave Ex

I can vouch for this too! Tip given to me (by Gasketsgone) when I bought the car. Always do it now and not had any probs to date (fingers crossed).

[David T 0]

Hello all, I am a brand new list member. I have had my car (a '99) for about a year now. I had problems with shifting too. I replaced the clutch and it fixed most of them. Now it is just hard downshifting into 2nd and 1st. I think I can fix that by lubricating the shift cables, they are dragging. On another car I did it by disconnecting the transmission end, putting a short hose on with a clamp, filling the hose with oil and using pressurized air to force the oil in. Work the cables a little, adjust and reconnect. It is also VERY important to use the correct oil in the transmission and have the correct amount in it.

David T

[Che 7]

DANR---could be right.

I used to have problem similar to what you described. At that time, my 2nd gear is already bad (grinding).

I can shift to reverse when cold but can't when the engine is hot. I have to stop the engine to put in reverse. Very embarrassing!

I replaced the bad 2nd gear and the problem is gone!

[DanR 61]

Do you have a pic/drawing of the alpine gearchange?

What parts did you change in your gear change?

No haven't got any illustrations. The set up though is like the Porsche 911s, where the box is before the engine.

As for changes, I replaced the translator bearings, all rodends and made another adjuster link. It has both a right and left handed thread so I could more precisely adjust it without needing to remove that link from the translator each time. I also used a different method for adjusting the link which I mentioned on here previously.

[50nny 0]

Hello, everyone.

I would like to apologize for this very late response but I do very much appreciate all of your advice and suggestions. I still have the "crunchy reverse syndrome." It's been to a major Lotus dealer but can't rectify the problem. Since I brought it from sunny and warm Florida, USofA, I'm now inclined to think that the car is unaccustomed to the cold and damp weather in the UK. Hopefully, it will adapt.

Kind regards,

Sonny

[gmendoza 4 1 Vehicles]

Wow. Alot of worst-case senerios are being thrown in. Most, if not all, Esprits crunch if you go straight into reverse. If it does have a syncro, it doesn't do a good job. The way around this is to push the clutch in, select a forward gear (this stops everything), then select reverse, then ease off the clutch when you are ready to go on your merry way.

Now if it still grinds, THEN you have a dragging clutch.

[toyroom 5]

Sorry, I've been away for a bit. Gonzalo's right. If a gear is selected and the car is stationary, nothing behind the clutch pressure plate is moving so syncro or not, reverse should engage without a crunch. If you still get a crunch after engaging a different gear and then reverse with the car not moving at any stage, the only possibility of getting a crunch is if the input shaft is moving. If you still have your foot on the clutch, the problem is clutch drag. If the weather isn't too hot and the hydraulics check out, you probably have a plate sticking on the clutch cage (I've had this three times)

[Paul C 15 1 Vehicles]

Even the Elise crunches!

Unless...

Put in neutral, put in forward gear, put in neutral, select reverse.

I can do a 'non crunch' reverse every time if i follow this, but when i forget:

Crunch!

[DanR 61]

Not always clutch drag that causes a grating reverse selection. There's also the inertia/flywheel effect of the spinning mainshaft and clutch plate(s) whilst in neutral. Reverse selection can be ok when cold but as the oil heats up the viscosity drops so there's less drag to stop the spinning mainshaft while in neutral. That's where selecting first before reverse stops everything spinning and helps with a cleaner reverse selection.

[toyroom 5]

What I mean is that if you select first gear with clutch depressed and thenreverse crunches, the motion which causes the crunch must therefore be from the clutch failing to disengage fully. If the clutch is pressed and the car stopped and in any gear, nothing at all should be moving, Change to another gear with the clutch still pressed and still, nothing should be moving until the car moves or the clutch is released.

Let's face it guys, the clutch is crap and if there was a better one available (which there might be), I would have my GTO box back in like a shot !