Gearchange Issues dissected

[TBD]

Having gone through most of the different non-terminal issues with regard to the Evora gearchange mechanism it seems sensible to post a summary of my investigations and experiences. These results should be applicable to all pre-MY2012 non-IPS models. Fortunately most issues are actually not related to the transmission itself, so the repairs do not require removing the clamshell or similar.

The whole Evora shift mechanism is pretty much pre-historic. Using a cable mechanism is as such already a poor solution for a high priced sports car, but then using a transmission from a Toyota diesel to start with was already a poor decision. But then, reading the Esprit forums and the experiences with its Citroen gearbox, this seem to be Lotus tradition. Why couldn't they have chosen a ZF-gearbox?

There are several very distinct issues related to gearchanges and it is most important to first clarify which of these is actually causing problems. Here are the top three, that seem to cause the most problems and I've gone through them all:

Issue #1: Clutch pedal falls to the floor when pushed and does not return. The clutch is not released. Quite a few owners seem to have experienced this at least once, which seems to occur only upon starting the car after having it sit at least a fwe hours (for example starting the car in the morning after a ride the day before). Lotus has identified two sources for this failure:

• There is a Service Bulletin related to installing a heat shield around the clutch hydraulic pipe to prevent the fluid from boiling with subsequent bleeding of the pipe. Gas bubbles building up within the pipe would explain the behaviour as these would contract once the car cools down, leaving an empty pipe in the next morning. I had the SB applied, which resolved the problem for about 3 months.
  
• Secondly Lotus has stated that several main cylinders were manufactured with incorrect or insufficient filling holes that prevent the main cylinder being replenished from the reservoir, specifically if the cylinder is not absolutely at the top. We noticed when bleeding the system that we had to press the main cylinder absolutely to the top to get any fluid into the system. Fluid contraction through colling woul consequently not be compensated, leaving a soft pedal.
  
• There is, however, an instant remedy for the problem until you get to your dealer (and he gets the parts). You can manually pull the pedal up and cycle it a few times until it is solid again. Pumping the pedal a few times every time before you start the car should get you throgh a few weeks at least. If there are gas bulbbles in the system the pedal should firm up once the car gets hot.
  

Issue #2: The gearchange mechanism is stiff, changing gears requires considerable effort.

This seems to be the most serious issue and many owners have complained about it. Further this issue generally comes together with issue #3 below, which is actually more aggravating.

• It is quite easy to Separate Issue #2 from Issue #3 by observing the behaviour of the shift lever in neutral. If the cables are tightened the lever will likely not return to its center neutral position by itself. If the lever stays left or right you are facing Issue #2.
  
• Lotus has taken several revisions to the shift cables and made a redesign with MY2012. Unfortunately the MY12 cables are not a plug-and-play replacement for the older cars, making the upgrade difficult (the MY12 cables also on extreme short supply).
  
• Again thermal constraints within the engine bay seem te be the key issue here, Lotus has stated that the cable sleeve can schrink if it gets too hot, increasing friction and, of course, causing a change in effective cable length leading to Issue #3.
  
• Only solution to fixing the problem is exchanging shift cables. The exchange is generally covered by the Lotus guarantee and takes about 5hrs of labour effort in the shop., the car interior has to be pretty much removed t gain access to the cables.
  
• My service technician went a step further and actually greased the cables with ceramic grease prior to installation and then wrapped the ends in the engine bay with thermal protection. This should resolve the problem quite well, but I will have to observe the effects over time.
  

Issue #3: Misadjustment of the cables making it difficult to change gears. Typically changes between 2nd and 3rd gear are affected most, but also changing gears at high RPM's can become difficult. This seems to be the most common problem overall, and seemingly every Evora car test has mentioned at least this issue. As a simple cable mechanism the whole shift experience is quite uncontrolled and subjec to aging, wear and tear. Again thermal effects contribute to the problem, as do changes in effective cable length through engine vibration or movements from load changes. You can well imagine the cables moving a sevveral millimeters when the engine load is taken away by pressing the clutch. This may well be the reason why also the engine mounts were changed in MY2012. The photos below show the mechanism including the levers attaching to the two cables through ball-joints. Not that there is no shift plate under the sack, the whole mechanism is actualy only guided at the back end from within the transmission (with the exception of the reverse lock-out mechansism).

• Fortunately it is quite simple to adjust the shif cables, though miracles are not to be expected. Specifically the left-right moving cable is critical, the front-rear cable should be less susceptible to misadjustment.
  
• To gain access to he mechanism you hve to remove the HVAC panel, which is held in place by 5 clips underneatch (2x front end, 2x in the middle and 1x at the back end. Be carefull prying the panel off, it is very easy to end the stainless steal covering. Don't lose the holding clips, which end to fall of. You can grip under the leather sack to hep you push the panel up.
  
• You can then pull the ball joint off and loosen the countring nut (10mm) to be able to adjust the cable length - just turn the ball joint. Make sure not to overdo it and remember your setting. You may have to make a few tries and see if and how things improve. Notice that lengthening the cable gives you more freedom towards the left side, shortening increases movement to the right.
  
• When adjusted correctly the shift lever should have the same amount of play left-right when in all gears.
  
• I've just made the adjustments and gear change should be now be sustantially better. In my case, lever movement was at its end when engaging 1st/2nd gear with almost no play (which is why these gears went in so bad). Reason is that the reverse lock-out presents a hard end limiting movement.
  

The Evora gearbox and change mechanism will never win a prize, but at least there seem to be a few possibilities to alleeviate our biggest problems.

[rafphillips]

Great stuff, top post / work!

[Bibs]

What he said, thanks for sharing Thomas and I'm pleased these problems are hopefully behind you now

[MHC]

Just had my cables adjusted as per #3 by B&C under warranty (MY11 S and they reckon the cables were as good as any they have seen). Has made a massive difference to changes from 1st to 2nd to 3rd - much smoother now. To be seen whether I will have to keep adjusting them over time as the cables stretch and the mechanism wears, but at least the solution is relatively simple. The M100 used to have problems with the gear cables as well - the ends used to break off!

[mdavies]

Thomas, you have my vote for the tech post of the year to date. Even though I've suffered none of those issues ........yet. (13K miles since June 2010.)

[TBD]

I'm going to amend this thread regarding a further issue that may be common to the Evora and that we are currently analyzing on my car.

Issue #4: Synchronization (unconfirmed): Gearchanges are balky, gear engagement is seemingly blocked, causing very long shift times. Issue is prevalent specifically above 3500 / 4000 rpm, more pronounced on downshifts than upshifts. Specifically between gears 6,5 and 4 (affected gears may vary).

Now that all the "simpler" issues above have been resolved in my Evora the true nature of the key problem is becoming more evident. Whilst synchronization sometimes works quite acceptably (specifically when the car is cold), downshifts following a longer high speed run are nearly impossible and in no way worthy of a sports car. From various posts here and on LT it seems that several owners have a similar issue, whereas others reply that they have no problems.

Status/resolution: Our design analysis to date has shown no potential for adjustment, fitting or alignment that would affect the synchronization, leaving only a gearbox internal issue as potential cause. We have asked a Lotus Engineer to inspect the car on next opportunity in order to clarify whether this is a bug or a feature.

Clearly the Evora gearbox from Aisin was originally designed for use in a Diesel powered car, i.e. not specifically designed for the high rpm's reached in the Evora. Don't you wish their choice had fallen for a ZF-gearbox, or a dual-clutch unit?

I'll keep you posted....

[TBD]

I'm going to amend this thread regarding a further issue that may be common to the Evora and that we are currently analyzing on my car.

Issue #4: Synchronization (unconfirmed): Gearchanges are balky, gear engagement is seemingly blocked, causing very long shift times. Issue is prevalent specifically above 3500 / 4000 rpm, more pronounced on downshifts than upshifts. Specifically between gears 6,5 and 4 (affected gears may vary).

Now that all the "simpler" issues above have been resolved in my Evora the true nature of the key problem is becoming more evident. Whilst synchronization sometimes works quite acceptably (specifically when the car is cold), downshifts following a longer high speed run are nearly impossible and in no way worthy of a sports car. From various posts here and on LT it seems that several owners have a similar issue, whereas others reply that they have no problems.

Just to give an update on this:

Status/resolution: We finally concluded together with Lotus Service Engineering that changing the transmission oil would be sensible task to takte prior to removing and exchanging the gearbox. Surprisingly the oil change improved the situation considerably, to a point where gear changes are on par to other Lotus Evora. I have now covered 250 kilometers since, covering from stop-and-go through 250 Kph and gearchanges remaine reasonable throughout.

Though we didn't see an contamination our assumption is that some dirt was hampering movement of the synchromesh. We did replace the original fluid with highest grade synthetic oil.

I'll be going on vacation with the car next week, and will gladly report developments after 3000 kilometers following my return.

[Trevsked]

Which was the oil you used, Brand and grade? I did think about a change for my car that is a little baulky going up through the box when pressing on.

Trevor.

[TBD]

Which was the oil you used, Brand and grade? I did think about a change for my car that is a little baulky going up through the box when pressing on.

Trevor.

Castrol Manual TAF - X SAE 75 W 90 / API - GL 4

[Bibs]

That's what the Esprit uses and Castrol are stopping making it!

[insertaliashere]

How is the gearbox noise with the new tranns oil?

[TBD]

It was never noisy, just didn't change gears well.

[Trevsked]

I would be tempted to try my favourite Redline MT90. When talking to the factory staff about it in reference to the Esprit they regarded it as good oil.

Trevor.

[TomE]

That's interesting - I had a similar issue on my Elise SC with a baulky 2nd/3rd up/down shift which was cured by replacing the gearbox fluid with a motorsport-rated version.

[TBD]

If you've been following my threads you know I've had issues with changing gears on my Evora for almost a year. We've changed the shift cables twice and even changed the transmission oil, all without enduring improvement.

Well, things continuously degraded during our vacation, a 3.000 KM trip to Southern France. Gear changes became increasingly difficult. In fact, sometimes the only way to get into reverse was to stop the engine. At least this had the advantage of making a sporadic problem reproducable.

So, today the car went to the shop. I had also noticed in the last few days, that the car would start creeping once I put 1st gear in, despite having fully depressed the clutch. Kind of like an automatic transmission when you release the brakes.

Well, it now looks like the clutch isn't releasing fully, despite full movement of the pedal and clutch lever. At least this is the conclusion reached wih the Lotus service engineer and would explain why gearchanges are difficult and synchronization doesn't work.

Looks like its going to be a big job, as I'm told replacing the clutch on this car means disassembling the complete clam and removing the engine.

Lets hope this is the true cause and I can finally enjoy the near perfect Evora in its totality! I'll keep you updated.

Oh, and if anyone else has had a similar problem I''d be glad to get more feedback.

Edited September 27, 2012 by TBD

[Snoopy1969]

All the best - do you have put it to westside in HH?

[TBD]

Yes, the car is with Timmy at West Side Cars.

[TomE]

Watching this thread with interest. Am aware of a few owners who have been told "it's just the cables" or "they all do that" but are concerned about it possibly being clutch-related. Dealers and factory understandably reluctant to go down that route initially given the major work (30+ hours) to get the clutch off for inspection.

Hope you get it sorted and look forward to hearing what they find.

[Stirling_Villeneuve]

Yeh.... I have...

I P S

ps At least the manual gearbox owners won't' have software issues!

Edited October 23, 2012 by Stirling_Villeneuve

[TBD]

The clutch and transmission were exchanged yesterday. We weren't able to see what the actual root cause was, so its good that everything is simply being exchanged. I was hoping to get the car back on Friday, but now it looks more like next Tuesday. The recall for that oil pipe came through, so it makes sense to take care of that at the same time.

I'm really missing my car!

[Snoopy1969]

Thomas, is that still a warranty issue?

[TBD]

Thomas, is that still a warranty issue?

Yes!

[TBD]

I finally got my car back last Wednesday after my dealer exchanged both the clutch and the gearbox. It was a major job taht took 5 weeks, including waiting for the clutch plate on back order. I also had the MY12 steering wheel installed while the car was there.

This week I had the chance to do some travels and can report that the effort was worth it. Finally I can change gears without hassle or other troubles. Must have shaved at least a second off my 0-100 kph time. :thumbsup:

We weren't actually able to identify what was wrong with the old setup. We did notice some wear on the main shaft of the gearbbox, which was also unexpectedly sticky (as if covered by some gum). Clutch plate seemed fine though, but with a slight hot spotting on the pressure plate.

Notice the beautiful De Tomaso Pantera in the first photo.

[spunagain]

Issue #4:I and one other owner I have spoken to had a problem with pulling away and gear changing. What happened was that when you released the clutch pedal and just as you add power as the clutch bites, the engine cut out causeing a kangaroo effect. The effecct was more fierce in 1st and second.

Resolution: The Clutch pedal has a position sensor mounted in it which had developed a fault. The sensor is used for the cruise control and also to protect the engine if you do something daft. Position sensor replaced and all is now well.

[92spicer]

Bringing up an old thread...

for issue #3, does this affect the car with engine on as well as the engine off?

With the engine off I can cycle through all gears very smoothly, but while driving I find 3 > 2 a bit tricky to get in.

I have a 2014 S

Edited February 8, 2022 by 92spicer