Gripper Gearbox Issues

[J90RDN]

Need some advice. Purchased a gearbox with a gripper diff installed from this forum some weeks ago. Got it fitted today, went out for a drive, and it has crunching into 3rd gear. Was advised it was a freshly reconditioned box, with 90 mins use. I've ensured the clutch is bled correctly (twice), the clutch and slave are new genuine Renault parts.
If this is indeed a reconditioned box, which I've been assured had no issues when removed, what else could be at fault? Could it be faulty gear linkage? All other gears work fine, so surely can't be a clutch problem?

 

[sevenfourate]

No actual proof / a receipt of being reconditioned ? Could you not even find out who did the work and ring them if not: to double check ?

Not ‘just’ a case of not trusting anyone’s word - but ultimately about getting to the bottom of the issue....

 

[J90RDN]

At this stage I want to rule out anything on my car which could be causing the problem.

 

[Foxspeed]

if its crunching as you say its the synchro is bolloxed...

 

[A1axx]

Other thing to check as it leads to the problem is clutch biting when pedal is depressed.

Assuming you purged the slave before fitting, so there's absolutely no air, and bled correctly.

Put the car in 1st gear, hand brake off, and clutch in. Rev to the limiter. It shouldn't creep.

If it's creeping, it's either not bled correctly or it's a faulty clutch causing it to bite.


197 Meglio Racer ! http://www.clio197.net/threads/gw-197-track-sprint-car-cup-racerified-and-now-boosted.53560/

 

[J90RDN]

Thanks - will give that a try. Slave was bench bled before fitting, and clutch is new genuine item (as is slave).

 

[A1axx]

Thanks - will give that a try. Slave was bench bled before fitting, and clutch is new genuine item (as is slave).

Renault with plastic slave or LuK?

Problems I'm told come from standard genuine Renault clutches


197 Meglio Racer ! http://www.clio197.net/threads/gw-197-track-sprint-car-cup-racerified-and-now-boosted.53560/

 

[J90RDN]

Standard Renault clutch and slave.

 

[J90RDN]

Interestingly conducted the above test and in 1st gear with clutch completely depressed the car does start to creep at around 5k. Having bench bled the slave, and bled the clutch 3 times now, I'm going to strip the engine and gearbox out of the car and bench bleed the slave a second time. Only thing I can think is that when putting the gearbox back onto the engine, as the slave depressed and squirted fluid out, some air may have got in (although god knows how). Clutch is only 400 miles old and showing no signs of slipping, so don't think it's that, but will inspect when it's out.

 

[tombate911]

Interestingly conducted the above test and in 1st gear with clutch completely depressed the car does start to creep at around 5k. Having bench bled the slave, and bled the clutch 3 times now, I'm going to strip the engine and gearbox out of the car and bench bleed the slave a second time. Only thing I can think is that when putting the gearbox back onto the engine, as the slave depressed and squirted fluid out, some air may have got in (although god knows how). Clutch is only 400 miles old and showing no signs of slipping, so don't think it's that, but will inspect when it's out.

I doubt bench bleeding will make any difference. Out of the gearbox replacements I've done this year about 6 I've never even bothered priming the slave before I put it in and never had any issues bleeding it. I always bleed with a pressure bleeder. Pump it for a few minutes and then rebleed. Done.

 

[J90RDN]

Bench bled slave again yesterday and bled clutch (both manual pumping method and pressure system), but still getting same issue. Crunches into 3rd gear even at low revs (as it's always done).

The synchros on this box were new and been told they were only used for 30 mins track use. I do know that the gearbox oil used was Millers CRX LS 75w140NT (competition heavy duty fully synthetic). Could this have chewed through synchros within 30 mins race use?

 

[A1axx]

Bench bled slave again yesterday and bled clutch (both manual pumping method and pressure system), but still getting same issue. Crunches into 3rd gear even at low revs (as it's always done).

The synchros on this box were new and been told they were only used for 30 mins track use. I do know that the gearbox oil used was Millers CRX LS 75w140NT (competition heavy duty fully synthetic). Could this have chewed through synchros within 30 mins race use?

Is this dave bells old gearbox?

 

[J90RDN]

Is this dave bells old gearbox?

Yes

 

[A1axx]

Yes

I do mind he had gear selection issues with it before, not sure if it was the same build. The story just reminded me of that box.

Jade developments built mine, it was the only tl4 I've had out of a few that had no issues.

I used 75w90 Fuchs race synchro. Its for gl4 boxes.

 

[J90RDN]

Yeah, looking more and more like the synchros are gone. I just don't understand how they can go within 30 minutes of operation. Looking at a gearbox rebuild now. Really not happy!!! If it was the oil that could have possibly caused the issue then I want to avoid using the stuff again. Wouldn't mind but I went and brought 5 litres of the expensive stuff for future gearbox oil changes!!!! Not a happy bunny.

 

[A1axx]

Yeah, looking more and more like the synchros are gone. I just don't understand how they can go within 30 minutes of operation. Looking at a gearbox rebuild now. Really not happy!!! If it was the oil that could have possibly caused the issue then I want to avoid using the stuff again. Wouldn't mind but I went and brought 5 litres of the expensive stuff for future gearbox oil changes!!!! Not a happy bunny.

Doubtful. Mine has done a few thousand miles of hard use. Cringe watching back one of my sprint videos, as it was competitive I was seriously ramming in gear... Gearbox is still going strong with Danny using it for another track day. Probably had a good 30 hours of hard use and it was rebuilt before I bought it.

 

[J90RDN]

Thanks man - at the minute I can only dream of quiet 3rd and 4th gear changes like that!!!!

 

[J90RDN]

Update on this one. 3rd gear completely gave up half way through the day at Oulton on Saturday, so spent last few hours driving 2nd and 4th only. Looks like the gearbox was a bad one all along, and I was sold a complete PUP !! Will have to transfer the gripper to another box and see if I can get this one rebuilt. Very Very annoying as I could have purchased a brand new gripper for the price I've paid for a second hand one and a crap box!!!

 

[Daverb]

I almost bought that one too. Not good but at least the diff is ok and another box / rebuild will sort it.

 

[tombate911]

Sad news mate. Defo best to transplant it into a new box, sounds terminal if you've lost that gear completely. Worth stripping the gripper and inspecting the condition of it while it's apart too.