C3 Race Car Build

teamzr1

Supporting vendor
Be interesting to see if using a Dba sound meter what level is at a right angle of exhaust tip and also in the cabin area

Maybe the shift linkage needs adjusting, quality and level of tranny fluid, or a synchro issue ?
 

Roscobbc

Moderator
If you have a Hurst shifter not only can you (as TeamZR1 suggests) check adjustment of linkage with the Hurst 'tool' or the correct diameter drill bit - but also adjust the shifter 'stop' bolts, allowing you to really bang the shifter home without stressing linkage.....
 

Oneball

CCCUK Member
Be interesting to see if using a Dba sound meter what level is at a right angle of exhaust tip and also in the cabin area

Maybe the shift linkage needs adjusting, quality and level of tranny fluid, or a synchro issue ?

Its engine, gearbox, final drive and suspension that’s all the noise in the cabin now. It’s 95dba outside at 5000rpm now. Don’t know what it is inside but I don’t need ear plugs.
 

Oneball

CCCUK Member
Box jumping wise. It is a Hurst. I’ve checked the linkage and the stops. They’re as they should be. If you put it in 3rd then remove the linkage it’s as far into gear as it’ll go.

Fluid is at the right level

Ive rebuilt the box and it’s mainly new. So either something is amiss with what I’ve done, I’ve missed something that was worn or the shift boot is pushing it out of gear. I’ve pulled the boot off and will see what happens.
 

Roscobbc

Moderator
Box jumping wise. It is a Hurst. I’ve checked the linkage and the stops. They’re as they should be. If you put it in 3rd then remove the linkage it’s as far into gear as it’ll go.

Fluid is at the right level

Ive rebuilt the box and it’s mainly new. So either something is amiss with what I’ve done, I’ve missed something that was worn or the shift boot is pushing it out of gear. I’ve pulled the boot off and will see what happens.
TBH mine jumps sometimes jumps out of 'first' on an 'extended' over-run. Its always done it - previous owner had the gearbox overhauled and it came to me like that. TBH its not so much of an issue for me being as its in first gear.......guess it would be if racing and looking for all the engine braking I could get.
 

Oneball

CCCUK Member
TBH mine jumps sometimes jumps out of 'first' on an 'extended' over-run. Its always done it - previous owner had the gearbox overhauled and it came to me like that. TBH its not so much of an issue for me being as its in first gear.......guess it would be if racing and looking for all the engine braking I could get.

This is extended overrun too. I’m not sure if it’d happen racing as you’ll probably be down the gears quicker than that but it’s annoying and shouldn’t really do it.
 

Roscobbc

Moderator
This is extended overrun too. I’m not sure if it’d happen racing as you’ll probably be down the gears quicker than that but it’s annoying and shouldn’t really do it.
Running no power brakes - and the fact that its a 3.08 rear end and theoretically can wind up to ver 70 mph in first gear does really mean that engine braking is/could be a helpful addition.......I just need to make sure I don't rely on engine braking in first........despite all that it makes you look an 'ass' to any onlookers!
 

Forrest Gump

CCCUK regional rep
My gearbox needs to come out. It began with jumping out of 2nd gear a couple of second after lifting off, just as you have. The problem has now developed though into becoming reluctant to change into second gear unless I double de-clutch. Pita. I’ve decided it must be synchro. Did you renew all the synchro rings?
 

Oneball

CCCUK Member
My gearbox needs to come out. It began with jumping out of 2nd gear a couple of second after lifting off, just as you have. The problem has now developed though into becoming reluctant to change into second gear unless I double de-clutch. Pita. I’ve decided it must be synchro. Did you renew all the synchro rings?

Yep. The only original bits are the case and mainshaft. Interlock and shift quadrant.
 

Oneball

CCCUK Member
PS synchro rings won’t cause it to pop out of gear. Detent plungers in the hubs, either worn, lack of sprung pressure or not properly engaging and load from mainshaft bearing play or the shifter are what causes poping out of gear.
 

Oneball

CCCUK Member
Going to try and get a camera into the box through the fill hole. Been racking my brains to work out why and hoping I’ve not clocked the synchro slider so it’s not engaging the three detents. They’re lightweight sliders with only half the teeth. 5C52F7B0-8228-416F-83E4-F36579D2FCE9.jpeg
 

johng

CCCUK Member
I reckon you did it on purpose, to make me feel better about rebuilding my car only to find the gearbox didn't work properly :) Thanks, I feel better already.
 

CaptainK

CCCUK Member
When I'm enthusiastically going up through the gears, on the rare occasion mine pops out of fourth seconds after I put it there. I blame it on user error and just re-engage fourth and all is well with the world.
 

Oneball

CCCUK Member
Synchro slider is on correctly. I’ve adjusted the linkage from scratch and removed the gaiter so will give it a go and see if anything has changed.
 

Oneball

CCCUK Member
Popped to Tesco to get milk first thing and it still pops out of 3rd. Might be regretting not fitting a removable gearbox crossmember soon!
 
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