Problems selecting third gear on track again.. Ideas?

[Martin.]

In the past I've often had issues selecting third gear on track days. Mainly because 3rd and 4th are the only gears I use at Brands Hatch.

Anyway, I'll will be flat out in 4th, brake hard pre corner, down into 3rd and often I just cannot select it. It happened on a few occasions last night. It feels stiff and as if the gate is closed. Seems to be worse the faster the engine is spinning. (bare in mind I'm also very mechanically sympathetic and never rush changes as it is). When ever I change down on track it'll only be into the 4-5k rev range, not making the engine scream like some do. When I cant select it I have to coast for a second or two and then by the time i've got third the car will be much lower in the rev range and it seems fine.

If driving on the road, on warm up, cool down laps or just not at 10/10ths then it doesn't seem to be an issue.

My concern is the clutch. Although having recently fitted a new Helix organic with upgraded cover I'm hoping it can't be the case this time. But last time when I had very bad issues the clutch ended up dying at Snetterton and I wasted the entire track day after one session. Going back even further into the past when I've had the odd issue here and there nothing broke at the same time but I have been through 2 Valeos in very minimal miles.

I have a PMS shifter also.

So I'm just posting to see if anyone has experienced this before??

Or whether someone has any more ideas?

Cheers

 

[imprezaworks]

Linkage not set up properly?

 

[Martin.]

Well it feels lovely and like a rifle when driving normally. Even most of the time on track. It's only when I'm at 10/10ths and the car is moving around under heavy braking.

I've hopefully caught it on video a few times so I'll check the Go Pro too.

 

[imprezaworks]

@NorthloopCup

Is probably the chap to advise.

 

[green]

I had this at my last trackday...high rev range changing from 4th to 3rd. Every off putting. If I didn't rush the box I could easily select 3rd.

I've used the pms shifter and box in a different shell and it was fine so I'm thinking the linkage isn't quite lined up ( even though I marked it when taking it a part!)

Also...like you it drives fine on the roads.

How easy can you select reverse ?

 

[Martin.]

I had this at my last trackday...high rev range changing from 4th to 3rd. Every off putting. If I didn't rush the box I could easily select 3rd.

I've used the pms shifter and box in a different shell and it was fine so I'm thinking the linkage isn't quite lined up ( even though I marked it when taking it a part!)

Also...like you it drives fine on the roads.

How easy can you select reverse ?

You laugh but on the road I actually drive it like a granny (it was driven to and from track and didn't go over the speed limit). I get the fun on track. Also it's too stiff and crashy to go over anything other than smooth tarmac.

Can select reverse perfectly fine without issues.

 

[brisa4984]

Movement with the gearbox as you break hard ?

 

[Martin.]

Movement with the gearbox as you break hard ?

This has crossed my mind. Or something moving anyway. But then I have solid mounts everywhere so I don't see how it could move that much....

 

[JB21]

Mine does it mate if I don't heel and toe matching the revs on down shift into 3rd, mine also does it on up shifts and to combat this I keep my foot on the gas slightly, not great on the clutch as it rides slightly but doesn't crunch on fast changes. If like mine your gear box is due a rebuild.

 

[Martin.]

I can't heel and toe in mine, so I'm not sure I'd be able to test that. When on the brake the throttle pedal is too hight to get near. Can do it fine in my Cayman.

Although I still can't get my head around how it would benefit as it seems the engine is already spinning too much for the selection. Only after the speed drops can the selection then be made. Surely the throttle blip would therefore make it worse or harder??

What I don't get is how can it be completely fine most of the time. Then only when I'm hard on the brakes and on the limit is there an issue.

 

[NorthloopCup]

That's either the engine and box moving under heavy braking (dog bone is the most likely candidate) or the synchro ring is on its way out as it's unable to do its job of slowing the gear down for the change.

What oil is in the box?

 

[Martin.]

That's either the engine and box moving under heavy braking (dog bone is the most likely candidate) or the synchro ring is on its way out as it's unable to do its job of slowing the gear down for the change.

What oil is in the box?

I've got the powerflex purple dog bone mount, checked the torques on that the other weekend so it's not loose or anything, but maybe could be past its best? What do you recommend for them?

Fuchs Titan Race SYN 5 - 75W-90. Was fresh oil in May with the new clutch kit.

I've got a Gripper in the box too (it's porkies old box) but I don't think that makes a difference for this issue does it..

 

[NorthloopCup]

Grab the engine and try and pull it out the bay. If there's any movement it's time to replace the bushes. Or you could get someone to put the handbrake on, then put it in gear and let the clutch up to put strain on the engine/box mounts. If they're quite violent with the on/off of the clutch, you'll easily see any movement in the engine.

Right ok, so a decent spec of oil then tbf.

Do you know any rebuild history on the box at all?

 

[Martin.]

Grab the engine and try and pull it out the bay. If there's any movement it's time to replace the bushes. Or you could get someone to put the handbrake on, then put it in gear and let the clutch up to put strain on the engine/box mounts. If they're quite violent with the on/off of the clutch, you'll easily see any movement in the engine.

Right ok, so a decent spec of oil then tbf.

Do you know any rebuild history on the box at all?

Will try exactly that when I can and report back :up:

No real knowledge on the box history. I think James said it was refreshed when the gripper was put in, but that would have been a long while back as I've had it in since Spring of 2015.

 

[Martin.]

Right ok, so a decent spec of oil then tbf.

Worth going back to a standard grade of oil to look after the box over an oil more focused to the Gripper? Then change it every 6 months?

Box rebuilds are probably more expensive than a gripper rebuild....

 

[NorthloopCup]

Will try exactly that when I can and report back :up:

No real knowledge on the box history. I think James said it was refreshed when the gripper was put in, but that would have been a long while back as I've had it in since Spring of 2015.

I'll message James and ask him if he can remember when it was refreshed and by who.

Worth going back to a standard grade of oil to look after the box over an oil more focused to the Gripper? Then change it every 6 months?

Box rebuilds are probably more expensive than a gripper rebuild....

No mate don't go back to standard oil as you'll need a rebuild a lot sooner than you'd appreciate. With any gearbox fitted with brass synchros and a plate diff, you need to use the best oil for the gearbox, not the diff. So no specialist lsd oil or friction modifiers.

If it is 3rd that's gone, you're looking at about £220 in parts to sort it.

 

[JamesBryan]

Could that oil be too slippery for the synchros Mark, being a GL5?

 

[NorthloopCup]

Could that oil be too slippery for the synchros Mark, being a GL5?

I've seen people running it before without issue mate tbh, but it's definitely something to consider. @Martin. redline mtl or mt90 are my go to oils for reference.

 

[Martin.]

I'll message James and ask him if he can remember when it was refreshed and by who.
No mate don't go back to standard oil as you'll need a rebuild a lot sooner than you'd appreciate. With any gearbox fitted with brass synchros and a plate diff, you need to use the best oil for the gearbox, not the diff. So no specialist lsd oil or friction modifiers.

If it is 3rd that's gone, you're looking at about £220 in parts to sort it.

Isn't the standard oil most suited for the box though? I was told the oil I'm using now was the oil most suited to the Gripper and not the box, hence me wondering if going back to Renault oil might be better.

Titan is slightly thicker than the Elf stuff at operating temp isn't it.

My main concern is that the clutch is going to break again to be honest :-(

 

[JamesBryan]

The Redline MTL in mine is a belter, so smooth!

 

[Martin.]

I've seen people running it before without issue mate tbh, but it's definitely something to consider. @Martin. redline mtl or mt90 are my go to oils for reference.

How often would you recommend to replace with fresh stuff too? At the moment I'm doing around a year, or maybe a bit more if I haven't done many trackdays. I only did 978 (mostly track) miles since June2016

 

[NorthloopCup]

Isn't the standard oil most suited for the box though? I was told the oil I'm using now was the oil most suited to the Gripper and not the box, hence me wondering if going back to Renault oil might be better.

Titan is slightly thicker than the Elf stuff at operating temp isn't it.

My main concern is that the clutch is going to break again to be honest :-(

The standard gear oil can't work at the operating temperatures your box will be seeing mate, so you will need a rebuild quicker using the renault oil.

I'll have a look at the specs for that oil you're running now mate too. I'll have a better idea of what's what.

 

[NorthloopCup]

The Redline MTL in mine is a belter, so smooth!

You listen to ya dad. He knows. 😂

 

[NorthloopCup]

How often would you recommend to replace with fresh stuff too? At the moment I'm doing around a year, or maybe a bit more if I haven't done many trackdays. I only did 978 (mostrly track) miles since June2016

For that sort of mileage mate, once a year is fine.

 

[JamesBryan]

You listen to ya dad. He knows. 😂

You've lost me... 😅

 

[NorthloopCup]

You've lost me... 😅

Wasted humour! It's a Peter Kay line! You should know this as he's from your neck of the woods!!

 

[JamesBryan]

Wasted humour! It's a Peter Kay line! You should know this as he's from your neck of the woods!!

Haha, that makes sense now.

 

[Martin.]

The standard gear oil can't work at the operating temperatures your box will be seeing mate, so you will need a rebuild quicker using the renault oil.

I'll have a look at the specs for that oil you're running now mate too. I'll have a better idea of what's what.

You are a babe x

 

[Aydon182]

Was you at brands on the 14th?

 

[Martin.]

Was you at brands on the 14th?

Nah mate, last night with OpenTrack

 

[TirelessEnigma]

There's a couple of corners at brands indy were it's borderline 3rd or 4th gear. I stay in 3rd. Going into 4th at those corners means you'll be changing back into 3rd at too high revs. Well if you want to look after the gearbox that is. Down cooper straight and through Surtees stay in 3rd.

 

[Martin.]

There's a couple of corners at brands indy were it's borderline 3rd or 4th gear. I stay in 3rd. Going into 4th at those corners means you'll be changing back into 3rd at too high revs. Well if you want to look after the gearbox that is. Down cooper straight and through Surtees stay in 3rd.

Yeah I always change into 4th there. I'd bounce of the limiter a few times if not I think but maybe I can try staying in third next time to see how it feels.

 

[TirelessEnigma]

It's something to try. You will probably be at the limiter at the end of that straight. Really you gearbox should select 3rd still. But better to limit high rpm downshifts if you can. Maybe worth doing the oil as well.

 

[M.C..]

I've had this issue a couple of times.
If it does happen it only seems to happen once or twice then it is fine again, I use standard elf box oil changed once a year.