CRex

Been noticing an increasingly severe problem with my gearbox after periods of "heavy use". During periods of high gearbox temps (end of track sessions or 60+ minutes of constant-speed highway drives) the gearshift would feel very sticky and wouldn't easily come out of its current gear. The level of "effort" required can be as much as, sometimes more so than, forcing the gearshift out of gear without applying the clutch pedal.

This problem got so bad yesterday (2/3rd through a 120-mile drive after a DE weekend) that I realistically doubted if I might have to drive the remainder of my way home in 2nd gear...

Getting the gearshift into neutral is the hard part. Once the gearshift is past the gate, going into the next gear doesn't require more than the usual effort. The "stickiness" happens in all gears, with both upshifts and downshifts. I reckon if there's a clutch problem I should be looking at problems both ways...

The interesting bit: this problem goes away ENTIRELY once the gearbox cools down--shifter feels 100% normal after a 30-minute cooldown. This whole affair has happened multiple times since July, and I'm certain gearbox temperature is a contributing factor.

Other pertinent facts:
- Clutch/PP is a 4.0 part that's been on the car for about 1,000 track miles and 3,000 street miles
- Clutch engagement point is normal (as in the lowest quarter of pedal travel) and there's no clutch slip whatsoever
- Tranny oil is the factory-spec Mobil PTX 75-90W fill

I'll be taking this for post-even service at my indy--not going to hazard a clearly worsening condition at my next DE. Would appreciate an educated guess at the situation so I could consider the mechanic's input in context...

Thanks in advance!

Izzone

I have the exact same problem

First gearbox did it, so does the second one

TRAKCAR

Trakcar 3.1 did it but it went completely away with the 4.0 clutch and PP.
Trakar 3.2 did it sometimes and is still on original clutch and PP
Trakcar 4.0 does it sometimes.

I guess the gear box over heats so that it wont let go of gears. Seems to do no harm.
LSD makes it is little worse, side muffler delete helps a little is my theory.

I now replae trans fluid every 6 track days.

Only right after coming off the track and it is completely gone after the car cools down completely hours later. Mine needs longer than 30 minutes, even after a 10 mile cruise at 50 MPH to gas station and back.

AudiOn19s

What fluid are you running? Mine seemed a little sticky when hot on factory fill molilube but not nearly to the extent that you're describing. Does NOT do it with Delvac though.

Also fresh fluid every 6 days as noted above is critical I feel.

maybe apples to oranges though as I know the 7's internals are slightly different than the 6.

Mvez

Stock LSD creates alot more heat in the gearbox. You can look up posts here where Matt from Guard posts pictures of the extreme heat wear shown on the factory clutch pack, due to not locking and just spinning.

Delvac seems to handle heat better, I'd switch to Delvac. It's a little notchier when cold, but at track temps, seems to work better than factory fill.

M3EvoBR

I have delvac in my box, and so far no problems. On my previous car I used to run different fluid, can't remember the name now, maybe 85Gold can chime in and refresh my memory.

fc-racer

My local track requires a lot of shifting and we often have the track to ourselves, so 30+ mins sessions are the norm, sometimes I even go as long as 45 mins. The only thing that fades is my brain; the gearbox has never been sticky. I use Delvac and I have a 3.6 (maybe the higher torque of the 3.8's create more heat?).

NITEALB

been meaning to ask this same question. i have got this alot after 20 mins plus sessions (same tracks as fc-racer). car feels ill at ease going from 3-4 and vice versa. it got to the point at the end of this season i nearly drove thru the back of the car i was following at the end of the braking zone cos i couldnt get out of 4th in to 3rd! this problem seems significantly worse and happens earlier in a session since installing the guard 4.125 ring pinion. i have not replaced the pressure plate, its stock. the car is almost impposible to get out of the gear when its rested in the pit lane after 30-40 mins post driving driving. is this the same as CRex or is entirely different?
thanks.

P.J.S.

hard to get back into neutral... fingers of the pressure plate may be getting weak
in any event fluid is worth a shot...

My car showed the same symptoms (hard to get out of gear) and it was the fingers on the pressure plate...

M3EvoBR

happens under high temps, after that goes back to normal...

P.J.S.

keep heating the pp fingers to that degree repeatedly... they will fatigue

GTgears

Running Delvac instead of the factory fill definitely has an impact on gearbox shift quality at higher temps.

Frequent changes also make sure that the oil maintains proper friction properties and hasn't broken down to the point where it doesn't have enough friction for the synchros.

PJ's point is also worth considering.

Izzone

Running Delvac is better correct?

Im on my second transmission.....both have done the exact same thing when hot

I change the fluid every six days, with Delvac. Magnetic plug is always pretty clean

When car gets hot the shifter sticks in gears. As soon as it cools off its fine.

It also "pops" from three to 4 or vice versa when hot under load

Sweeper

Anyone thought of checking the factory SSK. Why would it be the clutch?

85Gold

Syngear II, hard to find, but really handles the heat well. A little notchy when cold.

Peter