mark kibort

Ive always been fearful of the 928 gear box popping out of gear when in second. (my old 84 used to do this for many years). anyway, the s4 didnt really do it, until during this last race at sears. it stays in 2nd gear fine, unless you are not accelerating or decellerating. in a neutral power mode, it will pop right out of gear and go into neutral. (actually that grinding position between neutral and in gear)

Is there kind of part that really keeps the transmission in gear? if so, can it be changed or modified while the transmission is in the car, if i have the transmission access on top of the trannie?

Thanks,

Mk

mark kibort

Nobody has had this issue before? com'mon guys, a little help!!!!!

hacker-pschorr

What kind of transmission fluid are you using?

GregBBRD

Everything that keeps the transmission in gear is inside the transmission, unless you have something restricting the gearshift movement or something loose (like the torque tube.)

What year is the transmission?

Kiln_Red

Synchros? That's the only thing that comes to mind for me.

Mrmerlin

could also be a bent shift fork once its bent then the fork will move the gear back just enough to jump it out of gear usually happens from shifting fast through the gears

Mark Anderson

I've heard of this happening with Amsoil because it is so slippery
try Mobile 1

Mike Simard

I've had alot of trans issues but never that.
I'll bet that it's an external force of something moving or the linkage never having made it all the way in the first place.
Any flopping or vibrations in the chassis will have an effect on the shift linkage.
Do you have a stock shift coupler with compliance?
If you disconnect the coupler, is there resistance in the shifter at #2 position?
This could also simply be your mAd sk1lls!

GregBBRD

The syncro only slow or speeds the gear up. It doesn't actually do anything to keep the slider engaged with the engaging teeth on the gear. The "teeth" have a "negative angle" on both the engaging sleeve and the engaging teeth on the gear. When the teeth are fully engaged (and in good condition) these two "negative angles" are touching each other, which effectively "locks" the two pieces together.

If the "teeth" are not able to fully engage (something limiting the travel of the shifter, bent shifting fork, etc.) the transmission will pop out of gear. Wear on the teeth can also this to happen. Excessive endplay or a bearing issue will also allow enough movement to allow them to pop out of gear.

Speedtoys

Im voting bent fork.

GregBBRD

Never seen one. The forks are either a bronze material or aluminum, depending on which year it was made. Neither one "bends" very well.

Speedtoys

If gear jammin enough, you cant lose some form..which wouldnt put the gear in enough?

Rob Edwards

Can't imagine how one could bend a fork when they're captive on a 1/2" steel rod, but if there has ever been a 928 drivetrain that had a significant amount of bending force sent down its torque tube and pinion gear, it's the Holbert car:

Kiln_Red

Makes sense. Thanks for the explanation. I'm happy to admit I'm no transmission guru but that doesn't mean I am not curious to learn more about either the manual or automatic transmissions in the 928. The reason why I thought synchros was because a friend suggested a synchro issue in another vehicle when it would keep kicking me out of 3rd during normal driving. Pretty frustrating as the vehicle was a DD. Believing the advice, I simply replaced the transmission. The symptoms were gone and I was happy. Now I realize that synchros may not have been the issue.

GregBBRD

Far be it from me to say what is possible and what isn't possible. I'm just saying that I've never seen one. The aluminum forks are made from such a stiff aluminum that they crack and break when stressed. The bronze material....I have no idea. Never seen one bent or cracked in a 928 transmission.