popping out of first

[airedale]

In my last autocross (SOLO II) I was able to run it in first the whole way, only hitting the rev limiter in the 100 yds to the finish. At one part, coming into a hairpin I abruptly let off the gas, the rpm's dropping from 7500 to about 2500 (I didn't need brakes) and it kept popping out of first. The second 2 runs I had to have a passenger keep his finger on the shift. What's happening?

 

[KGP]

From the Snap Ring FAQ :

The giveaway for snap ring failure is the shifter moving fore and aft in first or second on deceleration or acceleration from slow speed. This happens because when the snap ring breaks (which holds the countershaft top bearing into the case) the whole countershaft moves back and forth in the case when the direction of load / torque changes. Since first and second selector are on the countershaft, and the selector hub hooks into the selector fork which hooks into the shifters.

Most people experience a loud crunch or mechanical grinding sound as the shattered fragments of the broken snap ring grind around in the transmission.

There are no warning signs prior to failure.

Check your transmission number!

 

[MiamieNeSeX]

Sorry to say but it sounds like the dreaded snap ring

 

[airedale]

Snap ring was fixed by Basch thousands of miles ago along with installing the short gears and lightened flywheel.

 

[JPS Europa]

I know this one sounds like the snap ring. However on most cars, ie, those without snap ring issues, this problem is usually caused by an improperly adjusted shift linkage or a failed spring detent on the selector shaft.

 

[Larry Bastanza]

This problem sounds somewhat different then the classic snap ring issue. If the snap ring breaks, then the countershaft will float back and forth and the shifter will "move" for and aft as you increase/decrease throttle, however it would not neccesarily cause it to jump out of gear.

This sounds like an abused first gear syncro spring, maybe from many hard downshifts to first at the autocross??? Just a thought

Will the trans not stay in first anymore? Needless to say, the snap ring can be checked easily by removing the inspection bolt to be sure.

HTH,
LarryB

 

[airedale]

Thanks for all your replies. I can't reproduce this so it seems just from the rapid engine deceleration. In all the Solo II's, I almost never have to downshift to first once I get to second; with a supercharger I have enough torque so that it's usually not worth the time. So I doubt I've worn the linkage (although I can't speak for the previous owner-if there were a problem I think MB would have picked it up).
BTW, what happened to my avatar with the picts of my Airedales?

 

[nsxtasy]

what happened to my avatar with the picts of my Airedales?

That's a question for Lud, but... is it possible it was disconnected when he migrated the forums to the new version of the software? Have you tried editing your options to add it back (by clicking on "user cp" and then "Edit Options")?