db327

Hoping for some diagnostic help...

I had my 1999 Spec Boxster (90k miles) at the track last weekend. Part way through the day, the manual transmission started slipping out of 3rd gear. All other gears work fine. I could shift into 3rd ok, but it would slip out of 3rd when I let off the gas or went over a bump.

I tried adusting the linkage at the shifter to bias the shifter more toward 3rd, but that didn't help.

I jacked the car up and manually worked the linkage at the transmission while manually turning the wheels, and was able to reproduce the slipping out of 3rd.

Any ideas what the problem is or how to diagnose it better without dropping the tranny? Since all other gears work fine, the clutch seems fine.

Thanks, dave

amondc

Check the linkage at the back. And the sockets where the cables snap on. The cables can also come out of the clips.

Macster

Doesn't read like a linkage problem but you may not have done enough to eliminate this possibility. A proper adjustment of the linkage or a check of its adjustment could be called for to eliminate a linkage problem. At the same time a careful inspection made to ensure the linkage is intact.

If not a linkage problem the symptom can arise from a bent shifter fork. The fork, being bent, doesn't move the gear into complete engagement -- the gear dogs that is -- and the transmission pops out of gear.

This is probably helped by worn dog teeth.

Or the shifter fork is fine the gear dog teeth are worn out and no longer hold when a load is applied.

Regardless, if the problem is not found with the linkage outside of the box I think your only option then is to get inside the box and give the internals a proper evaluation and whatever you find out of the norm repair/replace.

3_Angels

Have you solved this problem?