what is gear play? what wears in a m. tranny?

[iayers]

hi everybody.

so, obviously, transmissions wear out over time. my 990bw manual tranny doesn't feel like it did when it's new. (125k on it) but i don't understand what causes it to feel different.

 

for example, lets say I'm in 3rd gear, and i'm driving down a flat road with my foot on the gas. if i quickly take my foot off the gas, the car will sorta lurch forward as it initially starts to slow down. if i were to step on and off the gas, say every other second, the car would be jumping backwards and forwards. when the car is new, if i were to do these same things, the car wouldn't lurch or feel as rough. i don't know if i'm describing this right....

 

in my mind, i mechanically visualize "play" in the gears, so when i'm stepping off the gas and the torque on the tranny reverses, the lurch i'm feeling is the transition from when the engine is pushing the transmission to when it is slowing the transmission.

 

how do i get the transmission to feel "tight" like when it's new. does the clutch have anything to do with it? might the tranny mounts be loose? what have people typically experienced?

 

thanks.

[All_talk]

Sounds more like tranny/engine mounts to me, maybe some were in the chassis or rear diff mounts too. Typically the only measurable wear in a MT over a normal lifetime (barring running it out of oil) is the syncros, first sign is normally stiffer shifts or slight grinding on fast shifts.

 

Try this to check the mounts, open the hood and lock the park brake. Then watch the engine as you come up on the clutch (dont stall it) in first and reverse. There shouldn't be major movment, but it can be hard to tell if you don't know whats normal.

 

Gary