HELP, manual transmission diagnosis?

[iSynthetixx]

Please help me diagnose what is wrong with my car. I have a 2008 S5 6SMT. 80,000 miles on it.

The gear shift shifts fine when the vehile is off and has no problem engaging gears.

When the car is in 1st, 3rd, and 5th gear (the up gears) and you accelerate the shift knob moves as if being pulled forward. When you let off the gas it returns to its resting position.

If you engage the clutch while on the throttle the clutch doesnt engage properally until almost all the way to the floor.

If you let completly off the gas and then engage the clutch the car shifts fine as if there is no problem.

When shifting into third, sometime the gears grind if you attempt to make a quick shift but this really only happens with third gear and when shifting quickly.

Every so often the clutch wont engage at all and its almost impossible to shift into any gear, they really need to be forced but this seems to only happen after a bad shift engagment previously.

I have no check engine lights on.

[iSynthetixx]

I'm thinking its the transmission mount now becuase the whole transmission seems to slide front to back when accelerating and letting off the gas.

The issue with third gear I now beleive is the synchro.

[Jeff V.]

Do you have the problem where you have to nearly stand on the clutch in order to start the car? I have that problem, and finally blew out the clutch hydraulics.

Once all of that was replaced, I noticed the car shifted much better. So I'm wondering if your problems are a combination of worn hydraulics and a worn mount.

[Audibot]

My c5 sort has the same issue with the shifter moving around, but my trans mounts are fine. Rear diff mounts, however, are shot. Mine doesn't have a clutch issue either.

[SLU_S5]

Sounds to me like you need at least a clutch (and flywheel also since ours can't be resurfaced). While you're in there, I'd suggest replacing the clutch lines with the stainless steel braided one from USP. You'll also probably want to replace the slave cylinder, clutch fork, and all associated hardware. Audi will probably quote you somewhere in the neighborhood of $6k, but you could probably get it all done for between $3k and $4k.

Mine used to be near impossible to change gears while on throttle, and had an occasional light grinding sound when shifting to third. Had all of the above replaced and now it shifts smooth like new.

Since then, I've noticed that my shifts have been slightly clunky. I scanned for codes and noticed that my engine mounts are failing - ordered a set of the 034 density line mounts and will have them installed next week.

I'd first take it to get diagnosed by your local Audi specialist (dealer or trusted independent). It might cost an hour or two in labor, but it might confirm some things that could save you later.