2001 S8 130,000. It runs fine, shifts and downshifts nicely--for about ten miles. Then starts slipping out of gear on acceleration and thumping into the next gear. This quickly gets worse until it goes into LIMP mode. Foreign car guys are convinced I need a new (rebuilt) transmission. I don't wanna believe them. Any reason not to?
Thanks.

 

it sounds like a synchro problem

 

Would that necessitate a whole new transmission? I should have mentioned also that it is "throwing a gear ratio code." Also, the foreign car mechanics, (nice chaps but expensive,) tell me that it could be a bad seal on the torque converter. I checked the "area under the passenger carpet." Dunno if I actually found a TCU, but the area was dry. Also tried the reset trick with the car on and the gas pedal down. No apparent result. If it is a syncro problem, is there something to check before we pull the tranny out and have a look at the torque converter seal? Anything else I can possibly look for before going this route? Thanks.

 

im pretty certain thats your torque converter going. syncros are only in manual transmissions.

 

Well, if it is the torque converter, is there any way to test to be sure? I just don't want to shell out the money for a rebuilt tranny/torque converter, (I'd imagine one would want to buy them together, right?) and then find out it was actually the TCU or ECU or something and I didn't need the tranny.

 

not sure if there is any way to test the TC without pulling the tranny and opening it up. i went through this same problem a couple years ago. i ended up swapping out transmissions. in retrospect i would have it rebuilt instead. where are you located?

 

I'm in Fairbanks, Alaska. Which means that shipping costs are of concern, obviously. Maybe I could have it sent somewhere to be rebuilt, but wouldn't buying a rebuilt tranny instead of a used one be the same difference, really, with only one shipping charge? Also, I was thinking: Could I get a '02 or newer transmission, with an S mode, installed in this car? I read somewhere that you can install a TCU that would upgrade a '01 to have an S mode. I wonder if I couldn't just get a newer transmission out of this?

 

if you rebuild the tranny you can upgrade the torque converter and seals to beyond factory spec. dont know if youre able to put a tranny with s mode onto your car. that would be cool though. if you are lookin to upgrade you should check these guys out.

http://www.517trans.com/catalog/11b.php