911cedric

Hi

i just received a new 993 convertible today with a transmission issue; about 65k miles on it.
The transmission makes a nasty grinding noice when shifting into either 5th or 6th gear at high rpm. All other gears are flawless.
I started with replacing the transmission fluid but it wouldn't improve the shifting.

The first gears synchros (especially the 1st and 2nd) typically wear much faster than the 5th and 6th gears so i am wondering if the problem could be something else

any idea?

cheers

boman993

Maybe a saggy engine or transmission mount is the culprit? If the shift linkage is off a bit, there could be shifting and gear engagement issue...this is totally a guess though because not sure if that would only affect 5th to 6th specifically . But worth checking out.

shadow993

Has it been upgraded to a golden rod?

pp000830

If shifting feel is like the syncros are slipping over multiple teeth and the problem doesn't go away once the tranny is warmed up it points to your synchro friction rings being at the end of their lives. Uusually first and 2nd gear start dinging earlier as they are subject to much greater use. The only way I can see 5&6 having this issue is if the previous owner was hard on the tranny and had 1st and 2nd gear synchros replaced and now the higher gear synchros are showing their ware. Not sure how the shifting function described by the posters above relate to this issue and so my explanation is only a secondary issue once the shift linkage issues are sorted out.

911cedric

It was also my assumption that the first gears synchros only could have been replaced.
However, the car only shows little wear and only 65k;
if it is the original mileage, i would be a very rare failure

I will drive it a few more miles with the new oil and see how it goes.
Otherwise that will be a transmission drop:/

Leander

sagged motor mounts?

911cedric

This wouldn't cause grinding; there is only one external shift rod linked to the internal shift rods forking the gears sliders; if this part was bent or the linkage defective it would affect the shifting operation of all gears even when the transmission shaft isn't engaged

911cedric

It was also my assumption that the first gears synchros only could have been replaced.
However, the car only shows little wear and only 65k;
if it is the original mileage, i would be a very rare failure

I will drive it a few more miles with the new oil and see how it goes.
Otherwise that will be a transmission drop and a new set of synchros

vincer77

Any clutch slippage?

boman993

I see. The only reason I brought it up, is that when I replaced my stock shift linkage on my AWD car with the Golden Rod, it took some adjustment to the length of it in order for the car to shift smoothly. I noticed any slight adjustment in that area would affect shifting significantly. Specifically 5/6th. Thought maybe if the engine or trans is sagging a bit, this could affect it too! Thanks for that info though!

Hope it's not the synchros and the new fluid will do it's thing!




.

Drisump

I had a shifting issue which although not the same as yours, it demonstrated to me how important the quality of your motor mounts and shift linkage bushings are in these cars. After recieving a couple of opinions that the problem was in the box I thought I had nothing to lose so I changed out the motor mount (they were shot), installed a GR/SSK kit (upon disassembly found out the OEM bushings were in very poor shape), changed the tranny fluid for Porsche OEM stuff ($$$) and flushed the clutch hydraulics.....problem disappeared. The car shifts so nice now! Hope your answer is painless.