geetee

you sure its not tranny mount? Made sure bolts on new tranny mount are secure?

Ck986

Maybe it's just very worn mounts. I felt my motor lunge with the old mounts or rock back and forth when in first gear. I really needed to feather the clutch in that gear. The new 997 mount improves the drive immeasurably when driving around town at lower speeds.

rmc1148

I believe he changed all mounts.

up4speed

I changed all the mounts and torqued to factory specs.

mcbit

I thought I had.

"02996ttx50

than we share the same experiences as even our cars share a heritage and much technology btw various vag auto divisions ( sad i suppose to say lol ) but then you also know exactly what i'm trying to describe. the gti HATES going into 1st from anything other than a standing start, and even then wants out within milliseconds

i always likened the first tips to the old vw 411's with their semi auto shiftable 2 speed? or was it 3? LOL transmissions. that is exactly what tips felt like to me in the porsche 96 turbo, which is the first configuration of them i drove. in point of fact, i was turning in a bmw and they had a tip on the lot, and having had a number of pervious porsches and given i was then approaching or perhaps already well ensconced in my "mid life crisis" period, i had to test it. i did, and went immediately from there to a porsche dealarship and grabbed a cpl yr old cpo;'d 6spd x50 and been hooked ever since.

the poor guy at the bmw dealership was left standing there with the porsche keys in his hand and was fully expecting me to get back into an m3 or m5 as i had just turned in a lease. i can still see his face lol

sorry for the rant.. the point i was trying to make while sharing my life story ( i know, highly unusual lol ) is that the tip in the 996t really harkens back to vw's first "semi auto" transmission cars, and acts in very similar ways.. and hates being in first!

as i and others have said, just avoid it unless necessary, and if you find it downshifting at inopportune moments and with a clunk that assures! you something is amiss? then have that thing serviced pronto! a very expensive unit to repair i am told! good luck, and yeah.. gtis' are a gas!

mcbit

Just to reconfirm my original belief, I went and tried a number of 2 to 1 changes at speeds between 0 and 40 mph this morning. To be perfectly honest, they are just as smooth and seamless as down changing between any other 2 gears.

Now I just need to see what the change from R1 to R2 is like.

up4speed

Thanks for confirming. Now that I know that it's not normal (as I suspected), I need to figure out what can cause those symptoms. I'm obviously going to start with a fluid and filter change. However, I have no idea where to go from there. 😰

rabbit1445

Not so fast. Mine acts in the same way as you described earlier in the thread. I have discussed this with several other tiptronic owners and we all (except for mcbit it seems) experience this issue if trying to decelerate and manually shift into first gear. If it is stationary and manually shifted to first, no problem. However, I have never manually shifted into first while already accelerating, so I am unsure as to how it would behave. After experiencing this, I simply do not do it even though it may be deemed normal for this transmission.

For reference, I have the newer 997 trans mount as well as rs motor mounts installed.

up4speed

I don't think that anyone tried downshifting while "accelerating".
I'm pretty sure we are all talking about decelerating only. I also tried to make sure that I made it clear that I wasn't trying to downshift when I was traveling too fast for 1st gear. The bang on my car happens when it's crawling slowly. If I'm stopped or moving faster than a crawl, it doesn't bang. It's also not a gentle bang that I'm talking about, it's a noise and feeling that makes you feel like you just dropped the tranny onto the street! I'm pretty sure it isn't "normal".
Especially since it's a random thing. I actually thought that it fixed after I did engine and transmission mounts because I couldn't duplicate it afterwards. Then I tried it a few days later, and BANG!!!
I did find in the paperwork that the TCU was replaced by the prior owner, but I think he had some kind of error light which initiated the replacement... I wonder if there's a problem there?

mcbit

I certainly didn't attempt to changed down whilst "accelerating" in 2nd. I did: decelerating, flat at a crawl, flat at higher speeds and probably whilst slightly increasing in speed. There was nothing to suggest in any way that I was doing some thing that the box didn't like. Previous to the turbo I had a C4S with the same tip box, I did not try these particular tests in it but have no recollection of anything untoward during the occasional 2 to 1 shifts which I did. The only time I have had any transmission clunks or thumps in either 996 was when I first bought the C4S and the transmission mount was shot.

If Porsche didn't want us doing 2 to 1 shifts, it would have been pretty simple to stick a bit of code in the transmission controller which would prevent it.

Last930

When I first took delivery of my '02 TT Tip it went into 1st gear very abruptly if I manually shifted it while coming to a stop. The dealer reprogrammed the software at one of the service visits and it went away. The first thing I'd do is make sure any software updates have been done.

up4speed

I was starting to think that it may have a bad valve body, but now that you mentioned software, that very well may be it. As I mentioned, the TCU was replaced a while ago because of an error light (according to the paperwork)....Maybe it has improper software....hmmmm
I'll bring it to the dealer next week to have them hook up the PIWIS computer to check it.

up4speed

I just checked the receipts and the TCU# is:
996-618-180-04 which I believe to be the newest version for the 996's.

Pseudo Nim

Curious if you ever managed to figure this out. I have a 2001 996 with _precisely_ the same symptoms, up to and including the transmission mount / AOS swap that "seemed" to make things better but didn't. Ive resorted to being careful when downshifting (I only do it when I'm about to go up a steep slope, like a parking garage, and I've found it works OK if you let off the gas and go very slow with very little engine braking) but it's still unsettling.