Tiptronic Boxster Won't Go Into Park - Cable seems fine

[mrk]

Hi all, I am a new owner of a 1997 Boxster automatic with tiptronic (95000km/60K miles) and a new member of the forum.

I am hoping someone can help with a problem I am having. The car will not shift into park. I am able to force the shift lever into the park position (with a fair amount of force) but the instrument display shows it being in reverse. The instrument display does show the correct gear for D, R and N.

I had a mechanic friend look at the problem. He disconnected the shift cable from the lever at the rear of the car and we pressed on the rear lever to change gears but were still unable to make it shift into P. The cable seems to be ok, and the shift knob in the cabin moves freely through all gears including park with the cable disconnected from the rear.

Another thing to add is that I did have a previous instance a couple of months ago where the car was stuck in Park and wouldn't shift into gear. I finally gave up and left it alone for a while and it somehow worked several hours later. The transmission seems to shift just fine while driving so I think the problem is something related to the 'park' mechanism only.

The info that I have read online seems to suggest that the next thing to check would be the multifunction switch located on the left side of the tranny, but my repair manual says you need to remove the transmission lower cover, catalytic converter, suspension, etc to get at the multifunction switch. Has anyone had to replace one and is there an easy way to test it before going through all that work?

Any advice would be greatly appreciated!

[mrk]

It gets worse...

While the car seems to be able to shift between all gears except Park, it seems that none of the gears actually engage. When you press the gas pedal while in drive or reverse, the engine revs but the car doesn't move.

As you move the shifter between D, R and N, the lights on the instrument display change accordingly and the engine idle seems to change as though the transmission had changed gears, but the the wheels do not turn.

The car is presently stranded in a friend's driveway. The only thing left that I can think for me to do (within my capabilities) is to check the automatic transmission fluid level. I know this is supposed to be 'life time' ATF but perhaps the transmission has lost some fluid over the years. I just don't understand why I was able to drive it there and now suddenly it won't drive at all.

Does anyone have any suggestions on anything else I can check? Could the problem be the multi function switch? I would like to check all obvious things before I tow it to the dealer or independent euro mechanic.

[Xpit77]

Check for corrosion and dirt on the lever pin on the tranny. Mine did the same and my guy did the same trouble shooting. Mine had corrosion on the pin where the lever is attached so he cleaned it with some sandpaper and lubed it. All good now.

[BirdDog]

To check the Tiptronic fluid level the car has to be up in the air and some under-car components have to be removed (to gain access to the fill port). Then, with the transmission warmed up to between 90 and 100 F, you have to pump more fluid in through the fill-tower. When the fluid starts raining down on you from the fill tower, it's full. Has to be done in this temp range. If colder you'll overfill it. If warmer you won't be able to add fluid.

As far as I know, there's no other way to do it.

It's a royal pain, but there it is.

As to the "lifetime" fluid, don't believe it. The manufacturer now says to change it (I can't remember if it's at 50K miles or 75K miles).

Try what Xpit77 did. I hope it works for you!

[Uta]

Hy, I saw your post from 2 years ago with the porsche gearbox problem., and I've just bought one with the same problem ,how did you fix the issue,?

[DMags]

Same issue here. Anyone figure this out yet?

[Sirius]

I'm happy to post that I found a solution to this problem. I had the same problem on my 1998 Boxster. The first problem I found was the linkage to the NSS. I replaced it and soon realized this was not the only problem.

The next problem was the Shift piston in the Valve body. Don’t worry it was easy to replace and it cost $23.00 Shipped. I have attached a link to an article that explains it all. It says 1997 only but mine is a 1998, it may be an early 1998 so that could be the reason I had the same problem.
https://www.transmissiondigest.com/1997-zf-manual-valves/
I hope this helps you!

[EJS]

I own a 97 Boxster equipped with the Tiptronic (ZF5HP19 / A86.00) transmission. I am experiencing heat related shifter/interlock problems. As the operating temperature rises, the Shift Selector becomes very difficult to move and does not consistently engage the proper gear. Eventually the car will not start in P until it cools down. When in gear, the transmission performs flawlessly.

After driving during a hot day, the shifter became extremely stiff. It eventually moved to N but would not move to P without considerable force. The shift linkage attaching ball socket was broken at transmission shift pivot. Shift linkage was replaced, but still unable to engage gears. Pan was dropped and the shift linkage pin was not attached to the valve body selector valve. The linkage was reattached and adjusted. This made the car road worthy, but did not address the heat related problem.

The transmission digest link that Sirius posted on 12/26/22 seems to match my problem exactly. Sirius mentions this valve can be replaced. Can anyone advise where a replacement selector valve / shift piston can be obtained?