Questions on Automatic trans!!!

I am working on my car, but miss driving a 928. Mine is a 1985 5 speed, I am looking at is a 1985 automatic, with 150,000 mile on it. I always wanted an automatic for the traffic where I live is horrible sometimes, I have eaten up 2 clutches sitting on the bridge moving at about ½ a mile an hour. I would never get rid of my 5 speed but might add this to the stable. Below is the transmission problems, is his response bull** or is it time for a new transmission?
I lost park on the shifter not too long ago. After reading many forums, it sounds like the linkage. $200.00 part. It starts fine in neutral and have been using the parking brake when not in use.
The transmission started downshifting at speed from 4th to 3rd. You can simply shift back to 4th by accelerating to get the rpms up enough until it up shifts. Forum reading recommended using a transmission cleaner to resolve problem. Just put some in last week and seemed to lesson occurrence, but still happens.

I would question the internals of the transmission. Sounds like it is slipping to me. Of course he doesn't mention if the fluid has been checked or replaced, so it could be a cheap fix. But if I were buying it as is, I would presume a transmission replacement is needed, and buy it with that in mind. Of course you aren't really looking for another project 928, are you?

That does not sound good... Normally these transmissions are pretty good and when they start acting up if a fluid change does not fix it that is usually a bad sign...

Neutral and park are the same valving in the trans.
The difference is that in park a finger with a square cut end drops into a squar cut gear stopping the trans from rolling.

It sounds like the finger (parking paw) snapped.
The shifting change sounds like debree may have got into the modulator valving which is in the same area.

On the bench it is a simple replace the paw and blow out the debree.
But I have been wrong before and you just do not know until you look inside.

at this link it is part #8

www.jimellisporscheparts.com/showAssembl...ukey_product=3630500

Trying to decide if I want another project!!

You never know what you will get from your box of chocolates...

If you are really, really lucky, the transmission will need adjusting. Shifter adjustment might solve the Park problem, but it doesn't sound likely.
Throttle cable adjustment might solve the 3-4 shift problem, or a full fluid change might help.

Removal and repair/rebuilding of the automatic is a major project. The cost will be close to the value of the car if you have it all done by a shop. The Park pawl is nearly the last part that comes out of the case.

Bottom line - a big gamble. Take the cost of the car, and add estimates for the rebuilding or replacement of the transmission. How nice an automatic could you buy for the total?

Wally