94 PA Ultra Overdrive problem

Maybe this has been dealt with in this forum already, however I did not manage to make a proper search..
My 94 PA Ultra (SC) happens to act as follows from time to time: especially in summer at high outside temp, after having cruised for about 30 miles, overdrive will disappear for some reason resulting in cruising at very high rpms at regular speed. Stopping and restarting the car sometimes helps, sometimes it won't.
Any ideas or experience on that??
Thanks,
XR7

It could be the solenoid that engages forth gear. You could have other internal problems also. Time for a visit to a transmission shop?

Tnx HotZ28,
meanwhile I've found extensive info in a former thread/posts, and bottom line seams to be it's an electrical issue (that's why OD/4th gear sometimes comes back after having shut off & restarted the car) and apparently it's the solenoid as you've stated.
However, going to parts america homepage (entering ''94 park ave ultra'), there are different solenoids (with differing descriptions) offered and now I'm lost, whether these are just different products from different manufacturers or there are various solenoids in my car? i.e: Buying and replacing the solenoid Borg Warner S9818 (which was referenced in that earlier thread) will that do the job or are there any other parts/solenoids to be possibly replaced??
Tnx.
Btw: I love that Park Ave Ultra because I consider The PA as a milestone in '90es US-car development and I really like the design, which could be described as a (bigger and cheaper though) all-american version of a Jag XJ. Having had no real issues with a '91(regular) PA, my '94 PA Ultra (only 60K miles, very well maintained)really is a t r o u b l e m a k e r, full of ugly bugs, popping up at any times.. extremely unreliable... however, I will stick to it a put it aside, once I'll will have made up my mind how to replace it (SRT-8 'Charger' or muscle-Stang, yet to come, or should I wait for that COUGAR, hopefully to come out within 2-3 yrs?!!

Listed below are several different brands listed for your car. They range in price from $25 to $50 based on brand name. You should have three solenoids in the trans, one for 1-2 shift, one for 3-4 shift and one for TQ lock-up. The shift solenoids are identical and the TQ lock-up is a different part number.
You have to pull the pan to replace them, and no more than they cost, I would replace all three as well as the trans filter & fluid.

ATC 520216
4T60E; 4 Spd; 20 Bolt Pan; Torque Converter Clutch Lock-Up and Shift Solenoid 1st-2nd and 3rd-4th

GP Sorensen TSS35
Tcc Pwm Solenoid; TH4T60E (M13) 4 Speed Transmission


GP Sorensen TSS21
On/off Lock-up; TH4T60E (M13) 4 Speed Transmission


Borg Warner S9818
Transmission Control Solenoid


Niehoff Ignition DR9818 S
Transmission Control Solenoid

Hi Hot Z28!
Tnx for the advice, meanwhile all solenoid heve been changed and car does fine (exeppt for all other issues!), the bill I've got for changing all solenoids amounted to the equivalent of 1 grand!! And on top, they managed to twist the chassis one way or the other while fiidlling with the gearbox. Kinda expensive ride, my PA Ultra!

Listed below are several different brands listed for your car. They range in price from $25 to $50 based on brand name. You should have three solenoids in the trans, one for 1-2 shift, one for 3-4 shift and one for TQ lock-up. The shift solenoids are identical and the TQ lock-up is a different part number.
You have to pull the pan to replace them, and no more than they cost, I would replace all three as well as the trans filter & fluid.

ATC 520216
4T60E; 4 Spd; 20 Bolt Pan; Torque Converter Clutch Lock-Up and Shift Solenoid 1st-2nd and 3rd-4th

GP Sorensen TSS35
Tcc Pwm Solenoid; TH4T60E (M13) 4 Speed Transmission


GP Sorensen TSS21
On/off Lock-up; TH4T60E (M13) 4 Speed Transmission


Borg Warner S9818
Transmission Control Solenoid


Niehoff Ignition DR9818 S
Transmission Control Solenoid