Symptoms of bad Shift Solenoids

[BodybyFisher]

I have not driven it yet because when I see him there are no symptoms but my friends 95 Eldorado I am told gets to a speed and from his description the RPMs surge like its slipping I took that to mean it freewheels. There is a difference between slipping and freewheeling, where the gear's limit has been reached and RPMS increase dramatically from that point because a shift didn't occur.

Can a bad shift solenoid cause this symptom?

He had the shift solenoids replaced about 7 years ago. If I recall the solenoids were redesigned with a bracket to limit the cracking potential.

When he was in the hospital about 6 months ago, his wife had me check the tranny fluid because she said the tranny was "slipping". The fluid level was fine and I didn't detect slipping at all.

The "slipping" is back at least intermittantly. I have assumed it IS shift solenoids as it is intermittent for the time being.

I checked codes and don't see anything related to tranny. I don't know if shift solenoids produce a code in 95 (OBD1)

I have not experienced bad shift solenoids or slipping of the tranny, so this is new to me. I am reluctant to do this job because we have had a few members have it turn into a bigger problem with NO drive at all. I understand there are check balls that must be placed properly. I have a dedicated tranny manual I need to refer to.

Any ideas or experience with shift solenoid (especially pre-96) symptoms appreciated, thx

[Cadillac Jim]

I went through my OBD I list and there are a surprising number of transmission codes. Here is what's left when I culled everything that did not relate at all to the transmission:

B124 Speed Sensor Circuit Problem
B127 PRNDL321 Sensor Circuit Problem [Park Brake Release]
I027 PRND321 switch failure
S043 Speed Signal Fault
P024 (E024) Vehicle Speed Sensor signal to TCC
P026 (E026) Shorted Throttle Signal Switch
P027 (E027) Open throttle signal switch
P028 (E028) Open 3rd or 4th Gear Shift Or Shorted 2-3 Shift Solenoid [VCC]
P029 (E029) Transaxle Shift 'B' solenoid problem (1st, 3rd, 4th gear)
P039 (E039) Torque Converter Clutch/Viscous Converter Clutch Engagement Problem
P050 (E050) Second Gear Circuit Pressure
P056 (E056) Transmission Input Speed Sensor
P057 (E057) Shorted 4th Gear Switch Circuit Or Shorted 3-4 Shift Solenoid
P059 (E059) Transmission Input speed sensor
P060 (E060) Cruise-Transaxle Not in Drive
P075 (E075) Intermittent VSS Signal
P076 (E076) Transmission Pressure Solenoid
P086 (E086) Undefined Gear Ratio (Transmission Pressure Control)
P088 (E088) Torque converter clutch did not disengage when commanded OFF by PCM
P089 (E089) Long Shift and Maximum Adapt (Trans Pressure Control)
P090 (E090) VCC/TCC Brake Switch/Park/neutral switch Input Circuit Problem
P091 (E091) PRNDL Switch Problem (transaxle range switch problem)
P094 (E094) Transaxle Shift "A" Solenoid Problem (Vehicle Speed Sensor)
P096 (E096) Torque Converter Overstress
P097 (E097) High RPM P/N to D/R Shift
P098 (E098) High RPM P/N to D/R Shift Under ISC
P117 (E117) Open/Short Solenoids/Solenoid Wiring (Transmission)

[Cadillac Jim]

From the 2002 FSM, there are lots of missing gear symptoms. I selected "No 4th gear" to show a table:

Checks Causes
1-2 Shift Solenoid Valve • Inoperative
• Debris
• Pinched wires
3-4 Shift Valve Bore Plug Misassembled
4th Band Burned, slipping, missing
4th Servo Cover Cracked
4th Servo Pin Broken, seized
4th Servo Piston Damaged
4th Servo Seals Rolled, cut or damaged

These are symptoms related to one gear, 4th gear for this table. There is always the EITLR, slipping sprag or bad line pressure(s).

[BodybyFisher]

Thanks Jim, my memory told me that shift solenoids didn't set codes but it looks like they do from the above and from this thread

http://caddyinfo.ipbhost.com/index.php?showtopic=43079&hl=

I sent the member from that thread to see the outcome. I didn't find even a history code on my friends car so I am a little perplexed. I told him the very next time it acts up to drive over and let me pull the codes while its active.

[Eldor.94.CadySo]

Quote

P076,P056 etc etc etc. Many people wont tell you this. All the looking I did and only seen one 2 minute video on you tube. JUST RESET YOUR ELECTRICAL SYSTEM. Dont know if pcm reset will work but sounds good too. just had the P076, shifting very rough into gears. So, either somethings broke or i did something. 

  always have had concerns abou my battery (complicated side port), cables, and bolt. Have a bolt for it with an extension on the end and another bolt on top of that ( darn thing cost me like 10 dollars ). i loosend the outer bolt to adjust a wire on the + side.. . . A day or two later. Im in this position. I just disconnected the battery (- then +) let it sit for 30 min. then went back and connected it (+ then-) Works fine. Even think my radiator stopped leaking)

 

[rockfangd]

lol.

I would have suggested that also.

You would be amazed what a good reset will do.

Most of the time when a shift solenoid is bad it will not be intermittent, unless it is a harness issue. 

Not saying it is not possible though. Nearly every shift solenoid I have done was broken. 

[Cadillac Jim]

The radiator stopped leaking too?  I'm not superstitious, so I would suggest that when you get time, you check all the hose clamps, including the ones on the bottom of the surge tank and the heater hose tee low on the firewall on the passenger side.