Weird Tranny Problem

[TruckMuddr]

Hey Eveyone,

I got a problem. My tranny is acting like a manual valve body and I don't know why. It used to do it every now and then, I'd just shut off the car and start it back up and it'd be fine. Now it is doing it all the time. If I put it in drive, that is what gears it starts in, 3rd is 3rd, and if I put it in 2nd it starts off in second gear. My shifter doesn't have a first, but you can pull the shifter back far enough to get first. When I try to put it in first it still starts in 2nd gear. The tranny was rebuilt September '02 w/ kevlar bands and about Febuary '03 it was parked and didn't move until about September '03 when I got the car. and it was fine untill now. Anyone know what could be the cause of this??????


Thanks,

[Craig 94 TA GT]

I'm a bit confused...
Are you saying that in drive, the car will only run in 4th, or the .7:1 ratio - or does it only take off this way, and somehow shift from 4th to 1st to 2nd to...? Just for a starting point, did you check the fluid level, smell it, or look at the color?

[TruckMuddr]

ok, it is acting like a manual transmission, on a manual tranny if you put it in 3rd that is what gear it is in. Same with mine, if I put it in D it will alway be in that gear it doesn't shift up or kick down. If I put it in 3 it is always in 3rd gear, same with second, but there is no 1st at all. In drive I can barely get the car to move off the line, I have to move it to second to get it to move and that is still hard for it to move.

Fuild level was in the middle of the two holes on the dipstick, I added some to it, but didn't change anything. it smells alittle burnt but barely and the color looks like I just put it in there. I'm wondering if because it sat for almost a year if it got something in it.

[Dave M]

You say the tranny was rebuilt september of 02. Are you sure a manual valve body wasn't installed during this rebuild? That wouldn't explain why it just started doing this though.... maybe some of you're seals dried out when it sat so long?

[TruckMuddr]

Yeah, I know it doesn't have a maunal valve body, because it was fine right after they rebuilt it and until the last month or so then it started screwing up.

[N20LT4Bird]

Chance are, one of the shift solenoids took a dive. The computer is probably starting the tranny in a limp mode. Maybe other possibilities as well - anywhere from Elec. pressure control switch to vehicle speed sensor (or other elec probs)?? Finally, it could be a wiped clutch pack or other internal leak, bleeding pressure. This is unlikely though; on the 4L60E, you will usually lose 4th gear before anything.

I am no expert, and I am taking a few guesses here; you need to take it to a GOOD tranny guy. One who will fix the problem and not just rebuild your tranny for you.

[Joe 1320]

I would at this point ask if you can manually shift into first, but since you can't do that, I can't ask. Could also be a bad low sprag. In any case, it's rebuild time. Since it has to be opened up, when it is rebuilt, make sure that a few parts are upgraded. You want a hardened sun shell, a higher number element low sprag, corvette servo should help in the longevity dept. The low sprag and sun shell are common failure parts. The servo just helps with fluid control.

[MikeE24]

hey guys i just ran a search and found this thread. last night i began having the same problem w/ my 98' T/A. mine has a 3.23 A4 with a whisper lid and borla y-pipe as the only mods. i was wondering if the problem was fixed and if so how much it costs to fix.

[TruckMuddr]

Well, Mine quit doing it by itself. So I haven't takin it in yet.. it did do it again about a week ago. I was sittin at a light and it started off in second and then when i was slowing down for the next light I felt it go back to normal. So I have no clue what it is. I was thinking a shift solenoid, or maybe just the connecter is bad/loose.

[TruckMuddr]

Ok, N20LT4Bird nailed it. I got around to scan it with FreeScan on my laptop and it came up with a trouble code 81 SHIFT B SOLENOID FAULT (ODM).

I got this off of AllData:
-------------------------------------
Diagnostic Trouble Code (DTC) 81

CIRCUIT DESCRIPTION
The 2-3 shift solenoid is used to control fluid flow acting on the 2-3 shift valves. The solenoid is a normally open exhaust valve that is used with the 1-2 shift solenoid to allow four different shifting combinations. The solenoid is attached to the control valve body within the transmission. Ignition voltage is supplied directly to the 2-3 shift solenoid. The Powertrain Control Module (PCM) controls the solenoid by providing the ground path through CKT 1223.

DTC 81 WILL SET WHEN
The PCM commands the solenoid "ON" and voltage remains high (B+) for 2 seconds. The PCM commands the solenoid "OFF" and voltage remains low (zero volts) for 2 seconds.

ACTION TAKEN (PCM WILL DEFAULT TO)
If the solenoid is shorted "OFF" third gear only will occur. If the solenoid is shorted "ON" second gear only will occur. DTC 81 will be stored in the PCM memory but will not turn "ON" the Malfunction Indicator Lamp (MIL) .

DTC 81 WILL CLEAR WHEN
The fault condition(s) no longer exist, and the ignition switch is cycled "OFF" then "ON."

TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.


This test checks 2-3 shift solenoid and the internal transmission wiring for shorts.
This test checks for power to 2-3 shift solenoid from the ignition through the fuse.

DIAGNOSTIC AIDS
Check all connections at the transmission.
An open in the ignition feed circuit can cause multiple DTC(s) to set.
-------------------------------------

So now I gotta jack it up tomorrow and test the connection and test the solenoid.

[Jeff_in_Atl]

FYI A guy where I work had a solenoid go bad in his 2000 S10. The solenoid was $11 plus a pan gasket and fluid. He said it wasn't hard to fix except the mess from dropping the pan.

[TruckMuddr]

Well, Not so lucky here.

Parts - OEM Part # - Price
2-3 Shift Solenoid - 8683187 - $39.44

[Jeff_in_Atl]

$22.48 from http://www.gmpartsdirect.com

[TruckMuddr]

I saw that but was wondering why it said valve.

GM PART # 8683187
CATEGORY: All
PACK QTY: 1 CORE CHARGE: $0.00
GM LIST: $39.44
OUR PRICE: $22.48
DESCRIPTION: VALVE

[Jeff_in_Atl]

Their descriptions are ofen wrong or missing. If you know that is the part number for it, it is the correct part.