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Posted By: 33films won't shift out of first - August 19th 2012 2:50 pm
I have a 94 g10/15 with a v6 with 108,000 miles. I have been having some shifting problems lately. Couple weeks back going down the interstate at about 65-70 it fell out of gear and started revving. It would only do this if i had the cruise on and wipers which i thought was weird. Put some Lucas in and it's been doing fine. a little rough shifting into second but otherwise ok.

Coming home in heavy rain tonight (wiper's on again) hit a few big puddles it fell out of gear again and now it won't shift out of 1st. drove 20 miles home in first gear.

Any ideas?
Posted By: 33films Re: won't shift out of first - August 19th 2012 2:51 pm
I figure i'll start with a fluid and filter change at the least
Posted By: draggnastro Re: won't shift out of first - August 19th 2012 5:01 pm
Torque convertor is hashed, which most likely has gotten a ton of crap in the trans and trashed it as well. Sounds like time for a new trans. thats exactly what my 4.3 Astro did when it blew its trans.
Posted By: 33films Re: won't shift out of first - August 19th 2012 5:15 pm
from what i am reading online, a fuse or solenoid has gone out.
Posted By: frscke1 Re: won't shift out of first - August 19th 2012 8:12 pm
Originally Posted by 33films
from what i am reading online, a fuse or solenoid has gone out.


Thats wishful thinking....
Posted By: wrcsixeight Re: won't shift out of first - August 19th 2012 8:38 pm
Hitting a puddle then it acting up would have me checking and cleaning all the wiring and connections leading to the transmission.

It might not help, but it will not hurt.

Go crawl under the van follow some tranny wiring around.
Posted By: draggnastro Re: won't shift out of first - August 19th 2012 11:16 pm
700r4 theres only one plug going to the trans, a white or grey 4 pin square plug on the driver side. All it controls is the tc lockup. Even if you unplug it, it'll still have more than one gear.
Posted By: 33films Re: won't shift out of first - August 20th 2012 2:27 pm
well here's an odd update. went out to my van this morning. Took it around the block and all my gears were there.
Posted By: CatFish Re: won't shift out of first - August 20th 2012 4:52 pm
If it's a '94 it's most likely a 4L60E or other ECM type trans and you could have a bad solenoid or gunk in it or just a bad connection. My '94 is a 4L60E. Do a filter swap and see whats in the pan. If the pan's clean put it back with a new filter. Make sure the fluid level is correct (not under or over).
You may need to clean the wiring connector on the transmission case. Clean around it, if it's dirty, before unplugging it and then clean the inside of the connector (both sides) with electrical contact cleaner. Put it back with some dielectric grease on the rubber water seal on the plug.
On most of the ECM controlled trans, if the ECM loses contact with the trans (or it has a shorted solenoid, etc.) it will go into "limp home" mode. You will then have reverse and one forward gear but no shifting. Some will reset if you turn off the ignition but, if the problem is still there, will revert to that mode once you start moving. I've heard of some acting this way when the trans had a corroded ground connection thru the connector plug. The ECM couldn't compare input to ground.
None of this will cost much but it's worth a try before buying a transmission.
Posted By: josh_performanceinc Re: won't shift out of first - August 20th 2012 8:08 pm
The little plastic gear that drives the governor (housed inside the metal "bubble" on the tailshaft) blew up on mine. I found its pieces in the pan. Put in another out of a spare I had laying around and it worked great. Since you got your gears back I suppose it wasn't that, but maybe some crud is in that area and hanging up the springs in it. Just another thing to check if it flubs up again. Good luck! cool
Posted By: 33films Re: won't shift out of first - August 20th 2012 9:11 pm
thanks. it makes sense of a dirty connector with it only giving me issues when its raining. I'm about to crawl under and see. thanks
Posted By: Keep_On_Truckin_WNY Re: won't shift out of first - August 20th 2012 11:44 pm
my '95 G30 had a bad alternator at one time and when the battery got too low the trans would slip into 'limp mode'...

that's something else to check - when i would hit a puddle my alternator used to scream and the volts gauge would drop...

i eventually put in a new alternator and battery...

never had another problem until my battery hold down broke during a panic stop - the battery flew forward and shorted out and blew 'something' in the trans electrical - i also had to drive 40 something miles home in first gear... that was fun...!!!!!
Posted By: 33films Re: won't shift out of first - August 21st 2012 9:52 am
that is a possibility. First time it gave me trouble I had wipers, cruise, and the radio on. and it fell out of 4th. but came back when i turned the wipers and cruise off. hmmm.

the connector at the transmission was fine. still snug and clean. there was a trace of fluid around the gasket and the rear seal. So I am thinking low fluid made it do this.
Posted By: CatFish Re: won't shift out of first - August 21st 2012 10:03 am
Check and clean your ground cables. I add a couple of small ground straps on most of my vehicles just to keep down trouble.
Posted By: Bullet Re: won't shift out of first - August 21st 2012 12:08 pm
They also occasionally have problems with the wiring harness inside the tranny, they are available aftermarket, I know rockauto has them.
Posted By: Doc 2% of Canada, EH!!!! Re: won't shift out of first - August 21st 2012 12:14 pm
Like Catfish says check the grounds, but also the Battery and alternator.....sometimes the alternators on the way out fluctuate the voltage and drives the puter crazy and affecting everything electrical...Next time it won't shift out of first check the voltage at the battery and leave everything on.....
Posted By: Keep_On_Truckin_WNY Re: won't shift out of first - August 21st 2012 2:20 pm
I came across this on AllData; i don't think it's your problem - but it may be good to post here for someone who also has a problem with their trans:

TECHNICAL

Bulletin No.: 08-07-30-027

Date: June 04, 2008

Subject:
No Movement When Transmission is Shifted to Drive or Third - Normal Operation When Shifted to Second, First or Reverse (Replace Forward Sprag Assembly)
Models:
1982 - 2005 GM Passenger Cars and Light Duty Trucks
2006 - 2007 Buick Rainier
2006 Cadillac Escalade, Escalade ESV, Escalade EXT
2006 Chevrolet SSR
2006 - 2008 Chevrolet Avalanche, Colorado, Express, Silverado Classic, Silverado, Suburban, Tahoe, TrailBlazer
2006 GMC Yukon Denali, Yukon Denali XL
2006 - 2008 GMC Canyon, Envoy, Savana, Sierra Classic, Sierra, Yukon, Yukon XL
2006 Pontiac GTO
2006 - 2007 HUMMER H2
2006 - 2008 HUMMER H3
2006 - 2008 Saab 9-7X
with 4L60, 4L60E, 4L65E or 4L70E Automatic Transmission (RPOs MD8, M30, M32, M33 or M70)

Condition

Some customers may comment that the vehicle has no movement when the transmission is shifted to DRIVE or THIRD position, but there is normal operation when it is shifted to SECOND, FIRST or REVERSE position.

Cause

This condition may be caused by a damaged forward sprag assembly (642).

Correction

When inspecting the sprag, it is important to test the sprag for proper operation by holding the outer race (644) with one hand while rotating the input sun gear (640) with the other hand. The sun gear should rotate only in the counterclockwise direction with the input sun gear facing upward. If the sprag rotates in both directions or will not rotate in either direction, the sprag elements should be inspected by removing one of the sprag assembly retaining rings (643). Refer to SI Unit Repair section for forward clutch sprag disassembly procedures.

If the sprag is found to be damaged, make repairs to the transmission as necessary. A new forward roller clutch sprag assembly is now available from GMSPO.




If clutch debris is found, it is also very important to inspect the Pressure Control (PC) solenoid valve (377) fluid screens. Clean or replace the PC solenoid (377) as necessary. It is also important to flush and flow check the transmission oil cooler using J45096. Refer to SI Automatic Transmission Oil Cooler Flushing and Flow Test for the procedure.




The notches above each sprag must point up as shown when assembled into the outer race.

Bearing Assembly, Input Sun Gear

Snap Ring, Overrun Clutch Hub Retaining

Hub, Overrun Clutch

Wear Plate, Sprag Assembly

Retainer and Race Assembly, Sprag

Forward Sprag Assembly

Retainer Rings, Sprag Assembly

Outer Race, Forward Clutch

Washer, Thrust (Input Carrier to Race)

The following information applies when this sprag is used in 1982-86 transmissions.

The new design sprag can be used on models 1982 through 1986, by replacing the entire assembly (637 - 644). Individual components are NOT interchangeable.

Important: The wear plate (640) and input thrust washer (660) are not required with the new sprag. Use of the thrust washer and wear plate with the new sprag assembly will cause a misbuild (correct end play cannot be obtained).



...more coming
Posted By: Keep_On_Truckin_WNY Re: won't shift out of first - August 21st 2012 2:26 pm
Like stated above, it definitely sounds more electrical than mechanical - something about putting electronics in control of mechanical; if it turns out that your electrical system is in fact good, i think this might be another problem: it's basically the 2-3 shift solenoid inside the trans.


INFORMATION

Bulletin No.: 01-07-30-036H

Date: January 29, 2009

Subject:
Diagnostic Tips for Automatic Transmission DTC P0756, Second, Third, Fourth Gear Start
Models:
2009 and Prior GM Passenger Cars and Light Duty Trucks
2009 and Prior HUMMER H2, H3
2009 and Prior Saab 9-7X
with 4L60-E, 4L65-E or 4L70E Automatic Transmission (RPOs M30, M32 or M70)

Supercede:

This bulletin is being revised to add the 2009 model year and add details regarding spacer plates. Please discard Corporate Bulletin Number 01-07-30-036G (Section 07 - Transmission/Transaxle).

Some dealership technicians may have difficulty diagnosing DTC P0756, 2-3 Shift Valve Performance on 4L60-E, 4L65-E or 4L70E automatic transmissions. As detailed in the Service Manual, when the PCM detects a 4-3-3-4 shift pattern, DTC P0756 will set. Some customers may also describe a condition of a second, third or fourth gear start that may have the same causes but has not set this DTC yet. Below are some tips when diagnosing this DTC:

^ This is a performance code. This means that a mechanical malfunction exists.
^ This code is not set by electrical issues such as a damaged wiring harness or poor electrical connections. Electrical problems would cause a DTC P0758, P0787 or P0788 to set.
^ The most likely cause is chips/debris plugging the filtered AFL oil at orifice # 29 on the top of the spacer plate (48). This is a very small hole and is easily plugged by a small amount of debris. It is important to remove the spacer plate and inspect orifice # 29 and the immediate area for the presence of chips/debris. Also, the transmission case passage directly above this orifice and the valve body passage directly below should be inspected and cleaned of any chips/debris. For 2003 and newer vehicles the spacer plate should be replaced. The service replacement spacer plate is a bonded style with gaskets and solenoid filter screens bonded to the spacer plate. These screens can help to prevent plugging of orifice # 29 caused by small debris or chips.
^ This code could be set if the 2-3 shift valve (368) were stuck or hung-up in its bore. Inspect the 2-3 shift valve (368) and the 2-3 shuttle valve (369) for free movement or damage and clean the valves, the bore and the valve body passages.
^ This code could be set by a 2-3 shift solenoid (367b) if it were cracked, broken or leaking. Refer to Shift Solenoid Leak Test in the appropriate Service Manual for the leak test procedure. Based on parts return findings, a damaged or leaking shift solenoid is the least likely cause of this condition. Simply replacing a shift solenoid will not correct this condition unless the solenoid has been found to be cracked, broken or leaking.
It is important to also refer to the appropriate Service Manual or Service Information (SI) for further possible causes of this condition.
Posted By: Keep_On_Truckin_WNY Re: won't shift out of first - August 21st 2012 2:35 pm
if i were in your shoes, i would take the van to an Autozone, Advance Auto Parts, or Pep Boys and have them do a charging system test, then a battery test...

from there, they could tell you if there's something weak (maybe the alternator's on it's way out and not giving min. 12.6V at load) or, maybe there's a fault in the alternator feed line...

next, i would check all the fuses and make sure they're correct...

you can check here for any history fault codes, it is OBD1 (pre-1996): http://www.troublecodes.net/GM/

you could also check your belt tension, and the wiring going into/out of the computer (the computer's under the driver's seat)...

did you drive the van any more last night...?
Posted By: 33films Re: won't shift out of first - August 21st 2012 8:51 pm
I am gonna drive it to Auto Zone and have it checked out. thanks. I really feel it's electrical too
Posted By: 33films Re: won't shift out of first - August 22nd 2012 12:45 am
Ok, took it to autozone. they said the battery and alternator are fine. I did notice that when the wipers come on the amp gauge drops to almost red. I drove it for about 20 miles with the air, wipers, radio, cruise and interior lights on it struggled a little but did 65 fine. Got off the interstate and it had gone back into limp mode. Checked the fluid when i got home and it was fine. This is stumping me.
Posted By: Bullet Re: won't shift out of first - August 22nd 2012 11:51 am
Pondering on this, what do the tranny and wipers have in common? Only the steering column. May have a chaffing problem, hot grounding in column and following some path to the tranny and flipping out the solenoids. Just saying, there has to be a common point when two unrelated systems freak each other out.
Posted By: Keep_On_Truckin_WNY Re: won't shift out of first - August 22nd 2012 3:35 pm
on an older van like yours (or pretty much all the GM's) the shifter is all mechanical linkage until you get to the trans... the trans does have outside wiring to control things, but if i remember correctly, none of that control wiring goes through the steering column...

but then again, with all the movement that happens inside a steering column, it is possible there is a pinched wire or a broken ground or something...

did Autozone give you a printout of your charging system...?
did they run the test with your loads off and then on...?

if turning your wipers on drops your voltage, there's either a TON of resistance in your wiper motor, or the alternator is failing... might not be dead yet, but going out...

how were the volts while you were driving 65...?

is there an aftermarket alarm system in the van...? how about extra lights, or some switches, or possibly some shoddy repair work done previously...?

if you have the time, start looking at the wires under the dash, at the computer, or even the alternator feed line (it bolts to the back of the alternator and feeds the electrical system)...

it might be a PITA, but i don't think you have a mechanical problem - so if you do decide to take it to a shop, make sure they don't just put a new trans in it or something...!!!!!!
Posted By: 33films Re: won't shift out of first - August 23rd 2012 4:17 pm
I don't really trust the guy that did the Autozone test. I'm gonna get it tested a different place today. At 65mph it would still drop the volts down to the red. if i turn off the wipers the volts go back up. I am gonna do the drive i did the other day without running the wipers and see if it fails.

I appreciate all your help in this annoying as hell problem.
Posted By: 33films Re: won't shift out of first - August 24th 2012 5:09 pm
I drove it around last night on the interstate for about 30 minutes. Never touched the wiper and it did fine.
Posted By: Keep_On_Truckin_WNY Re: won't shift out of first - August 24th 2012 6:56 pm
that's pretty crazy... maybe it's about time to check the wiring in the column, around the column, maybe even try 'just' the wipers with the van running and no other loads on...?

i wonder if the wiper motor is going bad and drawing a ton of power (i've never heard of that before, but it could be possible...?)

Posted By: Bullet Re: won't shift out of first - August 25th 2012 3:14 pm
Yeppers, theres a lot of wiring in a small space under there. Begin by unplugging the wiper motor and turning the wiper switch on to see if you have the same problem. If not, then the wiper motor is suspect but I am betting it's fine. If there is some sort of connection sending power from the wiper switch to the tranny, it will act the same. There is also the torque converter circuit that comes into the brake light switch that is supposed to unlock it when you hit the brake pedal, it also disengages the cruise so there's another connection. The brake pedal bracket has the column bolted to it, the column has the shift linkage and the wiper/cruise combo switch. Wipers, cruise, tranny all come together at the column.
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