Transmission won't shift ?

[Low_Bridge]

94 4WD 6.5 TD 4l80e tranny

On the way home I pulled off road & got in just a bit of sandy terrain. The thought crossed my mind to put her in 4wd But I just got a little wheel hop for maybe 100ft. I never took it out of regular Drive (2wheel)

So back on the highway I go -

Immediately she won't shift up from 1st when in drive & has never acted like this before except when I bought the Truck in July. & she did it when I tried out the 4WD but worked fine by just turning the truck on & off. I thought I didn't use the right sequence for placing in 4wd. Other times Once or 2wice the 4wd operated fine.

I've tried shutting her off

Putting in 4wd & taking her out.

Everything else seems fine it just won't shift out?

SO - I guess I'll go disconect the batteries & try again. - Tried & no Luck Rats! :(

Appreciate any direction.

[ 10-17-2004, 06:10 PM: Message edited by: Bill D'Addio ]

[kowsoc]

I had trouble with the 11 wire connector on the drivers side of the trans. Disconnect it, clean with contact cleaner and check the condition of the terminals/pins. The wheel hop and/or sand may have moved the connector enough to lose connection. Good luck, keep posting. smile.gif

[Low_Bridge]

I finally crawled back under & noticed the the harness that plugs into the side of the tranny on the drivers side was getting smashed by the bottom of the shifter lever for the 4WD.

I bent the lever away 1/2 inch unplugged the connection, a couple of the wires going into the connector were bare & the may have made contact. But I went ahead & made shure not were touching & plugged her back in. To be safe I disconnected the batteries for a cold boot.

She still won't shift out

Honestly I can't beleive I can't tell if it's shifting into 2nd.

Question:

How hard is it to take out the above harness to put it on the bench to check it over?

How sensitive is the thingamjig it plugs into? could it of been hurt?

What next?

Do I need to buy a tool to "pull codes" (*&%&*^%$&* I hate the thought. I've got enough tools to sink a battle ship. Feeler guages, vacuum Gauge & dwell meters have gotten me by for 25years!

Any direction would be appreciated.

Happy thanksgiving!

[JohnC]

No tools are needed to read the codes on a '94.
It probably isn't using first at all, just second, which is the fail mode. Check the trans fuse. It may have blown when the shifter contacted the bare wires.

[Low_Bridge]

You were on the money!!

My wife Hates driving old faithful. She extends her eternal gratitude.

Kind of embarrasing simple fix

How tough is it to pull that harness to R@R the bare spots?

Thanks !!!

[Low_Bridge]

OK so I did a McGiver fix on the harness. Changed the the oil & took the 94 on a 100 mile trip. creature comfort is nice w 3.5 kids

RPMS Going down the road we were hitting 2600 at only 66MPH? All shifting seemed fine. it seem like the motor is just working a bit too much? Tires are 265/75 16's

Is there a proper size for the alternator pulley to report rpms correctly?

I really don't think I have 4.++ gears but anyone have the codes for a 94 2500 4x4?

Thanks All

[rjwest]

http://www.troublecodes.net/GM/94-95_65.shtml

[Low_Bridge]

Thanks Rj but I guess i refered to it wromg as I ment the code in the vin # to designate axel ratio. My mistake.

[gunner 6165]

Hey Bill

Check in the bottom of your glove box, there should be a sticker with numerous 3 digit codes. You can learn alot about your truck with these. Go here (http://www.angelfire.com/ny2/96transam/rpocodes.html) to see which axle ratio you have. It's got alot of codes, not all are applicable to trucks.

GT4 = 3.73
GT5 = 4.10

and for a 1500 you can also have

GU6 = 3.42

2600 RPM and 66mph sounds like overdrive didn't engage. My 98 has 4.10's and at 65 I believe it's only turning 2200-2300 rpm.

Forgot to add my tire size is the same as yours on both trucks.

[Low_Bridge]

:eek: Wow got the GT5 code:

GT5 : AXLE REAR, 4.10 RATIO

But I guess it seems a little high the rpms but I know my 6.2 91 seems to work pretty hard. Could it be that altenater pully? I get 3 Shifts after I start up? What next?

PS IS this it? Topic: OD shifting oddly
PPSS: Now here may be the: fix that first stupid part. There are 2 autometer guages & when you hit the brakes those to lights for those gauges have always come on. I'm going to take the same trip today as the other day. I'll disconnect those lights!

[ 12-01-2004, 04:10 AM: Message edited by: Bill D'Addio ]

[Low_Bridge]

Back again from a micro Vacation -

1. Unhooked wire to gauges I mentioned.

2. AT 50 MPH while holding throttle steady w/ foot I hit the brakes & gey about 200 increase in RPM

3. 2450rpm @ 60 mph

This was the first set of short road trips for the truck. I never cranked her up to the 70 MPH speed limit. Most of our daily driving is around town so she'll stay around 2100-2200 RPM.

BUT it does still seem a little high.(the RPMS)

Any suggestions?

[ 12-02-2004, 11:11 AM: Message edited by: Bill D'Addio ]

[rjwest]

Tire size higher than stock?, MPH reads low.
1 in crease in dia is approx. 3 % slow.

Tach 's are not accurate, 100 rpm error not uncommon.

Alt pully size, very important for tach accuracy.

I would guess nthat you have an accumulation of
errors and that tranny is ok.

[Low_Bridge]

I agree RJ. Just not dialed in.

The previous owner did report numerous alternater changes.

So do you know if the 91's 6.2 2500 R alternator pully is the same diameter or better yet can someone give me a clue?

Tanks fo D'A help y'All

[ 12-03-2004, 01:06 PM: Message edited by: Bill D'Addio ]

[Low_Bridge]

Well the quarter fell on the floor and I loaded the the family in the 94 to take a 1200 mile trip for an unexpected funeral :( . She performed flawlessley and usually set the cruise on about 62 mph.

I didn't check the mpg but she used alot!

Thanks again as always for helping with the tweaks!