shift ???

[profox02]

Ive Got A Problem With My '94 Chevy Silverado Z71...
The Problem Is That When U Take Off And Its Is 1st Gear The Rpm's Get Really High Before It Goes Into 2nd.....and When It Goes Into 2nd Its Hard And Gives It A Jerk...how Do I Get Rid Of This.......1994 Silverado Z71..350..not To Sure Bout The Tranny, But, I Will Find Out....thx

[profox02]

The Tranny Is A "4l60e" ....i Think Its The U-joint....

[GlacierDragon]

My 87 is doing the same thing. I've still not gotten it fixed yet. My best friend's suburban is a 90's version and her problem was the Throttle Positioning Sensor. Replaced that, and no problem!
My truck has that sensor, but in 87 regulating that process wasn't it's job so I'm still trying to get it figured out.
The transmission was rebuilt a year and a half ago, the engine is high mileage but still strong. Cleaning a vacuum line fixed the problem for an entire day. Driving it for a while causes everything to smooth out, so I think it just needs time to build up the vacuum pressure. Just can't figure out why it's not starting out with good pressure or what is getting the line dirty.
The transmission mechanic thinks it is a bad engine or a plugged catalytic converter. My regular mechanic and I don't think it's the engine and the catalytic converter was replaced only a few years ago.
Anybody have any ideas?
I'm having to surrender my truck for a couple of days so the mechanic can check it out again. By the time I drive the half an hour to the transmission place, the thing has just gotten back into shifting okay and so it's hardly getting looked at because it's not misbehaving that much.
Anybody have any ideas? If I can't get it to shift right, I'm not going to be able to even attempt emissions testing where they want you to hold it at speed for however long it is and the deadline is looming!

[Bonner03]

Originally Posted by profox02

Ive Got A Problem With My '94 Chevy Silverado Z71...
The Problem Is That When U Take Off And Its Is 1st Gear The Rpm's Get Really High Before It Goes Into 2nd.....and When It Goes Into 2nd Its Hard And Gives It A Jerk...how Do I Get Rid Of This.......1994 Silverado Z71..350..not To Sure Bout The Tranny, But, I Will Find Out....thx

Did you do anything to the throttle body or work in or around that area? When I removed mine I unhooked the detent cable. When I installed it I had to adjust and readjust the detent cable to get it to shift properly. I don't know if your truck has one, but it may have something like it. I had hard shifting and high RPM's like that. 88-92 - detent cable. 95-98 - transmission shift cable. I don't know about a 94. Hope that helps.

[2000CAYukon]

On the 4l60e, the TPS is used to control shifting instead of a TV Cable.

The TPS can cause your problem; however, internal valve body issues can also cause it.

//2000CAYukon

[akz71]

I have a 97' that does the same thing. I found some info. saying that these problems can be from the input/output speed sensors. On the 4L60E the valve body was a crap design, and many people recommend to replace the valve body and install a sonnex Valve Kit TCC Regulator w/sleeve.

[Arrowshooter]

I'm with akz71, your problem is most likely in the valve body. Get into a trans shop and have them checkout.

[jcdubbu]

i had the same problem in my 6.5 diesel after replaceing the tps sensor. solution was to losen the tps sensor and adjust it by rotating it about 30 degrees. if u have the same tps sensor that has this adjustment, i would try this first. it fixed my problem immediatly. good luck!

[MyTOY]

I haven't heard of too many probs like this on your year with
the valve body but here's some info

Bulletin No.: 01-07-30-023B

Date: March, 2002

TECHNICAL

Subject:
Harsh 1-2 Upshift, SES, MIL, or CEL Illuminated, DTC P1870 Set
(Replace Valve Body)

Models:
1996 Buick Roadmaster
1996 Cadillac Fleetwood
1999-2000 Cadillac Escalade
1996-2000 Chevrolet Camaro, Corvette
1996-2000 Pontiac Firebird
1996-2000 Chevrolet and GMC Light Duty Truck Models
1996-2000 Oldsmobile Bravada
with 4L60-E Automatic Transmission (RPO M30)
Built Prior to January 15, 2000 (Julian Date 0015)

This bulletin is being revised to update VIN Breakpoint Date information and revise the Parts Information table. Please discard Corporate Bulletin Number 01-07-30-023A (Section 07 - Transmission/Transaxle).

Condition

Some customers may comment on a harsh 1-2 upshift and the Check Engine Light or Service Engine Soon indicator is illuminated.

Diagnosis

Typically, these vehicles will have been driven more than 32,000 km (20,000 mi) before this condition occurs.

The scan tool may show a DTC P1870 set as a history code.

A harsh 1-2 shift or DTC P1870, caused by wear in the control valve body, may be difficult to duplicate when the transmission temperature is below 93°C (200°F).

Cause

The condition may be due to wear in the control valve body. This wear occurs in the bore that contains the TCC isolator and regulator valves, and results in poor, or no, TCC apply.

Correction

Install a control valve body with the revised TCC regulator and isolator valves. Refer to the Parts Information table below. These valves are used in all transmissions produced after January 15, 2000 (Julian Date 0015), and all of the service parts currently available through GMSPO contain revised TCC regulator and isolator valves.