97 Transmission problem

Hey guys. My Dad has a 1997 Chevrolet 1500 4-wheel drive with the famous and troubled 4L60-E tranny which has been working great up until a week ago. It started to shift very hard into first and second after driving on the highway for an hour. Guy at the tranny shop said it is the valve body sticking and said it should be totally rebuilt after something like this happens. :sly: The truck shifts ok now but I was wondering if it is really a must to rebuild the entire unit. The truck only has 60,000 on it. We are going to fix the valve body before we do an entire rebuild which comes to my main question. I doubt a few hard shifts would ruin the whole tranny. :screwy: I know these trannys have two valves that go bad and produce the code 1870 and that there arekits to fix this. Would it be better to replace the valves or buy the whole body? Also, what price would each option cost? Thanks for the help guys. This site is the best online!!

If it were my truck I'd flush the tranny and refill with top of the line fluid, and not worry about replacing/rebuilding anything unless the problem came back.

Get the kit that has the inserts for the valves and new valves. You have to ream out the valve body and install the hardened inserts and new valves.This will fix the notorious problem of wallowed out valve body. Just flushing and refilling the trans will not fix the problem.

Contact www.sonnax.com the transmission specialists. If you contact the tech guys there and explain your problem, I am pretty sure they can come up with a solution that doesn't involve a complete rebuild.

I would highly recommend the transmission flush too before you spend a large amount of money on your tranny. Flushing your transmission at regular intervals is a good maintenance practice, and it also can fix hard shifting symtoms like you are talking about.

Thanks for the guys. I called the experts at sonnax and they said that they have a TCC Valve and a valve body kit with a reamer that would clear this problem up. I think the kit costs a total of $175 or so. Guy at the tranny shop said he could install it for $150 plus filter and fluid. Looks to be about $350 to $400 in the end. A flush would probably help it last a little while but I figure I may as well do it right.

Not bad.....keep us posted on what effect the kit has on your transmission. I'm really curious to know. -Chris

I was also wondering if anyone else has done this repair and had good results. I am ordering the TCC apply valve kit along with the TCC regulator valve kit. THis is what was recommended and is said to clear up many of these problems. Any tranny experts recall any other things that should be replaced or checked while in there? Just want this to be done right. Thanks for the help. This site is great. Also I will let the rest of you know how it turns out. I know a lot of people also have or had this problem with these trannies.

hey guys i have a 97 silverado 37000 miles (im close to work) starting to get a clunking sound from the transmission area when the motor is cold it seems to stop once it warms up it is primarily from the 1st to 2nd shift any ideas or is this the same as the above post

When the trans went on my 97 at 83,000, It would shift
super hard 1st to 2nd after driving awhile (engaging OD)
Turning off the truck for a second would "fix" the prob.
until you went over about 40 MPH again. Also got the code.
This seems to be the classic prob. that the kits are supposed
to repair. I've heard some folks have luck with the bore kits. It was
too late for me and I needed a rebuild & new TC. when my truck
was in this hard shift condition it would also not go into OD and
would be erratic in other gears.
"captjpg"s prob. sound different. I know mine shifts rough
for the first couple miles on a cold day and others have said same.
I go a little easy until it warms up.

Important : If all of the following conditions are true, it is not necessary to rebuild the transmission or to replace additional transmission components beyond the control valve body.

^ Transmission operation is normal before the transmission reaches operating temperature, or before DTC P1870 is set (no slips, flares, or missing gears).

^ The torque converter is not blue or overheated.

^ The transmission fluid is not burned or has no burned odor

^ The transmission fluid pan contains no abnormal debris (clutch material, bronze, brass, or metal fragments).

When my trans started the hard shifting thing my local trans guy said it was the check balls boreing into the thin and too soft separator plate and sticking when things heated up. The extra flow makes the trans think it is slipping and it adjusts the pressures up accordingly, thus the hard shifting. He also said he has only had to do a handfull of the total revalve jobs. Sure as heck two of the balls had bored in with one half way through. He installed a TransGo shift kit with thicker plate and Corvett servo and all is still well after 35,000 miles and a whole lot cheaper. Unless you have a mound of clutch dust, or chunks of metal, in your pan I'd discount any total rebuild ideas.

My 97 silverado is shifting hard after being driven 30 to 40 miles without stopping, the lock up converter doesn't lock once the engine reaches operating temperature. Is the VB plate most likely my problem also? Thanks

I would say that if you were getting the hard shifting once you notice the slipping the VB plate is a good place to look. If not you have other issues. Once your tranny shop takes a look you will know for sure.

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.

My transmission doen't slip at all, just the hard shift after being driven 20 or 30 miles without stopping, It also sets no codes, yet. I just called my local GM dealer for a price on a VB. list for 536, my cost 382, complete transmission is 1375.

According to www.autorecallcenter.com there are no and have never been any recalls for that particular truck make, model and year. So I would assume this isn't a wide spread problem. I agree with you though, a few hard shifts shouldn't hurt the trans. I hope everything works out. Let us know!

I got my transmission fixed at a local shop $150.00 got the v/b repaired all is good now. He replace a valve as well as the plate. Thanks