97 Blazer tranny problem: suddenly no forward gears

jbarsalou · #1 04-25-2006, 11:00 PM

I have a '97 S10 Blazer 2 door, AT, 4x4 with 166k miles. I replaced tranny at 100k with a brand new GM tranny. Now all of a sudden the truck has no forward gears but reverse works perfectly fine. I performed a filter/fluid change after 30k and 60k on this tranny. Anyone have any ideas? Thanks!

OverBoardProject · #2 04-26-2006, 02:37 AM

Have you been keeping an eye on the fluid level? Even with a new transmission you can still have leaks.
Other than that I don't know

Southern Comfort · #3 04-26-2006, 07:26 AM

Has your tranny slipped at all? Have you ever heard a clang when putting it in any gear. It could be your sun shell reaction gear or valve body. Has your SES light show on your dash. Does it register any codes in your computer. If so, please post them. Lets take it from there. Has your truck made any noise or act
in any abnormal way?
SC

jbarsalou · #4 04-26-2006, 06:26 PM

Thanks for the quick replies. It was a new GM tranny replaced by the dealer 66k miles ago. I am 10 months past the warranty. I check tranny fluid level on a regular basis as well as maintain the truck well. Other than this the truck runs very good and is in great shape. There are no codes tripped, no leaks, and the fluid right now is showing on the dipstick (although I can't properly check it since I can't warm up the transmission.) There were no clunks, noises, or slipping whatsoever before this. The only problem I saw was when I did a fluid/filter change a couple months ago I saw a very small, thin, curved piece of metal in the pan. It was about 3/8" long and 1/16" wide. I obviously know this isn't good but I needed to get the truck back together asap. Any additional ideas would be greatly appreciated. Thanks!

blazes9395 · #5 04-26-2006, 09:53 PM

I think you answered your own question....it sounds like you have an internal problem. Either way, with metal that size being found, you have to pull it and tear it down to see what went. I hate to break the bad news, but it sounds like thats your only bet at this point.

OverBoardProject · #6 04-26-2006, 11:39 PM

Sorry to hear that it happened, and in all reality it shouldn't have on a transmission that is so new.

I wouldn't bother seeing the dealer over it since it's past the warranty.
Aftermarket transmission shops will install all the updates that the dealer might omit so the problem hopefully won't happen again.

BlazerLT · #7 04-27-2006, 12:26 PM

1997 ignition switch can cause an improperly working transmission.

jbarsalou · #8 04-27-2006, 09:11 PM

Thanks again guys! Yeah, it sounds bad. I'll remove it this weekend. I wish I had a lift.

BlazerLT, very interesting about the ignition switch. Do you have any more info on this? I did have a problem with my ignition switch for a while intermittently. Sometimes when turning the key forward, it wouldn't start and no light would light up on the dash. I would have to shake the key a little and try a few times for it to start. Then one day it just was fine from then on.

Someone I work with had problems with his '96 and after a rebuild he noticed just a slight slipping. After some investigation he found a technical service bulliton that listed a missing ground wire to the tranny. They checked it out and sure enough it was missing the ground wire in the harness. GM sent a new harness and that fixed the problem...still great after 6 years.

I got a new GM tranny a few years ago because I go it at dealer cost and because of the warranty. Unfortunately I just past the warranty.

Thanks!

BlazerLT · #9 04-28-2006, 12:53 AM

Yea, I just installed the ground update on my 1995, I was having a flaring 1-2 hift and since the upgrade, it has been smooth as silk.

As for the ignition switch, I am not talking about the key tumbler. There is a black module in the steering colum that will have a bad connection on a 1997.

It can cause:

- Fuel pump priming issues
- Misfiring issues
- Transmission issues
- False sensor issues

I just don't want to send you on a wild goose chase. It is a 1997 and the switch is the weakness for your year. When it goes, it can really screw things up and have people looking elsewhere and costing them 1000s.

Seeing you have been having some problems with it lately, you might want to swap it out. Your transmission is electronically controlled. And if there is some electronic issues, it can possible be the cause.

Also check your PCM harness to make sure it is plugged in firmly just in case. Just unplug the connectors and replug them in with the battery disconnected.

jbarsalou · #10 04-30-2006, 12:20 AM

Tranny's out! Not too bad even without a lift. I borrowed a tranny jack and got some larger jack stands. It took much of the day. The bolts for the Y-pipe were very tough! The tranny pan had a bunch of metal filings in it and a few larger chunks of metal. The fluid was loaded with a fine metal silt and was very dark in color.

BlazerLT, How do I know if I need the ground update? What is done to accomplish this? I asked my dealer but they couldn't find any TSB's on it. I got a new ignition switch just in case itr was causing any more problems.

I think there is definitely something outside the tranny that is killing them. I shouldn't be on my third transmission already. This is getting frustrating and very costly.

Thanks again!

BlazerLT · #11 04-30-2006, 12:29 AM

Quote:

Originally Posted by jbarsalou

Tranny's out! Not too bad even without a lift. I borrowed a tranny jack and got some larger jack stands. It took much of the day. The bolts for the Y-pipe were very tough! The tranny pan had a bunch of metal filings in it and a few larger chunks of metal. The fluid was loaded with a fine metal silt and was very dark in color.

BlazerLT, How do I know if I need the ground update? What is done to accomplish this? I asked my dealer but they couldn't find any TSB's on it. I got a new ignition switch just in case itr was causing any more problems.

I think there is definitely something outside the tranny that is killing them. I shouldn't be on my third transmission already. This is getting frustrating and very costly.

Thanks again!

This sounds like a major failure.

You might want to get your tranny cooler checked for a coolant leak.

That is how mine died.

blazee · #12 04-30-2006, 05:50 AM

Quote:

Originally Posted by BlazerLT

This sounds like a major failure.

You might want to get your tranny cooler checked for a coolant leak.

That is how mine died.

Yeah, and with all that metal , the cooler and lines should be flushed really well before installing the new tranny...... might even want to replace them.

jbarsalou · #13 04-30-2006, 09:55 PM

It looks like a grenade exploded in it. Does anyone have any info on the transmission ground problem and how to figure out if I have it?

BlazerLT · #14 05-01-2006, 11:51 PM

The ground has nothing to do with it.

Something has caused a major failure.

jbarsalou · #15 05-02-2006, 12:13 PM

I agree with the fact that it had major problem. But I figured it was easier to check the wiring while the tranny was out.

Hypothetically if I had the flaring problem, after 66k miles it would probably blow up in some way. I'm not sure which damage it would do if gone unrepaired though.

Thanks for the help.

POST REPLY TO THIS THREAD