I drove 5 blocks on a cold morning to 7-11...no problems, Turned right out of parking lot...accellerated like normal...about the time it would have shifted into 2nd gear...it seemed to pop into neutral...the shift selector was in OD...I had to pull it down into 1st gear just to start moving forward again...then when i put it back into drive it did not shift out of first gear all the way home... I parked it and went out later to check it out and when I put it into drive it engaged...but I have no reverse. I changed the filter and gasket, put new fluid back in it... No change. I bought the vehicle for $500.00 a year ago (with engine problems). Dont want to put too much money into it. Hopefully its something simple lol

 

That sucks. I've had my fair share of problems from this same transmission in a Safari van. I'm assuming you have a 4.3L and the automatic 4L60-E transmission. If you only have 1st gear and reverse, it is most likely a fractured sun shell. You could get lucky and have it be a valve body problem but I doubt it. The sun shell is definitely a weak point in these transmissions. They're the top cause for having no reverse. They cause all sorts of other problems as well. Anyways, if you have a bad sun shell, the transmission will need to be rebuilt. I had the one in my van rebuilt last year for a different reasons. I had the rebuilder replace the sun shell with a hardened one as I was aware that this is a problem part. I paid $1,500 to have the transmission rebuilt. I removed it and installed it myself. I also paid about $120 for the fluid to refill it. It was not an enjoyable time in my life.

If you have an older Blazer, I'm guessing that it has the 700R4 transmission. It's basically the predecessor to the 4L60-E. It is the non electronic version. Still, the internals are very similar and I'd guess that if you had that transmission, it still has a fractured or broken sun shell.

Sorry to be the bearer of bad news, but I'd say that you likely have a busted sun shell. It's possible that you have a valve body issue. I doubt it though. If you like the vehicle and think you want to keep it, then here's what I'd do. I learned a lot of things the hard way. Take it to a transmission shop and pay for a diagnosis. Most of them will charge you a flat rate diagnosis fee and not an hourly fee. The 4L60-E is a very common transmission. GM put them in Blazers, Suburbans, trucks, etc. There are a lot of them out there. Any transmission shop will have worked on them.

Another option if you don't want to spend a lot of money, is a junk yard or a salvage vehicle of some sort. You could probably get one from a junk yard for a few hundred bucks. The problem with that though, is that not all 4L60-Es are created the same. Some have different friction pads and internal components depending on the vehicle. You'd want to find one from another Blazer to play it safe. There's lots of them out there though. You might find a Blazer on Craigslist or somewhere with a bad engine. Buy it, take the transmission, and then part out the rest of the donor blazer. You have options. If you want to have the transmission rebuilt, don't drive it any more.

 

It does suck. Today it snowed here in Denver about 3 feet. lol... I do have the newer one, the 4L60-E and I do appreciate your response/advice. I think I will take it somewhere to have it diagnosed. I have been told it could cost upwards of $3000.00 to have it rebuilt, That wont happen. I haven't checked around at any junk yards yet, I just don't want to have to crawl around in the dirt to get one cheap, ya never know what shape it is in anyway. Your advice to pull it myself might be the way to go. I just got to find someone who will rebuild it for me. Thanks again.

 

Well, the 4L60-E and the Blazer are both very common. $3,000 for a rebuild is absurd. I paid $1,450 for mine to be rebuilt here in Alaska! It should be even cheaper in the lower 48. I hear ya about crawling around in the dirt. I hate working on my vehicles this time of year. We got 14" of snow today in addition to the 100+ inches that are already in my yard. When I was trying to figure out what to do with mine, I called the GM dealer to see what a new one would cost. A brand spanking new 4L60-E was a little over $1,800 here in Alaska. That comes with a warranty too! Honestly, I wish I had just bought the new one looking back on it. I had issues with my transmission after I had it rebuilt. The rebuilder fixed it for me but it was still a pain in the butt. I was pretty limited in my choices for transmission shops here in Anchorage. There are a lot less places to choose from.

For you, I would say that your first step is a diagnosis. Don't tell them what your suspicions might be (sun shell). Just see what they say and if it makes sense to you. I don't put up with any place that is rude to me or talks to me like I'm an idiot. Down there in Denver, you have a lot more choices to choose from. I'm guessing a lot of places already have a 4L60-E that has been rebuilt. A good shop will have rebuilt it with a hardened sun shell. They're not very expensive, relatively speaking. I think it added $50 to my rebuild. So, all you would have to do, is bring them your bad transmission and then just take the new one. No waiting for the rebuild to be done. Overall, it wasn't too hard to remove it, but I had a lift to work with! If I had it to do over again, I could have the transmission out in less than three hours. My van has torsion bars on it too. You won't have to remove that nonsense on your Blazer.

I have learned a lot about these transmissions since I had my problems. They are great transmissions. A proven design. However, if they are neglected or abused, they'll make you pay. I had only owned my van for a few days before the transmission gave it up. It was obvious to me that the previous owner had totally neglected it. If you take care of the 4L60-E, it will last a really long time. If they get overheated, they'll die really quickly. When I reinstalled mine, I put in a Hayden 679 transmission cooler. It was about $50 on Amazon. The install is super easy. I also put good synthetic fluid in mine. Dexron 6. Dexron 3 will work just fine too. It takes about 12 quarts to fill it. Synthetic Dex 6 is about $10 a quart here in AK. Probably the same down there. Regular Dex 3 can be had for about half the price and will work fine. Just keep it full!

 

Thank you KC10Chief for supporting on this topic. I'm very pleased with all of the abuse I've put them through. Manually downshifting to the point of locking the rear tires and putting the car into a slide (Beast sun shell). We've even snapped the tail housing off the transmission on my friends car when it hooked after a burnout (Beast sun shell). Granted his is a 4L65e but is running 22" wide street slicks.

I'll second your sun shell diagnosis.
I have a post up about everything I've learned so far about these transmissions. I should make up a parts/price list for a DIY most common failure repairs. Yes it would be hard for most people but when it comes down to it there are not a lot that can afford $1000+ for a new/rebuilt transmission when they could spend $100 to fix the one they currently have. No special tools are required to at least replace a sun shell.
It's either that or take a gamble on used one.