Transmission Issue
 

Salutations!
Recently I changed my sparkplugs, now my transmission is giving me troubles I think..

When I press down on the gas pedal the RPMs will go high but the gearing will stay the same and my MPH will max out at ~30 but then I let go of the gas and press down again and i can feel the car lurch into the next gear and the MPH will rise as they should. Sometimes it'll stick in a gear too then I'll stop and the car turns off. Sometimes when I start it, I'll have to crank it once or twice. I was thinking about putting some new transmission fluid into the thing or at least putting some in so I could top it off but I'm not entirely sure what to do. Could the order of the sparkplugs cause the transmission to act up? I did accidentally mix up the spark plug order the first time which caused my exhaust to keep backfiring.

Any advice is appreciated and, if it IS the transmission what are the fixes for it? I will take it to a mechanic if needed but if it's something a novice can tackle then I'm more than willing to get my hands dirty.

The firing order of the spark plugs being mixed up would affect all engine performance.

So for the shifting, is it that when accelerating, when you get to about 30 mph where you might expect it to up-shift, the engine instead revs higher with no change in speed? And perhaps with the accelerator pedal not depressed so much (either after trying to accelerate harder or starting with a more gentle acceleration) it will up-shift?

If what I wrote describes the symptoms, then it is possible the "3-4 clutch pack" is bad. This is what happened to my truck. (I burned out the clutch pack by committing the sin of towing my boat while in over-drive.)

However, as always, start with the easy and hopefully less expensive stuff like checking that the transmission fluid is full up. It can help to smell it to see if it has a burned smell to it. If you find the fluid level was down and after topping up the transmission works fine, you are (almost) good to go. I say almost because you should try to find the source of the leak. If you cannot find a leak for the transmission fluid, then it might be that the previous owner(s) never bothered to check it.



Also If

The first part of your post sounds word for word what is going wrong with my acceleration. Which would be good except I dunno what 3-4 clutch pack means, I'll have to look it up. If that is what's wrong with it then is it something that I could do or would I be better off taking it to a mechanic? Can you ballpark how much it would be to get a mechanic to do it?

I was checking the fluid last night. It's not black but it's a little dark red as opposed to the pink red of new ATF. I also read that putting too much ATF is just as bad as putting in too little... I pulled my dipstick and saw that the bottom hole had some in it but the top hole didn't have anything so I think I'll get some fluid and make sure I got the sparkplug order right for the fifth time lol

Thank you!!

So here is a video that helped me understand the way our transmissions work. My understanding is that the 3/4 clutch pack works as the clutch mechanism to allow 3rd and 4th gear to be engaged. When the engine is reving, it is that clutch that is slipping and preventing engagement.

Unfortunately, if I am correct in diagnosing what is wrong, your transmission will need to be replaced or rebuilt. Many people will replace their transmissions with one from a wrecked Blazer. If you do this, I would make sure you learn about how to find one that is compatible. There are also many options for installing a transmission that has already been rebuilt. Of course finally your original one can be rebuilt too. Depending on your skills, you may be able to do all this yourself; i.e swap with a used or new, or rebuild. I had my local shop rebuild mine. It pays to shop around and get recommendations. Also, try to go to multiple shops to get it diagnosed.

Alright, that sounds like a lot then. I'll definitely shop around and try to get it diagnosed by different shops. Do shops normally charge for diagnosing? It sounds like maybe a rebuild might be the cheapest.
For now though I'll put in new ATF and recheck the sparkplug order, I found a diagram online. Is there anything else I should do to it? I've seen videos where they drain it but I think that I can just top off.

Hopefully that takes care of it but if I do have get the tranny worked on... I dont wanna think about it :icon_cry:

EDIT: WOWIE!!!! THIS THINGS A BEAST IT GOES FROM 0-??? FAST (is it supposed to be like that?? I'm not used to driving so damn fast with cars. It doesn't feel like its hurting it or anything)
I swapped the sparkplug order according to a diagram I found online and it starts right up the first time, no extra cranking either. The gear shifts were phenomenal!
I dunno if it was cause of the ATF I put in or what, but man!!! That thing flies!!!
I'll take it in for a code check this Friday, but right now I'm hoping it doesnt' spit out any hard codes.
Thanks again for all your help!!!:icon_party:

One last thing that I've noticed consistently, there's usually smoke coming from here after I take it for a drive. It doesn't come up always, it'll start smoking and then I'll stop the car in my garage, Rev it some to make the smoke come back but it doesn't show back up.
Any idea what that would be coming from?
https://cimg1.ibsrv.net/gimg/blazerf...6ea64d6417.jpg

Glad the transmission issue has gone away.

The smoke might be from some oil dripping onto the exhaust manifold from part of the engine or valve-cover. Be sure it is not brake fluid as that would mean your master cylinder might be on its last legs.

I had a similar problem and I thought my tranny was toast. Turned out to be the rear wheel speed sensor on the tailshaft of the transfer case. About 100 bucks. My ZR2 blows one every few years so get one with a lifetime warranty.

You prob know this BUT you are checking the trans fluid when trans is up to temp, with the engine running and trans in park .....