I am having a hard shift too but it doesn't matter if it is hot or cold it does it all the time. I did read on here that the wheel speed sensors might be the issue but need to have a confirmation on it before I rule it out so I will post up when I change them out. I will check on the other items like the diff and the tranny fluids too to make sure mine doesn't go all south on me.

 

Just to update you, I replaced both he shift solenoids, filter and added just over 4 quarts of transmission fluid, Took it for a drive and it is still doing the same thing, hesitating when cold in first and shifting hard into second. Better when warm...

Any ideas?

 

I'm going to bump this one. 98 Jimmy

1st to 2nd especially when cold can give a real solid kick. When it's warmed up, 1st to 2nd is still a relatively hard kick (just not as hard). I've added the Lucas stuff with no change. Plus it's kinda thunky when down-shifting.

I've also got issues with it grabbing when getting on the throttle after letting it cruise for a second (the grab being the engine revving up then feeling it finally lock in) generally accompanied by a nice thud.

I've had work done on the trans before because it was a throwing a code when we got it (don't remember) but it involved metal shavings in the pan, having the torque converter replaced and something else (might have been the valve body).

Thoughts? Hoping OP's is the same issue as mine.

 

Spitting image of my issues. Would be really interested to find out wtf is going on. Been driving it like that for a year/13k miles lol

 

Check engine light came on, P0300, misfire, p0446 evap vent, P0452 Fuel tank pressure low voltage, P0453 Fuel tank pressure high voltage

What the heck is it?

 

No kidding? Yeah, this isn't a new issue for me either. Just getting to the point where I feel like something is going to break eventually, and in a big way. I'm really not sure if it's in the tranny, torque converter, or even possibly the rear diff.

 

Either ****s going south fast, or you've got an electrical gremlin somewhere. In regards to your very first post and the brake pumping feeling, I had the same exact same issue when my plugs, wires, and dist. cap failed within the same general time frame of each other, and it was misfiring like you wouldn't believe. At one point, I was down to 4 cylinders. But like I said, new plugs, wires, cap, and rotor fixed it. Well, until now anyways (misfiring again) but that's not for this thread.

I would research the codes real quick and find out what they're referring to exactly.

Here's something on p0446 https://blazerforum.com/forum/diagno...plained-35143/

 

I've read that the hard 1-2 shift is caused by the valve body in our tranny's. There are kits you can buy. I've watch a video on doing the valve body removal and install; it's not awful, but it's not great either. Especially considering most of us will be doing the repair under our truck as opposed to on a lift, or even with the whole tranny removed. As for the clunking it could be the the u-joint in front of the rear diff going bad. I'll lift the *** end up at some point and poke around.

 

If your problem has not been solved, hopefully you can benefit from my own fight towards the belligerent Blazer I own. I like most went through all the common replacements before stumbling on the real problem. I hope our nightmares will give you a solution.
https://blazerforum.com/forum/engine...04/#post598340

 

well from everything I have read....if it feels like your power breaking it off an on...leaving from a dead stop or it stays in first two long and then kinda hard shifts to second gear an almost barks the tires...and on the interstate if you driving at say 70mph and wanna go faster to say 80 or 90 and it will go there but just seems to be taking awhile....well it is probably already set or goin to set a p1870 code the torque converting is slipping causing the transmission to raise the pressure causing the hard shift....the surge feelin would be the torque converter slipping...and of course if its slipping well then we know its not transferring power as it should...ive only had one blazer do this to me however I just the had hard 1-2 shift nothing else but you know