2000 Blazer Zr2 just over 170,000 kms

Just started doing it this winter. Any speed between 80km and 100km I can feel the vehicle stutter / buck.

Only seems to happen while holding the speed. Don't feel anything if I go right through to 110km

No drop in RPM or speed.

If I go above or below there is no issue.

New fluid and filter changed on the weekend with no change

Any thoughts?

 

I'm not even close to being an expert and I don't consider myself very experienced in diagnosing mechanical problems but it sounds to me like something is trying to lock up. May be one of the front cv axels or a u-joint or a diff. Thats just my opinion since you say rpms dont drop. Hope you figure it out though.

 

Reminds me of the time my TCC lockup solenoid started to fail on my Camaro...Anywhere between 60 - 70MPH , the TCC would lock , unlock , lock , unlock..If I hit 80MPH , the thing seemed fine....If i put the thing in 3rd instead of Drive\OD it wouldn't happen..

 

Just to cover all the bases, could it be one of your front wheels threw off its balance weights?

 

Sounds like same thing mine was doing right before trans went out. Occasional sharp jerk - mine felt like a single misfire - felt only at steady even speed between 50-60mph with TCC engaged - could see it in the tach. Eventually too much of the facing off the clutches ended up in the trans pan and plugged the filter - then started howling and soon left me sitting on the side of the road. You can always service your trans and look for material accumulating in the trans pan. Might save you a tow bill.

 

Pretty much spot on for what mine is doing

 

Could be other things, but something to consider. I was really surprised when trans went out (on a 275 mile RT drive), and then problem was gone when trans was fixed again.

 

Taking it in this week. I'll let you know what they say

 

Any update on this? I had a weird bucking/jerking in my 03 Blazer on the highway today. Happened three times, but then didn't do it again when I drove it on the highway again later in the day. No codes, shifts normally, engine runs good.