My rpm's are at 2500 at 60mph and at around 3000 from 70mph and up. Is there a reason they are that high? Is that normal for blazers? 1999 4wd

 

that's about right depending on rear end ratio. But commonly the 4wd's have a higher gear ratio which results in higher rpm at highway speeds. Ensure it shifts into all 4 gears but like i said it doesnt sound like a problem.

 

It does shift into all gears. It just seemed a little high. My rpms are normally at around 1800 when I drive. I don't take the highway too much, so I just wanted to be sure. Thanks for the info

 

That sounds high to me, I have a 2000 4x4 and at 70mph the tach shows about 2100rpm. Even as high as 80mph the tach only shows about 2300rpm. Im thinking your overdrive isn't kicking in possibly, because when I get mine to kick out of overdrive, it puts the rpms at about 3k at 70mph, right where you said your rpms run. I'd look into that. It wont hurt anything, but you will be getting HORRIBLE highway mileage running the rpms that high. Just my 2 cents.

 

Yeah, I get better mileage off highway. I'll do some searching around just to be sure. Thank you

 

I had a similar issue...highway rpm's higher than normal and the tranny could not stay in lockup. Turns out, I had a fouled spark plug! Changed my plugs and wires and waddya know...tranny stays in Overdrive and rpm's returned to normal.

 

Smaller gear number=higher gear ratio=lower RPMs
Larger gear number=lower gear ratio=higher RPMs