As it says on the title I have a 2001 Blazer 4 X4 with 2 doors in need of a transmission.
My question is about the tranny or differental gear ratios.
I have driven similar Blazers and S10 pickups that have the D (D for drive) with a circle around it indicating Overdrive. When I drove them they demonstrable dropped in RPMs at freeway speeds. My blazer does not have a D with a circle around it.
At 65 to 75 the RPMs are reaching 3000 RPMs.
I was told that my model a 4x4 with 2 doors, is a "sportier model" so the gear ratio is different???
The trans is a 4L60E/4L65E probably 4L60E.
Were is the gear ratio changed in the transmission or the differential to have a true overdrive?
Thanks

 

I've never heard of a 4L60E that did not have overdrive.

What does your gear selector display say? Mine has the following: "P R N D 3 2 1"? If so, then D = over-drive, and 3rd gear is 1:1.

According to my GM service manual, all 4L60Es for the S10/Blazers had these gear ratios:
1st 3.059:1
2nd 1.625:1
3rd 1.000:1 (direct drive)
4th 0.696:1 (over drive)
Reverse 2.294: 1

Also according to the service manual, the 3 to 4 shift happens at about 2400 to 2600 rpm, depending on the rear end ratio.

 

Hi Christine,
Yes, the gear selector indicates "P R N D 3 2 1" and the literature states that D is indeed Overdrive. However, my experience is that S10's with a D that has a circle around it used geared differently. When driving those S10's no, to me at least, there is a demonstrable drop in RPMs when they shift into the circled D. I don't think it would be my imagination.
Just thinking it out it doesn't make sense that a vehicle with four forward gears would have the third in a one-to-one ratio anyway. Just a personal frustration of mine because the only answer I got was that the four by four four door was considered a "sportier" model. What exactly does that mean?
Probably just need to find a old-timer Blazer mechanic.
Thanks for your answer.

 

I used to have a 92 Blazer and it had the "O" round the "D" for overdrive but mine does not. However, my owners manual does mention the use of an "O" around a "D" indicator for the top gear.

Perhaps your transmission is not working properly and never up-shifting? I could imagine some sort of signal it needing but never receiving in order for the transmission to up-shift. That seems much more likely to me than the transmission being geared differently.