Have a friend who has a 99 Blazer 4x4 4 door and another with a 2002 S10 pickup. Both have overdrive. I have a 2001 Blazer 4x4 2 door....WITHOUT overdrive. I was told the 2 door was considered a "more aggressive version" (by who I don't know....GM?) I am getting a new transmission and wonder if there is any potential problem installing one with overdrive since it is electronically controlled. Don't know if it makes a difference to the CPU or other computer already onboard.

 

Does your 2001 2dr have an AT or MT? How many forward gears does it have? So the highest gear ratio is 1:1 and not less than 1:1 (e.g. 0.7:1)? If you don't have overdrive, what is your mileage like?

According to the attached 1999 sales literature, both the AT and MT are overdrive transmissions in that the final gear ratios are 0.73:1 in the MT and 0.70:1 in the AT.

 

Hanr3 pretty much nailed it here:

https://blazerforum.com/forum/engine...-has-od-41624/

 

I respectfully disagree with Hanr3. When I am going freeway speed ~ 70 mph my Blazer is cranking out about 2400 rpm's and gets 16 mpg. The other s10's I have driven with overdrive as indicated by the D with andO around it hit between 1500 and below 2000 rpm's at the same speed. I have an automatic WITHOUT overdrive.
The specs on a 2001 Blazer state mileage at 16 city/23 highway - I get 11 city/16 highway. Don't try to convince me I have overdrive. (Not trying to be sarcastic.)
Yes, I know that 1st gear and first and so on, I don't require remediation in that area.

 

It is an automatic. Mileage is 11 city/16 highway.
From wiki Re: the 4L60-E transmission ratio's 1st 3.059/ 2nd 1.625/ 3rd 1.000/ 4th .0696
From 2001 4 door LT 16 mpg city/ 23 mpg highway. I have never gotten near those numbers.

 

Disagree all you want, but the fact of the matter is that if your truck is an automatic equipped S-series SUV it would have come from GM with a 4L60E 4 speed overdrive transmission. They dropped the circled-D icon in 98 or somewhere there about in favor of the D-3-2-1. Your observations as to speed vs. RPM could indicate that your truck doesn't have a functioning 4th gear, but that's besides the point or maybe is the reason for the transmission replacement altogether..?

With that said and to answer your question directly, since your truck came with a 4L60E transmission, any 4L60E transmission from '99 on up should be a direct swap in. I say '99 on up because there were enhancements made along the way. If you can find one from a '01 or newer, even better. I can't recall the specifics into the enhancements as it's been years since I've dug into the ATSG manauls and mine are quite old at this point.

Good luck with your repairs.

*Moving to 2nd Gen Tech* - Please read the descriptions of the forum sections and choose the section that best matches the content of the post you are creating. The Lounge is for off-topic discussions.

 

I can feel it shift from 1st to 2nd to 3rd to 4th and in 4th at freeway speeds the rpm's are...
(Before I needed a new transmission). Thanks for the info about the swap.

 

My 2001 auto trans. g80, runs at 2000 rpms and 68 to 70 mph.........this was just yesterday, with maybe some headwind..........top tier exon 87 octane........65 miles of hiway and 120 miles in town and mountain driving for that tank........16 mpg even..........and I don't think that i have ever done any better ...and I can feel the OD kicking in.......up and down.......

 

When comparing other vehicles, it is always good to understand what equipment each vehicle has; factory tire size & final drive gear ratios being options of importance for this comparison as is whether a vehicle has the factory spec tires on it or larger aftermarket tires.

Regardless, you've confirmed what everyone else is telling you in this thread; i.e. you have a 4 speed automatic transmission.

 

Okay. I have a 4-speed automatic with an Overdrive that revs the engine higher than any other S10 Model I have driven and my highway mileage is 7 miles per gallon lower then stated on the S10 specs.