RPMs vs. speed

[callcameron]

Hi, I finally have my 92 Explorer 4x4 XLT running again. I got so busy that I took it to my mechanic to finish. However, I can't tell if it's going into overdrive or not. I only see two noticable drops in RPM's (going from 1st to 2nd then 2nd to DRIVE). My question is first of all, from a dead stop, does the car start in 1st or 2nd? Next question, for those that have the same power train, how many RPMs are you running at 65 mph? Any info that you can give is greatly appreciated. Or if anybody knows of a way that I can test if it's going into overdrive, I would love to know.

Cameron
1992 Explorer XLT 4x4, 4.0 automatic

 

[NusenseSD]

does your truck have a over drive override button on the shifter? If it does when your doing 65 do you notice it downshift? If its in OD at 65 hitting the OD Off button should make it go down a gear into drive...

 

[dman726749]

also your rpm is going to be effected by your gearing in the diffs, so if you want some ones rmps you need to post what diffy gears you have so others with the same gers can help you... also your tire size has soemthing to do with it.

 

[Electrohacker]

in stock setup yoiu're not supose to disable over drive over 50.. it's in the manual...

 

[goobenet]

might mean nothing but my 94 is about 2100rpm at 65, and i know overdrive is on... i have stock 3.27 gears

 

[Electrohacker]

my 96' stock v8 awd gets 2000rpm at 59.5 (ish) mph

 

[N7XME]

With 3.73 gears and the A4LD tranny, I am running 2400rpm at 65mph.


It's a 93 4x4 as well.

 

[snocross1985]

might mean nothing but my 94 is about 2100rpm at 65, and i know overdrive is on... i have stock 3.27 gears

Then why is it that i also have 3.27 and am turning 2000 rpms at 70 mph? I know i have 3.27's, I've looked it up several times.

 

[MrShorty]

in stock setup yoiu're not supose to disable over drive over 50.. it's in the manual...

That must have been added to later manuals; the manual for my '92 makes no mention of such a restriction. I've dropped from 4-3 without a problem at 65. That said, it's not like you have to be doing 65 for the computer to shift into 4th gear. The computer will shift into 4th gear at speeds around 35-40 regularly. The best way to determine if it's shifting into 4th gear is like NusenseSD suggested, though you don't have an override button, but separate selector positions for D (3rd) and OD (4th). Put the selector in OD, get up to a cruising speed (40-50 would be good), drop the selector into D, and see if it downshifts. If, yes, then 4th gear is working. If no, then 4th gear isn't working.

 

[NusenseSD]

in stock setup yoiu're not supose to disable over drive over 50.. it's in the manual...

Doubt that since all manuals tell you to drive on D when you are towing.. Also if your not supposed to disable it then why would they put a overdrive defeat? Mine will shift out of OD whenever its engaged and I press the OD OFF button.. I have a 02 Explorer XLS 4 door..

 

[Electrohacker]

no it's the switching they advise against over 50 or 55 of course over 50 in drive is fine...

 

[goobenet]

Then why is it that i also have 3.27 and am turning 2000 rpms at 70 mph? I know i have 3.27's, I've looked it up several times.

Eh, between 65 and 75 my tach varies very little, between 2100 and 2400 rpms... climbs a bit more once i hit 80... Then again my gas, oil pressure, and battery all vary wildly. Hell the spedometer from time to time will spin upside down if i kick it down to pass... I trust very little of what my cluster tells me.