Been trying to find the answer by searching on here and Google to no avail... so, say I'm cruising in my '95 XJ, not accelerating or decelerating. What is the maximum speed I can safely downshift to 3rd? What about to the 1/2 setting?

I'm asking because sometimes I like to select 3 for passing, a hill climb, or whenever else I want higher revvs at around 40 to 55 miles-per-hour. Now, sadly my Jeep didn't come with a tachometer... ...and I've yet to install one, but whenever I downshift from OD to 3rd the revvs don't sound too high, so now I'm wondering if I couldn't go all the way to 1/2 setting at 45 MPH or so, to downshift to 2nd gear presumably.

What's the skinny?

 

40 to 55 is entirely safe.

 

A little research (I needed Oreo DoubleStuf) indicates that redline in 1st gear is ~42 mph, redline in 2nd is ~70. I know that prior to installing my 1st gear lockout switch, my AW4 downshifted (abruptly) from 2nd to 1st at 35 mph.

So, downshifting to pass is safe, but not necessarily useful, at:

D to 3rd: Anytime
3rd to 1-2: ≤60 mph

If you install a 1st gear lock-out, 1st gear can be selected at
≤35 mph.

I'm running 235/75-15s on stock (3.55) gearing but these numbers are safe for 215s and 225s, as well.

 

Awesome info!

Wow, that is way higher than I expected. My XJ usually switches to OD before 45 MPH and doesn't usually downshift past 3rd unless I go from very slight throttle to HAMMER DOWN in less than half a second.

 

They are NOT tractor motors. They shift at 4800 RPM when floored!!

 

Why even worry about it? When you need it to down shift you put your foot in it, if you need more you give it more. The pcm will determine the lowest best available at WOT.

 

Well yes... generally one does that to get > 1 MPG and an engine that isn't a pile of shrapnel spread along the road lol. Just because the redline is 70 MPH doesn't mean you should do anywhere NEAR that...

While I disagree with the notion that these old transmissions should never require human interaction, it does sound like the OP has a problem he's correcting for manually.

You sure your TPS is good and your TV cable is nice and tight? Tuneup and all that, everything in good shape? It doesn't sound like it!

These go to 4800 RPM??? I hit 4000 once, that was scary.

 

4800 all the time. Don't be a weenie.

 

You know we actually have to pay for gas up here lol

 

No, everything is definitely not in good shape. Unfortunately, the list of these little things is enormous. Right now I'm trying to tackle some more pressing ones.