97 V6 4R70W automatic transmission
Does anyone know at what speeds the transmission shifts? Thanks.

 

You did not provide enough information to give you a simple answer.
JL

 

Uh, I missed the axle ratio. Thanks.

97 4.2L V6 4R70W automatic 3.55 non-slip

 

You don't get it.
There's not a preset "shift point" for every gear. The shift point varies dependent on load, throttle position, fluid temperature, etc,etc,etc.
JL

 

You are correct. But there must be a ballpark figure. City road. Warm engine. Normal cruising.

 

There's NOT.
JL

 

Let me change the question.
When do your 4th and OD engage? No towing or heavy acceleration.
Thanks.

 

A 4R70W is a 4 speed trans.
4th gear IS OD.
What exactly are wanting to figure out?
JL

 

Thanks. I didn't know that. I just want to know when it switches to OD. I don't have a tach and cannot tell when.

 

It's not RPM based. All trans shifts are commanded based on vehicle speed.
What are you trying to figure out? You're asking for a reason.
JL

 

Thanks for the explanation. I thought knowing when OD engages would help me drive fuel-efficiently. With my other vehicle, OD engages at around 45 mph. I wish I had a tach in my pickup. Can I grab a tach from a jy and retrofit? Fuel efficiency is the reason I asked the question.

 

That's where I thought you were going by the way you were asking. Getting the vehicle into OD sooner isn't going to help your fuel economy any. In most cases, lugging the engine along in OD will actually hurt the mileage. higher RPMS do NOT always mean worse fuel economy. It's all about the load.
JL

 

Thanks for the explanation. It makes sense.

I still have the same question. When does OD engage? At what speed? Anyone?

 

For the F150 in my signature, with 3.55 rear end and 265/70-16 tires:

Warmed up engine, gentle acceleration, between 35 and 40 MPH, probably closer to 40.

Cold engine, gentle acceleration, closer to 45 MPH, but I can get it to upshift to OD if I'm at or over 40 by abruptly letting off the gas for a moment, and getting back on it. Which I only do if I'm on a stretch of road behind somebody that will poke along for the next mile and I get tired of seeing the tach up when I know it is that close to upshifting.

Don't know if they have your V6 setup the same in the ECM.

 

....Cold, the transmission will not shift to OD until the temperature sensor on the transmission valve body reaches a min of about 95° +/- a little.
....You could notice in winter temps the trans won't go into OD for an extended time when driveoff is done right after starting.
.
....The trans shifting per throttle movement is delayed in time by a 'software timer' offset function. That means you can't force a near instant shift by letting up on the throttle. There will always be about a 5 second delay on throttle let up.
.
....OD min. road speed for upshift at min throttle is 45 +/- a small amount and can change somewhat with large tire diameter differences and gear ratio changes away from stock without a program alteration.
....Full throttle upshifts are determined by throttle position, engine RPM and road speed depending on what year and method of detecting road speed and a value in software.
.
..Within the software program are seperate lines of program instruction.
..While the lines are about the same for up and downshift, the 'values' (a number) loaded in those lines are different to prevent gear hunting up and down with throttle movement.
..These values are among the reasons a fast up shift can't be done in a stock transmission and program unless modified to bring them closer to the 'edge' of a hunting situation.
..This is why the use of the term 'hunting' to discribe a stock setup for towing is not a proper discription. It can't happen under stock conditions in a fault free system, by design, or owners would have complained years ago about it.
..So the software was written to guard against it.
..Normal downshift and upshift under load changes is not hunting.
.
***Next, on 4x4 Low, the shift sked is altered to move the shift points to better reflect the very low road speed and high engine RPM that results so reasonable shift points occurr without over revving the engine to get desired shifts to occurr.
.
..In the old manuel self controlled transmissions, they could be made to upshift quit fast with throttle control.
..In electric control, they do as there told by the PCM so could shift as fast as you would want so there contol software has to be quite restricted to keep out of undesired operations for the average application and use.
Good luck.