Rpms to high??

[Rampage]

Hello i bought my daughter a 1989 bronco 2 with the A4ld trans. The trans had just been rebuilt when i bought it but my problem is when were going about 55-57 mph the truck is at 3000 rpms. That seems high to me for a 4 speed trans. Im thinking maybe its not shifting into 4th? It has the 3.73 gears with 31 inch tires. Is that a normal rpm range for these broncos?

 

[ab_slack]

Never had an automatic so don't know what is typical.

You have to keep in mind this was made when 55mph was the national speed limit so they aren't geared for high speed.

On the other hand the 31 inch tires should lower the RPMs.

I know with my manual trans I am often at 3000 rpm at highway speeds but that is on the order of 65 to 70 mph. My wheels are bigger than stock and that is in 5th gear.

 

[3rd Petal]

With those gears and tires, you should be turning about 1700 RPM in overdrive (4th gear).

Does it do this going downhill also, or just when cruising down the freeway. Because it usually take 3000 RPM to move these things down the road, so what might be happening is that you are so far into the throttle just to keep it doing 55 that it won't shift into overdrive

 

[efilnicufecin]

How many times does it shift?
It should shift three times.....watch the tachometer to see.... if you have one.
Could also be the downshift "detent" rod is out of adjustment.