Ok I have 235/75/r15 tires. I asume that these are the recommended tire. I thought that my od was broken but then on the highway I saw and felt it shifted into 4th or it could have been 3rd but I dont think so because because I was getting onto the highway and was doing about 35-40. The rpms were at 3000 and it shifted at 65 mph and the rpms droped to about 2800. Maybe my gears have been changed? The label on the door has I have a 3.27 rear end. Some times when I am on the high and go to pass someone and gun it while going like 45-60 the rpms just stay a 3000 grand and dont move. What could cause this. By the way the rpm readings where down on a flat stretch of highway. and there were only 2 people in the car.

actually sounds about normal

my 94 with 3.73 gears and 31" tires revs at 3000 rpm in od on hte freeway

With 3.27s and 235 size tires and the OHV, you should be getting about 2200 rpm in overdrive at 70 mph. If you're getting 3000+ rpm then your tranny is not dropping down into overdrive.

I am feeling it shift four times, And my torque converter unlocks when I touch the brake doing 45. So it cant be that

There is one way to tell, switch it to D when you are at 3,000 rpm. Tach may be off, but that sounds high. You can also lightly put your foot on the brake and the rpm should increase about 300 when the TC unlocks. I drove for a couple years without overdrive.

Ive got 3.55's with 31" tires, and I sit at 1900-2100 rpms on the highway at 65-70....... Seems like your ridin' in third gear.(D)

That does seem high...
My truck will run at 3000 rpms at 80 mph
I have 3.27's and 225/70/R15's
I have a 5 speed though.

Mine runs around 2900, 3000 rpms at 70mph. But then again, I have 4.10 limited slip and runs stock 255-70R16.

ill tell ya'll now that 3 grand at about 60-65 mph is telling you that your transmission is either not in lockup or in 4th gear. I have 3.73 with 31x10.5-15's and run about 2500rpm at 60 mph this is after i had my transmission rebuilt. i had bad od and torque converter lockup solenoids. my truck would be over 3 grand on tach at highways speeds. btw your torque converter will unlock when you take your foot off the gas pedal not when you use the brake. lock up will occur at about 45 mph and the shift to 4th will be sooner than that. this all assumes that your shifter is in OD not drive.

2200 rpm at 65 with 3.73's and 235 75 15's (5 speed manual)

Mine does about 2650 rpm at 65 mph. I've got 3.73 and 235/75/R15 tires.

At 65mph in fourth with the converter locked and 235-75 R15 tires a 3.27 rear-end should be at around 1856 rpms.
With a 3.73 rear it should be 2116 rpms.

i have a first gen with an out auto tranny and 3.27's
with 235/75's, i was right around 2000 at 70 mph. if i gunned it, it would rev way higher than 3000.

With 235/75/15,93 EB with 70,000.I rev. About 2900 @ 65 in O/D. So the my O/D is shot?? I hope not. fluid is full, but not real red. I will change the trany filter and gasket after I pay it off in about a month or so, $600 more. :D and it is mine
What should I look for and/or do?? I want this truck to last my at least 5 to 7 years, hopeful more.
PS am I hurting anything, now driving like it is, I drive at that speed 65, 120 miles a week "to and from school."

thanx in advance Charlie

It could also be your torque convert lockup.

Take it onto the freeway.. and at about 55mph.. start watching the tach. Step on the gas some (not enough to make it drop down a gear etc). If the rpms move up with the speed, the Lock-up is working. If the RPMs move up, then the speed catches up with it then the lockup isn't working (but your od is).

Either way.. Crawl under your truck and check the 2 connectors on the drivers side of the tranny. At one point I was working on the truck and I pulled one of the connectors and forgot to put it back in.

With the connector disconnected I was driving in 3rd gear with lockup (no od).. When we did that 3000 rpms (give or take a bit) was 65 mph.

Another way to test this is to just put your truck in D (not OD).. and drive it.. and check the rpms at 65.
Now put it in OD and check again. If the rpms are the same, you dont' have OD.

~Mark