RPM @ 65MPH?

[Guest 9mil]

Well, I said screw it and got the trans rebuilt...and bypassed the stock trans cooler, which is what makes the trans fail in the frist place ( do yourself a favor and put an external one on it if you havent yet! and save the 1500$ for a reubuild) ...anyway, it doesnt feel like it is falling into to lock-up. It will go through 1-2-3-OD but I can't feel it hit LU...and I remember it running a little lower RPM on the highway...so if someone would be so kind as to check to see what RPM they are at on the highway, flat, static throttle- in an automatic of course - I would love it..mine is about 2500RPM and I dont have huge tires or anything.

 

Thanks!

 

Phil

87 2 Door auto 6cyl 4X4

[denisb]

My 90 is about the same RPMs at the same speed. Auto also. But the difference from lock up to unlocked is only about 3k. At that speed it should come out of lock up when you let off the accelerator, and lock up 1/4 to half a mile later when you reapply acceleration.

[Guest 9mil]

Thanks! - I figure it is working, I just cant feel it slide in -

 

oh well-

 

phil

[88pathoffroad]

Mine runs about 2200-2300, tops with the converter locked up. If you have a tachometer on yours, watch it to see if it falls a little bit lower after it hits final drive and you let off the gas at cruising speed on the freeway. It should.

[denisb]

Sorry, I was rereading my post, I meant it only droped by 300 rpms when it locks up. So goes from about 2600 to 2300.

[Guest 9mil]

that makes more sense! thanks!

 

phil

[Guest pathOHIOfinder]

Lock up? I've read about it in here, but i've never felt it when i drive my pathy. at 65 mph i'm still pushing 2700 rpm. it seemed odd to me that it would rev that high at reg hwy speed, so what's the deal if it's not going into LU at all?

[88pathoffroad]

When the torque converter is locked, the fluid coupling and the drive coupling are spinning at the same speed and it will not slip. It will only lock up when at a constant speed at part-throttle in 3rd gear. When it's unlocked, the fluid coupling and the drive coupling inside the torque converter spin at different speeds, the fluid takes up the difference in speeds and allows the transmission to shift gears up and down. If the converter were locked fulltime, it would jerk badly when you upshifted or downshifted.