RPM drop into overdrive

[sk8er32283]

I am wondering how much my engine rpms should drop when my transmission shifts to overdrive. Right now it drops almost 1500 rpm and almost feels like it imediately has more power. I am afraid that my torque converter may be going bad or maybe even the transmission. I have 35" tires so I don't know if that makes a difference or not.

 

[bigrigr]

Sk8er32283, fill out your signature so we know what ur driving. It helps us know how to reply. My first guess is that is normal. The trans has the extra(overdrive) gear, and the torgue converter will lock up at higher speeds as well. Combine the two and it could feel that way.

 

[Stroked68]

I'd say yer ok. Mine does the same thing. Once it hits third, the rpm's drop quite a bit. Mine has over 260k on it now. With runnin 35's I'd say that would make a diff. I've never ran that size tires on mine but thats more meat yer tranny has to turn.

 

[Dogman]

I am wondering how much my engine rpms should drop when my transmission shifts to overdrive. Right now it drops almost 1500 rpm and almost feels like it imediately has more power. I am afraid that my torque converter may be going bad or maybe even the transmission. I have 35" tires so I don't know if that makes a difference or not.

I have 35" on my truck with 3.73 gears and it drop like that. Other then a regearing you'll have to deal with. I figured the stock tires I had 265/75/16 worked out tire size to a 31.5" tall tire, so 35" tires would not be a big jump but it is. Funny how tire size can give your truck that lugging feeling when the converter locks up.

Did you have your trans. shift point changed when you put the larger tires on? If not if you have a tuner it can be done there.

 

[bigrigr]

X2, what he said

 

[02SilverStroke]

I'd say yer ok. Mine does the same thing. Once it hits third, the rpm's drop quite a bit. Mine has over 260k on it now. With runnin 35's I'd say that would make a diff. I've never ran that size tires on mine but thats more meat yer tranny has to turn.

X2. I think you're okay. Mine dropped a good bit when shifting into OD. I always ran the stock tires on mine (LT285-75R16's).

 

[superdub01]

i have 40" tires with 4:10 gears on mine and feels the same way. i agree totally normal.

 

[hrc200x]

Anyone know a test to do to make the converter unlock in OD? I've tried just letting off the throttle and pushing it again, still no RPM change, also tried touching the brakes a bit while giving it throttle and no rpm change. It seems like its working, as it runs 1500-1600rpm at 55mph 265 tires and 3.73 gears, but it would be a good piece of mind to be able to hear it unlock and lock back up.