2450 RPM vs 2550 RPM

[David Ponder]

Question for you.. I noticed on the way home today that at 70 MPH the tach showed slightly above 2500 RPM (Perhaps about 2550) ... Well, I swear that previously at 70 MPH it would show slightly BELOW 2500 RPM (about 2450) ... I am hoping this is not a beginning sign of transmission failure.



So, any of you with an 01, Job 2, 4:10 Gears, & 4X4 want to check your RPMs and let me know I should be concerned? If this is higher than others, where should I start? I have not noticed any slipage at all during acceleration...



Thanks for your input. Dave

Edit, it has 119,000 on it.

 

[Dave S 2]

During cold days / nights, I've noticed that rpm's are higher for the first several minutes or so.

On "un-cold" days, I usually run about 2100rpm @ 60mph. When cold, It runs about 2400 rpm @ 60mph for about 5 minutes or so then it settles back to around 2100rpm.

I justified it in my head as needing the higher rpm's until the tranny fluid warmed up since it was too slow to flow until it got to "operating" temperature.



During the transition for cold to warm, I don't feel any slippage.

 

[Mike Dziubina]

i believe dave S hit the nail on the head

 

[Jim parnell]

I think DaveS is right, I didn't notice the change in RPM's on my 02 4wd, but on my 07 2wd, there is a 400-500 variance in the rpm's until things get warmed up good, then it reverts to the normal rpm range for the speed.

 

[David Ponder]

Thanks for the feedback... I know the difference you state, but I still have this differnce even after 30+ minutes on the highway. (When fully warmed up).



Its winter, and I havent had a chance or reason to really "lay in to it" lately, but today I did when merging on the highway. (Someone changed lanes INTO the right lane where I was trying to merge, and I floored it.) Anyway, I noticed that it downshifted quickly, but It didnt seem to want to upshift after you let up on the gas. It seems to hang for a second or so. I repeated this several times, and it did the same thing.. Any other ideas?



I may drop it by a Transmission shop and see what they think, otherwise, I guess I will just have to watch it and see if it gets worse.

 

[Todd Z]

Service the tranny, and do a battery disconnect to reset the tranny... They have an adaptive learning on them that throws things wacky.....



IF Rachel drives my truck for a couple of days, then I do, the tranny acts weird for a couple of shifts..



Todd Z

 

[Gavin Allan]

Ugh, don't our Tracs have lockup torque converters? If so, that RPM variation is either a bad tach or else you better go see the AAMCO Transmission Man...