High RPMS 5th speed

Just bought a 2003 v6 manual 4x4. I had an 02 automatic, but unfortunately rolled it last week. I noticed that when I'm in 5th speed, going 65, my rpms run at about 2500 on a flat. Is this normal? In my automatic they were usually about 2100 unless I went over 70. I haven't really had the chance to look over this truck yet as I've been working and someone else picked it up for Are these geared differently? Don't have much of a maintenance history for it. Truck has 176,000 miles on it. Thanks in advance.

 

Maybe so. It's always good to baseline a used vehicle you have no history on. All fluids, plugs, examine brakes, etc etc.

But the plugs have nothing to do with your question about RPM.

Common differences are gearing and gearing changes caused by tire size. So for example, is the tire circumference on this vehicle smaller than your previous?

Have you verified your MPH with a GPS? Sometimes that gives a clue too.

Someone will be along soon to give you OE data on axle ratios.

 

A 2003 v6 4x4 almost certainly has 4.10 differential gears, and your 02 automatic probably did too. Assuming that’s correct, and they had similar tire sizes, the main difference is in the transmission gearing. The manual trans has lower gearing than the automatic, even 5th gear is lower than 4th gear overdrive in the auto. So it’s reasonable that you’re seeing higher RPMs at the same highway speeds between the two trucks.

You should definitely do any maintenance items if there is no record of them being done, especially things like timing belt, spark plugs, and lower ball joints, as well as fluids and such. None of those will affect cruising speed RPM though.

 

Yep...I did a manual swap into my 04 Dbl Cab back in 2010 ...errr uhhh actually paid someone to do it... lets not sweat the details....and yes I can attest with a 4:10 rear I see 2350-2500 at 65. When I finally get this transmission rebuilt I would love to get 5th gear swapped out.