I was pulling out from a side street onto the main road the other day and got on it pretty good because traffic was coming and the back end broke loose. I shifted as quickly as I could but I saw the tach at almost 3500rpm. The truck still runs and drives fine but any time I see a tach in the red zone I get scared. I've got a smarty jr and exhaust but other than that the truck is stock, did I hurt anything?

 

Don't exceed 3500 or you will risk slapping a piston. I have hit 3500 on several occasions and have been fine, but that is its limit. You will be fine bud.

 

doesn't the computer limit the motor to 3400 or so?

 

I can hit 3500, but I also am running beta programs.

But yea there should still be a limiter for safety.

 

I dont really know alot about our truck programming but I can tell you my mustang will limit the RPMS to 6250 no matter what the crappy factory tach says. So I would think if our truck has a factory rev limiter it wouldnt go past that set rpm no matter what. sorry i could give you more info

 

A guy stopped me yesterday and asked about my 5500 truck. Said he just bought a used 2500 and wanted to know the difference. I admitted I just put some extra 5's on it.

He told me about his new muffler and I said I ordered a shift kit. Then he said maybe he needed a shift kit because his truck will rev to 5500 rpms before it will shift. I said that would be really bad because redline is 3200.

He mentioned hitting 5500 to 6000 a couple more times. I don't believe it could ever happen, but I do know some trucks that will run 4200.

A quick burst above 3200 with a stock engine shouldn't hurt.

 

2500 Hemi perhaps?

 

Nope, diesel. He kept calling it the small 5.9 engine.... New to Cummins I'm sure!

 

What year? Maybe it's the old 5.9 Magnum? Chances are they had no idea what they were talking about. I don't think our RPM gauge even shows above 4K does it?

 

It's an 06 and a diesel. I think our tach goes to 4500 but I may be wrong.

 

Ya, I just checked it goes to 5k. Maybe they're just used to seeing a 7-8k Tach and needle placement at a 2 o'clock position which would be around 5-6K if I remember my Mustang and Jeep well enough.

 

He's taking it back to the dealer, I advised him NOT to tell them it's revving to 6 grand....

I think I convinced him Smarty jr is a great addition....

 

I have had mine to 4k two or three times due to mechanical over rev. Always scares me bad.

 

I've had mine over 3500RPM's. Tow/Haul Mode when coasting down a decent grade with light braking it'll downshift and hold 3500RPM's or so. I can't imagine it's too dangerous if the computer is allowed to do it.

 

Thanks for the replies guys, that puts my mind at ease. Still not something I plan on doing ever again but at least now I know that if it happens I don't have to worry too much.