High Rpm....low speeds

1800 ain't gonna hurt anything. Most big bore diesels are governed to around 2000 to 2100 RPM. 1650-1750 seems to be the sweet spot, at least on the older engines anyways.

 

Here, I did it for you because I was bored. Everything seems to match up with what you are saying. Just a direct drive trans in action. Probably not the best spec for running local if that what you are doing with it..




This screen shot matches up pretty well with the 7th gear picture you posted IMO..

 

Math looks pretty spot on..
Again these are all for 1500rpm


Your 6th @ 1475rpm looks like 20mph on the
speedo



Your 7th @ 1400rpm looks like 25mph on the speedo




Either your tachometer or speedometer was off at one point, or your memory has slipped on this one..

This is all I can figure..

 

There’s nothing wrong with it.

 

A few things and I won’t say anything else.


First is this isn’t a clutch issue, never was. The clutch slipping would still not cause this issue so replacing the clutch was a waste of money.

second is the mechanic is a ... well I can’t post what I think but to me he is a pos parts changer, and you - op - should consider suing him. One thing that the mechanic should have done is check the actual speed, if the shop has a dyno, stick it on the dyno and see the actual wheel speed or at least to take the truck for a ride with a second mechanic following him to determine the actual speed, nothing less than this.

third the op has some holes in his story, and what he needs to do is go to a mechanic or a shop that is not just certified to fix the engine but also has the factory diag system to stick the truck on the computer to see what was screwed up because I am thinking that the stupidity of deleting the emissions system screwed a lot more up than what appears to be screwed up, one reason why I dump any truck I get that has been deleted as fast as possible.

 

How was it not described as a clutch issue? OP stated the RPM was higher in each gear, climbed faster than the speed and I believe it was mentioned it was worse when loaded. Classic clutch slippage symptoms. Not our fault OP couldn't effectively describe the symptoms.

 

The dd routinely go 22-23 under full jake with the autos 1800 is fine. You said it's deleted and probably putting down some more horse? Change up your driving habits if you want any longevity from it. Lugging a diesel that's been turned up some is putting even more stress on the bottom end. Don't be afraid to hold it 1700-1800 on a pull. And get a pyro if you don't already have one.

Take that down speeding fleet Bean counter bs and forget you ever heard of it