Engine/Transmission (1994 - 1998) Driving At High RPM's

[Forrest Nearing]

LOL @ the engine "coming apart" at 4000rpm :-laf :-laf



*hint* they don't

 

[Howard Durand]

One option to allow you to stay in OD would be to manually lock out the TC.

 

[Vaughn MacKenzie]

There's an RPM range around 4300 where Cummins says 'destructive harmonics' occur. So if you rev through 4300 instead of hanging out there you should be OK (up to something reasonable like 5000 RPM, LOL)

 

[fortunate1]

When running on fairly level roads in "boulevard mode" at around 50 mph, I will usually lock the TCC with the mystery switch. If there's lots of traffic and lights, then maybe not. The reason is that the engine is not lugging if the roads are not hilly AND the truck is not loaded up/towing. RPMs are 1300 to 1600 (55 is right on 1500 rpm in mine). Just don't try to accelerate quickly past the 50 mph range; that will be lugging. Also, the trans fluid stays cooler in lockup AND you can use the engine braking for an easy slowdown (remember to UNLOCK the TCC or you will stall). This mode is like loafing along in 5th in a stick-shift.

 

[biggy238]

Is it really that humorous gents?? I know people spin them harder than that while pulling and racing but I thought maybe that the bottom end had to be balanced. . I hadn't read anything that just blatantly said "Good to 5000RPM"