Improper use of gear limit

[Kyang]

I have a 22 ram 2500 with the 6.7 Cummins. The cruise control was confused with the gear limit - button resulting in the truck cruising on the highway at about 3000 rpm for about 1hour. Could this have cause any damage to the engine? Also do y’all know if there is a safety built in for the gear limit buttons?

What happened-

A employee of mine was driving the truck and called me to ask how to set the cruise control. Since we were over the phone and he was driving I tried to keep it simple. I told told him to push the Speedo looking button and the (-set) button, he told me he pushed a (-)button but the cruise control didn’t set. After a couple of tries he figured it out.

Today it dawned on me that he may have confused the (-set) button with the (-) button for the gear limit. So I ask him where the rpms was at. He said it was high but doesn’t remember exactly where. I think it may have been close or past 3000 not knowing how many times he push the (-)button for the gear limit.

He had cruise control set at 65 for about an hour drive. With the gear limit active.

 

[BowDown]

Not likely and you'd already know if it did.

 

[Kyang]

I think it was basically at redline for about an hour of highway driving. Do you know if the computer will force it to shift?

 

[jdmartin]

No idea about your question but: I can't believe your truck was running at redline for an hour and you didn't hear or notice anything was wrong? Were you in a coma? In any case, the RV people say that it can go to 4k without damage and that the computer won't let it go beyond safety anyway. You are probably fine.

 

[Kyang]

[MOD: Please don't edit an original post and delete follow-ups like this, UNLESS you add "ETA:" to the new comments; it confuses people. Then we get jerks that admonish people for not reading. In fact, it's best not to delete follow-ups at all because it messes with the flow of the thread and replies.]

A employee of mine was driving the truck and called me to ask how to set the cruise control. I told told him to push the Speedo looking button and the (-set) button. He got the (-set) button confused with the - button for the gear limit.

Today he told me that he press the - for the gear limit instead of the (-set). Which made me realize that he was probably locked in a lower gear since he pushed the - for gear limit, so I asked him what the rpms were. And he said about 3000. He had cruise set at 65mph but I’m not sure how many times he push the - on the gear limit before figuring out the -set buttton. He drove like this for about an hour

 

[Rick3478]

Should be well broken in now. Most likely just a little accelerated wear. I might be inclined to change oil and filter.

 

[Kyang]

Should be well broken in now. Most likely just a little accelerated wear. I might be inclined to change oil and filter.

Yeah that’s what I was planning on doing tomorrow. Tonight I noticed when the truck is at idle there is more of a vibration in the cab, but the truck may have been in regen. Or I may be just paranoid. I did some accelerations and power seems the same. I slowly revved it to listen to engine noise and it sounded fine.

 

[Brutal_HO]

Cummins engines do not require any break-in, nor do they use "break-in oil." The cylinder walls will "finish" polish faster with heavy daily heavy towing at around 6K. Light use could take up to 20-30K. Running at a higher RPM will only accelerate that "finishing," but a heavy load is best to keep the oil control rings in check.

Cummins 6.7L industrial engines run at 3K 24x7 except when down for maintenance.

You didn't hurt it.

P.S. Come join the forums at HDRAMS.COM. No offense to the membership here, but we talk diesel there.

No idea about your question but: I can't believe your truck was running at redline for an hour and you didn't hear or notice anything was wrong? Were you in a coma? In any case, the RV people say that it can go to 4k without damage and that the computer won't let it go beyond safety anyway. You are probably fine.

The cab noise in a Cummins isn't much difference from idle to redline (3,250). ANC does have a small role in that.

 

[Kyang]

Cummins engines do not require any break-in, nor do they use "break-in oil." The cylinder walls will "finish" polish faster with heavy daily heavy towing at around 6K. Light use could take up to 20-30K. Running at a higher RPM will only accelerate that "finishing," but a heavy load is best to keep the oil control rings in check.

Cummins 6.7L industrial engines run at 3K 24x7 except when down for maintenance.

You didn't hurt it.

P.S. Come join the forums at HDRAMS.COM. No offense to the membership here, but we talk diesel there.



The cab noise in a Cummins isn't much difference from idle to redline (3,250). ANC does have a small role in that.

He told me the rpms were high but didn’t know exactly where. 3000 rpm is a guesstimate since 3k is basically redline. Not knowing how many times he pushed the (-) gear limit button. Do y’all know if there’s a safety built into the (-) gear limit button?

 

[jdefoe0424]

He told me the rpms were high but didn’t know exactly where. 3000 rpm is a guesstimate since 3k is basically redline. Not knowing how many times he pushed the (-) gear limit button. Do y’all know if there’s a safety built into the (-) gear limit button?

All that does is limit the highest gear it will go to. I.E. if it's set at 5 it will never go to 6th until you hit the + or shift out of drive.
It will go down 4 to 3 to 2 etc. as you slow down.

 

[JF19Longhorn]

I'm pretty sure the transmission will not downshift if the resulting shift will put the engine beyond redline.

I'm not sure how your employee did not notice the engine running at that high RPM for that long.

 

[Kooch80]

Had a safety built in. Won't let you down shift into an unsafe gear

 

[bigdodge]

I have a 22 ram 2500 with the 6.7 Cummins. The cruise control was confused with the gear limit - button resulting in the truck cruising on the highway at about 3000 rpm for about 1hour. Could this have cause any damage to the engine? Also do y’all know if there is a safety built in for the gear limit buttons?

What happened-

A employee of mine was driving the truck and called me to ask how to set the cruise control. Since we were over the phone and he was driving I tried to keep it simple. I told told him to push the Speedo looking button and the (-set) button, he told me he pushed a (-)button but the cruise control didn’t set. After a couple of tries he figured it out.

Today it dawned on me that he may have confused the (-set) button with the (-) button for the gear limit. So I ask him where the rpms was at. He said it was high but doesn’t remember exactly where. I think it may have been close or past 3000 not knowing how many times he push the (-)button for the gear limit.

He had cruise control set at 65 for about an hour drive. With the gear limit active.

because you have a heavy duty truck you will get better answers here

Ram Heavy Duty Forum

Ram Heavy Duty forum, Ram 2500 and 3500 news and information.

hdrams.com

 

[jdmartin]

did you read the ops post?
they were not in the truck!

He edited the post later. All of that information you see below the first paragraph wasn't there when I posted. It says "Edited today at 1 AM" on the post.