Ive had my LMM for 3 days now and I tried the manual mode and in 1st gear once I hit 4k rpm it just fell on its face and didnt pull any harder. I shifted into 2nd and when the rpms dropped it kicked right back up.

Is 4k like the redline for diesels? What should I be shifting at?

Maybe at 3,200 RPM which is peak horse power?

See my garage for torque and HP chart.

The stock turbo doesn't make power above 3600. Why are you manual shifting. Put it in drive and let the Allison do it's thing

Ive had my LMM for 3 days now and I tried the manual mode and in 1st gear once I hit 4k rpm it just fell on its face and didnt pull any harder. I shifted into 2nd and when the rpms dropped it kicked right back up.

Is 4k like the redline for diesels? What should I be shifting at?


I shift at 2300-2500 When pulln hard Not 4k:o:

its the fact the the tuning runs out over 4 grand. the stock tuning remove fuel at this point to prevent oyu from over reving. with a tuner like PPE or EFI LIVE you can change that

Is 4k like the redline for diesels? What should I be shifting at?

Let the allison shift for you.

stock, around 3300, the fuel tapers off fast after that.
If you want to rev higher, you need a programmer, efilive las the most bells and whistles, but is not plug and play. Most others increase power, not rpm's (AFAIK).

stock, around 3300, the fuel tapers off fast after that.
If you want to rev higher, you need a programmer, efilive las the most bells and whistles, but is not plug and play. Most others increase power, not rpm's (AFAIK).

You got it! It's not the turbo or anything like that - it's the electronics.
It says at a certain RPM to starve the truck for fuel and when the RPMs go under a certain preset point shove to coal back to it (an upshift)!
What gets me is I think it fuels up to 3250 in regular and 3400 in manual mode - how in the hell are you getting yours up to 4k?
And by fueling I mean accelerating... it's perfectly normal and even EXPECTED for going down hill and grade braking the truck to go well above the 3400 RPM 'fueling' line.

You're REALLY breaking that sucker in aren't you?? LOL 3 days and already complaining about the redline!! LOL!! :thumb:

The stock turbo doesn't make power above 3600. Why are you manual shifting. Put it in drive and let the Allison do it's thing
:agreed:

Not a civic. Diesels are low rpm pullers, torque/grunt=move mass.

Uh, that's an awfully heavy bottom end to be swinging around above 3500!!

GM would love to see your ECM printout when you have it towed in! Be advised.

His 35" tires already voided the warranty...... So no worries.......

His 35" tires already voided the warranty...... So no worries.......
While there is no disputing the fact that any dealership COULD refuse warranty service for ANY mods from stock......I haven't witnessed any radical behavior as such. I also agree that swinging any larger tire than is necessary is crazy, but to each their own.

I have been in for two warranty issues with THIS truck and had no issues.

My last dually ('98) was very similar to this one, but gas powered. 6/8 drop, airbags, headers, intake, blaw, blaw. Right toward the end of the extended warranty (5/75), I took it in for missing coolant. I kept filling the jug, but it kept going empty - and it wasn't going on the floor. Ended up being an intake gasket. The dealership changed it, but in the process, droppped an intake bolt down the #4 intake runner. The tech decided to put it together and hope it "passed through". Broke a piston. So, back apart it came, oil pan off, they replaced the #4 piston. Head/valves were OK.

My point is, they had to order header gaskets to put the header back on. Technically they DIDN'T HAVE to do that. They could have just fixed what they hurt and made me put the header back on. No problem. They fixed it up and made it right. Granted - they should. But, they didn't have to. I also had to remind them that it had Mobil-1 in it. They didn't HAVE to put M1 back in it, and technically could have voided me right there.

I just don't think dealerships are as unforgiving as most people think they are. If you treat the service writer-manager with respect and ASK if they have any problem with your mods, they seem very open to just fixing what went wrong and not worrying so much about stock parts.

[ If you treat the service writer-manager with respect and ASK if they have any problem with your mods, they seem very open to just fixing what went wrong and not worrying so much about stock parts.[/quote]

If you treat the truck with respect-- it will last a long time-- your truck will not because you are beating it pretty hard. Tranny, pistons, head gaskets anyone-? :eek:

You got it! It's not the turbo or anything like that - it's the electronics.
It says at a certain RPM to starve the truck for fuel and when the RPMs go under a certain preset point shove to coal back to it (an upshift)!
What gets me is I think it fuels up to 3250 in regular and 3400 in manual mode - how in the hell are you getting yours up to 4k?
And by fueling I mean accelerating... it's perfectly normal and even EXPECTED for going down hill and grade braking the truck to go well above the 3400 RPM 'fueling' line.

You're REALLY breaking that sucker in aren't you?? LOL 3 days and already complaining about the redline!! LOL!! :thumb:

lol, nah I just wanted to see what it can do. Why does it go up to 5k then if it wont even hit 4?

And if I did get it tuned to go above 3500 is that safe for the engine and tranny? Id rather keep longevity than get a fast ass truck that breaks on me quicker.

lol, nah I just wanted to see what it can do. Why does it go up to 5k then if it wont even hit 4?

And if I did get it tuned to go above 3500 is that safe for the engine and tranny?


No....

No....

Higher RPM's are safer on the tranny

Please take a few minutes possibly an hour or two and read the manual that came with your truck..esp break-in part(took me a couple times to find everything).They are great trucks but i think the break in is very important to the longevity of this truck..they are fun,enjoy.

I agree with everyone else, there is no reason to manual shift unless you want it to control speed going downhill or use the somewhat "traction control" feature of putting it in manual and selecting second gear.

Put it in drive once and see where it shifts when you get on it. You may be in manual mode but it still doesn't work like a true manual transmission so let the engineer that programmed the truck make you the most efficient use of power.


This is another reason why I buy new trucks and don't let anybody else drive them tuned or stock...

Please take a few minutes possibly an hour or two and read the manual that came with your truck..esp break-in part(took me a couple times to find everything).They are great trucks but i think the break in is very important to the longevity of this truck..they are fun,enjoy.



Break in!? :eek: Break in for the OP's rig takes on a whole new meaning - good thing the rig is smart enough not to let you blow it up right away.

:agreed:
The stock turbo DOES make power above the red line... DOES, I promise ;)

lol, nah I just wanted to see what it can do. Why does it go up to 5k then if it wont even hit 4?

And if I did get it tuned to go above 3500 is that safe for the engine and tranny? Id rather keep longevity than get a fast ass truck that breaks on me quicker.
The tach goes up there because when you're grade braking it WILL allow upper RPMs but NO Fueling - so you can't accelerate past a certain point, but, when grade braking it will allow the upper RPMs to help slow you down.

I honestly have no experience tuning above the stock rev limiter - there's plenty of guys on here that do it though; but, they're running HIGH HP so if something does break you don't know whether it was the power or RPMS...someone with more experience in that area hopefully will chime in here.

Might be de fueling between and before shifts to prevent premature trans failure .

The stock turbo DOES make power above the red line... DOES, I promise ;)

So whats red line?
And NO it doesnt

So whats red line?
And NO it doesnt
In most circumstances it's either 3250 or 3400, I can't remember which and don't have efilive open.
How do you figure? People with sled pulling trucks, drag racing trucks, and others bump up the RPM's to take advantage of the useful RPM range... if it DIDN'T make power why in the heck would someone do that?
Why raise your upper RPM limit to INHIBIT the truck's performance??? :rolleyes:

"I" would not go much above 3200 just being conservitive and nice to the engine, I usually top out somewhere between 3000-3200 depending on the grade.

The tach is for our diesels and gassers,just because the tach tops out at
5000 or 6000 rpms does`nt mean the vehicle you have will do that.
A gasser will redline much higher than a diesel.
Apparently some needs to read up on diesel rpms v.s. gasser rpms, diesel torque and how and what rpm they achive that v.s. gassers torque.
Are you speaking to me? If so please feel free to elaborate... If not, I'm mistaken and apologize for this response.

Ive had my LMM for 3 days now and I tried the manual mode and in 1st gear once I hit 4k rpm it just fell on its face and didnt pull any harder. I shifted into 2nd and when the rpms dropped it kicked right back up.

Is 4k like the redline for diesels? What should I be shifting at?

So I guess GM feels that 4000rpm is safe to fuel to which is redline

The stock turbo doesn't make power above 3600. Why are you manual shifting. Put it in drive and let the Allison do it's thing

:agreed:

The stock turbo DOES make power above the red line... DOES, I promise ;)

So if redline is 4000rpm just you cause you promise doesnt mean the truck will make power that high

The tach goes up there because when you're grade braking it WILL allow upper RPMs but NO Fueling - so you can't accelerate past a certain point, but, when grade braking it will allow the upper RPMs to help slow you down.

I honestly have no experience tuning above the stock rev limiter - there's plenty of guys on here that do it though; but, they're running HIGH HP so if something does break you don't know whether it was the power or RPMS...someone with more experience in that area hopefully will chime in here.

And with a stock turbo 3600 is as high as you want to go

"I" would not go much above 3200 just being conservitive and nice to the engine, I usually top out somewhere between 3000-3200 depending on the grade.
There is nothing wrong with manual shifting, just using commonsense seems to be the difficult part.

The tach is for our diesels and gassers,just because the tach max is
5000 or 6000 rpms does`nt mean the vehicle you have will do that.
A gasser will redline much higher than a diesel.
Apparently some needs to read up on diesel rpms v.s. gasser rpms, diesel torque and how and what rpm they achive that v.s. gassers torque.

:agreed:

In most circumstances it's either 3250 or 3400, I can't remember which and don't have efilive open.
How do you figure? People with sled pulling trucks, drag racing trucks, and others bump up the RPM's to take advantage of the useful RPM range... if it DIDN'T make power why in the heck would someone do that?
Why raise your upper RPM limit to INHIBIT the truck's performance??? :rolleyes:

Yea they raise the shifts to 3600 which is not past redline

NO ! I guess you missed gmduramax that was in the quote, I replied to.
Oh, I'm so SORRY, I totally missed it!! I need one of these :chillpill:chillpill

So whats red line?
And NO it doesnt

NO ! I guess you missed gmduramax that was in the quote, I replied to.

I think there has been a misunderstanding. I was asking Jason what he thought red line was. I know what it is, and I know the difference between a gas and diesel

Then what is redline? we're going round and round - I'm talking about the FUELING redline...I should have stated that 3250 rpms and up is what i had in mind.

Then what is redline? we're going round and round - I'm talking about the FUELING redline...I should have stated that 3250 rpms and up is what i had in mind.

The truck is fueled to 4000. In drive it only goes to 3250 because thats when its told to shift.

The truck is fueled to 4000. In drive it only goes to 3250 because thats when its told to shift.

I'll be damned! Learn something new everyday!
NOW i see what you're talking about - all this time I've honestly thought the FUELING was being cut @ 3250 - your way would make much more sense seeing as the original poster explained he could hit 4k in Manual.

I'll be damned! Learn something new everyday!
NOW i see what you're talking about - all this time I've honestly thought the FUELING was being cut @ 3250 - your way would make much more sense seeing as the original poster explained he could hit 4k in Manual.
Well technically it was 3800-3900

As many have already said I was under the impression that 3800 ish was redline with fuel but under engine braking the engine would go to 5k without fuel without trouble.

Whoahhh, how are you guys getting fuel to 4000 rpm's ???? Mine hits a wall at 3250 but will rev to 3400 or so before it will quite excellerating at all, doesn't matter what gear I'm in. Of course all of this is in manual mode because the ECM will shift @ 3200 drive.

Never thought of putting in 1st and flooring it to see what it do. Maybe it can do 4000rpm in 1st. I also thought even if in 1st it would shift into 2nd for safety?

I think your right, if will shift into second for safty reasons. Never thought of putting in 1st and flooring it to see what it do. Maybe it can do 4000rpm in 1st. I also thought even if in 1st it would shift into 2nd for safety?

I think your right, if will shift into second for safty reasons.
If it shifts when in manual mode, then you have a different tranny then I do. I have "redlined" it in first and it never up shifted when in manual mode. Of course what I did was by accident, but never the less there was no upshift.

If you're doing grade braking and the truck and trailer keep pushing past 4800 RPM it will upshift.

The truck is fueled to 4000. In drive it only goes to 3250 because thats when its told to shift.

Are we speaking stock here?

If so,
No it won't fuel to 4,000... 3,450 is the max it will fuel to. Put it in P or N and wood the throttle. It gets no where near 4,000. And no this won't hurt anything either. 3,250 is the max upshift rpm.

Never thought of putting in 1st and flooring it to see what it do. Maybe it can do 4000rpm in 1st. I also thought even if in 1st it would shift into 2nd for safety?

ummm nope, didnt shift until I told to

No more manual shifting for me though thats for sure

Are we speaking stock here?

If so,
No it won't fuel to 4,000... 3,450 is the max it will fuel to. Put it in P or N and wood the throttle. It gets no where near 4,000. And no this won't hurt anything either. 3,250 is the max upshift rpm.

Nearly all trannys are rev limited when in neutral or park.

Me personally, I perfectly happy letting the Allison shift at 3200rpm. It's a heavy duty diesel. I like the extra revs when going down hill though, tow/haul mode works great on this 6-speed.

Nearly all trannys are rev limited when in neutral or park.

Me personally, I perfectly happy letting the Allison shift at 3200rpm. It's a heavy duty diesel. I like the extra revs when going down hill though, tow/haul mode works great on this 6-speed.

It does the same thing in gear too. Has nothing to do with the transmission.


Put it in M1 or 1 and do the same thing. It'll shift to 2nd, but 3,450 rpm is all it will fuel to. ~129 mph is the top speed (@ 3,450 rpm) with stock size tires if you wanna try that one too.

It does the same thing in gear too. Has nothing to do with the transmission.


Put it in M1 or 1 and do the same thing. It'll shift to 2nd, but 3,450 rpm is all it will fuel to. ~129 mph is the top speed (@ 3,450 rpm) with stock size tires if you wanna try that one too.

True. However, my point was a general one. Most trannies are rev limited in park or neutral. My sedan would explode if it wasn't.

The 129 is interesting, I'd have thought no more than 120mph. Impressive but I won't be trying three figures in a truck anytime soon.:D

I have seen little differences in the LMM 07.5 and the LMM 08. My 08 LMM Limits at 3500 my brother in laws 07.5 LMM doesn't tap until almost 4k. I have another question to somewhat go along with this. I bought a superchips programmer and programmed performance and drove it for 15 20 and the next morning my truck now sounds like a 16 valve 5.9 cummings. ANY THOUGHT would be great.

Alot of tuners alter the timing to help in making more power, in cold weather is where you usually will hear the changes in it.

If I am reading his post correctly, he has owned the truck for 3 days but he is not breaking in the engine as it is a 2007.5 LMM.