towing at higher RPM

[brainpause]

I have a 2006 Silverado CC 4x4 with 5.3L, 3.42 rears. Tow rating is about 7100#, so I thought a 5000# hybrid travel trailer would be a good fit.

 

We brought the trailer home from Knoxville, Tennessee last weekend. I drove in tow/haul mode, in 3rd gear, because it just couldn't stick to 4th gear anyway. But what bothers me is that I spent a lot of time in 2nd gear, even if I slowed down to 60 or 65, and even up to 75mph. It would drop down to 2nd, give a big jerk, and wake up my pregnant wife (have you ever awakened a pregnant wife, suddenly?).

 

If it was a long hill on the interstate, and there are several long ones here in Tennessee, especially in the eastern part of the state, I would be running 4500 RPM for several minutes. It really bothered me, and was quite loud and annoying. I just got rid of a 4-banger truck that did a better job (though it was pulling a popup). I was hoping I was out of the towing worries by getting a bigger truck, but I'm not.

 

So, am I hurting the truck by running 4500rpm for several minutes?

 

I am looking at custom tunes, particularly Jesse's wait4me tune.

 

Larry

[pwall]

I would think that the 3.42 gears are hurting you.

Running at 4500rpm for several minutes.....too high for me anyways.

 

I would recommend looking at a tune (http://wait4meperformance.com) and wake the truck up. ;)

[C & A s Dad]

It is those gears that are killing you. A tune will certainly help overall but I do not believe it will cure this issue. My 4.10s allow me to stay in 3rd and run 2200 to 2400 at speeds for 2 lane roads. I have pulled my 6500 lb camper on the Interstate only 2 times with some gentle rolling hills. I was able to use OD much of the time but had to stay above 70 to keep my RPMs in the sweet spot. This is too fast for me to feel safe pulling this kind of load with my family in the truck. I now simply keep it in 3rd and keep it under 65 MPH. The 327 and the 4.10s love this RPM range and it never kicks into 2nd.

 

I hate to tell you, you need to look at some 3.73 s or if I were you, I would go for the 4.10s.

[Trouttrooper]

It's the gearing that's hurting you. A tune would help but your still fighting against those highway gears. You're truck isn't really set up as a towing rig (no matter what they want to say).

 

As for running at 4500rpm. You're not going to throw a rod or anything. They redline at 6000 so you're not running that risk.

[sbatzold]

I've got the same truck but its a 2005. I pull my 4600 dry weight camper around upstate and the figerlakes of NY no problem, in OD with T/H and the engine temp, oil temp stay low an dmy RPM don't go above 3500 even on most hills.

[brainpause]

Going to try the tune first. But how much would gear changing cost? It's a 4x4, so I'd need front and rear.

 

LC

[Bowler807]

I have an 06 Sierra CC with the 5.3 and 3.42 gears. I pull a 6250# 30 foot travel trailer several times a year. When I pulled it the first time I found that the tranny would keep down shifting and the RPM's would shoot way up even in the tow/haul mode. I didn't like this situation either. My old Jeep Grand Cherokee with the 4.7 v8 pulled better.

 

My cure was a Waitforme tune. I had Jesse tune for 89 octane with good towing performance and reduced torque management. I now have great towing performance and improved overall performance. I even gained about 3 to 4 mpg on the highway when not towing. Other than buying the Sierra, this is the best investment I have made.

[Bish]

Agree the gears are hurting you. I have 3.73 and when I tow heavy (5,000lbs), I drive in 3 any time I am not on flat land. When I go through Tennessee, it will drop to 2 occasionally on a steeper hills. I have driven at 4K rpms for long periods in the mountains (Colorado) and it hasn't caused any problems and I'm at 190K on engine and 50K on rebuilt trans. IMO, these engines prefer to rev over lug like the older 5.7L.

[xsports33]

As everyone else has said you should re-gear. It cost me $1400 to get it done front and rear. You might want to look into a larger transmission cooler as well, especially if you're towing often. Not sure if you have a trans temp in the cluster, but you should check that out too. When i had 3.42s, 6" lift, Oversize tires, and towing a 4K boat through the desert and rolling hills my tranny temps were very high. I attribute it to the constant shifting of the tranny trying to find the sweet spot and the TC not locking up. Good luck!

[Schmids5.3l]

Well, like everyone else said, gears. I'd get a tune also, since its cheap, but you might want to wait on it because your speedo's gonna be off with new gears. When you get the tune he'll correct your speedo for the new gears.

 

I towed 4500lbs in OD fine, think it downshifted into 3rd twice going up hills. Even then it was runing maybe 3400ish rpms. The car sitting backwards on the trailer didnt help aerodynamics either. But it was the only way we could get the car on the trailer with the space we had.

[PharmZ71]

Since this topic seems to keep coming up...

 

I am also thinking of re-gearing to 4.10's (from 3.73) since we just acquired a small fifth wheel and I want to pull a boat behind that (looking at around 10,000 lbs total). To those who have done it...where should I start looking for a place to do it? I couldn't find a "differential" shop in the phone book.

 

Will a shop (besides the dealer) be able to re-program the computer?

 

Is calling the dealer a waste of time?

 

Thanks...hope I didn't get too off topic :-)

[xsports33]

Any truck specific shop should be able to re-gear or find a shop that works on axles. You're going to have to purchase a programmer too with the gears to program for the new gears (you'll throw an ABS light if you don't). You could get a complete re-flash of your PCM but the plug in tuners are easier. Also depends on what other mods you plan on doing.

 

PharmZ71 - I'd look into 4.56 gears if you're going to be towing that much, especially around town and up hills. If you're going to tow mostly on the highway on flat ground then 4.10 might work.

[PharmZ71]

Thanks for the reply Xsports..

 

Will those 4.56's make it undriveable when not towing (ie where will the rpms be at around 75-80 mph?)

 

How do they affect your fuel economy when unloaded (it should help when towing though right?)

[xsports33]

check out this link... it will tell you your RPM's with a specific gear ratio and tire height based on speed.

 

http://www.ringpinion.com/Calc_RPM.aspx

 

It would most definitely help with towing, but daily drivablity will be affected. I wouldn't say it would be undrivable, but you will be pulling of the line a lot harder and have a lot more power down low. You MPG will suffer at highway speeds with 4.56, that's why i recommended 4.10 if you're mostly highway driving and not climbing too much. Around town your MPG "could" go up because you'll need less throttle to get going, but you have to keep your foot off it. "thrill factor" of a high gear ratio will contribute to lower MPG at first.

[xsports33]

Also, with a high gear ratio you will lose some top end speed. Unless you consistently drive over 100MPH you shouldn't notice though.