Just spit-ballin' here, but has anybody changed their 4.10 (alpha) gears for 4.56 (I5). Since adding all the weight from rockrails to bigger tires to UCP, my truck has gotten alittle sluggish of the line. I've never been amazed by GM small block (mainly 4.8 and 5.3) low end torque. It's torquey *** hell above 4000, but below that well....... So anyways, i was wondering about swapping the 4.56 gears in, and helping the off the line performance. With gas prices the way they're going, I feel like I'm wasting alot by keeping the throttle down on starts, and going up freeway on-ramps. Truck wants to downshift alot getting up to freeway speeds. I figured the gears would help with that. The off-set would obviously be a higher cruising RPM, but I think it would have more of a benefit being light on the gas from a start. I'm trying the "egg between shoe and gas" theory, but just not enough grunt w/ out down-shifting! What are yall's thoughts?

 

I never have given it much thought but if anything I'd like to go to the 4.10 gears on my I-5. The I-5 is a torquey little plant with aflat torque curve of about 230 lb-ft from 1500 to 5000 RPM. The 5.3 plant also has a flat torque curve of 300 lb-ft from about 2000 to 5000 RPM.
http://media.gm.com/us/powertrain/en...VORTEC37LI5VVT
So, I don't know how you can say the GM plants don't have thetorque they need. I guess it's all relative, they're not diesels or big block Chevy's but but who can afford either of those anymore? I'll be willing to bet that the I-5 could handle the 4.10 gears just fine!

 

I'm not saying the motor is a turd or anything. I'm just saying 300-320 lb ft combined with a 4 speed auto and a 5000 + lb curb weight along with the wind resistance of a brick seem to have caught up with me. My wife has an F150 FX4 w/ the 5.4 (365 lb ft.) and it feels a hell of alot quicker on initial throttle tip-in than mine does. And that's with 3.73 rear end. I just thought the 4.56 would help with the ti- in, and keep the 5.3 in the sweet spot more often, lessening the need to constantly dig at the throttle. I drove an I5 as a loaner, and I agree that it is a torquey little bastard. Great throttle tip in and pull, but seems to fall off towards redline or in passing situations. The V8 is the opposite. Sluggish at frist, but starts to pull like crazy in the mid range. I've tried to adjust my driving habits in the hopes of getting better MPG's, but the motor/tranny combo doesn't seem to like a real light foot, especially with the weight i've added.Never really noticed when I was all stock. (I know, I know, I chose to add all the crap and I have to deal with it!) I'll bet the venture isn't even financially feasable anyway. I could prob. buy 6 months worth of gas for the efforts. I was just curious what everyone thought of the idea. Every little bits help with these gas prices!

 

Sounds like yall havea trade ready to go.

Josh, have you checked your air filter? We know you like the mud. I just replaced mine and it was caked in mud. The motor couldn't breath. I changed the filter the same day I went with 2" taller tires and it feels stronger now than when it was being suffocated.

 

Yeah Josh, Steve may be right. If you were closer and I know the carriers would fit a swap might just do the trick. I wonder if anyone has swapped in the 4.10 gears for the OEM 4.56 gears? I'm sure that would get you another couple MPG's and it wouldn't sound like a nest of mad Bee's at 80 MPH. Maybe I'll just wait for these skins to wear out first and stick some 35's on there. That will change my final drive a few tenths of a percent.

 

Dang it! [sm=why.gif] Now you have me thinking too hard and I'm going to hurt something.


Let's see... My H3 has a GM 4L60 tranny and a Borg Warner BW 4494 T-case. My 4th gear is .70:1 and my T-case is 1:1 in High range.

With 33" tyres in 4th gear I should be going 70.8 MPH at 2300 RPM.
With 35" tires in 4th gear I should be going 75.1 HPH at 2300 RPM.
Thus I should be able to lower my RPMs to 2150 to keep 70.2 MPH a net savings of 150 RPM.
"Can you tell I'm making this up as I go?"
So... With 35" tires and 4.10:1 gears I'd lower my RPM's @ 70 MPH to 1928 RPMs. A total of 372 RPM off of stock.

All of those numbers mean I'd be running about 70 HP at just under 2000 RPM with about 210 lb-ft of torque. Man! Those sound more like Tractor numbers than ones for a truck! John Deere and GM must be thinking alike, no wonder the I-5H3 with an aftermarket exhaust sounds like a piece of farm machinery.

Where was I going with all of this? Oh yeah...Would I save money with bigger tires and 4.10:1 gears? I'd still have a 17:1 crawl ratio in 3rd gear Low Range and a 54:1 in first gear Low. So it's not like I'd be losing a great deal in the off road department.

I hope someone else reads this and gives me feed back. Does it sound like it would work?

 

That's what my co-worker calls "circle talk".

You need to factor in the added weight of larger tires, but, what you said is probably detailed enough to confuse most wives in to OKing new bigger tires.

 

I think the alpha is geared well, Throwing in the 456 gear will help everywhere,but the will lose mpg. Thats why you have 300hp, i would add a Cai,Catback,Headers, and street tune it for max mpg.. I sure you would see 15 city

 

Checked air filter. it was clean.

I As soon as somebody makes a damn filter![:@] I want an exhaust as well, but I'm waiting to see if anyone is going to make a single outlet. I don't like the duals sitting under the bumper just waiting to be crushed. I've also been looking at the superchips programmer, but was hoping for a filter(for Docs cold air kit) before i pulled the $400 trigger. Oh well, guess I'll just have to hurry up and wait.

 

I would just geta magnaflow single dual outlet inplace if the stock resnator and dump it.
Also look for a diablosport predator,i have had lots of luck with there tunes..

On the intake side,just open up the snorkel, i had some 4" drain pipe laying around.
The fender has a 4" opening. what a differnce,and then just wait for a drop in.