Need some mod advice

03Avifamily · 08-22-2011, 08:39 PM

So we have a discussion going on a racing forum that I frequent locally about my Avalanche having the capability to pull our camper. It pulled the camper ok this past weekend albeit there were a couple of places that it struggled a bit. It seemed more because the transmission kept trying to shift into a higher gear than anything else.

Some members tell me that the Avi is not capable of towing a 29' BH but I beg to differ. While I know there are better vehicles, this is what I have so it has to work.

I'm looking at making a couple of mods to the Avalanche to help it pull a bit easier. It currently has the 3.73 gears with LSD rear end. I'd like to get a custom tuned computer which will remove most of the torque management to allow the thing to get out of it's way instead of pulling the timing out when I press the go pedal. (Thanks GM!)

I'd also like to install a larger trans cooler to make sure I don't over work that trans. Some of the guys keep telling me I need 4.10 gearing, but I travel empty on the interstate from North to South Bama frequently and I don't want to kill my mileage any more than necessary.

Thoughts and opinions? I'd like to know the best bang for the buck for pulling and if you guys think I'm overworking the Avalanche.

clutch · 08-22-2011, 09:10 PM

Dosen't the Avalanch have the 1/2 ton Suburban/pickup frame? It should also have the same engine, transmissionj, and differentials. It should be close to it's limits with that trailer. The transmission cooler would be a good idea.

3Pillons · 08-23-2011, 05:08 AM

Depending on your Expy's options, it may be the better TV. Mine has a towing capacity of 8950lbs, that's over 1K more than your Avi if my memory serves me correctly.

03Avifamily · 08-23-2011, 05:35 AM

The tow rating on the Avid is 8100 lbs if jot mistaken.

Seann45 · 08-23-2011, 07:08 AM

Check is the Ava not a unibody design? if so it may tow it but how long till it weakens the structure?

buckeyejim · 08-23-2011, 07:19 AM

My truck has the 6 liter V8, Chevy Max, try towing in 3 rather than drive, eliminates the hunt and peck of the transmission, mileage is about the same 7-10 depending on the roads, hills. I tow a 8600# 322 Eagle, does a great job!

29BHS ECO · 08-23-2011, 07:31 AM

03avifamily-- I don't think you need to change to 4:10 gearing, 3:73 is the ratio of choice in many medium weight tow packages. The trans cooler is probabley a good idea. I assume that your tv's tonge weight spec is above the tt's weight, that can be a problem as the tv can pull all it wants but if the b umper scrapes the ground you've got a problem. The other item of concern is if you have changed the tires to a lower rating since youv'e owned the Avi. Larry

3Pillons · 08-23-2011, 11:27 AM

I've always believed that the best way to get more juice from a motor was to improve it's breathing. Of course computers control that now so I'd bet a computer programming endeavor might be best. Also, the Expy might have a little more towing capacity than the Avi, but the Avi does have a longer wheelbase and a solid rear axle as opposed to the Expy's independent rear (built on a GM Suburban/Yukon XL chassis). I'd probably stick with the Avi and soup it up a bit. Wouldn't mess with the gearing though, 3.73 is where you should be for the best of both worlds. Best of luck.

03Avifamily · 08-23-2011, 02:36 PM

It actually sits perfectly level with the Husky leveling bars/stabilizers on it. It has the Z66 package which I believe gives it a bit stiffer suspension. I would rather leave the gearing alone. I am a Ford guy so this is my first GM in forever. I am used to pressing that O/D on/off button and not worrying about it. I assumed the tow/haul mode was the same thing. I assumed wrong.

I have a K&N drop in air filter, and a Flowmaster single in/single out exhaust on it now. That's it for mods. I'm thinking maybe the corvette servo in the transmission, a Transgo trans cooler rated for 20k lbs, and some sort of tune that will remove the torque management. I think with a little bit of money spent in the right place, I would have a nice tow rig myself.

**Crabman** · 08-23-2011, 03:12 PM

" I am used to pressing that O/D on/off button and not worrying about it. I assumed the tow/haul mode was the same thing. I assumed wrong. "

No, it will still drop into overdrive in tow haul mode if it conditions are right, just at a higher speed. I just pull in 3rd gear, no annoying hunting in and out of OD.

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