Suburban gearing question

[mchambers]

http://img.photobucket.com/albums/v77/bentoy/Towing/GCWR_2001_GM_TowingGuide.gif

I was looking up towing weights for a 2001 1500 suburban with the 5.3 engine and an automatic trans and 3.73 ratio rear end. Not sure if I have the towing package or not, there is a small cooler in front of the radiator but I haven't verified what it goes to yet. I found the above chart that states that the GCWR is 13,000. If I have the 4.10 ratio it goes up to 14,000.
My question is this: Does it matter whether or not it has the towing package? This chart makes no reference to vehicles that do or do not have that option.
If it doesn't matter then is the only difference the gear ratio?
How much of a hit will I take on mpg's?
Does anyone have any links to information on this subject that I could edumacate myself on? I want to retain the road manners of the suburban as it is but will need to replace my shocks soon and I want to go through the drive train and have everything checked over. I have already put on new rubber, replaced brake rotors, calipers and hoses.
I have learned a lot by just cruising through threads on here and appreciate any input you might have.

 

[BradyD]

im not an expert but I have and 04 with 5.3 and 3.73s. I know that different manufactures offer different options for "towing packages". some as basic as a receiver hitch and trailer light plug and some take it as far as lower gears and auxiliary transmission fluid cooler maybe a trans temp gauge. my original "window sticker" claims mine has a towing package but as I am not the original owner I cant verify what is factory and what isn't. that being said it does have a receiver hitch and lights and "tow" mode on the shifter, which im pretty sure all chevy trucks and big suvs have. I guess I really didn't answer any of your questions. sorry, but I hope someone can. I too would like those answers.

 

[BigDan]

normally towing package includes : Gears , transmission oïl cooler , harness & Hitch ( some a tranny temp gauge ) .....

with your serial number, you could get all the options list ,,,

personally Id keep the 3:73`s if you run 31" or lower tires , and dont tow nore then 5,000 pounds

 

[mchambers]

I am running GY duratracs with "silent armor". Doesn't mean any thing but it just feels good to say "silent armor"!
I weighed and with full fuel but no gear or people I clocked in at 5860 pounds. So 4 people a dog and gear I would say add a 1000 pounds.
I am considering a bumper pull camper in order to get my wife and kids to step away from electronics and see what lies over the mountains.
Most campers I have been looking at are 6000 to 7000 pounds gvwr. Which is why I want the 14000 Lou d gcwr.
Of course the next question is whether or not a 2001 5.3l with 125,000 on it will like pulling this up a hill!!!
Previous owner pulled a boat and replaced the trans. For me before I bought it. It was owned by a guy who owns a Chevy dealership so I feel confident the work was done properly.

 

[DaveNay]

From my experience, most "towing packages" don't change the GCWR of the vehicle, they just add things that are either convenient (hitch & wiring) or aid in extending the life of the vehicle while towing (transmission cooler & temp gauge) or change the performance or fuel economy (gears).

 

[Jkenosh]

I just bought a 02 Yukon and buy rear brakes on it and there were bigger brakes with the towing package

 

[Kaisen]

You have all of the RPO (Regular Production Option) codes listed in the glovebox. The ones you're interested in would be 'Z82' towing package, 'G80' locking rear, and 'GT4' for 3.73 or 'GT5' for 4.10

There were no bigger brakes included with the Z82 towing package. All Suburbans have transmission coolers. It's really just the hitch and wiring (and trailer brake harness).

The difference between 3.73 and 4.10 is really a matter of speeds. 4.10 may be more suited to towing at 50-55mph, where the 3.73 may perform better at 60-65mph. So will you be mostly Interstate, or back roads?

 

[mchambers]

I anticipate 70% interstate, 20% back road and 10% or less mountains. The gearing must make some difference if the chart indicates higher gears give you another 1000 lb. Weight capability.

 

[Kaisen]

The gearing only makes a difference in terms of the amount of work that can be done... it's mechanical leverage. But that's also a function of engine speed and road speed, hence the effective gearing. In other words, a 4.10 gear is accomplishing the same exact work (and rpm) at 55 mph in third gear as the 3.73s are accomplishing at 60 mph. But getting the load moving gives the 4.10s the advantage, hence the additional GCVWR

 

[mchambers]

I couldn't read the chart I posted so I know you guys can't. Going to try and post it again

 

[mchambers]

Ahh OK. That makes sense. Thanks Kaisen! A d thanks for the codes for options.

 

[mchambers]

Also explains why the gross trailer weight increase 1200 lb. From 7200lb. To 8400lb. When the total gcwr only increased by 1000lb.

 

[rayra]

I've basically got the same suburban, 1yr newer.

Factory tow package will also include a 'haul mode' button on the end of the shift lever, which cues the vehicle computer to alter the shift points / range of the trans. And your tow capacities ought to be on your factory hitch by the wiring port. And don't tow in OD.

The 4th digit of your VIN is your GVW rating and brake system rating.
E 6-7k #
F 7-8k #
G 8-9k #
H 9-10k #
J 10-14k #

I don't know if the factory towing package includes a brake system upgrade. It's very unlikely you have or can handle the 10-14k range without substantial upgrade to your brakes.

Our '02 Z71 Sub k1500 5.3L and '05 Z71 Tahoe k1500 5.3L both have the same hitch package, rated at 12k tow weight. I've towed a 14' tandem axle U-Haul stuffed to the gills with household goods behind our 4:10 equipped Tahoe thru mountains and up the vehicle-killing Grapevine highway pass without any trouble whatsoever. In fact like it wasn't even there. I would guesstimate it was about 5-6k pounds. The 7-8K box camping trailer does indeed peg our limits. But I'd be more worried about braking power than hauling power.

And don't get bogged down in the ratings numbers, they're for lawyers. And they are always on the low side. Use them as a general guideline, not an 'exceed and disaster will strike' indicator. Rent a similar trailer, do a test run. You could readily tow such a trailer down the highway. And be necessarily slow in the mountain roads anyway. Maybe increase the cooling capacity of the trans.

I'm planning on towing my neighbor's Coleman Evolution pop-up camper-trailer up to Mt Whitney portal and down into Death Valley and environs late this winter. Room for 4+ and gear and its loaded weight is <3500#

(Looks like this, not his)

Should also be an easy haul. He tows it behind his Dodge Ram 1/2ton short bed. Maybe a pop-up camper design would solve your family comfort dilemma.

 

[mchambers]

Thanks for all the info. It does have the Z82 towing package rear locker and already knew it had 3.73 gears. Makes me wonder what all the other codes mean.

 

[Kaisen]

Makes me wonder what all the other codes mean.

http://www.cadillacfaq.com/rpo/