Ford Ownner Coming Over To Gm

BillH · January 24, 2008

I plan on selling my F250 and have been looking at some 2005 4wd Silverado and Sierra 1500's, mostly lease returns. After owning a 3/4 ton, I know that a 1/2 ton is all I really need. I live in upstate NY, and plan on using the truck as a daily driver, as well as hauling 7 or 8 cords of wood a year, a 14' aluminum boat, and some dirt road hunting use. All of the trucks that I've looked at have the 3.42 rear diff, is that enough for what I've described ? The z 71 package has me confused too. Do all z 71's have the locking differential ? Do they sit higher than the other 1/2 tons, and if so, is it from heavier springs or higher blocks ? Lastly, most of the ones that I've looked at have the 5.3 L33 aluminum block engine. Is that a good engine. A lot of questions, I know, but I really don't trust all the dealers, they seem to tell you whatever you want to hear. Thanks in advance..Bill

asilverblazer · January 24, 2008

Z-71 will five you better shocks and larger jounce bumpers. For as little towing as it sounds like you will be doing I imagine a 3.42 ratio will work for you.

pm26 · January 24, 2008

I believe the locking G80 differential was optional on the 2006 and previous model Z71s. It was usually included in the light duty powertrain package which included the 5.3 liter engine, locking differential and the tow package.

Z71 trucks sit about 2 inches higher than 2WD versions of the same truck. I think they use different springs on them in the back and the front has torsion bars. The z71 package will also have skid plates. Suggest you get a truck with 3.73 gears - they are the best compromise for all around use. Also, with the factory tow package you get an external transmission oil cooler. I also recommend one with the autotrac trasfer case. It will enable you to use 4WD on hard pavement on slick roads. Autotrac is standard in crew cab Z71s and optional in others.

The aluminum block engine was only used in extended cab Z71 before '07. I think it is just as good as its cast iron counterpart. Both engines use aluminum cylinder heads.

HawkeyeOC · January 24, 2008

To add to what everyone has already said here, the 5.3L engine (aluminum or cast iron) is a very good all around choice for what your say you will use it for.

Good power, good all around fuel economy for a full size, and decent towing ability. With the 3.42 gears you will see a little better highway mileage but you will lose a little lower end grunt.

The only difference I am aware of between the aluminum and cast iron 5.3L is a slight weight difference between them.

pm26 · January 24, 2008

The only difference I am aware of between the aluminum and cast iron 5.3L is a slight weight difference between them.

And I believe the HO 5.3 liter aluminum version has about 15 more HP.

silveradocoa · January 24, 2008

and alum should cool a lil better. but just a lil

desrtrat · January 24, 2008

i would rather go with 3.73 gears myself. your MPG will not be that much different, and it would be better for towing. it's better to have a little bit more gearing all the time, than not having it when you REALY need it. plus your throttle response it

good luck on what ever you decide

Mark_in_Tulsa · January 24, 2008

i would rather go with 3.73 gears myself. your MPG will not be that much different, and it would be better for towing. it's better to have a little bit more gearing all the time, than not having it when you REALY need it. plus your throttle response it

good luck on what ever you decide

It is really worth the wait to find one with 3.73 gears.

zibzer · January 25, 2008

look in the glove box for RPO code G80.. if you see that, then it is a limited slip differential. As long as you only pull 1 cord of wood at a time (preferably on a trailer) you will be fine with any rear end and a 5.3l. and if the weight starts to feel a little much, then push the tow button and she'll pull a house down.... good luck!

Mark_in_Tulsa · January 25, 2008

look in the glove box for RPO code G80.. if you see that, then it is a limited slip differential. As long as you only pull 1 cord of wood at a time (preferably on a trailer) you will be fine with any rear end and a 5.3l. and if the weight starts to feel a little much, then push the tow button and she'll pull a house down.... good luck!

Good points, but for the record to make sure we don't miss lead anyone, hitting the tow/haul button does not increase power at all. Just pretty much raises the shift points and firms them up a bit like all the other full size truck manufactures. (not sure about toyota)

Beer Belly · January 25, 2008

look in the glove box for RPO code G80.. if you see that, then it is a limited slip differential

I thought the G80 was the Central Locking Diff...not Limited Slip ??...maybe I'm wrong on what the differance is

tigerbait · January 25, 2008

Th G80 is essentially a locking differential that uses the mechanics of a limited slip to accomplish this. The G80 uses clutch packs just like a limited slip, but it acts like a normal open differential until the difference in speed between the wheels is >100rpm. When this occurs a torsion linkage engages to lock both wheels together. Thats basically the G80 in a nut shell.

As a former ford truck owner, and as one who comes from a ford family I can attest to the build quality and power of these trucks. I can honestly say that after owning my GMC, It will be hard to go back to anything else.

Thanks for buying AMERICAN!

rossn2 · January 25, 2008

Believe one of the forum tech's should answer this because don't believe the G80 contains any clutch packs. Does the G80 require a "posi" additive to it's fluid? If not, then there's not clutch packs in it. It operates as a normal "open" rear end. When one of the wheels starts spinning, a mechanical weight-slide inside the unit moves and locks the other axle so both wheels put traction to the pavement. This type of rear end operates basically the same as the Dodge 2500 trucks.

Th G80 is essentially a locking differential that uses the mechanics of a limited slip to accomplish this. The G80 uses clutch packs just like a limited slip, but it acts like a normal open differential until the difference in speed between the wheels is >100rpm. When this occurs a torsion linkage engages to lock both wheels together. Thats basically the G80 in a nut shell.

As a former ford truck owner, and as one who comes from a ford family I can attest to the build quality and power of these trucks. I can honestly say that after owning my GMC, It will be hard to go back to anything else.

Thanks for buying AMERICAN!

anonemouse · January 25, 2008

I had an F150 for 9-months. During that time it was in the shop no less than 8-times!!! I now have an '02 GMC Sierra and couldn't be happier! Ford lost me as a customer, but GMC gained one.

No regrets!

Anon