Towing Upgrades for a 2004 Sierra 1500 4x4

[clinebarger]

Originally Posted by bambbrose

Hey guys, my daily driver 2004 GMC 1500 4x4 is about to take on some extra towing duties.

My wife and I discussed upgrading to a 2500 or diesel, but we don't tow all that often and I really like my truck, so I've been considering just doing some upgrades.

My rear-end is a factory Posi but a 10 bolt I think 8.6". It had some shavings and what looked like parts of a needle bearing in the fluid last change. It's working fine now but I know it's a ticking time bomb.

I'm considering the following:
-Upgrading the rear to a 14 bolt (brake upgrade included?)
-Babying the 4L60E, but planning on swapping for a 4L80 at some point.
-Putting on some better springs/shocks (they are getting older now).

Anybody have any useful links or info on the above three tasks? Any reason I shouldn't head down this route?

I figure my truck is paid for, and I don't want a new truck payment, so why not just upgrade what I have and keep it that way.

I'll be towing a 6000 lb horse trailer (gooseneck), along with up to 3 horses and some gear. I'll be pushing 11,000 lbs worst case.

Thanks for any advice

The "pieces" you found in your diff are from the "Gov-Loc" posi, They are known to spit things out, & Explode in spectacular fashion

14 bolt axles (9.5" SF & the 10.5" FF) use a 8 lug wheel pattern.
A 4L80E swap would require....
A 4x4 LS 4L80E.
LS/4L80E dust cover & bolts
Dipstick & tube.
Flexplate & spacer kit.
Torque converter bolts.
Wiring harness mods.
Custom PCM tuning.
4L80E Cooler lines.
A transfer case thats compatible with your truck & a 4L80E.
Transfer case adaptor.
Move the crossmember back....NOT an easy task on these trucks!!
Both driveshafts will need to be reworked.

This mod alone can cost MORE than selling your truck & buying a 04 K2500HD with a 6.0/4L80E/14 bolt FF/Bigger brakes factory installed. And has higher weight ratings,

Modifying your K1500 truck does NOT change the weight ratings your truck had from the factory.
So even if you go through all the trouble of making your truck safely handle the weight.....Legally its still a 1/2 ton truck