02 GMC Yukon Towing Question

[aklim]

My vehicle has 3.73 ratio for the rear end. 5300 Vortec with 3.73 rear end Since it is 4WD, I would rather not go to 4.10 since I have to change both gears. The book says the max capacity is 7500. However the 4.10 ratio one gets to tow 8500. Why the difference? Because the RPM is higher from the 4.10 gears?

Also The trailer dry weight will be 6000. Add about 1500# of ATVs and a few items and that should bring me to about 7500 and a couple more for other misc stuff. I would estimate that it shouldn't exceed 8000 . I will have a weight distribution hitch with the sway controller.

The good part is that I have Dynatech long tube headers, Transgo shift kit, larger transmission cooler and Billet Transmission servos and a Granatelli Intake. Also I have got Jesse to take out all torque management and abuse mode. Is this going to be enough or should I have to do more modifications? TIA

[Hit Man X]

That'd be my assumption as to why you can pull more, it's higher up in the torque band.

Your setup is pretty good for towing, just with that much weight I'd keep it in 3rd and watch ATF temps closely.

[aklim]

My Auto X-ray even with the enhanced OBDII enabled, doesn't read tranny temps. Any idea why?/

[Hit Man X]

Weird, I think my AutoTap Enhanced does. I don't have a laptop anymore so I can't go check.

Have you considered picking up an HD truck cluster with a temp gauge? It should be semi accurate.

The reason for driving in 3rd (1:1) is no mechanical disadvantage on the trans like you'd have in 4th (0.70:1). You'll get a bit more RPM from the gear so you'll probably be limited to around 60mph unless you want to really burn some fuel up.

[aklim]

Problem is just like in Sammy Hagar's song. I can't drive 55

[RedHeartbeat]

When in OD you give the mechanical advantage to the transmission to destroy itself.

[aklim]

Besides the shift kit, billet servos (1-2 and OD Servo) and bigger transmission cooler, what else can you to to make the transmission take the abuse on OD?

[Hit Man X]

LOL - I prefer The Best of Both Worlds.



The 60E really is a crappy trans. You could tow light stuff in OD but I wouldn't risk it for that much weight like you're planning. 4.10:1 gears or 4.56:1 would get those cruise RPMs up but then it's bad when not towing.

It's going to generate a lot of heat and work against itself.

[chrisj6]

My autotap even when I had general params read tranny temps, if you are going to upgrade clusters, I would look at an Escalade cluster, they look much nicer and has the temp guage ready to go.

Chris

[aklim]

Will have to check into that