5.13 axle gears, towing review
 

Well, here it is, the moment that we've been anxiously awaiting. Well, I've been anxiously awaiting anyway. Got mjy 500 break in miles done and took a trip with my trailer holding 2 side by sides and camping gear. 8000 lbs approximately, maybe a little more. I don't have mountains in KY, but I do have hills, one after the other and they're long. The first one was on I65S headed to Elizabethtown. It starts at a gradual incline and transitions to a pretty steep hill, and long. The kind of hill that has semi trucks and people with V10 Excursions with 3.73 gears trudging along in the right lane at 50-55mph.

So, my V10, with 32.6" tires, 5 star tunes, loaded with 4 people and an 8k lb. trailer, made it to the top and didn't drop below 65mph. Finally! I am able to use 4th gear to tow, as my RPM at 70 mph is 2750. Only on the long steep hills does it drop to third at about 64 mph. At that speed, it's spinning at about 3600 RPM and pulls pretty strong. This hill prior to the gears was one that would have had me down to 55 mph and 2nd gear, struggling to maintain 55mph to the top. On the rest of the trip to Land Between the Lakes in Western KY, there were countless long hills that had me down to 65 or even 63 if I didn't pay attention and feed it a little throtle to get it to downshift.
I don't know my mileage as I forgot to check but my estimate is that it's no worse than the 7mpg I was getting with the 3.73s. It's still not a diesel but at least I"m not getting passed by semi trucks any more!
I have a set of 35s I'm going to throw on just for fun to see how that affects it. If I can get the same performance while lowering RPM a little, that won't be a bad thing. Plus, 35's look cool!

So, bottom line, the gears work and get me up the hills satisfactorily. Well worth they money in terms of frustration while towing. Thanks to all who advised me subsequent to my purchase of the truck on what to do in order to improve towing performance.

Makes me not want to burn the truck to the ground! Thanks for all your advice.
I just put my set of 35s on and they look good! Hopefully they won't hurt my pulling power too much. If so, I'll put the 32s back on for trips.

Glad to hear it. Let us know how it does with the 35's. I'm planning on going to 35's when I wear out the 32's that are currently on mine.

Lets not get carried away...…...:D

I'm kind of afraid to tow with them. I was still screaming in 3rd going up some of these hills with my 32.6" tires.

Hahahaha, I'm just glad to be able to pass semi trucks. I got passed by so many prior to the gears, I couldn't stand it.

That's part of the "learning curve" I mentioned in another thread when going from diesel to gas. It took me a couple of weeks to stop looking for the EGT gauge every time I hit a hill. Then a while longer to figure out that my V-10 is truly miserable pulling at 1800 rpm but will turn 4000 all day long. Couple more trips and you won't even notice it.

True. when I drive a sports car i don't care to rev it to 7500 RPM or whatever it 's made for. Still kind of strange to drive a truck like that but i'm getting accustomed to it.

IT really is weird for a while. You'd think 2800 would be plenty but it's just getting going about there.

And let's also remember that a stock V10 will out pull a stock 7.3L PSD with a trailer, up a grade, in real world situations as proven by FTE members. ;)

I'm sure the OP will encounter a few stock 7.3's being pulled by a gentle, older dude who just likes to keep the tires moving, and he will pass them with a smile on his face.

Stewart

I passed a few people towing last weekend and I was happy! I don't think I passed any diesels but finally passed some other gassers at least. Everyone was passing me before the gears so it was exciting to not be the slowest guy up the hill. I used to be the fastest in my Dmax though hahahaha!

Good to hear the gears did make a difference.
Looks like I have some 4.88s in my future....

BTW - 2800-3200 RPM is the sweet spot for towing with these. Don't expect to lug it around like a diesel. When I drive manually (no cruise) I can keep the thing in 3rd over almost anything just by speeding up / keeping it in the powerband and reading the terrain . . . Letting it grab OD then lug way down . . . this transmission is too stupid for that type of driving. Can't wait to get a new Godzilla / 10 speed.