4.10 gear change to 4.30- Anyone done this? - Diesel Forum

pegleg · 08-15-2008, 03:04 PM

I'm towing a fairly heavy 5th wheel with my 2007 F-350 CC DRW with a 4.10 rear end.

Has anyone changed their 4.10 gear to a 4.30 gear to help pulling heavy loads?

If so, were you happy with the results? If you had it to do over again, would you?

Thanks!

Rich

Chillinthemost · 08-15-2008, 03:57 PM

What is your truck lacking? 4.1 to 4.3 is not much of a difference, I wouldnt think it would be worth the $.

pegleg · 08-15-2008, 04:32 PM

I'm pulling a 40' Toyhauler and it gets pretty heavy when pulling through the mountains of TN on I-75.

I'm pushing the limits of the specs of the truck with the 4.10 when I've got the harleys in the box. The 4.30 would put me (on paper) back to within the limits.

Just wondering if 4.30 gear is really going to make a big difference pulling the long hills.

Coming back from Daytona in March, I blew the lower turbo boost boot on the truck. Could have just been a faulty part, but...

Rich

MikeL46 · 08-15-2008, 11:19 PM

It's only a 5% change in gearing.

You could get the same by going from a 33" to a 31.3" tire - and for a lot less money.

Mike

pegleg · 08-17-2008, 05:33 PM

The towing guide indicates that a tow boss (4.30 rear end) will tow a 5er up to 18,100 pounds vs. 15,600 pounds with the 4.10 or a difference of 2500 lbs.

Just wondered if anyone had actually made the change and if it made a significant difference when towing heavy... especially in Mountain areas like TN.

Rich

PStroked444 · 08-17-2008, 07:08 PM

Your sig doesnt show any But, Try an exhaust and intake first. Then maybe a tuner. Gears will help but fuel milage will go down too. I suggest this cause intake and exhaust "in a way" pay for them selves. JMHO

pegleg · 08-19-2008, 09:24 AM

Quote:

Originally Posted by PStroked444

Your sig doesnt show any But, Try an exhaust and intake first. Then maybe a tuner. Gears will help but fuel milage will go down too. I suggest this cause intake and exhaust "in a way" pay for them selves. JMHO

I have a 21 point warranty on the truck. Trying not to void the warranty. The Stealership indicates that if I change the gearing, I would only void the gear change, not everthing else. From what I've heard, intake exhaust and tuners will pretty much void everthing...

m3nschmeyer · 08-19-2008, 11:02 AM

pegleg,

I have a 2007 F-350 CC DRW PSD and it came with the 4:10 limited-slip. I converted mine to 4.30 and am pleased with the results, I get better fuel economy both towing and bobtail. last year I towed a 10k 5th wheel from Virginia to NM and back and averaged about 10 mpg with the 4.10 gears. This year I did the same trip pulling a 14k 5th wheel and averaged over 10.5 mpg with the 4.30 gears.

Before converting to the 4.30's I tried getting more torque by mounting 245/70-17 vice stock 245/75-17 to see if that would help and it did but now my speedo and odo were not accurate so I bought a Hypertech programmer to fix the speedo and odo and it did but I blew my head gaskets trying to tow the 14k 5th wheel over Skyland Drive, Virginia. That little experiment cost me about $2,000 (7 tires, mounting, and programmer). I converted back to the stock tires and decided to change the gears and that cost me about $3000, wish I would have gone directly to the gear conversion.

Hope this helps.

pegleg · 08-21-2008, 09:36 AM

m3nschmeyer,

Sure does help! Did you find that the 4.30's gave you more pulling power in the hills too, or did it just help your fuel mileage overall?

Thanks much!

Rich