4.30 or 3.73 gears for F350 7.3L?

Being a diesel guy at present, it may not be my place to offer any solid advice, however in consideration of the relatively uber light (2000# +) camper and in the interest of better MPG I’d be tempted to lean towards the 3:73…I say this mainly because of the 10 speed tranny (in which you could manage a downshift where needed), and because of the higher torque of the new 7.3.

Phil

I too am unqualified to give a valid response, but in theory, if you can hold that 10 speed transmission in any gear you want, I’d see no reason to not have the “long legged” rear end. For example, if with the 3.73 you found yourself on a stretch of road where the transmission might “hunt” one would think that in the tow/haul mode, the TCM would simply choose to keep it in a lower gear, or by taking manual control, you could simply choose a lower gear. Again this is just theory……

I would choose the 4.10 for a dedicated tow mule, dump truck body, heavy camper or other heavy hauling application, but then again the anticipated weight of your camper is 2,000lbs which is approx equivalent to a ton.

Been all over the country and my 2012 F350 6.2 with standard six speed has no problem anywhere we have been hauling 1,300 pounds more weight so really it is just an issue of preference in my opinion, not need.

3:73 for your setup

Mello Mike wrote:

3:73 for your setup

Mike,
Would this also be true if hauling a #4300 (fully loaded and wet) camper? For that much weight, would the 4.30 be better?

Thanks!

Mello Mike wrote:

Yes, I was responding to the OP who said they would be hauling a relatively light Scout Kenai. 4.3 gears would be better for heavier campers, though if I was running a diesel I’d still go with a 3.73.

I’m ordering a F350 Dually with the 7.3l gas engine. I’ll be carrying an Adventurer 901SB with a dry weight of about 3300 lbs. I don’t plan on towing anything.

I’m getting mixed directions on the 3.73 vs 4.30 in various forums. The salesman recommended the 3.73, but I’m not sure he understands what I’m doing with the truck. (hauling vs towing).

Is the mpg that much better with the 3.73 when the camper is loaded? Otherwise, I don’t see the advantage of the 3.73 over the 4.30. This truck won’t be much of a grocery getter, it’s almost exclusively for the TC. (90% of the time it will be loaded).

Get the 4.30 rear end for the 7.3 gasser.
It is perfect with our Northstar camper.
If you get the 3.73’s, even at freeway speeds you will not be able to use the top 2 or 3 gears without lugging below 1500 rpm unless you are going 85 mph. Maybe the trans will not let you lug down below 1500 rpm.
I thought the same as the diesel guys above, until I actually owned and had time in the saddle with an F-350 with 7.3 gasser.
I wrote a long response to both questions, but it disappeared into the ether.
I found it, but the site says, “Forbidden” and it won’t load for some reason.
I added it here:
Brett: I do have a 2020 7.3 gasser Ford F-350 and have some real world experience with it. I’ve been in both camps (diesel and now gas) and from my own diesel experience would have suggested what the above boys are suggesting for gearing if I hadn’t driven the 7.3 gasser. But…..
Jamie:
I have the 4.30 gears and would have no other for our load: 2020 N* Laredo SC. Weight (not dry weight) with full water and propane: 2350 pounds. That brings our traveling weight up to about to around 3300 pounds. The payload is over 4000 pounds, so we’re not close to overloading especially with all the suspension goodies. I just ordered another pair of upper overload leaves and will add them into the mix. With only Sway Stops, a factory anti sway bar, Rancho 9K shocks, and 2 upper overload leaves, I submit I’ll be very close to a fine tuned compromise between too much sway and a harsh, gerky ride. Our factory GVW is 11,300 pounds. The empty truck weighs 7215 pounds with that light little gasser engine. A 6.7 Ford diesel engine weighs at least 600 pounds more.
I find the 4.30’s to be just right for the engine torque and the way this old man bumbles around and drives; namely around 62 mph on the freeway with an egg under my foot on the stupid pedal. If i need instant power, the Godzilla supplies. The engine is right on 1500 rpm in 10th gear at 55 mph. This is the sweet spot for mpg.
I think you will have to lock out gears 9 and 10 and possibly 8th if you get the 3.73 gears. The transmission may automatically do that for you with 3.73’s. I’ve had plenty of diesels and would have lower numerical gears if I were driving one, like 3.31’s, 3.42’s, or 3.55’s. I did have 3.55’s on my 2001 Dodge Cummins/6 speed manual but changed to 4.10’s when I put 35 inch tires on it.
Brett: AFA your proposed load with a 3300 pound camper, I think you will be above the payload rating right away if you use the, “add 750 to 1000 pounds of people and stuff” rule. In that case you will need more suspension support than I have to survive, or consider a DRW truck. We have a saying in the TC biz: “No one ever complained about having too much truck.” It’s a perspective thing. Higher rated tires to some with a higher than 4000 pound capacity. Much better shocks. The factory shocks are junk. I dumped my factory Ranchos the first week I had the rig. A big wig sway bar with the 1-5/16’s inch bar. That will give you some backbone.
If i were you, I would get on FTE (Ford Truck Enthusiasts) facebook page and browse the RV-truck camper section to see what Ardvark and others have done to wrestle a heavier camper.
Jamie: You would do well to pretty much go the route I did with the 7.3 gasser.
jefe

I know this is a different question, but just curious how the new 7.3 gasser would carry a 5k pound camper??

Thanks,
Phil

Some new input about the diff ratios with the 7.3L gasser.
As above, the 4.30 is just right for me but a couple weeks ago I accompanied my brother John (JR) to Kelso WA to pick up his brand spanking new 10 foot ALASKAN camper to go on his 2022 F-350 SC LB 7.3L gasser.
I’ll be doing a writeup on here about my findings.
He chose the 3.73’s as he plans on not leaving his AKan on all the time and using it a s a pickup.
I drove quite a bit both going to Kelso and the 1K miles back down to CA.
I can report that the 3.73’s were perfect for his rig and did not cause a lot of downshifting….some, but not much. Bro and I got really good mpg going home; a couple pops better than my similar Ford sled. I attribute this to a much lower wind resistance with the hard top down.

For the OP,
What jefe4x4 says here is real. I also have almost identical rig he has and can verify. I have a light Milner on mine, loaded pushing 2200lb with a 4300lb payload.
I have one thing to ad though.
If you think you might tow a trailer while the camper is on, go with the 4.3.
I sometimes tow a 6×12 cargo trailer or a sxs with a 18ft car trailer.
I been up and down the sierras and cascades a number of times and can not even tell I am pulling and hauling. (The Godzilla and that 10 speed trans with tow/haul is great)
Remember tongue weight on trailer is approximately 10% of total trailer weight, you need to know your trailer weight and tongue weight.

Walker is also real here. After riding in and driving Bro John’s 350/ALASKAN rig with 3.73’s at length over steep hills and across the fruited plain, I have come to the conclusion the best overall gear ratio for an F-350 SRW SC SB or CC LB that carries a medium weight truck camper (2500-2900 pounds dry weight) is…..
4.10 or 4.11:1. Bigger size pinion. Sturdier ring gear. You can get lockers and limited slips.
The only problem is Ford does not currently offer that gear ratio in an F-250-350. I think in some F-450/550’s (maybe) you can get 4.10’s, but their stock ratio is around 4.56-4.88:1.
Mind you, I still like the 4.30’s with the gasser and my driving style.
jefe

Phil Patterson, I had a hard time posting on here before this week.
The problem was, I’m too wordy; too many characters.
The very belated answer to you question is:
No I don’t think an F-350 SRW or DRW with a 7.3L gas engine and 4.30 gears would be a good thing. My cutoff is the GVWR of the truck, in my SRW case 4100 pounds.
You’re stuck with a diesel.
jefe

Phil Patterson: Did you buy a gasser for hauling your 5K# TC? What kind of TC is that?

Thanks, Kevin

Jefe 4×4: your last post in this string in response to Phil Patterson regarding the 5k# TC is to get a diesel.

I am looking to get an Arctic Fox 1150 that loaded and wet is about 5200 lb. I plan to buy a F-350 SC Dually with 7.3 gas and 4.30 gears. This has a payload around 6300# so will be close to maxxed out with fuel, wife, dogs, additional stuff and me. Are you recommending the diesel for this? Not sure that i understood you correctly.

Thanks,
Kevin

No idea why the forum gave me a frown emoji! Kevin

Sorry, Kevin, but the emoji’s are auto generated. I have nothing to do with them.

Mike

Thanks Jeffe, for your sage advice, and sorry for my belated response. It was great seeing you guys again at QZ, and that’s truly a very sharp rig you’ve got as well!!

Kevin, after doing a bunch of deep contemplation, and after talking with a few fellow late model Cummings folks at the QZ rally, I’m now planning on sticking with diesel…

My previous 07.5 first gen 6.7 was uber solid, except for the Dodge spec’d emissions
add-ons, so lots of issues (most under warranty) – however, in spite of these several first year 6.7 beta maladies (turbo’s, DPF, CEL’s), the truck was truly amazing…So in 16 I traded in for another 6.7 3500 DRW,CC, 4×4, however, this time (somewhat reluctantly) with DEF…

Now at 7yrs and 84k miles, I’ve yet to have even a single CEL or shop issue as it appears that the bulk of the NOx emissions is now done chemically in the exhaust track – this post-beta update has proved a far better strategy and so far a VERY reliable truck 🙂 !!… I haul a 2009 single-slide Eagle Cap 995 (60g water, two 30# LPG, heavily optioned), can exceed 5k lbs… The truck hauls it effortlessly, hills, towing or not (occasionally towing a 4,500 UTV trailer) – Even when FULLY loaded for bear (ugg!) I’m a bit over the 14k GVWR (although honestly, due to the DRW this has never once been even slightly perceptible!)…

Still, a Great truck with no complaints, but after seeing a whole bunch of interesting rigs at QZ, I’m now considering for my last and ‘final truck’ a new chassis cab 5500 6.7, with a flatbed and storage side boxes – My hope, and longevity willing is that this would be the rig to see me through to the last of my camping days – lol!

Hope this helps,

Phil