What rear end do you have in your E350

IIRC most of the older 350s like you mentioned had 4.10 rear ends. I wouldn't hesitate to tow a CRV with one as long as it was a V10 and not the 5.4 V8 which some smaller rigs had. I used to have an E450 based C, a 1998 with "only" 265 horsepower. I towed different cars up to 3200 lbs all over the Northwest and could always maintain 45-50 on hills, even running over the North Cascades highway at close to 17,000 lbs combined. It would even outclimb some of the diesel boys of the same vintage running similar weights. 4.10s might even be a little better since you can run faster in 2nd gear. With my 4.63s (yes, that's accurate) 2nd gear was good for about 55 max.

Pinichols
You have about the ideal configuration for a Class c. Perfect size and power train in my estimation. If I were going to buy new that’s what I would go after but I refuse to spend that kind of money at my age. I don’t have that many years left to RV so it would be irresponsible of my to reduce the wife’s little nest egg. The women usually out last us it seems. Any way I’ve set a limit and it pretty well dictates what I can purchase. I did see on a 2001 spec sheet that Tioga provided an option for a 4.56 rear end on a 24 ft. E350. I would imagine it would be hard to find a used one with that gearing. I’ve seen a few short E450’s in my price range this winter but they are always 3 or 4 hours away and by the time I can catch the weather they are spoken for. Too far for a look and see in bad weather. Thanks for your post, great way to set up a rig. Makes me wonder about ford transmissions though. I don’t think anybody could be more diligent maintaining a transmission than I have been with my class A and I still lost it.
Stan

My sermon for the day: I prefer chassis overkill, operating systems with design specs well over expected use, and "using heavy duty stuff in a light duty way." ;)

We searched for and found a 24 foot Winnebago Itasca Class C on the E450 chassis when we bought it new in 2006. However, this was a rare combination ... we were fortunate. I partially compensate for it's 4:56 ratio differential by using taller tires on it, which moves it's overall gear ratio closer to what a 4:10 differential would provide RPM-wise and gas-mileage-wise. The taller tires give me more ground clearance for our off-highway rock hounding and occasional boondock camping. It's of no concern how much we load the RV down due to it's excessive weight carrying capacity relative to the coach's as-built weight.

The E450 chassis also has a wider rear stance for improved lateral stability and it's frame is slightly thicker steel for added rigidity that provides for less end-to-end twisting on rutted roads. A coach frame does not like to be twisted. The E450's brakes also contain larger swept areas - which means pads need to be replaced less often for any given Class C weight and driving style. The E450 drive shaft is also larger diameter - for whatever that's worth. For the year we bought ours, the E450's power brakes also were hydraulic boosted as opposed to the E350's vacuum boosted power brakes back then. We have almost completely compensated for the stiff ride - which is mostly felt in the rear - by using automatic variable rate shock absorbers back there.

Regarding using Tow Haul mode versus rear differential ratio versus towing or not towing: We do not tow and we burnt out or mysteriously lost our Ford TorqShift 5-speed computer controlled 5R110 transmission in only around 61K miles. Ford started using this tranny with the 2005 year chassis. I rarely used Tow Haul mode up to that point and rev'd up the V10 to whatever necessary to run at full highway speeds up whatever long grades presented themselves. I may have been slipping the transmission too much - but the fluid was still a healthy pink color in the failed transmission ... so the failure is somewhat of a mystery. $5600 later I now use Tow Haul mode a lot and try not to rev past about 3700 RPM. I ordered a heavy duty replacement version and it's smooth as silk in Tow Haul mode (the original one was a bit jerky in TH mode).

As a point of FWIW reference: Lazy Daze makes one of the finest Class C motohomes available and they use only the E450 chassis regardless of model length. Their smallest Class C is 23'11" long bumper to bumper.

By golly those are some straight answers. Thank you. My budget is 10-20 K so I’ll be limited to older rigs with the 4 speed. Not my favorite transmission as I’ve had to replace one in my present class A. I’ll be towing a CRV that with full gas weighs a bit under 3700 and I’ll probably be doing it with an E350 which is more readily available and more affordable. My concern has been the 4.10 rear end but your information has eased that a bit. Everything is a trade off so if I can get a softer ride and have something my wife will drive then I think I can handle climbing in second gear if I have to. I have to do that now if I get bogged down behind a truck. Thank you for taking time to respond. Maybe a few more will chime in. There may be more people interested in this subject besides just me.
Stan

I will just double what Desert Captain says above. I have had both chassis on small rigs and we pull a Jeep Trailhawk behind our current Phoenix Cruiser. The Jeep will weigh out at about 4200 pounds with all the camping junk we carry in it on most trips. The 350 does fine in normal terrain pulling the toad, but on big mountain passes at high altitude, we usually just unhook and the DW drives the Jeep up and over. Otherwise, we are really creeping at 20-25 mph and the engine hollering.

It has been a learning experience for me with the V10 again. Our previous unit was a Roadtrek 210P with the Chevy 6 L engine. Getting comfortable with the high rpms which are normal with the Ford was trying for many miles. I guess Old Goats have trouble adjusting :)

Paul

If you end up with an E-350, which is the way to go in a class C at 25' or less, you will get a 4:10 rear end. Any model 2008 {I think}, or later will have the 5 speed Torque shift transmission - the 2016/17's have the six speed.

An E-450 in a 25' or less class C is overkill and you will inherit a stiffer ride and worse mileage vs the E-350. Keep in mind you will be running the exact same V-10 and trans. I love our E-350, 24' Class C with the V -10 and 5 speed Torque Shift trans married to the 4:10 rear axle {vs the 4:56 in the E-450}.

If you plan on towing heavy, more than 3,000#, then the E-450 might be a better choice but as noted you will give up ride quality and mileage.

With any V-10 the worst thing {as in least efficient}, you can do is to baby it. Put your foot down and go. You can run a V-10 at 5,000 rpm all day and never hurt it but since max torque comes at 3,250 and max HP at 4,250 it is not likely you will ever need to.

"The good thing about the E-series chassis, is you can lock out overdrive."

You should be running with Tow Haul engaged {or overdrive locked out, basically the same effect}, anytime you are towing or are running anywhere near your GVWR. This locks up the torque converter eliminating any slippage/friction and keeps your trans temps down where they belong. On long down hills {think 8 to 10 mile 6+ per cent grades}, you will be able to descend without touching your brakes or burning a drop of fuel. So what's not to love about using TH?

As always .... Opinions and YMMV

:C

4.10 gears is enough if you stay within the GCWR of 18,500. If you plan on towing heavy, and need the extra GCWR, 4.56 gears bumps you 22,000 pounds.

With the old 5-speed, 4.10s would net a little better highway fuel economy. With the 6-speed it does not, and that's why 4.56 gears became standard when the 6-speed came out (double overdrive is too tall with taller gearing, for a full profile motorhome with cabover).

The good thing about the E-series chassis, is you can lock out overdrive.