1998 E-150 Club Wagon with 5.4L automatic.

Currently I haul an open trailer with 3-4 dirtbikes and it shifts out of O/D a lot. I'd like to upgrade to a toyhauler soon to be able to do some camping too.

My issue/question is about gear ratio. Everything I can find says my van has a 3.55 gear ratio. I am curious how much going to a 3.73 or 4.10 would help. I'd be towing 4-5000 lbs and I am not much worried about fuel mileage since I only use the van 2-3 times a month.

I'd like a "happy medium" of not a lot of shifting, but also not driving around at 3k RPM. Preferably without buying a diesel.

 

I'll take a shot at this one...because I have (had) the same issue and questions with my setup.

Mine is a '95 Club Wagon Chateau with E4OD and 3.55, factory tow package and I pull a tandem 7x16 Cargo Conversion. It seemed whenever I wasn't going downhill or completely flat, and under 65 or so, the trans would shift out of OD. Silly me had the idea towing in OD (which my manual says if fine btw) would yield a tad better MPG.

I installed a factory tach from a F-250 into my stock gauge cluster, and discovered if I wanted to be towing near my max engine torque ~ 2,800 RPM at speed, then I really needed to stay in Drive (3rd) most of the time.
https://www.ford-trucks.com/forums/9...ap-w-tach.html

This setup reduced the dreaded hunting in/out of OD, kept the motor happy when pulling a load, and I discovered like many veteran RV haulers always said, you can't improve on much when you are pulling a barn door down the highway except "slow down". My gas mileage was bad at 65+ in OD and not really much worse at 65+ in Drive. I now just relax a little, lockout OD, target ~62 MPH, keep the 5.8L singing and all is well. It was really a dog in OD around ~1,900 RPM. Legend has it the old 5.8L marine engine will run day in, day out at 3,500 and never complain... (we'll see)

I was going to install 4.10 or 4.30 gears to try to hit the sweet spot and stay in OD while towing, but it just wasn't worth it, maybe another day. I really had no idea how far I was missing the torque curve when I was towing in OD, until I put the tach in. 3.73 isn't a big enough jump to make a difference, this from my old drag race days, and other feedback.

Here's an online chart you can work with different gear ratios. Lotsa fun.
Visual RPM, Speed, and Gear Ratio Calculator

Luckily, you have a 5.4 with 235HP at 4,250 RPM and 335 ft/lbs torque at 3,000 RPM if I recall. You have a wide "sweet spot" to operate in. The modular motors love to rev and you might be missing out on decent potential when towing if you don't wind that one up a bit.

My rear springs are getting a little tired, I'll upgrade those next. I previously added Firestone Sport rite air springs (big sale and coupon) and really like how they work. Load capacity is not increased, just used for leveling/dampening. Freed up the exhaust a little, put the largest case size Magnaflow muffer in to stay quiet.
1975-2007 Ford E150 Van - Firestone Sport-Rite Air Bag Helper Springs [REAR] - 2171 | $301.72

Well that's all I have to say about that...(thank goodness) maybe some 'real' experts will chime in.

Good Luck... oh, and welcome to the van forum.

 

Thanks for the reply. I was leaning more towards a 4.10. That's a cheaper option than buying a different vehicle, but would suck if it didnt accomplish what I was hoping.

Either way, I can't drive 55!

 

Didn't Sammy Hagar once say that too?

 

I was quoting him directly.

 

There was a pretty cool video he did for that tune----very inspiring to the rocker/gear heads in the world.

Many may not remember the times which begat that song---'twas mid-80's IIRC. Inside a then-current magazine called Auto Week (???) was an ad for "persistent violator" sweat shirts. It was white, a 55 MPH speed limit sign with the European stop sign image printed over top of that.

I still have that somewhere in my collection--have to dig it out and post an image maybe?

 

I would look around and see if you can find a graph of your powerband vs RPM. IT is possible that you may even see a mileage increase it you can keep it closer to the torque peak....even if it is higher RPM's.

I would also look further into towing in O/D. Do you have a large trans cooler and temp gauge. I know the gear hunting while towing in O/D can produce a some heat and cause transmission issues.

Have you done any intake or exhaust work? Changing to 4.10's would aid in towing, but would raise your rpms. I haven't done the math, but it may be about the same with 4.10's in O/D and 3rd with your current gears. Where you would notice the 4.10s would be getting the load moving and in hills.