I HAVE A 93 E-150 CONVERSION VAN, 5.0 AOD WITH A 3.55 REAR END. I NEED MORE POWER WHEN TOWING MY APROX 5500# CAMPER. ? IS WOULD CHANGING THE REAREND TO A 4.10 OR EVEN A 4.30 BE THE BEST BET FOR TOWNING? ANY IDEAS WOULD BE GREAT! THANKS MARK

 

I have a 91 E-150 Club Wagon w/302 AOD and I wouldn't tow a 5500# camper with it. I think that you would want at least a 351 or better yet, 460 to tow that sized load. Also, what is the listed towing capacity for your van's engine/trans/rear combo now?

 

I tow about 6500# with 351 and 3.55 (e4od no overdrive) and get about 8 mpg.

If I had to change something I would at least go to 3.73 or 4.10 rear. The e350 v-10 I got to drive had a 3.73 in it and it was just about right.

You can tow anything if you have the right ratio but you have to live with it .

I don't know if you can shut off your OD in AOD but you definitly need to do at least that

 

a 302 in a van with #5500 in tow will never feel likie it has any power. gears or not thought they will help some.

 

Changing the rearend to 4.10s would be desirable.
Assuming a tire size of 235-75R15(29")
And running in D position
You'd be spinning around 3300 rpms at 70 MPH
about 2850 at 60 MPH.
Not accounting for torque converter slip.
You'd be keeping your engine at its happy spot.

 

I just installed a tach in my van and it is very interesting.

I like to run it at 70-75 mph towing. The motor spins sbout 3,000 with OD off which is a little high for my taste. It spins about 2200 with OD on at 75 mph. I thisnk the sweet spot for my motor is about 2500. Now if I can calculate that back I will let you know as far as what rear ratio I would like.

 

I got it. I would need 4.10 to get it to spin 2538 rpm in OD

3.73 would spin about 2308 (not enough)

 

With OD off, you're at 1:1 engine to transmission, so:
if 3.55 = 3000
2.96 = 2500

I don't recall a 2.96 ratio, but something close should work.

 

I was trying to calculate what it would take to do 70 mph with OD on so that I could spin the motor less (less than 3000 but more than 2200 rpm). At 2200 it wants to shift too much and it's out of its powerband for pulling.

3000 rpm w/ 3.55 = 70 mph or 845 rpm axle speed

to back figure 845 x 4.10 x .71 (OD ratio) = 2529 rpm. bingo!

a nice compromise.

But to save 2 mpg to change the ratio probably not worth it to me. I'll keep the OD off and run it at 3000 to make my 70 mph.

 

AOD ratios 2.40 : 1 1.47 : 1 1.00 : 1 0.67 : 1

E4OD 2.71 : 1 1.53 : 1 1.00 : 1 0.71 : 1

AOD is worse than e4OD as far as pullin' goes

 

3000 is the sweet is closer too your sweet spot than 2500 is. As your motor makes full power closer too 4000 rpm torqe is somewhere between 2800 too 3400. that is also about where the older trucks ram normally.