3.45 to 3.73 Axle Swap for Towing — Worth It on a '93 Splash?

[hashcraft]

Hey everyone, long-time lurker, first post here. I recently picked up a manual '93 2WD Splash with the 3.0 and 3.45 axle. I was a little bummed to find out it's only rated to tow 1,800 lbs. I searched around but most of the axle discussions seem to be off-road focused. Apologies if I missed something relevant.

My goal is to tow at least 2,000 lbs, and I'm weighing two options. I'm curious which route you'd take.

1. Tow 2,000 lbs as-is.

It's only marginally over the rating, and the bumper hitch is rated for 2,000 lbs with a 200 lb tongue weight. Mississippi is pancake flat, so grade isn't really a factor. The biggest concern seems to be braking, but since the automatic 3.0 with the 3.45 is rated for 3700lbs, I figure the brakes aren't the weak link.

2. Swap in a 3.73 axle and add a receiver hitch.

A 3.73 bumps the tow rating to 2,800 lbs. My local yard has several Rangers and sells axles with drums for $150. I'm assuming a 3.73 shouldn't be hard to find and bolts right up. I know I'd need to address the speedometer/odometer with the new ratio. Are the clusters adjustable for this, or would I need to pull one from the donor truck to get accurate readings?

I appreciate your time and input!

 

[alwaysFlOoReD]

The 3.0 likes to rev, it's a car engine. So no down low torque. 3.73 or 4.10 would help. It doesn't change your legal tow limit though. But I've never paid too much attention to that limit as regards to a manual transmission. I think the manufacturers is covering their ass re: warranty claims by people that don't know how to start off with a clutch without slipping it and burning up the lining. You can achieve the same result by putting on smaller diameter tires. It might look funny but much less work. And it will let you know if a gear change is worth the trouble.

 

[RobbieD]

Are the clusters adjustable for this, or would I need to pull one from the donor truck to get accurate readings?

If the donor axle is from a truck at least through 1994, just also grab the plastic gear on the lower end of the speedometer cable.

Earlier trucks used mechanical speedometers, with a gear-driven cable. The gears have different tooth counts (in different colors to identify them), to accommodate the different rear axle gearing ratios. If you also get that gear out of the new axle donor truck, and replace your current one with it, that should take care of changing the speedometer to read correctly with new axle.

It'll be just one bolt, and one circlip to nab the needed gear from the donor.

 

[SenorNoob]

So the difference between 1800 and 3700 is the transmission? I knew there was big difference but that's wild in a 3.0 truck. Especially since it's the same transmission in the 4.0 manual.

Here's the 93 chart:

I wish those 4.10 front differentials from 93 weren't hybrids. Even so if I stumbled upon one with the inner stubs, I might still use it.


I wonder what Ford would've put for a 4x4 supercab 4.0 with 4.10s?

Full size chart for LULZ.

So a regular cab 2wd auto 4.0 Ranger with 3.55 is almost the same tow rating as a 4x4 auto 7.3 F350. One of those ratings seems wrong.

 

[Curious Hound]

If you're going to swap it out, get the 4.10 gears. You'll enjoy driving the truck a lot more in all conditions. Everybody else covered the important parts. Swapping the speedo gear at the transmission is easy.

 

[PetroleumJunkie412]

If you're going to swap it out, get the 4.10 gears. You'll enjoy driving the truck a lot more in all conditions. Everybody else covered the important parts. Swapping the speedo gear at the transmission is easy.

This.

If you're changing gears, just put 4.10s in. Limited slip if whole donor axle. 8.8 if you're feeling especially frisky and can be down for a few days wrenching on dumb shit like brake lines.

Fuel economy will mildly suffer. Drivablity will not.

I've swapped gears once, and swapped axles once. Axle swap was easier.