Automatic Trans VS Manual

[73cntry]

Actually It's more a two part question I'm looking at a 03 F3504x4 Crew cab dually with a 4spd automatic, and was wondering if a 5spd automatic is better or not, and how long do automatic trans last compared to manual. My other truck I had was a 5 spd manual which was Awesome but had to sell it at the time.

[deereman4020]

with atuo trannys you loose up to 25% of the engines power and dont last long if you start modifying the truck id go with a manual tranny besides you dont have to modify the tranny to hold up to the power but if i had to go with an auto id go 5 spd more fuel ecomomy at crusing speed

[papadelogan]

5spd auto (5R100) only came with the 6.0 motor or newer so if it's a 4-speed auto (4R100) you've got a 7.3 underhood. We're biased here, but the 7.3 is definitely the slower, but more reliable, serious workhorse engine. The 4R100 is certainly the weak link in the drivetrain, but mine's at 139,000miles and still going good. WHEATINA is a wheat farmer and told of once needed to pulled a dead harvesting truck up a slight grade for 1/4 mile with his 99 dually auto - that harvesting truck weighed 49,000lbs so it's not THAT weak (unless you plan on racing it). I don't tow super-heavy or very often but if you are easy on it, change fluids regularly, and watch your gauges you can make them last. Once your tranny does go, you can get a BTS or John Wood tranny and be pretty much bullet-proof.

The manual tranny is the same (though gearing *might* have changed slightly over time - not sure) and is the ZF-6 whether it's a 7.3, 6.0, or 6.4. You'll get better mileage with the manual, just be busier while driving is all. If you loved the 5-speed manual then look for a manual. All about personal preference basically, but 6-speeds are pretty rare.

[73cntry]

Thank you deereman4020 and papadelogan for your knowledge that helps in my decision. So I'll keep looking for what I want. Though the truck I was looking at had 136,411 miles on it for a diesel that's nothing. Just prefer a manual trans but also wanted to know how well automatics held up to the average daily driver who doesn't haul much either but has the ability to.

[Mark Kovalsky]

Originally Posted by deereman4020

but if i had to go with an auto id go 5 spd more fuel ecomomy at crusing speed

Why would the five speed auto have any better fuel economy at cruising speed? The overdrive ratio on both transmissions is 0.712:1, so there should be no difference in fuel economy at cruising speeds.

[mueckster]

Originally Posted by Mark Kovalsky

Why would the five speed auto have any better fuel economy at cruising speed? The overdrive ratio on both transmissions is 0.712:1, so there should be no difference in fuel economy at cruising speeds.

The only advantage, I see, would be a a lesser drop in rpms between shifts due the closer gear ratios of having the extra gear. I would seem to give better pulling and acceleration torque, but the economy would basically be the same as Mark said.

[Izzy351]

If you're just a daily driver, without a lot of power adders, and don't tow a lot of weight, the 4R100 should last a nice long time with proper maintenance. I am pretty much in the same boat as you -- I don't tow much and I'm only running around 310 RWHP. But, I have done the VB mods and switched to full syn fluid (Mobil1 Mercon V). The truck isn't getting driven this summer, but next spring, it will get a bigger cooler. If you do the VB mods and keep it cool and clean, it should last a nice long time.

If I towed heavy, I'd invest in an upgraded TC on top of the other mods I already listed. That really cuts down on the heat produced and increases the efficiency greatly as well (hence the heat reduction). The only variable for you is how well it was cared for previously. In my case, I saw all the maintenance records so I got a pretty well cared for truck. I bought it with 60k on it, and the tranny fluid, oil, and fuel filter changes were all documented and done on time.

Now that I've done the mods and have my tunes to match, it's like a whole new truck. I wouldn't be afraid of the auto by any means if you know it was well taken care of. If you get a real good deal on the truck, I wouldn't be afraid of it either. When the tranny goes, consider the $4k BTS/John Wood/Suncoast tranny part of the initial deal. And you'll never have to worry about the trans again. I paid 21k for mine back in Jan '07. If you get the truck for ~16k or less, you'll still be ahead of the curve, even after dropping $4k on a bullet proof tranny, IMHO.

[Smokin']

what Joe said! After the maintenance of the truck itself has been examined, it really comes down to personal preference.

[Mark Kovalsky]

Originally Posted by mueckster

The only advantage, I see, would be a a lesser drop in rpms between shifts due the closer gear ratios of having the extra gear.

The real advantage is launch. The TorqShift has a 3.1 first gear, the 4R100 is 2.7.

[73cntry]

Thank you all for the help my wife is worried about there being something wrong with it since there asking 14,700 for it. Which is a little more than trade in value for an 03 F350 Crew Cab 7.3L 4spd auto FX4. I'm hoping it's just the market with the fuel prices being so high I'm sure car sales has to be down some.

[mueckster]

Originally Posted by Mark Kovalsky

The real advantage is launch. The TorqShift has a 3.1 first gear, the 4R100 is 2.7.

Didn't know that. I wish I had one now. Good info, Mark.

[Shade]

My 03 is a six speed stick and my dad's 02 is an auto, I like the convienence of the auto but still prefer my manual. You can't race it but that's not why we have 7.3's is it? Plus if you like the low gears to play with I can put mine in 4 low and low gear and walk backwards faster than the truck will go, the speedometer won't even move but anything hooked to the truck will!