Hey guy's I need some advice on a possible trany swap. My 92 F250 7.3 has a 5 speed in it right now, due to problems with my feet driving a stick is a real workout for me.

I love my truck as it is but could benifit from the ease of an automatic. I have done manual to auto swaps before in gasers.. my first when I was 16 and dropped a 3.8 turbo v6 with 350 trany into a 72 vega so I know how involved the process can get.

So to my questions....
Whats the best auto to get for this truck?
What do I need to do to that trany to make sure it can stand up heavy towing besides a big cooler?
How involved is the swap and what parts should I buy new verses salvage yard?

If I do this swap I want to do it right and make it last.

 

Well the C6 is indestructible, but the E4OD will net you better fuel mileage. You can build an E4OD up to be just as good as a C6, but im unsure how much it would cost. Im pretty sure David85 has a built up E4OD in his truck.

 

You also have to use a stamd alone computer with the E40D but the C6 is easier but you are used to the overdrive you wouldn't be happy with a C6 although it would be cheaper.

 

Most guys go the other way around with these trucks. E4OD is the only real option you have and yes it can be built up stronger than any ZF5 (ducks benind chair).
The electronic issues will probably be the most complicated.

You can use a donor truck to swap everything over as per OEM spec, or go with a stand alone setup like me that works parallel to your current electrical. Your truck will still have a PCM to run things like speedo and ABS but cannot run an auto transmission.

I love the TCS I am running but it takes some time to set up a shift map that you will like and its $650 for the computer and wiring harness. If you are able to get a cheap donor truck that has everything you need, you can but a fair amount of tranny upgrades for that amount.

 

If your anywhere near Atlanta I'd swap my C6 for your 5spd.

 

LMAO I'll be willing to bet that there are several members wiling to swap there E40D for your weak old ZF tranny(hows that david) but you will have to rebuild the E40D.

 

Ok so next question... what kind mileage difference between the C6 and the E40D?

David what type of upgrades am I looking at? I plan to pull a 3500lb boat/trailer along with my overhead camper. And I will be launching this old heavy boat with the camper on the truck!

As for swapping someone... I am in Oregon and it's too darn cold right now but come spring If I decide to do this I would swap, even if I had to get the auto rebuilt.

 

For mileage, I would say a minimum of 2MPG loss in swapping to a C6. Highway cruising at 55 will see a bigger hit. 75 MPH speed zones are the most noticable.

Puttering around in 35 MPH zones will see virtually no difference and it will be hard to notice anything different by driving it. I couldn't tell the E4OD from the C6 when it came to 1st, 2nd, and 3rd at suburban speeds. Steep inclines give the E4OD the advantage in 1st, while the C6 is better in reverse.....go figure....

Engine noise on the highway will also be higher.

3500lbs is nothing to drag around. If the transmission has all the factory/ford recommended upgrades, it will last for years even on a mild torque converter.

The danger comes if you ever decide to tow much more weight and/or add a turbocharger. Thats where I advise a stronger torque converter and steel gears on top of the usual upgrades.

Usual upgrades being:

roller bearing center support,
3 friction overdrive clutch (some have it, some don't)
Larger cooler,
mild shift kit,
1995 model front pump
There should also be a way to upgraded to larger diameter cooler lines, but my dealer was unable to locate the correct parts for me. The fittings allow you to run 3/8" lines instead of 5/16".

Sonnax and TransGo also have great "correction packages" that are good for fixing a lot of the smaller problems that often come up.

Boost valve,
pump mods,
A few upgraded steel valves for the valve body,
overdrive return spiral snap ring,
heat resistant front seal,
Heat resistant pump check valve,
and a few others.......

 

I vote C6 just because its purely mechanical/ hydraulic in nature. No electronics, no electric solenoids to stick like in a E4DOA. The E40D has it's place. But for my peice of mind, I'd use the C6. Overdrive is nice, gotta admit, but for the price of the upgrades to a E40D ,labor involved, and the mess of electricals to do (unless your doing it yourself), you can have one STOUT C6 that will live behind the diesel for a very long time.

We like these truck for the simplicity, the E40D seems to contradictory to that.

Just my .02........

 

Ditto on the c6. They are simple and hold real well unless you have my luck lol. I am also one of those guys that would love to have a 5 speed for the milage but for shear stock rugidness you can't beat the c6.

 

The E4OD is based heavily on the C6 transmission so both have similar structural limits. Technically, the E4OD is potentially stronger with a stiffer case, and better internal hard parts or possible factory upgrades.

Its also not unusual to see them roll past 200 000 miles before needing a rebuild so long as the rest of the truck is well cared for and left bone stock. Modify the power output without adjusting the tranny, and you are asking for trouble.

I will never dispute the lower up front cost of swapping to as C6, but when you consider the legacy costs of running an open torque converter and no overdrive for several years, it will add up quickly depending on how much you drive or how long you want to keep the truck for.

It cost me about $3000 to have a transmission that I was happy with and that included some costly mistakes on my part. It meant that when ULSD became standard, I actually gained slight MPGs because of how I timed my transmission swap. About 2 years later, the transmission is holding up fine and more than paid for itself.

If you don't spend much time above 55 MPH, then the C6 will do fine, but you might not enjoy the truck as much the odd time you have to get on the freeway. My engine is almost impossible to hear at 70 MPH in 4th (I have 3.08 gears, but 3.55 will have similar results).

As for my little jab at the ZF5 tranny, there are a list of problems that they can have too:

worn out dual mass flywheel,

worn out synchros (more likely than on a T-18 or T-19)

Case is prone to cracking under heavier load,

Torque limit is well under 500 Ft/lbs (in the case of turbocharging, otherwise its enough)

Very little aftermarket support for upgrads other than a single mass flywheel and perhaps a liquid cooler.


There are some companies that build high end E4OD transmissions that have no horsepower or torque limit the warranty. I'm not advising that anyone spend $5000 on a rebuilt, but considering some of the 7.3 powerstrokes running them out there, I would say with some confidence that build for build, you cannot make a 5 speed stronger than an auto. And since there are no upgrades that I am aware of for the ZF, I feel the E4OD can be made stronger than the 5 speed.

 

find a donor truck , for all the little essentials including the processor and wiring harness
must be a 92-94 model , due to wiring harness change in 95
install the e4od , a c-6 will kill your mileage i dont know what your axle ratio is but with 4:10 gears 65 mph is the top speed running against the governor
you can use a trans from up to a 97 model however the solenoid connector would have to be changed to fit 95-97 trans is an easy swap

 

I have what you need, I pulled the computer/harness from my truck while parting her out, still have the transmission but its probably a little expensive to ship, heck I still have the steering column.
I'm not sure to the value of the electronics but let me know a fair offer and we'll see how we end up.

Mike

 

i did a zf to C6 swap on my 88.
i love everything about it except for setting the VRV, it has been 5 years now, and it still is not set properly.
i used to get 18-22 mpg with the 5 speed, combined driving with 60% being highway miles..
i no longer use the 88 for highway runs. it is now a plow, local tow rig, and gets about 12 mpg. but it will also pull a house down without even knowing anything is hooked up to it.

 

ill trade u a fresh rebuilt c-6, new pump,new torque converter, plus the gear vendors overdrive system.