Want to put overdrive on 88 f-250.

[My88f250]

I just bought an 88 f-250 that I want to put an overdrive transmission in. Are there any trans' that will bolt to my transfer case that are overdrive? By the smallest amount of work possible obviously. If it's not to much to ask. And if not some fairly cheap options would be much appreciated. Also I do need it to be able to pull just as strong as the trans in it currently, which I am positive is a C-6. Checked it on LMC.

This truck will be a tow truck and I need some better mileage so I don't rape the company on fuel. Thank you guys by the way for reading this. I am trying to get some kinda better fuel mileage outta the truck. I am at 10.5 right now and am looking to "try" to get around 14. By the way 10.5 is at 60 on the expressway. This has a special order rear end which came in the super duty's. It's the same rear as in my brother's 1993 super duty wrecker. Yes I am positive. It's the exact same rear end. Any suggestions on how to get better mileage outta this 5.8 liter would be educational and much appreciated. I don't have a tach, so I am afraid of riding any faster than 60. I have no idea where the RPMs are and I know the gears are ridiculously high. Any help will suffice. Thanks allot gentleman.

 

[Raptor22]

What engine do you have? You have the option of an E4OD 4speed overdrive automatic (an Electronic C6 with O/D). Or the ZF5 5speed overdrive standard transmission. If you have a 300/302/351, you always have the option of an M5OD (5speed standard O/D), which may not be the strongest, but you can pick one up cheap.

 

[My88f250]

I appreciate the quick answer. I was thinking about the e40d but I didn't know if it would attach to my t-case. If it does like you said I would rather go with that. One question I do have is, would I be able to take or make an o/d switch so I can turn it off when towing? Meaning were the switches for the EOD trans' separate or were they like Dodge and put in the shift lever? As you can tell I am not a Ford guy and am learning as I go. This is the first Ford truck I have ever owned but I have driven them before as tow trucks. Meaning a regular pick up with a boom in the back. If you haven't figured it out yet, I am a repo man.

 

[Raptor22]

I appreciate the quick answer. I was thinking about the e40d but I didn't know if it would attach to my t-case. If it does like you said I would rather go with that. One question I do have is, would I be able to take or make an o/d switch so I can turn it off when towing? Meaning were the switches for the EOD trans' separate or were they like Dodge and put in the shift lever? As you can tell I am not a Ford guy and am learning as I go. This is the first Ford truck I have ever owned but I have driven them before as tow trucks. Meaning a regular pick up with a boom in the back. If you haven't figured it out yet, I am a repo man.

Well, for that transmission in the Gen8 trucks there was a switch on the dash for O/D off to the left of the steering wheel. You would have to purchase that switch (from LMC for instance) or find one at a junkyard, good luck.

 

[My88f250]

Thats a very big help. So the t-case isn't a problem I am guessing? And are the cases the same on all e40d's? The reason why I am asking is I was wondering if I could just get one from a 4x4 f-150 and have it rebuilt for the extra towing capacity. GM makes different cases for there 700-4r's in there 4x4 HD'S. I figure maybe Ford did the same. Thanks.

 

[Raptor22]

Thats a very big help. So the t-case isn't a problem I am guessing? Thanks.

I have no reason to believe it would be. Especially with the E4OD. Just make sure you get a 4x4 transmission. They started putting the E4ODs in our trucks in 1990.

 

[LEB Ben]

Have you said what engine you had yet? That year the C6 was available behind the 351W and the 460, both of which were offered in the 250. If you have a 351W, it'll work, if not they won't match up. Won't he also need a stand alone computer to operate the e4OD? I'm also not set on the fact that both trannies are the same length. I don't have the exact lengths, so I could be wrong, but I'm sure someone here will have the answers.

 

[Raptor22]

Have you said what engine you had yet? That year the C6 was available behind the 351W and the 460, both of which were offered in the 250. If you have a 351W, it'll work, if not they won't match up. Won't he also need a stand alone computer to operate the e4OD? I'm also not set on the fact that both trannies are the same length. I don't have the exact lengths, so I could be wrong, but I'm sure someone here will have the answers.

Yeah, I dont know 100% either. This is the place to find out though.

 

[My88f250]

Yeah it's a 5.8 351. And the length isn't much of a problem. If I have to have the drive shaft shortened, I got a guy that cuts welds balances the whole works. I'm in Detroit, they are all over. New mounts shouldn't be a problem either, I can weld something nice up. The question I really need answered is, are the casing's the same on all e40d's? Like I said I was thinking maybe they made the heavy duties a little thicker. Thanks

 

[My88f250]

Well I appreciate the help guys. I am starting to think I am sh*t outta luck. Unless I wanna pay 2700 for a splitter. Looks like slow goin. I got a set of 31 E rated tires I am about to put on the truck, anyone have any idea what RPM I will be running at around 65? I got the 4.10 gears and obviously the 351 like I said before. Thanks again.

 

[LEB Ben]

At 60mph...about 24-2600rpm is max.


On edit...with 31's, 4.10's and doing 65...you'll be at just south of 2900rpm. Sorry bud, but 4.10's aren't the best for highway driving. So you're either looking at eating the mpg's, getting a gear swap or coughing up the cash for a GV OD unit.

 

[Raptor22]

At 60mph...about 24-2600rpm is max.

Chris can answer that, he has that exact powertrain, 351W -> E4OD -> 4.10 LS....

 

[conanski]

The E4OD is computer controlled so you'll need a powertrain wiring harness and computer for the 5.8/E4OD combo as well.. that's not exactly a simple install. By far the best(easiest) option for you would be a ZF 5-speed manual from another F250 or larger truck, no wiring changes necessary just mechanical parts to install.

 

[My88f250]

Appreciated, is that ZF tranny overdrive or just a 5 speed? Just curious.

 

[Watchdog7]

Your gears are low. Not high.

E4OD is an option. Make sure to instal a shift kit. The E4 is a good auotmatic transmission but really needs a shift kit.

Good luck. =)