Need an overdrive for my 1986 Ford 6.9 diesel

[Tgould]

Getting a reman would be best. Can get it built as needed and a reputable one will use the latest version of parts possible. I had mine built for diesel with latest revisions but in a 460 case and mechanical speedo in the tail. Came with new converter. I didnt have a core so trans and computer had me about 5k deep.

 

[XOLATEM]

I have been up close and personal and fairly intimate with a number of E4OD's and 4R100's and it would be my unit of choice if I was to run an automatic in an F250-F350 size truck.

But...as long as I have a working left leg and right hand/arm then I am going to go with a clutch.

If I built another one (E4OD) in the future I would fortify it with every upgrade available and build it so carefully and lovingly with all of the right words and touches that my partner would probably look at me kinda sideways...

I'd try to not let Her catch me in the process....but...if She did, I am sure She would understand...

There. I said it. Doing transmissions, to me, is a craft that rises to an art form, if you are really into it.

I had a guy that worked with me a long time ago that said that I would not put any part in a unit that was not fondled and blessed.

Truer word were never spoken. I love me some E4OD. Talk about a Big, Beautiful Unit.

If your electronics are sound they are a tough unit to beat.

Sorry, guys...got a little misty-eyed and carried away....

 

[franklin2]

I have been up close and personal and fairly intimate with a number of E4OD's and 4R100's and it would be my unit of choice if I was to run an automatic in an F250-F350 size truck.

But...as long as I have a working left leg and right hand/arm then I am going to go with a clutch.

If I built another one (E4OD) in the future I would fortify it with every upgrade available and build it so carefully and lovingly with all of the right words and touches that my partner would probably look at me kinda sideways...

I'd try to not let Her catch me in the process....but...if She did, I am sure She would understand...

There. I said it. Doing transmissions, to me, is a craft that rises to an art form, if you are really into it.

I had a guy that worked with me a long time ago that said that I would not put any part in a unit that was not fondled and blessed.

Truer word were never spoken. I love me some E4OD. Talk about a Big, Beautiful Unit.

If your electronics are sound they are a tough unit to beat.

Sorry, guys...got a little misty-eyed and carried away....

If you do not mind doing a little fiddling and programming, the aftermarket shift controllers give you more options than the factory controller ever did. I like a manual also, the automatics seem to leave so much of the low end these engines have to offer on the table. But I bet if you could get a aftermarket controller to lock up the convertor in some of the lower gears, you could overcome that. Plus leave it locked in for engine braking when towing.

I see some of the controllers are almost $800 now. But at least it looks like they are including the wiring harness in that price. Boy everything is going up in price.

 

[lotzagoodstuff]

I have been up close and personal and fairly intimate with a number of E4OD's and 4R100's and it would be my unit of choice if I was to run an automatic in an F250-F350 size truck.

But...as long as I have a working left leg and right hand/arm then I am going to go with a clutch.

If I built another one (E4OD) in the future I would fortify it with every upgrade available and build it so carefully and lovingly with all of the right words and touches that my partner would probably look at me kinda sideways...

I'd try to not let Her catch me in the process....but...if She did, I am sure She would understand...

There. I said it. Doing transmissions, to me, is a craft that rises to an art form, if you are really into it.

I had a guy that worked with me a long time ago that said that I would not put any part in a unit that was not fondled and blessed.

Truer word were never spoken. I love me some E4OD. Talk about a Big, Beautiful Unit.

If your electronics are sound they are a tough unit to beat.

Sorry, guys...got a little misty-eyed and carried away....

If you ask nicely, there's an automatic trans expert on here who will give you the list of all best updates/upgrades/suppliers based on experience. I'm betting you've been on here long enough to figure out who that is, but if not I can point you towards him, or at least give you a hint until you figure it out

Lastly, I thought my E4OD was pretty soft when I bought my truck. I had a very well respected shop (refreshed what I thought was a pretty good race trans with a leaky front seal that they caught a couple of simple things <$100 in that C4 in my Pinto and gained me ET and MPH) and he told me "it's about where it should be at 90K miles: do a filter/fluid, put a better cooler on it, and put a chip in it to move the shift points as the factory settings suck". That was 30K miles ago, three trips from the Pacific Northwest to the Midwest, and countless heavy towing including a 30' cabin cruiser boat and many car haulers over the pass from Seattle to Spokane. I drive it like it's tired, and my PSD is stock with the exception of the air filter and the chip, which doesn't really do anything without an upgraded pump/injectors. Again, the E4OD really isn't that bad if you have realistic expectations and service them regularly.

 

[WrenchWhore]

Stock tires, 2800 RPM @ 58 MPH sounds like you've got 4.10 axle gears from what the gear ratio calculator with a no lockup converter says. If you're simply trying to just make something better without throwing thousands of dollars at it you could try dropping some 3.55 gears in the rear and see if it suits you better. That should drop you down to about 2300 RPM at 58 MPH. Only one axle to change no full blown transmission swaps or driveshaft changes.

 

[u2slow]

Fwiw, I had a 6.2L diesel suburban with 3spd auto and 4.10 gears. 12 mpg. I hated the arrangement for the highway use I was doing regularly.

I did the axle ratio and transmission. 3.21 axle swap and 4spd manual. I had 17mpg after that.

 

[david85]

After many years with my E4OD, I still like it. I'll agree with what others have said about a locking torque converter vs auxiliary overdrive. Lockup is better, even if you don't have the option of splitting gears. Gear splitters make more sense with manual transmissions, because you don't have a torque converter imposing a minimum RPM, no matter how tall your gearing is.

Here's a quick and dirty calculation of what you can expect with the E4OD:

2800RPM x 0.73(E4OD Overdrive Ratio) = 2044 RPM.

However, since the C6 is still slipping at 2800 RPM, the improvement might be even better:

(2800RPM - 150slip) x 0.73(overdrive ratio) = 1935.5 RPM

The E4OD is plenty strong in stock form, if you add a few fixes from Ford and the aftermarket. And don't go nuts with a shift kit. If you want bullet proof, there really is no such thing, but they can be made quite strong.

Having said that, I can also agree that swapping to a 5 speed will be easier, and cheaper. I like the aftermarket transmission controllers but they are an added cost that a manual transmission will not have.

 

[IDIBRONCO]

I can also agree that swapping to a 5 speed will be easier, and cheaper.

Yes but this is basically a van so the manual parts are quite limited.

 

[Dirtleg]

I have been up close and personal and fairly intimate with a number of E4OD's and 4R100's and it would be my unit of choice if I was to run an automatic in an F250-F350 size truck.

But...as long as I have a working left leg and right hand/arm then I am going to go with a clutch.

If I built another one (E4OD) in the future I would fortify it with every upgrade available and build it so carefully and lovingly with all of the right words and touches that my partner would probably look at me kinda sideways...

I'd try to not let Her catch me in the process....but...if She did, I am sure She would understand...

There. I said it. Doing transmissions, to me, is a craft that rises to an art form, if you are really into it.

I had a guy that worked with me a long time ago that said that I would not put any part in a unit that was not fondled and blessed.

Truer word were never spoken. I love me some E4OD. Talk about a Big, Beautiful Unit.

If your electronics are sound they are a tough unit to beat.

Sorry, guys...got a little misty-eyed and carried away....

I may be hitting you up for some advice here. I have now 2 E4OD's that are not in the best of shape. One might be toast. It's new to me and seems it'll need to be fixed if I ever want to use this truck for it's purpose.

Also I am tired of chasing 5 speed swaps. Was literally on my way to purchase one and the guy reaches out, doubled his price. I said nope. My opinion, if you can't get the whole truck for parts, not worth it.

Never done an Automatic before but with the idea of having to rebuild 2 of them, I don't think I can stomach paying to have it done twice. I do have a shop with a lift so might as well put it to good use.

 

[XOLATEM]

I bet if you could get a aftermarket controller to lock up the convertor in some of the lower gears, you could overcome that. Plus leave it locked in for engine braking when towing.

Great idea on paper. I only see one hiccup on it.

Before I get into that I do want to tell you how much I admire your insight into most every discussion you participate in.

Pretty often I find myself sitting up and taking notice when you make me want to say out loud..."Dang ! Why didn't I think of that !?"

Moving on to the E4OD...the early units had the input shaft splined into an aluminum planetary in the overdrive section of the unit. (The E4OD is basically a wide-ratio C-6 with an overdrive unit in front of it.)

I foresee a stripped planetary in the future of a unit that has not had the later upgrade...where they changed the planetary carrier to steel and you have an upgraded input shaft that has to match.

Other than that, sounds like a good idea to get a little more 'oompf' outta the driveline. Especially on the engine braking on a downhill. Expect a bit more harshness when the convertor is locked up.

As a matter of fact...it might be a good idea to have a custom convertor built for that. Tell your convertor builder what you are going to do with it. The factory convertor probably was not built for the harshness you are going to get when you couple a diesel with a manual-control lockup. Especially in the lower gears.

Fwiw, I had a 6.2L diesel suburban with 3spd auto and 4.10 gears. 12 mpg.

Years ago I had a customer with a Suburban that had a 6.2 and the 700R4. He had me build the trans. This was before any (decent) shift kit was available for it. I had to pull out a few tricks to get it to work right because a few people were getting fed up with them and changing them out with THM 350's.

Anyway, I can't remember what gear ratio he had (probably not a 4.10, more like a 3.00 or so.) but he reported back that he was getting over 20 MPG on the highway.

That was the motivation to fix the trans on that one...decent fuel mileage at a time when diesel was reasonable.

I did the axle ratio and transmission. 3.21 axle swap and 4spd manual. I had 17mpg after that.

I'll bet that a 700R4 swap would have got you into the 20's. I would have liked to see that.

Anyway, wishing you all a great weekend. Thanks for the chance to sound off.

Take care,

X

 

[u2slow]

I'll bet that a 700R4 swap would have got you into the 20's. I would have liked to see that.

Probably. I also knew it would need to be a rebuilt later model because those early 700's were failure-prone behind the diesel.

The manual was more what i wanted. The parts came cheap and easy enough.

 

[scsmith42]

Moved to start a new thread