Swapping a 6L80e into a 03 Explorer 4WD? | Ford Explorer Forums - Serious Explorations

  • Register Today It's free!

Swapping a 6L80e into a 03 Explorer 4WD?

racprops

Well-Known Member
Joined
January 25, 2019
Messages
255
Reaction score
98
City, State
Phoenix AZ
Year, Model & Trim Level
2003 Explorer XLT 4.6 4WD
Here is the problem, history saids the 5R55 is week, and I would really like a taller overdrive for better MPG high way, a 6L80 has that.

SO has anyone done this swap??


Rich

Here are the number:

5R55S Gear Ratios 6R80

1st 3.22 1st 4.03
2nd 2.29 2nd 2.36
3rd 1,55 3rd 1.53
4th 1.00 4th 1.15
5th 0.71 5th .85
6th .65

With this transmission I could run a 3.55 or 3.27 or 3.08

Question, will all three of these gear sets fit on a 3.73 limited slip carrier??
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





Follow up.

Talked with Ken at US shift.

Yes, it can be done, the 06 up Explorers came with a version of the 6 gear, a 6R60, and with 4WD.

He believes to do the swap it will take the whole transfer case, and drive shafts.

Plus no one makes a aftermarket controller for the 6R60 so there is that.

And he thinks you cannot run the factory PCM without a fair amount of rewiring, and the PCM may not be compatible with the 02/05 systems.

OK So now can anyone prove Ken wrong??
 






3.08 gears with a .65 OD would be great if you drive 80 mph or faster on the freeway. Any gear ratio will fit your carrier. As for the transmission swap, there are books available for the wiring changes to run the 6R80 using the 11-14 coyote ecu. Look at what the 99-04 mustang guys do.
 






I live in AZ so getting anywhere is a 75 Speed limit so 80/85 is what I love to do.

And that checks out great.

Now if the hype in an article is true:

"The torque curve for the 4.6-liter V-8 exceeds 250 foot-pounds at
revs as low as 1,500 rpm, and remains above that mark all the way to
5,000. This translates into responsive around-town driving and
freeway cruising."

If this is accurate she should be able to pull that gearing at 2000RPM with a light throttle and great MPG.

And thanks to the lower first and second gear still be as fast or faster than it was with stock gears and transmission:

Explorer 85MPH w 6R60w3.08 gears on 20inch.png 03 6R60, 3.08 gears 20 inch B.jpg Stock 03 Explorer 3.73 gears.jpg
 






So putting the stock transmission and rear end vs the 6R60 and a set of 3.08 gears it seems that Off the line (1St gear) to be just about the same. BUT second, third and forth are much taller, which means less performance mid range.

SO I am jumping back to the idea of adding a second over drive.

The performance of the stock transmission and gear set is near perfect BUT for a lack taller 6th gear. And as I have three of the 40 to 60 Old Three speeds with the added on old Borg Warner Overdrives which can be devoiced from the 3 speed and work as a stand alone transmissions, I find the costs of add one a LOT less that all that major swapping and I keep my performance.

03 Explorer 6R60 3.08 to 5R55 3.73 Stock with Bord Warner OD.jpg $_124.JPG
 






I know the guy that has 3 built explorers and one he calls Dora has a 6r80 in it. I'm not sure how he did it but know it's possible. He's also running a 5.4 so I wouldn't be surprised if he's using an expedition, f150 or later explorer pcm to run it all.
 






What is the overdrive ratio of that Borg Warner unit? I'd like to get my hands on one
 






Thanks, and thanks to my considering all of this I will go with my original idea (I came up with before even current automatic overdrive transmissions), and specialy the new 5/6/8/10 speed gear boxes.

The program at Gearing Calculator | RPM and Tire Diameter to km/h - mph with Shift Tracer uses your tire size, rear end gears, and transmission gears can really show how everything can work together. This is the kind of deep research you need to do to insure everything works out great and to avoid a costly mistake.

The problem is to get the high speed with low RPMs I will need to spend a LOT of money converting my SUV to the 6R60 and its 4WD drive train, and the rebuild the rear end to change it gears. I would guess something like $2k to $4K costs.

I already have the old overdrives. SO my costs is rigging up a front input housing to support the input yoke, a short front drive shaft and a short output drive shaft and transmission mounts. I guesstimate under $1K.

The ONLY small problem is rigging up a new SS or OSS output at either the output of the Overdrive or at the input yoke of the rear end and converting it to the correct pulse count.

First thing is to see how much MPG the SUV will get at say 50/55 MPH. That is basically the best MPG it will get.

Then I can see if I can improve on that.

Rich
 






They are .70, but when you take .70 to the final gear you end up with combined final ratio of .52.

Rich

PS sadly they are not cheap nowadays: 3 speed overdrive transmission in Parts & Accessories | eBay

But you might find some old car clubs guys with some they will let go reasonable;

I suggest you look for the models with the short tail shafts like this: And not the third picture. Four adn five is on a couple rigged into a drive line, the Model A cars guys do a fair amout of these set ups.

BW T86F 13 A.jpg 3Speed with OD studie.jpg 3Speed with OD.jpg overdrive from chris.jpg BWOD2.jpg
 






I'm slightly confused, are you 4wd now or 2wd? 6r80s come in both 2wd and 4wd units.
 






Lastly look at how far the RPMs drop when the 6r60 shifts to second and third compaired to the stock set up which hold an tighter higher RPM range and thus a better power range.

For a hot rodder the 6R60'/80 is great but not for me.

Rich
 






My current truck is a 4WD, and I will be using the "Brown wire" switch to insure it does NOT automatically shifts into 4WD when I am using my add on overdrive.

I have a 02 2WD with a sick 4.0 V6, which I will now keep for spare parts.

Rich
 






The 2012 6R80's are a much stronger transmission, PCM controlled, they have no bands in them at all. The high gears are all right about the same, .70:1, so you choose R&P gears to place the rpm's in between the best 1st gearing and high gearing. That ends up being about 3.08 R&P gears, maybe 2.74 if they were available.

The 6R80's and 10R's are made in a version that will bolt to any Ford late V8, including the SBF with a specially made steel separator plate. The high costs are the new R&P gears, drive shafts, and whatever controller you have to use, plus changes to the trans mount and TC's.
 






My only concern adding an o/d unit ontop of the current transmission is the extra strain that will be on that crappy 5r55 transmission. The problem with milage on those units is the servo bores wear out. When that happens you loose line pressure in o/d and it's harder to keep it in o/d w/ tc locked. I feel you'll have the same struggle unless you use the od unit above 75mph so your at least turning the rpms.

The strength you would gain with the 6r80 would be worth the effort alone but getting it hooked up would be fun. If your truck was an 04+ then can bus comes into play and it would make a pcm swap much easier talking to the other modules.

I'm still about giving the o/d unit a try for sure since you already have them. Since your 4x4 a 2wd conversion would net 1.5 mpg alone, not sure if you need 4x4?
 






3.08 rear gears will place the 70mph cruising at under 2000 rpm's.
 






My only concern adding an o/d unit ontop of the current transmission is the extra strain that will be on that crappy 5r55 transmission. The problem with milage on those units is the servo bores wear out. When that happens you loose line pressure in o/d and it's harder to keep it in o/d w/ tc locked. I feel you'll have the same struggle unless you use the od unit above 75mph so your at least turning the rpms.

Has anyone used the servo repair kit?? The one with O rings?? This:
Thransmissions 5R55e Repair kit:

https://www.fordservoboretransmissionfixsolution.com/



They clearly say so but 20 to 100K will most likely out live my use.


The strength you would gain with the 6r80 would be worth the effort alone but getting it hooked up would be fun. If your truck was an 04+ then can bus comes into play and it would make a pcm swap much easier talking to the other modules.

Mine is a 03 so no CANBUS...I really feel so much is lost with the 6R60 across the power band, I really want to keep the stock power band and how it drives.

I'm still about giving the o/d unit a try for sure since you already have them. Since your 4x4 a 2wd conversion would net 1.5 mpg alone, not sure if you need 4x4?

Are you saying cutting out the automatic 4WD will give 1.5 MPG??

Testing my 02 showed it could get around 25/28MPG at 50MPH as that is the speed it will do running around 1800RPMs.

So I believe it can do that MPG IF I can gear it to be going say 85MPH and still running a 1800RPMs.


And if you going to run out the old wife's tail of a box cannot do that consider this: A full size boxy van.

Rich


Sticker for a 29MPG custom VAN.jpg
 






Your front cv axles, diff and front driveshaft spin at all speeds. At 80 mph its a ton of rotational weight spinning. Deleting this will gain prob 1.5 mpg at 75-80 mph
 






There are a few thing to be aware of, 1St you must NEVER back up with it engaged. That will rip it to threads.

The can on the side is also a must have, it electrically shifts it in and out of overdrive.

The lever on the side also will shift it out of over drive, but should only be done standing still. But you can lock it out for city driving.

The odd looking housing on the other side is a speed governor, it kicks it out of over drive at around 30MPHs and will not allow it to shift into OD under 30MPh.

It add a few pounds as it is cast iron, and can also lower your ground clearance depending on mounting.

I hot rodded a 56 Studebaker with one for 4 years at a 16 year old never broke it broke a few rear axles.

Rich
 






"Your front cv axles, diff and front driveshaft spin at all speeds. At 80 mph its a ton of rotational weight spinning."

If it costs 1.5 MPG I think I can get that back by other MPG tricks.

I take it there are no lockout hubs for there SUVs to unlock them from the front wheels??

My understanding is the 4WD stystem in these SUVs are lighter and less a drag as with older add on 4WD conversions.

Rich
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





You can’t assume what MPG you will be getting by your RPM. That’s not how the science works.

It’s not a “wive’s tall”. Nothing is free. That van probably doesn’t get great MPG at 85. It’s performance is probably also dismal. The overdrive is going to eat up power. It’s also gonna tax your current garbage transmission.
 






Back
Top