I have an interesting idea. Is it theoretically possible to swap a 5R555 tranny replacing a 99-04 4R70W? I beleive the bellhousing will bold up. The possible issues I can guess would be clearance, flex plate fitment, and possible length of the tranny itself, electronics, and U joint fitment. I don't have use of my legs so I drive an auto with hand controls and can't do a manual swap because I live in Atlanta with insane traffic. I think I could drive a stick with a hydraulic clutch (street bike style clutch lever) mouted to the shifter itself (hurst style maybe). I'm tired of 3 speed with OD. A five speed with 4.10's would be sick. Back to the swap, has anyone heard of or attempted this swap? I'm very interested in an info. Thanks!
I would just build up the 4R70W. People have done it but there is no real use of it. Mines built and OD is just another gear now. The money you spend you would spend on the swap could get you a built and stalled 4R70W that will out perform a 5R555.
Rubish, go 5R555. I have a built 4R, and it's pretty awesome. But as much as you change the valve body and put in a stalled TC + hardened parts, you can't change how it's engineered; and the 5R is just a better tranny. It being a new platform tho, there are less aftermarket parts for it - and they are more expensive.
My only gripe about the 4r70W is that the overdriver isn't steep enough. Is there a way to replace the overdrive unit with a higher% OD?
By the way - I feel your pain about the Atlanta traffic. 5 lanes each way and it's still like a giant parking lot! I'm down here in Jax, FL and have been through the area several times - I always make I'm traveling through well after 7PM or before 4PM. And with hand controls too? Definite skill there - I just wanted to slam it in park the last time.
steep like tall? I believe you can opt for like a .92 OD servo gear - won't help much tho. I don't remember, but i think stock is .96 - been awhile. My gripe is with 4th as well, but not in it saving fuel, rather the clutch band actuator thats sucks to all hell. Racing with three gears is just stupid.
Didn't you build your tranny up? My OD is just like another gear now, it might not pull as hard but it still pulls pretty good.
Yes it's built, but it still uses a band clutch to engage 4th - even if it is a Kevlar band, it's still a pretty bad design. My 4th pulls fine, but i'm not about to use 4th for racing, even a hardened input shaft like i have can be twisted into licorice from the abruptness of that band. Not with the amount of power i have likely, but i'm still weary.
hey. thanks for all your replies. so my first question is, is the swap possible. second? the whole reason i want the 5R is cause i HATE 3 speed w/ OD. i'm already at 3000rpm @70 getting only 19mph with 4.10. My first gear is amazing, it should be. Second gear is the power gear but 3rd and OD SUCK. So I pretty much want the gear ratios and feel of a 5 Speed with 4.10 or 4.30 gears in it. I'm no genious, but if my OD is 3000rpm @70, maybe with the 5R the fifth gear would be 2800 @70? That way I'm getting better 60 foot, better street performance, and better mpg on the highway.
I had mine built and the guys that did it said to use 4th at the track. Thats the main reason I put my 4.10s back. I have the kevalr bands and PHP told me the tranny is good for about 800rwhp.
I've seen hand build trannys on TCCoA twist the input with kevlar bands twice in a row built by (if i remember right) DirtyDog himself. Regardless, if 4th's ratio is the same 4th isn't doing much of anything but allowing you to run shorter tires and gears - i doubt you're running a better time shifting into it than you would with taller tires or 3.73's and staying in 3rd. It'd be like a corvette shifting into 6th because they trap high with 4.11's. Although i could be wrong with both aspects, my tranny's built for around 500-520rwhp with the TC @ 550rwhp, but no one gave me a warning. I'm going off of what i've seen.
I would not do this swap for 2 reasons: 1) The 4R70W is a more stout transmission than the 5R55S. The 4R70W will withstand a higher torque load than the 5R55S with both in stock trim. 2) OD with the 4R70W is 0.70:1, OD with the 5R55S is 0.71:1. You will see a lower RPM with the 4R70W and 4.10's in OD than you will with the 5R55S and 4.10's in OD. The 5R55S will give you that extra gear for acceleration and will probably be more lively in city traffic. It also does not appear to have the WOT shift into OD problem that is the only weakness of the 4R70W.
Oh, I little thing I failed to mention... There is quite a few S197 autos and a few manuals that have been swapped to the 4R70W...
Actually the first 3.25 gear of the 5R55 is overdriven to achieve a "new" second gear, so when the 2-3 shift comes there's a short timing window in which the overdrive band must release so that the 2-3 shift can execute and the intermediate and can apply. This coupled with the small input shaft and planetary design makes prospects for long term high amounts of torque less likely. Yet, I thought we were talking about built trannys - and i sure wish i had 5 gears to play with.
After looking into the OD gear ratios of the 4R70W and 5R55S transmission, I looked at the entire gear ratios of the transmissions. 5R55S 1st) 3.22:1 2nd) 2.29:1 3rd) 1.54:1 4th) 1.00:1 5th) 0.71:1 4R70W 1st) 2.84:1 2nd) 1.55:1 3rd) 1.00:1 4th) 0.70:1 Swapping from a 4R70W to a 5R55S does not make a lot of sense. I am not sure the 5R55S will accelerate quicker than the 4R70W will because it will need to shift once( 1-2 ) and maybe twice( 2-3 ) before the 4R70W does( 1-2 ). That extra shift may or may not cost you valueable time. Because the 4R70W 2nd gear ratio is again close to the 5R55S 3rd gear, you are going to have that dead feeling when they shift into the next gear( 3rd for the 4R70W and 4th for the 5R55S ). I am not sure what you would be gaining. There is no advantage in OD, it is inheritently a weaker transmission and it will still have that dead space that the 4R70W has. IMO it seems like a lot of work/hassle for no real benefit. Now if the 5R55S gear ratios were something like this, it might spark a lot more interest: 1st) 3.38:1 2nd) 2.00:1 3rd) 1.32:1 4th) 1.00:1 5th) 0.62:1 If you start to look at having a 5R55S built, it is no where near as strong as a built 4R70W for what the transmission can handle.
having a .62 5th might be cool sometimes, but you'd have to always drive with the o/d off - cuz unless you're on full throttle, it'll shift into 5th way to early and you'd be lugging the car along like you just hit a 80mph head wind forcing the tranny to downshift with any amount of extra pedal. Also you can't just look at ratios. I've driven 1 S-197 manual and a Shelby GT-H auto pretty extensively. I was in the Sonoma mountains and coming back up the mountain i could lock it into 3rd and it was in the perfect power range for the corners, just enough to slow you down off pedal - and right where you want to be coming out of the corner. With my built 4R, 1st is useless to lock in, and 2nd is good all the way up to 40-50 depending on how far into the rpm's you want to be. So for the 10-35mph and 50-65mph range you have no gear that you can stay in that will be in power (depending on your rear gears). With the 5R55 you have again a useless 1st, but 2nd and 3rd are perfectly usable for those areas i mentioned. And i don't understand why you couldn't build a 5R to be just as stout as a 4R, are you referring to lack of aftermarket parts?
The 5R55S is a weaker transmission than the 4R70W in stock trim. Ford rated these transmission by the amount of torque they can handle. Right now, there is no components available that make a built 5R55S as stout as a built 4R70W. I have a 2005 Mustang GT with the 5 Spd Tremec 3650, so I know it very well. Those gear ratios I used as interesting for an auto swap are it's with the exception of OD which is 0.68:1.
How would you control the 5R with EEC V? I think that might be the biggest problem. Has anyone actually tuned a 5R to run on our cpu's?
hey guys. thanks again. this turned out to be pretty interesting i think. for the couple times a year i race it, i could easily sacrafice less than a tenth (at the most) for that extra shift. i just wanted the feel of a five speed and the 2-3 shift of the 5R. i think by the time i'd be ready to slap a supercharger on it, parts would be out for it. but, like you said, it's probably not worth the money and time. TGJ, thanks for all the info. i guess i'd be better off swappin a manual in it and make a clutch hand control mounted on the shifter.
You know, what about Fords 6 speed auto from the Ford Explorer... First Gear Ratio - 4.17:1 Second Gear Ratio - 2.34:1 Third Gear Ratio - 1.52:1 Fourth Gear Rato - 1.14:1 Fifth Gear Ratio - 0.86:1 Sixth Gear Ratio - 0.69:1 Reverse Ratio - 3.40:1 That one might be worth looking into... I haven't really looked at this transmission or asked any serious questions about it, so I really don't know much about it yet.
