Hi to all, My question is, which tranny is better, the 4R100 or the 4R70W? According to my owners manual, I have the 4R70W because it calls for Mercron V on the dipstick.
It says in the manual that the 4R100 learns shift patterns by driving habits. Does the 4R70W do the same thing? It didn't say in the manual. It seems that it shifts out of first kinda early, even when loaded with a car on a trailer, unless you really lay into the throttle. If it will relearn my driving habits, I will unhook the battery for a bit to reset it. By the way, I have a 2001 F-150 SuperCab, 4x4 5.4L, 3.55 Traction-Lock 9.75 rearend.
Thanks, Jimmy
PS I did some more research, it looks as if the 4R70W is preferred by some like Baumman and such. I just hope it holds up better than the old AOD's. Still curious about the shifting thing though, Jimmy

 

The 4R100 is the heavier duty tranny. Comes behind the diesels. As for the computer learning how you drive, I'll let someone else answer that.

 

Anybody have a clue about the learning mode on the 4R70W? It seems to shift early, and take a lot of throttle to downshift, eveny when towing 5000lbs. I didn't want to bother with unhooking the battery for awhile if it wasn't going to change anything
Jimmy

 

As far as I know, the 4R70W does learn, but Mark (the site's unofficial FoMoCo tranny engineer) said it has nothing to do with shift points, only the time it takes between shifts (felt as a semihard shift vs. a lagging soft shift).
The differences in feel seem to be with a torque convertor lock up. I guess the 4R100 doesn't do it? or does it in such a way that it stresses the system differently. Mark does a much better job of explaining it.

-Kerry

 

Ok, thanks. I'm thinking about slightly advancing the TPS sensor a little bit to increase the signal to advance the timing sooner and maybe raise the shift points a bit. It shifts into 2nd about 10mph if you don't give it enough throttle, even loaded. This can't be good on the tranny and would seem to create extra unwanted heat.
Jimmy

 

It won't hurt the transmission. Why would it?

Advancing the TPS isn't going to make any difference to anything.

Also, niether transmission learns anything about driving habits. I know the manual says they do, but they don't.

They both learn how long a shift takes. The time from when the computer asks for a shift until the shift is complete is measured. If it is too long pressure is added next time. If it is too short pressure is reduced for next time.

Both transmissions have lockup torque converters. They operate very much the same in both.

 

I don't like it because when hauling 6000lbs, plus the weight of the truck, accelerating from 10mph in 2nd gear puts the engine way below it's powerband and I hate having to mash the gas to get it to kick back into first and waste the gas doing it. I would figure that my computer controlled tranny would be smarter than my 77 C6. NOT!!
Jimmy

 

90% to peak for the 5.4's torque is made between 1000 and 2500 rpm. It's a towing engine... The tranny is merely a torque multiplier. If it makes you feel better, a chip can be installed or you can reflash the PCM to change shift points.

Oh yeah, the door jamb tranny code is U for the 4R70W... don't go by the dip stick

-Kerry

Thanks Mark.... I'll get the operation of these things right one of these days

 

Thanks for the info, I'll double check the doorjam sticker in the morning. I see that your 7700lb payload truck has the same tranny. The brochure for 2003 says that there is a special heavy duty tranny for this package. Was it that way in 2001 too?
Jimmy

 

When I initially shopped around for my truck, I knew nothing of the possibility of a 4R70W being behind the 5.4 at all. Since the last year has passed I've found that, while not as common, the 4R70W may very well be behind a quarter of the 5.4L trucks. My 7700 has a TSB (green sticker) that essentially says it is an experimental deal. Something about contacting Ford before doing anything work on it. Could it be a beefed up version? I haven't a clue. I think Ford wants to use real world data to study the trannies....Let's find out what fails and how they've been maintained and can the 4R70's handle themselves as well as the 4R100's. Some of the 4R100's have a similar TSB on them (orange sticker). As far as I know they never put a 4R100 behind a 4.6 or 4.2. So who knows what's up with that?

This is my round about way of saying I don't know which tranny you'll find in a 2001 or 2003 7700 for that matter. The options sheet I can remember from ordering on-line (which I never followed up on) said a special tranny on the 2002 model...but did not specify a model. The same seems to be true of the 2003.

Sorry I can't help you other than provide some more second hand info.

-Kerry

 

Well, I checked, I definately have a U tranny and H9 gears. So I have the 4R70W tranny and 3.55 traction lock rear. I guess I just figured that the wide-ratio tranny would shift a little later to keep the rpm from dropping down too far. I guess they are programmed for maximun MPG and not performance. I still love the truck, it's just going to take some getting used to. The poor little 330 ci. engine will never compare to my 460 in my 77. On the bright side, I am getting at least double the gas mileage and now have a/c to boot.
Jimmy