4R70W vs 4R75W Valvebodies

[STLR FN]

I know the 75W is a beefier trans via the clutches, bands, and TC but are the vb's the same? If so I'm looking into getting a FTVB as my first mod to the Merc. :D :burnout: The only thing I'll have to worry about is a :bop: from the wife.

[SergntMac]

I know the 75W is a beefier trans via the clutches, bands, and TC but are the vb's the same?
I'd love to see an itemized list of changes from the 4R70W to the 4R75W specs, with a referrence to your source. Can you help?

I have read here that the changes are great, but no one seems to agree on what these changes are, specifically. Since I got my clock cleaned over altenator pulleys and one-way clutches, I have reservations in accepting any 411 we post for our own benefit here, and I'd like to see a list, or, spec sheet of some sort, hopefully a web site somewhere backing this 411. Since you "know", please help?

Anyone?

[merc]

The 2004 Marauder gets a new 4R75W heavy-duty, four-speed automatic transmission for greater efficiency and low-end torque. Other refinements include the addition of needle bearings and Teflon seals to a new 11.25-inch high-stall-speed torque converter with a one-inch one-way clutch. The new transmission provides quicker upshifts and downshifts, and lets the driver “kick down” into first gear at a higher speed. That's all I know.
:o

[STLR FN]

It's a moot point now. Was thinking at work, I'd rather have a tuner. At least that way I can adjust the firmness of the shifts myself, whereas going with the FTVB I'm pretty much stuck with the prings that come with the kit. We'll see.

As for the spec sheet, let me talk to someone in pre-delivery/garage at Mich. Truck Assembly. That's where I work.

[JACook]

I'd love to see an itemized list of changes from the 4R70W to the 4R75W specs, with a referrence to your source. Can you help?
I'm with you, Sarge. Being's I'm kinda a transmission geek, I've been searching for this info as well.
So far, the only thing I've been able to document, apart from the improved torque converter, is the
addition of a turbine speed sensor, along with the programming revisions to use it. I've not found any
evidence anywhere of any differences in clutches, bands, or any hard parts. So, for the time being,
I'm going to continue to operate on the presumption that the "4R75" name is more marketing-speak
than anything of substance. A revised torque converter does not warrant a new model designation, IMO.

[BillyGman]

I'm with you, Sarge. Being's I'm kinda a transmission geek, I've been searching for this info as well.
So far, the only thing I've been able to document, apart from the improved torque converter, is the
addition of a turbine speed sensor, along with the programming revisions to use it. I've not found any
evidence anywhere of any differences in clutches, bands, or any hard parts. So, for the time being,
I'm going to continue to operate on the presumption that the "4R75" name is more marketing-speak
than anything of substance. A revised torque converter does not warrant a new model designation, IMO.I agree. I've never heard anything concrete stating with any cetainty and specificity, that the two transmissions are vastly different in any substantial way.

[911Racing]

I was also looking into that.........................I 'm also debating between "Baumann" or "Lentech" valve bodies. I'm kind of leaning toward "Baumann", anyone with input about them would be appreciated.:help:


Thanks,

Keith V.

[Bradley G]

The only thing I'll have to worry about is a :bop: from the wife(quote)come on!,
It only hurts for a while!:P
Bradley G

[MitchB]

So far, the only thing I've been able to document, apart from the improved torque converter, is the addition of a turbine speed sensor, along with the programming revisions to use it.

Now why would Ford use a turbine speed sensor? I take it this monitors the trans input shaft as opposed to the engine speed or turbine input. With this addition, you can monitor gear selection and shift quality. Did Ford incorporate EEC adaptive capability with this trans? I know Allison uses adaptive controls on some of their trans. Basically, it compares the input & output speed sensors to maintain correct shift quality as the clutches wear. Of course, the additional sensor could be used for diagnostics without adding adaptive ability.

Mitch

[metroplex]

The 5.4 makes more torque (350+ ft-lb) than the stock Marauder, so I'd just use whatever was in the 5.4's 4R70W.

[SergntMac]

The 5.4 makes more torque (350+ ft-lb) than the stock Marauder, so I'd just use whatever was in the 5.4's 4R70W.
I'd expect a different torque convertor behind the 5.4, but nothing different inside the tranny. I've seen a few Mustang 4R70W trannys, and internals are identical, just length different tailshafts. This is why I'm confused by the 4R75W designation, exactly what is the difference here?

[metroplex]

IIRC the "70" and "75" designation refers to the torque capacity of the transmission.

4R70W vs 4R75W vs 4R100.

Probably one reason you don't see a puny 4R70W behind a torque monster PSD or V10...

The "W" refers to the wide ratio gearset (vs AODE).

[JACook]

Now why would Ford use a turbine speed sensor? I take it this monitors the trans input shaft as opposed to the engine speed or turbine input. With this addition, you can monitor gear selection and shift quality. Did Ford incorporate EEC adaptive capability with this trans? The turbine speed sensor is as you say, to monitor the input shaft speed, rather than just engine speed.
Monitoring turbine, aka input shaft speed allows the PCM to more accurately control shifts, and manage
torque flow during shift events, as it can now know how much slip is happening in the converter.

I've never found any literature to suggest there's any adaptive control in the 4R75W other than whatever
was already in the 4R70W.