6R140 Identification Guide: Gas vs Diesel, Valve Body and Converter

Most 6R140 parts mix-ups do not come from somebody grabbing a 6R80 kit by mistake. They come from treating every TorqShift 6 as the same transmission. It is not. Ford built it for gas and diesel Super Duty trucks, changed the valve body castings and separator plates partway through the run, and put three different converter bolt patterns behind it. A kit, a plate or a converter that fits one of those can bolt into another and still be wrong.

This is the order I use to identify a 6R140 before I quote a job or order parts: the truck first, then the outside of the unit, then the valve body, then the converter. Each step narrows what fits.

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Recommended 6R140 parts

Rebuild kits matched to early (2011-2014) and late (2015-up) 6R140 valve bodies. In stock, ships from the USA. Secure checkout.

6R140 Banner Rebuild Kit 2011-14

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6R140 Banner Rebuild Kit 2015

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6R140 Master Rebuild Kit 2011-19

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Start with the door label, not the pan

Ford puts a transmission code in the TR field of the Safety Compliance Certification Label, on the driver door edge, latch post or hinge pillar. Ford’s own Super Duty owner’s guide lists the codes. For the 2013 model year, P is the six-speed automatic 6R140 behind gasoline engines, W is the 6R140W behind diesel engines, and T is the five-speed 5R110W that the 6R140 replaced (per the Ford 2013 Super Duty Owner’s Guide, Transmission Code Designation table).

That one letter answers the biggest question, gas or diesel, and on this transmission gas versus diesel changes the converter, the controller and parts of the valve body. The label also carries the build date. Several 6R140 changes follow build date or casting rather than model year, so write it on the repair order.

Two cautions. A label only tells you what the truck left the plant with. If the truck has a replacement or salvage unit in it, the label is a starting point, not proof. And the W suffix you see in some literature (6R140W) is the diesel designation, not a different gearbox family. Transmission Digest calls the diesel version the 6R140W and notes Ford markets both as TorqShift 6.

What the 6R140 is, on paper

Ford Component Sales, which sells the 6R140 for vocational and repower use, publishes the core specs. Keep these handy, because they are how you tell a 6R140 from its lookalikes:

Spec	6R140 (Ford Component Sales)
Max engine torque	935 lb-ft
Powerflow	Lepelletier: 1 simple planetary + 1 Ravigneaux gearset, 5 clutch packs (3 rotating, 2 brake)
Gear ratios	3.974 / 2.318 / 1.516 / 1.149 / 0.858 / 0.674, reverse 3.128
Converter K factor	125K gas, 97K diesel
Controller	PCM on gas applications, TCM on diesel applications
Weight	345 lb
Length / width / height	30.3 in / 18.7 in / 19.5 in
Fluid	MERCON LV, about 4 gallons
Output	Fixed flange or slip yoke; PTO option

Transmission Digest adds the dry-fill numbers most shops actually use: 16.2 quarts for diesel trucks and 17.2 quarts for gas trucks, with MERCON LV from the factory. The same article lists line pressure at about 90 psi at idle in Drive and Reverse, and 230 psi (Drive) and 240 psi (Reverse) at wide-open throttle, and seven solenoids, all of them regulating types. For level-check procedure and service intervals, see our 6R140 fluid type and capacity guide.

Telling it apart from the lookalikes

6R140 vs 5R110W

The 5R110W was the Super Duty automatic before the 2011 model year. It is a five-speed, it carries TR code T on the label, and it is a completely different design. If the scan tool shows six forward ranges, it is not a 5R110W. Our 6R140 vs 5R110W breakdown covers the swap questions.

6R140 vs 6R80 and 6R100

This is where people get burned. The 6R80 and 6R140 share the Lepelletier layout and a lot of control logic, so the diagrams look alike and some valve body kits cross over. But the 6R140 is sized for 935 lb-ft and weighs 345 lb, and the 6R80 lives in half-ton trucks and SUVs. Case, clutch packs, pump and converter do not interchange. If the truck is a Super Duty with TR code P or W, you have a 6R140. See 6R80 vs 6R140 differences for the part-by-part comparison.

6R140 vs 10R140

Ford replaced the 6R140 in Super Duty trucks with the ten-speed 10R140 starting with the 2020 model year. A 2020-up diesel Super Duty is a 10R140 unless something has been swapped. Ten ranges on the scan tool settles it.

Valve body: read the casting suffix

Once the pan is down, the valve body tells you more than the model year does. Sonnax groups 6R140 valve bodies into three versions:

Version	Lower / upper casting	Separator plate	Cooler bypass valve
Early	RFBC3P-7A101-EB / RFBC3P-7A092-EB	Smooth (no notch)	Yes
Middle	RFFC3P-7A101-BA / RFFC3P-7A092-BA	V or C notch	Yes
Late (2017-up diesel)	RFFC3P-7A101-BA / RFFC3P-7A092-BA	Double V notch	Blocked

Two things jump out. First, the middle and late bodies share the same casting numbers, so the casting alone will not separate them. The separator plate notch and the cooler bypass valve do. Second, the year break is fuzzy. Sonnax’s valve body guide labels the early body ’10-’13, while its separator plate guide says unnotched plates fit ’11-’14 castings ending in EB and notched plates fit ’15-later castings ending in BA. On a truck built across that window, I stop guessing at the year and go by the EB or BA suffix on the casting. That is the thing the parts actually care about.

Sonnax sells its replacement valve body in two versions for exactly this reason: one for ’11-’17 units with the cooler bypass valve, and one for ’17-later diesel units without it. Ordering the wrong one is an easy mistake if you only went by model year.

Separator plates: notches, holes and dampers

The separator plate is the part most likely to get swapped wrong during a valve body job, because they all look close and they all bolt on. Sonnax lists these Ford numbers:

• Early, no notch: engineering stamps BC3P-7Z490-EB, -EC, -ED, -EE; service numbers BC3Z-7Z490-E and BC3Z-7Z490-F.
• “C” plate: FC3Z-7Z490-C (stamped FC3P-7Z490-CA).
• “CC” plate: HC3Z-7Z490-C (stamped HC3P-7Z490-CA).
• “V” plate: FC3Z-7Z490-B.
• “VV” plate: HC3Z-7Z490-D (stamped HC3P-7Z490-DA), 2017-up diesel only.

The rules that matter on the bench:

1. Unnotched plates only fit the early EB castings. Notched plates only fit the later BA castings.
2. The VV plate needs the narrow-land 4-5-6 latch valves. Put a VV plate on a body with the wrong latch valves and Sonnax says to expect a harsh 5-6 upshift.
3. The cold lube passage is triangle-shaped on early and gas plates, and a round hole on 2017-up diesel plates.
4. Early plates have two dampers; everything from 2013 on has three.
5. The 2-6 cutback feed is present on every plate except the VV.

If a 6R140 came in with a harsh 5-6 after somebody else did the valve body, the plate and latch valve pairing is one of the first things I check. Our 6R140 valve body wear guide covers the bore wear and vacuum testing side of that job.

The solenoid tag belongs with the valve body

The valve body carries a tag with a 13-digit solenoid strategy number and an 8-digit solenoid body ID. Those numbers tell the module how each solenoid flows, and Sonnax notes the solenoids are banded 1 through 5, with black snouts on normally high solenoids and brown on normally low. When you ID a unit, photograph that tag. If the valve body gets swapped, the new strategy has to be loaded with a Ford scan tool or a J2534 pass-through. Details are in our 6R140 shift solenoid guide.

Torque converter: count the studs

The 6R140 converter is not one part. Sonnax identifies three stud patterns:

• 4-stud: gas engines. Higher stall and K factor, and a smaller clutch apply piston.
• 6-stud: diesel. Large apply piston.
• 8-stud: diesel. Internally the same as the 6-stud except for the stud count.

That lines up with Ford Component Sales’ K factors of 125K gas and 97K diesel. The trap is that a 4-stud converter will bolt to an 8-stud flexplate, with every other hole left empty. It looks like it fits. Under diesel torque, the smaller apply piston cannot hold, and Sonnax warns the lockup clutch fails early. Count the studs on the old converter before you order the new one.

The design itself is unusual. The lockup clutch is a single segmented, double-sided friction plate that reacts against an internal backing plate instead of the front cover. The impeller hub has splines on the outside of the leading edge to drive the pump, and splines at the base of the inside diameter that drive the PTO. A damaged hub spline can take out the PTO drive too, so inspect both.

Gas or diesel: what else changes

• Controller: gas trucks run the transmission from the PCM, diesel trucks from a separate TCM, per Ford Component Sales. Know which module you are programming before you load a solenoid strategy.
• Converter: 4-stud gas, 6- or 8-stud diesel, as above.
• Fluid fill: 17.2 qt dry on gas, 16.2 qt dry on diesel.
• Late diesel valve body: blocked cooler bypass and the VV plate on 2017-up diesel units.

A quick ID checklist

1. Read the door label TR code: P for gas 6R140, W for diesel 6R140W. Note the build date.
2. Count forward ranges on the scan tool if the unit might be swapped: five is a 5R110W, six is a 6R-series, ten is a 10R140.
3. Pan down: read the valve body casting suffix, EB or BA.
4. Check the separator plate for no notch, C, CC, V or VV, and look for a working or blocked cooler bypass valve.
5. Photograph the solenoid strategy tag.
6. Count converter studs: 4, 6 or 8.

With those six answers written down, you can order a rebuild kit, plate, valve body or converter once and get it right. Rebuild kits split on the same lines. Many are sold as 2011-2014 versus 2015-up to match the valve body and separator plate change.

FAQ

How do I know if my Ford has a 6R140 transmission?

Check the TR code on the Safety Compliance Certification Label on the driver door. In Ford’s Super Duty owner’s guide, code P is the six-speed 6R140 for gasoline engines and code W is the 6R140W for diesel engines. It was used in 2011-2019 Super Duty trucks before the 10R140 took over in 2020.

What is the difference between the 6R140 and 6R140W?

The W is the diesel version. Diesel units use a 6- or 8-stud converter with a larger apply piston and a lower 97K K factor, are controlled by a separate TCM, and 2017-up diesel valve bodies use a double V separator plate with a blocked cooler bypass. Gas units use a 4-stud, 125K converter and are controlled by the PCM.

How do I tell an early 6R140 valve body from a late one?

Read the casting suffix. Early lower and upper castings end in EB and use a smooth separator plate with no notch. Later castings end in BA and use a notched plate. The middle and late BA bodies share casting numbers, so check the plate notch (V, C or double V) and whether the cooler bypass valve is blocked.

Can a 4-stud 6R140 torque converter go in a diesel truck?

It will bolt to an 8-stud flexplate using every other hole, but it should not go in. The 4-stud gas converter has a smaller clutch apply piston, and under diesel torque the lockup clutch fails early. Match the stud count to the original converter.

Related 6R140 guides

• 6R80 vs 6R140 Differences
• 6R140 vs 5R110W Differences
• 6R140 Fluid Type and Capacity
• 6R140 Valve Body Wear: Symptoms and the Bench Fix
• 6R140 Shift Solenoid Symptoms