September 16, 2022

Troubleshooting Ford 6R80 & 6R140 2-3 Shift Quality Issues

Jim Dial

We all are too familiar by now with the numerous band numbers on Ford 6R80 and 6R140 transmissions. We know that — unless you are programming in a new calibration code — it is best to replace a solenoid with the exact same band number as what was taken out of that position on the valve body. Knowing which solenoid could be at fault can get tricky at times, and pinpointing an exact solenoid based on a specific complaint may cause you to pull the valve body a few times, which is no fun. ATF running down your arms and into your armpits can get irritating.

The complaint we have is related to the 2-3 shift. The shift sometimes flares and sometimes has a quick bind-up. Immediately after installing the transmission, we reset the adapts and did the 20–25 stop-and-start road test going from 1st all the way up to 6th Gear, then came down to a stop 20 times, which usually fixes an adaptation problem. Our situation now is that we still have the same complaint; it is like it can’t make up its mind. So, the first thing to do is to look at an apply chart, where we see that the 1-2-3-4 clutch is on in 1st Gear and the 2-6 clutch comes on in 2nd Gear. Then for the 2-3 shift, the 3-5-R clutch comes on as the 2-6 is released. Reviewing this data, we see that during a 2-3 shift, the 3-5-R is applied, but the 2-6 must release at the same time. Now that we know this, we understand that both the 3-5-R and 2-6 solenoids are in question.

After driving this vehicle a little longer — and paying attention to the 2-6 apply — we notice that the 1-2 shift is sometimes a little slow, then at times it has a bump at the end of it. During our road test, we record the upshift transitions on the scan tool and they look normal. Figure 1 shows the beginning of the 2-3 upshift (the figures show below are from a 6R80 application, but 6R140 is similar). Notice that the “C” solenoid (NL) for the 2-6 clutch amperage is 1.0 Amp and solenoid psi (not kPa) is low. The “B” solenoid (NH) amperage for the 3-5-R clutch drops to .564 mA, and the “B” solenoid pressure builds to 14.6 psi. Figure 2 shows the “C” solenoid amperage dropping off and the pressure dropping to 0. Figure 3 shows the completed 2-3 shift solenoid “B” amperage is .073 and solenoid “B” pressure is near 50 psi. The “C” solenoid amperage and pressure stay low while in 3rd Gear.

After reviewing this data, the electronics prove to be working correctly, as we see the “C” solenoid is fully off just before the “B” solenoid is fully off, and this pattern proves to be consistent. So in this situation, we choose to change both the “C” 2-6 solenoid and the “B” 3-5-R solenoids so that we only have to pull the valve body off once, as this seems to be more of a solenoid mechanical problem. See Figure 4 for solenoid locations for both 6R80 and 6R140.

Figure 1 – 6R80 2-3 Upshift
Ford 6R80, 6R140 2-3 Upshift
Figure 2 – 6R80 2-3 Transition
Ford 6R80, 6R140 2-3 Transition
Figure 3 – 6R80 Completed 2-3 Shift
Ford 6R80, 6R140 Completed 2-3 Shift
Figure 4 – 6R80, 6R140 Solenoid Locations
6R80 Solenoid Locations6R140 Solenoid Locations

Other considerations need to be looked at in the way of clutch clearances. Be careful not to tighten clutch packs up too much as this can also cause a binding condition. Stick close to the OE specifications as this can cause you to have to remove the transmission right after installing it into a vehicle.

After replacing both the “C” 2-6 and “B” 3-5-R solenoids, resetting adapts and going through the 20 stop-and-start road test, the problem was resolved. It is important to look at an apply chart and really get a good feel on a road test to make sure that diagnosis is not going to cost more time. Sometimes it may be more than one solenoid causing shift complaints or even a clearance issue inside of the transmission.

Jim Dial is a Sonnax technical specialist. He is a member of the Sonnax TASC Force (Technical Automotive Specialties Committee), a group of industry technical specialists, transmission rebuilders and Sonnax technicians.

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