5R110W Slipping: Causes and Fix

"It slips" is the most common complaint that brings a Super Duty with a 5R110W TorqShift into the bay, and it is also the least specific. Some owners mean the tach flares on the 2-3 shift. Some mean the rpm creeps up on the highway while the speed stays the same. Some mean Reverse takes a second to bite. Those are three different failures in three different parts of the transmission, and the parts bill runs from a quart of the right fluid to a full overhaul.

This guide sorts slipping complaints the way I do before anything comes out of the truck: check the fluid the way Ford says to, use the scan tool to decide whether it is the converter clutch or a gear that is slipping, then use the clutch application chart to name the circuit. The fluid facts come from Ford's 2009 Super Duty owner guide, the solenoid and pressure logic from Transmission Digest's TorqShift launch coverage and Sonnax's solenoid chart, and the valve body and center support failures from Sonnax and Transmission Digest. Everything is listed under Sources at the bottom.

Recommended 5R110W parts

The parts that fix a 5R110W slip, by cause: a master rebuild kit for a burned direct or overdrive clutch, a valve body when the TCC control sleeve is worn, and a pressure control solenoid when line pressure is low in every gear. Secure checkout on site.

5R110W Master Rebuild Kit

$623.99View part

5R110W Valve Body 2003-2016

$468.99View part

5R110W Pressure Control Solenoid 2004-2017

$146.99View part

Step 1: Check the fluid the way Ford specifies

Ford's owner guide says the transmission does not consume fluid, but that the level should be checked any time the transmission slips or shifts slowly. That makes it step one, not an afterthought. The procedure matters because the TorqShift holds a lot of fluid and the reading moves a lot with temperature:

1. Drive about 20 miles (30 km) to reach normal operating temperature. If the truck has been towing or run hard in hot weather, Ford says to shut it off for about 30 minutes to let the fluid cool before checking.
2. Park on level ground with the parking brake set.
3. With your foot on the brake, start the engine and move the lever through every range, giving each gear time to engage.
4. Latch it in Park, leave the engine running, and read the dipstick.

The hot range on the stick is for 150-170°F (66-77°C). There is also an ambient range for 50-95°F (10-35°C), but Ford warns that topping off cold can overfill the unit once it warms up. Ford also says not to drive the truck if the level is at the bottom of the dipstick with ambient temperature above 50°F.

Right fluid, right amount

Note the fluid change over the years. Transmission Digest's launch article on the TorqShift says it requires MERCON SP and that any other fluid can cause abnormal operation or failure. By 2009, Ford's owner guide lists MERCON LV and says transmissions that require MERCON LV should only use MERCON LV. Ford also notes the requirement is printed on the dipstick blade or handle. Read the stick on the truck in front of you, not a chart from a different model year. A unit that has been topped off with generic multi-vehicle fluid, or the wrong MERCON, can show shift complaints that look like wear.

The 17.5 quart figure is a dry-fill number. Ford says it varies with cooler size and that the final level should be set on the dipstick. After a pan drop you will only get part of that back in.

While the stick is out, smell and look at the fluid. Dark, burnt-smelling fluid with friction material on the pan magnet means a clutch has already cooked. Topping it up may help for a few days, but it will not fix it.

Step 2: Is it the converter or a gear?

This is the question that saves the most time. On a scan tool, watch engine rpm, turbine speed, output shaft speed, commanded gear and TCC command on a road test.

• Converter clutch slip: The truck is in top gear with the TCC commanded fully on, but engine rpm runs above turbine speed and wanders. The gear ratio itself (turbine divided by output) stays correct. The owner feels it as rpm creep or surging on the highway, often with heat.
• Gear slip: The turbine-to-output ratio does not match the commanded gear, or it flares during or after a shift. That is a clutch pack, its apply circuit, or line pressure.

Get this split right before you order anything. A converter clutch complaint does not need a rebuild kit, and a burned direct clutch will not be fixed by a converter.

Step 3: Converter clutch slip and the TCC control sleeve

Per Transmission Digest, the 5R110W's TCC solenoid is a directly proportional three-port solenoid: 0 to 1 amp, with 1 amp giving maximum pressure. The PCM commands apply by raising current, and a valve in the valve body turns that signal pressure into converter clutch apply pressure.

That valve is where many of these trucks fail. Sonnax lists the complaints for its 5R110W TCC control plunger valve kit (36940-01K) as overheating, excess TCC slip, TCC cycling, and codes P0741 and 1783. The cause Sonnax gives is wear at the TCC control sleeve. Once the sleeve wears, the valve moves too far for the solenoid signal and apply pressure is lost. You get slip, cycling and heat, or a lockup that comes in too hard. P0741 is the generic code for converter clutch performance or stuck off, and the heat that follows is why an overtemp code often shows up with it.

How I work a converter slip complaint:

• Verify the fluid level and type first (Step 1). Low fluid starves the converter circuit.
• Check the TCC solenoid and its circuit. Watch commanded duty or current against actual slip.
• If the command is correct and it still slips, the fault is hydraulic: the TCC control sleeve and plunger in the valve body, then the converter itself.
• If the TCC command and apply pressure are both correct and it still slips, the converter clutch lining itself is worn and the converter has to be rebuilt or replaced. On a heavily towed or tuned diesel, ask for a converter built for that load.

Step 4: Gear slip and the clutch chart

If the ratio does not match the commanded gear, use the Sonnax clutch application chart to find the clutch that is common to every gear that slips.

The ratios and the normal hot-mode shift pattern (1-2-3-5-6, with the 1.09 4th used only in cold mode) come from Transmission Digest. The clutch columns come from Sonnax.

Slips in 5th, 6th and Reverse: the direct clutch

This is the most common hard failure on the TorqShift. The direct clutch is the only clutch shared by 5th, 6th and Reverse. Sonnax says 5R110W units often suffer direct clutch failure because of insufficient clutch capacity, poor heat dissipation, and flexing of the apply and backing plates. A truck that upshifts cleanly through 3rd and then flares on every shift above it, and is also slow or soft in Reverse, has a burned direct clutch until proven otherwise.

Check one thing before you condemn the clutch: its feed. Transmission Digest documented a 5R110W with no Reverse and an apparent loss of a gear where the center-support sleeve had walked forward and blocked the direct-clutch feed holes. Replacing the center support fixed both complaints. If you have the unit apart for a burned direct clutch, look at that sleeve. Otherwise the new frictions will fail the same way.

If Reverse is solid and only 5th and 6th slip, look harder at the control side first. Sonnax shows the direct clutch in Reverse fed through the manual valve, not the solenoid. Its forward-gear apply is controlled by SSPC-D, which Transmission Digest describes as inversely proportional, with 0 amp giving maximum pressure.

Slips in 2nd and 6th: the overdrive clutch

The overdrive clutch is common to 2nd and 6th. A slip limited to those two gears points at its apply solenoid, SSPC-B (directly proportional, 1 amp for maximum pressure per Transmission Digest), its feed through the pump, or the overdrive clutch pack itself. We cover that circuit, including a documented missing pump bleed-filter case, in 5R110W Won't Shift Into Overdrive.

Slips in every gear: line pressure

If every gear flares and engagements are soft, the common factor is line pressure, not one clutch. Transmission Digest describes the line-pressure-control solenoid (PC-A) as inversely proportional: 0 to 1 amp, with 0 amp giving maximum pressure. A PC-A solenoid that is sticking, contaminated or seeing too much current from a circuit fault lowers line pressure everywhere. Low fluid, a worn pump and a plugged filter do the same thing. Put a gauge on it before you blame a clutch.

For reference, ATSG's 5R110W line pressure chart gives approximately 70 psi in Drive and 100 psi in Reverse at idle, and about 320 psi in both at stall; if idle pressure is already low, ATSG says not to run the stall test at all. Two hydraulic causes of low pressure are well documented. Sonnax notes the Gen. 1 pump in 2003-2004 units was redesigned for 2005 partly because of low pressure at the main pressure regulator valve, and offers oversized regulator valve kit 36940-03K for all three pump generations. Sonnax also flags the OE manual valve for anodization flaking and bore wear that bleeds line pressure and shows up as low pressure with delayed Drive and Reverse. If engagements are slow as well as soft, see our 5R110W delayed engagement guide.

Step 5: Use the pressure switches and relearn

The TorqShift gives you more to work with than older Fords. Per Transmission Digest, it has five pressure switches (PS-A through PS-E), one per shift solenoid circuit, and each opens when solenoid control pressure goes above 40 psi. If the scan tool shows a switch that never changes state when its clutch is commanded, the pressure never arrived. Look at the solenoid, the valve or a leak in that circuit before you open the clutch pack.

After any repair, battery disconnect or PCM replacement, the adaptive engagement schedule must be relearned. Transmission Digest gives the procedure: five each of Park-to-Reverse, Drive-to-Reverse, Reverse-to-Drive and Neutral-to-Drive engagements with the fluid at 130°F (54°C). Ford's owner guide also says shifts may feel slightly firmer while the strategy relearns. Do not judge a fresh repair as "still slipping" until the relearn is done.

The fix, by cause

If the unit had a burned clutch, flush the cooler circuit before the rebuilt unit goes in. Clutch debris left in the cooler goes straight into the new frictions.

Need parts for this job?

Our 5R110 parts page has 5R110W master rebuild kits, valve bodies, pressure control solenoids, solenoid kits and pumps, so you can buy the fix for whichever circuit you traced. Checkout is on site.

FAQ

Why is my 5R110W slipping?

Start with the fluid: Ford says to check the level any time the transmission slips or shifts slowly, hot, in Park with the engine running. If the level and fluid type are right, use a scan tool to decide whether the torque converter clutch is slipping or a gear is slipping. The most common hard failure is the direct clutch, which slips in 5th, 6th and Reverse.

What fluid does a 5R110W take and how much?

Launch-era literature called for MERCON SP only, while Ford's 2009 Super Duty owner guide lists Motorcraft MERCON LV (XT-10-QLV) and says MERCON LV units should use only MERCON LV. Use the fluid printed on the dipstick of the truck you are working on. Approximate dry-fill capacity is 17.5 quarts (16.6 L) including the remote filter, but the final level is set on the dipstick.

How do I tell converter slip from transmission slip on a 5R110W?

Watch engine rpm, turbine speed and output speed on a scan tool. If the gear ratio is correct but engine rpm runs above turbine speed with the TCC commanded on, the converter clutch is slipping. If turbine speed divided by output speed does not match the commanded gear, a clutch or its apply circuit is slipping.

What causes P0741 on a 5R110W?

P0741 is the converter clutch performance or stuck-off code. After fluid level and the TCC solenoid circuit, Sonnax points to wear at the TCC control sleeve in the valve body, which lowers apply pressure and causes TCC slip, cycling and overheating. A worn converter clutch lining is the other cause.

Will a 5R110W stop slipping after a relearn?

Only if the complaint was caused by stale adaptive values after a repair or battery disconnect. Transmission Digest gives the relearn as five each of Park-to-Reverse, Drive-to-Reverse, Reverse-to-Drive and Neutral-to-Drive engagements at 130F fluid temperature. A burned clutch or low line pressure will still slip after the relearn.

Related guides

• 5R110W Common Problems and Fixes
• 5R110W Won't Shift Into Overdrive: Causes and Fix
• 5R110W Shift Solenoid Symptoms
• 5R110W Rebuild Wear Points
• 5R110W Fluid Change Cost
• 5R110W Delayed Engagement: Causes and Fix