Does your Torqshift fail immediately after a rebuild? Do you have multiple pump failures after working on Ford diesel transmissions? Do you find yourself sitting on the side of the road, having a nervous breakdown because this Torqshift keeps failing?
Well, I have news for you: You aren’t alone. Many technicians are suffering from the same symptoms. It’s called pump failure and there’s a cure for it.
It’s time to try grounding, a revolutionary repair that only takes a few minutes and the results are wonderful. Some technicians have had side effects that included consistently smiling caused by joy and elation. In most cases it’s a first-time fix! Okay, I know, the silly commercial intro might be a bit much, but let’s face it: Everyone is dealing with this. In this issue of Let’s Play Ball, we’re going to cover the Torqshift pump failure. Let do this…
PUMP DAMAGE AFTER REBUILD
The customer comes in with a Ford 6.0L, 6.4L, or 6.7L diesel truck with a Torqshift transmission. It’s slipping and has erratic shifts. You determine the transmission needs to come out and be overhauled.
During the process, you replace some clutches and seals, replace the torque converter, and reinstall the transmission. Just another day on the job. After you’ve filled the unit and rechecked for leaks, you’re ready for the test drive. Ten minutes into the test drive the transmission seizes and kills the engine.
The Torqshift transmission has a common issue: pump failure in a short amount of time. Usually the pump gears break and look like they’ve been welded to the pump plate (figure 1). This is caused by bad grounds, so let’s cover the issues, one by one, and look at some of the things you can do to prevent the unit from the dreaded pump failure.
Ground issues are the most common causes for pump failure on these units. The problem is similar to other ground issues we’ve seen in the past. If you paint the case or the bolts are corroded, or the rust fairy decided to create a layer of corrosion somewhere, you’ll have a pump failure caused by a faulty ground.
In this situation, you should probably skip painting the case, and you should clean the bolts on a wire wheel. Clean the transmission and engine mating surfaces to remove all paint and debris. This is very important and should be done on every transmission.
Always make sure the batteries’ negative cables are clean, tight, and free of any debris. The fastest way to verify your ground is to perform a voltage drop test.
The first ground tests you should perform are on the vehicle’s basic ground circuits, as they support all other electrical circuits on the vehicle.
There are three sections to a vehicle’s basic ground system: the chassis-to-battery ground, the battery-to-engine ground, and the chassis-to-engine ground. There are three quick tests to check the basic grounds:
- Make sure the battery is fully charged.
- Set your DMM to the 4-volt DC range.
- Disable the fuel pump.
- Crank the engine to bleed off any remaining pressure (engine may start and run for a few seconds, but should stall out and not restart when cranked again)
- Connect your positive meter probe to the transmission case or engine block.
- Connect your negative meter probe to the negative battery post.
- Crank the engine for about 3-4 seconds. You should measure less than 0.10 volt. Some newer vehicles use smaller cables to cut down on production costs, so you may see up to 0.30 volts at most (figure 2).
If you’re specifically investigating a possible powertrain ground problem on a rear-wheel-drive vehicle, remove the driveshaft before performing this test. That’ll help make the voltage drop more apparent.
- Key on, engine off.
- Turn on the headlights, radio, and heater blower fan.
- Measure the voltage drop between the negative battery post and the frame, fenders, body, etc (figure 3).
The voltage drop should be less than 0.10 volts.
- Engine running.
- Turn on the headlights, radio, and heater blower fan.
- Hold the engine speed at about 2000 RPM.
- Measure the voltage between the engine and the frame or body (chassis ground; figure 4).
The voltage reading should be less than 0.10 volt.
TRANSMISSION FILL PROCEDURE
You can add fluid to the torque converter before installing it. When filling the transmission:
- Add 8 quarts to the transmission.
- Start the engine and run it for 30 seconds. Then shut it off.
- Add 4 more quarts of oil and restart.
- Finish filling transmission to the correct level.
We’ve found that the pump can run dry at startup when filling this transmission using the normal procedures.
With the pump on the bench:
- Thoroughly clean and dry the remaining pump components.
- Check the pump body, pump gears, and pump plate for wear and scoring (figures 5, 6, and 7).
- Check all mating surfaces for burrs or distortion.
- Inspect the stator bushings and replace as necessary.
In some cases, a machining problem from the factory may cause a sliver of metal to lodge into the pump casting. Always disassemble an ordered pump and check the clearances and the machine cut.
Damage to the pump can occur when the cooling system isn’t serviced correctly. Clogged filters due to debris are another common cause for pump failure.
Beginning in 2005, we started seeing a problem with mismatched pump parts. 2005-and-later pump parts aren’t interchangeable with the earlier 2003-04 parts. The 2005-and-later pump will retrofit as a complete assembly, but you can’t interchange internal components between early and late pumps.
You can identify the early 2003-04 by the rough forged date found on the castings #3C3P on the pump and RF3C3P on the stator (figures 8a and 8b). You can identify the 2005-and-later pump assembly by the rough forged date found on the castings #RF5C3P (figures 9a and 9b).
There are differences in the stator support, pump body, and plate. The obvious differences are in the worm tracks (figures 10, 11, and 12). You’ll usually see this about two or three thousand miles after rebuild; it won’t show up right away.
The most common problem is the ground issue. Just listen to what this technician said: “After just one day of using grounding I feel like I’m cured.”
Of course there’s always a disclaimer: Your results may vary; ATRA Members report a greater number of successes in most cases.
All kidding aside, there’s nothing more frustrating than comebacks. Take your grounding to a new level by using some simple techniques.
And that’s the game!