When a later-than-usual model arrives at your shop, the first thing you think of is, are there any updates we should be aware of? You check for parts and software updates online or through past seminar books and magazine articles, looking for the slightest parts change to identify what you’re working with.
Then you remove the transmission for a normal rebuild and you discover some dramatic changes. There’s no damage to these new, unusual parts… parts you’ve never seen in earlier units. So you go through the normal, routine rebuild and reinstall the transmission without a hitch.
Sounds simple, right? But what if the rebuild doesn’t go without a hitch? Let’s look at an example:
A typical Ford truck showed up at a local shop. It was a 2011 Ford F150 Super Crew equipped with a 6.2L V8 engine and a 6R80 transmission. The complaint was a torque converter shudder. No problem; they’d fixed dozens of these.
But once they had the transmission pan off, they discovered that the TCM was missing and the solenoids looked different. The valve body plate wasn’t the typical silk-screened type used in earlier models; it had a bonded gasket.
Then, further along into the transmission with all the internal components removed, they discovered the transmission had a one-way clutch (sprag; figure 1) located near the low/reverse clutches (figure 2). None of the internal hard parts were damaged, so they figured it was just a routine rebuild. They didn’t bother to look for updates to the hard parts.
Due to the original complaint and burnt fluid, they took the converter to one of the better local converter rebuilders to have it cut open. There, they discovered the converter clutch had come apart. The converter shop installed a new, aftermarket clutch, just as they had so many times before on this particular torque converter.
The shop technicians rebuilt and reinstalled the transmission and reset the shift adapts. During the road test, the transmission shifted fine, except for a noticeable lockup apply shudder, which was the original complaint.
Once again they removed the transmission and rechecked the valve body and pump; nothing worn or damaged in those areas. So it had to be a bad converter. Once again, they had the converter cut open; this time there was nothing wrong with the clutch.
According to Ford, the 6R60/75/80 transmissions are transmission control module (TCM) driven units. The TCM is located on the valve body. They initially released these units with Bosch solenoids and six dampers, and Ford continued using this configuration until 2008½ as 6R60/75 units; also referred to as J1 units.
In 2008½, Ford determined they only needed two dampers, so they eliminated four dampers and feed holes. These were referred to as J2 units.
This is where the not-so-minor detail that the rebuilder overlooked comes in: These transmissions called for Mercon SP fluid until 2009. In 2009, Ford eliminated the casting feed to the accumulator in bore 109 and switched to Mercon LV.
All these models are considered 6R80 units.
This is also when Ford switched from Bosch to Saturn solenoids, along with a different software strategy for the 2011 non-TCM transmissions with a one-way clutch (OWC). They relocated the TCM to the passenger compartment. Look for more about the addition of the one-way clutch in the June 2016 issue of Gears.
These Saturn solenoids required additional dampening, so Ford brought back the four dampers they eliminated in 2008½.
According to Ford, for a half year between 2010½ to 2011, vehicles were built with a 6.2L V8 engine, a non-TCM 6R80 transmission with Saturn solenoids, and without a one-way clutch.
They replaced the silk-screened separator plate with a bonded plate (figure 3) for the 2011 model year. This was a lower cost option than the silk-screened plate. Look for more about these valve body, solenoid, and separator plate changes in the July 2013 issue of Gears.
FIXING THE PROBLEM
Getting back to the truck with the converter clutch chatter, the technicians reinstalled the same unit and converter, this time using Mercon LV fluid. That took care of the chatter.
So, whether you’re working on a 6R60, 6R75, or 6R80 transmission, with or without a TCM or one-way clutch, always check to see if the unit you’re working on requires Mercon SP (figure 4) or LV fluid (figure 5).
It turns out, using the right oil really does matter. It’s a minor detail that could easily lead to some not-so-minor consequences!