Mopar Fix for RAM ProMaster Transmission Bracket Breakage

By Chris Adams, Diagnostician

Chris Adams started with Certified Transmission in 1986 as an R&R technician, and currently works as our Diagnostic Trainer. His current duties involve training and advising our retail diagnosticians, as well as assisting in the research and development of our remanufactured products. He also holds ASE Master and L1 certifications.

 

 

 

One of our retail locations had a 2015 Ram Promaster show up on the back of a tow truck a few weeks ago, and this truck is a service vehicle for a local grocery store. The driver said he was traveling at about 40MPH when he felt like he ran over a boulder in the road, heard loud noises, and the truck stopped moving. This is the first time that I have seen this happen; the transmission was hanging down so far it was almost on the ground. What the heck happened?

We carefully pushed it into the shop so we could try to raise the transmission up and secure it so no more damage could occur, it almost appeared that the heater hoses were the only thing holding it up as they were stretched tight. After we were able to get the transmission lifted up and secured with a chain we were then able to see what happened, the left transmission (Chrysler calls it an engine mount) mount bracket and the transmission case were broken. There was a lot of damage done: case broken, mount bracket broken, both axles were damaged, shift cable broken, and air intake tube was torn. What we did not know yet is what caused this to happen. These photos were taken before we removed the transmission.

Figure 1

 

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If this vehicle was traveling down the highway I’m sure it could have been much worse. There were wire looms that were at the verge of possible damage if it had dropped any further. We needed to find out why this happened and take the appropriate steps to make sure that it did not happen again. In a situation like this, if the root cause isn’t discovered there is a high probability of a customer comeback and another damaged transmission case.

We first looked for TSBs and came up empty, so I then contacted our technical director that is in charge of this unit model at our remanufacturing facility and asked if we were seeing cores come in that were broken like this. Sure enough we were, and he also informed me that the case for this particular application was just recently made available for sale from FCA. It was pretty clear that this was more of an issue than what I was initially aware of.

The next step I took was to call our local FCA dealer to check parts availability as I just wanted to make sure that everything was available to fix this vehicle before I turned this over for the service advisor to sell the job. This is where having a good parts professional to go to is always a good thing! After I gave him the VIN number and the parts that I needed, he said, “Hold on there are some notes on this one.” He then provided me with the paragraph below:

ALSO: This applies all Promaster (VF) 3.6L/62TE equipped vehicles. If the transmission bracket to the transmission case fasteners is removed during servicing, the fasteners (Part Number 06511385AA) are one time usage, and must be replaced. Vehicles built prior to 10/23/2015 require Service Kit PN 68461214AA; includes Transmission Isolator PN 68264483AA, and Adaptation Bracket 68264479AA, Fastener Service Kit PN 68329056AA. Vehicles built after on or after 10/23/2015 will require only the Fastener Service Kit PN 68329056AA (Please note that part #’s are subject to change, please check with your parts supplier) The production date on the vehicle we were working on was before 10/23/2015, so according to the notice we knew that we needed the complete service package.

With this newfound knowledge in mind, I was fairly confident that we could install a remanufactured transmission along with the updated parts and not have this issue after we completed the repairs. What I didn’t know at this point is exactly what was changed with the new bracket, isolator, and bolts.

Figure 3

 

This is the updated bracket compared to the OE piece, and it’s hard to tell from the picture but the new one had a lot more mass to it.

Figure 4

 

This is one of the new side bolts which are longer, have threadlocker compound on it, and even have some type of lubricant between the washer and head of bolt which I presume is for a more accurate torque reading. You will also need to remove the left headlight to properly torque the top mount bolt.

Please refer to service information for the complete procedure to install the mount, but I will cover the highlights here:

Note: Mopar lock & seal adhesive must be used on mount fasteners to prevent vibration loosening.

1. Hand start all five transmission bracket bolts, starting with the lower four and then the upper bolt.
2. Using four NEW bolts, beginning with the two outer, tighten all four side bolts to 77 ft-lbs.
3. Tighten upper transmission bracket bolt to 46 ft-lbs.

I believe that if you were to tighten the top bolt before the side bolts, this would create undue stress on the case and bracket.

What I believe causes this issue is the mount bracket bolts coming loose; it is really hard to come to a 100% conclusion when they come in all broken apart like this but I can see evidence of movement of the bracket. In these photos you can see some wear on the boss that mates with the case, and there are thread grooves cut into the aluminum from the bolts which I would only think would be possible with movement of the bracket.

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Programming Steps for 8L45/8L90 Units, Post Replacement

By Daniel Skinner, Diagnostician

Daniel is a Diagnostician for Certified Transmission’s Blue Springs, MO shop.

 

 

 

 

 

Quite a lot has been been written and many technical classes have been put on regarding the General Motors 8L45/8L90 family of transmissions. We are now seeing opportunities to put that information to use. The vehicles equipped with these transmissions are beginning to trickle into our shops as they are beginning to fall out of factory warranty. Many GM vehicles utilize these transmissions from 2015 to present.

Our first vehicle to come in with 8L90 problems was a 2016 GMC Sierra 4×4. The truck had 103,000 miles on the odometer. The customer’s complaint was that the vehicle had a “shake” feeling below 70 miles per hour. He also that there was a “rumble” feel occasionally.

When evaluating the vehicle I noted that there was a P0711 (transmission fluid temperature sensor “A” circuit range/performance) code present. The transmission fluid was dark red with a slight burnt smell. During the road test I was able to reproduce the customer’s complaint. I experienced a repetitive, systematic vibration and droning sound throughout the vehicle at highway speeds. I was able to capture the issue using the scan tool.

Figure 1

This photo illustrates (Figure 1) TCC slippage and the TCM attempting to compensate/correct for it. The rhythmic shudder I experienced coincides with TCC slip speed captured with the scan tool. The transmission fluid temperature shown on the scan tool also explains the P0711 code. A sudden change in fluid temperature (50?F or more within 8 seconds) will cause P0711 to set. Obviously the transmission fluid temperature reading on the scan tool was unstable, so an electrical system analysis was performed to ensure battery and alternator integrity. Excessive AC ripple can play havoc on any electronically controlled transmission. A pan inspection was performed; evidence found in the pan along with the fluid condition had eliminated the possibility of trying to flush out the fluid with the Mobil 1 LV product, per a GM TSB.

At this point the customer agreed to replace the unit per our recommendation. After the unit was installed, solenoid valve characterization reprogramming had to be done. This is required when replacing 8L45/8L90 transmissions, and accomplished through General Motors’ TIS2Web Service Programming System (SPS). When performing solenoid valve characterization reprogramming, it is crucial to have a good clean power source connected to the vehicle’s battery and have all vehicle accessories turned off, as with any other programming procedure. Solenoid valve characterization reprogramming is fairly straightforward. After logging into the SPS website and purchasing a subscription for programming the vehicle you are working on (programming subscriptions are VIN specific), SPS will verify the vehicle/VIN you are working on. After SPS completes the verification, you will be directed to the screen shown in figure 2:

Figure 2

Highlight “K71/Transmission Control Module” in the “Select Controller” area. Then select “MCVM (Mechanical Characterization and Virtual Matching) Operations” in the “Select Function” area. Verify that the RPO code given coincides with the vehicle you are programming. Finally, be sure you select “Solenoid Data Characterization” in the “Select Programming Type” area at the bottom of the screen, and click “next”. The next screen will be the “MCVM (Mechanical Characterization and Virtual Matching) Operation Selection” screen (figure 3). Here you will be prompted to select what operation to be performed. In this case I chose “Replace Transmission”, as the unit had been replaced. Clicking “Next” will move you to the next screen (figure 4). Here you will enter the TUN (Transmission Unique Number).

Figure 3

Figure 4

This number can be found on a sticker on the right side of the transmission as seen in the “Transmission Identification Information” section of the screen. After entering the TUN and clicking “Next”, SPS will then begin the programming operation and prompt you when the process is completed. SPS seems to be user friendly regarding this process. I had no issues getting through it for the first time. At this point it is also recommended that the ECM (Engine Control Module) is updated to the latest calibration. The ECM on this particular truck happened to be up-to-date.

The next step in the process is to perform a “Fast Learn”. This clears all adaptive values in the TCM. Using your scan tool, follow the on-screen instructions precisely. Keep in mind that if at any time in the process, there is an interruption; you could experience a false neutral condition with the transmission. If this happens, you will have to disconnect and reconnect the TCM to correct the issue.

On the initial road test after installation, I experienced very minimal flaring during shifts. This flaring cleared up within a few miles of stop-and-go driving. This may vary from vehicle to vehicle. When rechecking the fluid lev-el, the transmission fluid level must be brought up to 194?F to ensure that the thermal bypass valve is open, if so equipped. Allow the fluid temperature to cool back down to 95-113?F. With the engine running, remove the transmission oil level plug from the transmission pan. At the correct level, fluid should drip from the check plug hole.

On the final road test, I monitored “TCC Slip Speed” and TFT (Transmission Fluid Temperature) with the scan tool. As you can see in (figure 5) the TCC slip speed is smooth and now normal. The TFT was stable as well. A post scan also confirmed that no codes reset.

Figure 5

Other than routine maintenance, this was the first major 8L90 issue we have dealt with. In the near future, I foresee many more 8L45/8L90 transmissions showing up. The torque converter issue we experienced on this vehicle is a problem that many dealerships have already encountered. Don’t be surprised to see these vehicles begin to show up at your shop, if they haven’t already.