Top 10 Problems at Installation Part 1 - Transmission Digest

Top 10 Problems at Installation Part 1

Our company sells a large quantity of wholesale carry-out units in addition to performing in-house installations. We have a panel of technical advisers that provides guidance for both types of installations, and this article focuses on what we consider to be the top 10 issues that installers face today, based on the data we continually collect.

Top 10 Problems at Installation Part 1

R&R Tech

Subject: Common problems after transmission installation
Essential Reading: Rebuilder, Diagnostician, R & R
Author: Jim Stokes

R&R Tech

  • Subject: Common problems after transmission installation
  • Essential Reading: Rebuilder, Diagnostician, R & R
  • Author: Jim Stokes

Our company sells a large quantity of wholesale carry-out units in addition to performing in-house installations. We have a panel of technical advisers that provides guidance for both types of installations, and this article focuses on what we consider to be the top 10 issues that installers face today, based on the data we continually collect.

Number 1 – Software updates, clearing shift adapts and performing relearn procedures

Relearn procedures

Across the board, updating PCM/TCM software corrects more problems than anything else. It just makes sense that the OEM software may not operate the transmission as originally intended, and adjustments have to be made to correct problems. Where it gets tricky is when the factory doesn’t publish an update on a TSB to notify technicians that a change has been made. For that reason, the latest updates should always be installed when a replacement transmission is being installed.

Shift adapts

Shift-adapt strategies have been common for well more than a decade now. Whenever a transmission is rebuilt or replaced, the shift adapts must be cleared. As the previous unit was failing, the PCM/TCM would have been continually trying to compensate for the slipping or harsh shifts resulting from internal unit failure. A few years ago, disconnecting the battery would clear the shift adapts in most vehicles, but this is no longer the case. Often an OE factory scan tool is required. Many aftermarket scan tools have adapt-clearing functions, but the results are not always effective and the procedure may have to be redone with the factory tool.

As an example, we had a 2005 Mitsubishi Montero with a fresh reman unit installed that had a 1-2 shift flare and a harsh 2-3 shift. The installing shop had a new, top-of-the-line aftermarket scan tool that had a function test for clearing shift adapts. The technician had performed the shift-adapts clearing procedure prior to calling in the claim. After cleaning the MAF sensor and trying to tweak the TPS adjustment did not produce favorable results, we sent the installer a replacement transmission. The replacement unit had the exact same shifting problems, so we had the vehicle taken to the Mitsubishi dealer to have the shift adapts cleared. After the procedure was performed with OE equipment, the unit worked perfectly. We had a similar scenario involving a Toyota RX330.

Relearn procedures

After the shift adapts are cleared some units will function normally right away, but others must learn how to shift properly. Some also must learn how to engage into forward and reverse without excessive bump. There is a procedure known as “garage shifts” that involves engaging the unit into reverse five times at five-second intervals, and the same into forward. In some instances, this is all that’s required. The upshift relearn is normally performed with five to 10 shift cycles through all gears at 20%-25% throttle angle. Some manufacturers require more-complicated procedures, so some research may be required for specific vehicles.

Number 2 – Details in setup procedures

Throttle cables

Though these units haven’t been in OE production for more than a decade, they are still very popular:

THM 700R4, AOD

There is only one way to set up these units properly to shift correctly and survive, and that is with a pressure gauge. If you call in a claim on one of these units the first words you will hear from us are, “What is the pressure reading at factory idle speed?” If you don’t have the answer, I will request a call back with the information. This is a critical setting for these units, and use of a pressure gauge is the only sure way to get it right.

Most other types of units using a throttle cable are much simpler to set up, as they require only synchronized TV movement with the engine throttle. On the Chrysler RWD vehicles, make sure that there is a return spring on the throttle lever (at the transmission), or you will end up with harsh downshifts.

Range sensors/MLPS

The Ford Explorer equipped with the 5R55W/S transmission seems to have the most claims generated because of MLPS problems. The most-common symptom is delayed or no reverse engagement. In most instances this can be corrected with a simple adjustment of the sensor. Ford specifies a special tool used specifically for the adjustment, but some shops aren’t going to have access to one. A workaround is to monitor PID data on a scan tool. Using the scan tool, go to “live data” and find the digital-signal PID from the sensor; it is four binary digits. With the shift cable disconnected, shift to neutral at the transmission lever and adjust the switch to a signal of 0110, then shift to reverse and look for a signal of 1100, and finally to drive and look for 1111; if you don’t see these number sequences, replace the switch and adjust again. Shift back to neutral at the transmission and put the column lever in neutral, then adjust the cable so that it lines up exactly with the shift lever.

Honda units have a unique problem with their gear-position switches. Symptoms of problems with the switch can include no reverse, no forward upshifts, or neutralizing during acceleration from a stop. A common cause of these symptoms is the manual shift shaft getting damaged during the installation. The shaft is slotted to accommodate the switch actuator notch. The shaft can get pinched together during installation of the unit, and the switch cannot engage with the pinched slot. Figure 1 shows the shaft.

Number 3 – PCM/TCM

1993-95 GM trucks with 4L60-E/4L80-E transmissions

A common problem with these ECMs is high line pressure that generates customer complaints of harsh 1-2 shifts. Typically, line pressure will be 110-140 psi at factory idle speed and will rise to 160-170 with higher engine speed. This is normal pressure that occurs due to higher pump output caused by the increased engine speed. To diagnose a high-line-pressure condition, use an amp probe or meter hard-wired into the return circuit of pin D of the case connector at the ECM connector harness. Compare the actual amp reading with the scan-tool actual reading. Typically, if the ECM is faulty, you will see ammeter readings from 0 to 0.3 amp and scan-tool command readings of 1.0-1.1 amps. If the readings don’t match (as per this example), the ECM is the problem. Lately we have had some late-model 1997-2001 vehicles with the same problem, and the diagnostic process is the same.

722.6

We had a 2005 Sprinter setting several codes pertaining to GRE, solenoid electrical and performance, and speed sensors that was difficult to diagnose. We had shop ohm testing circuits and also load testing them with a headlight. This went on for about a week and a couple of calls a day without any progress. I was working on another problem vehicle when I found Wayne Colonna’s article “Coping with Capillary Action” in the June 2007 Transmission Digest. I immediately called the shop and had them remove the TCM from under the seat, and they found that it was full of fluid. We had them install a new TCM and seal the wire harness with solder, and the unit worked great after the repair. We still find this to be a continual problem with the Sprinter vehicles. We have seen TCM replacements also correct problems with GRE codes and no shifts past 2nd gear, though no fluid was found in the TCM.

2000-04 Jaguar S-type, 2000-03 Lincoln LS and Thunderbird

These vehicles can develop a pressure-control problem with complaints of harsh engagement, harsh up-shifts from 1st to 2nd, and 3rd to 4th, and harsh 2-1 coast downshifts. Pressure readings can be in the 170-psi range at factory idle speed. Idle speed is an important factor, as many of these vehicles have issues with high idle speed due to a faulty throttle body. Another common cause can be a bad PCM. To diagnose the PCM, an amp probe is the best tool for the job. If the actual readings measured with the ammeter on pressure-control solenoid A don’t match the PCM command, the PCM is faulty and will require replacement. The OE dealers usually do not stock these PCMs, and they are quite expensive. Some shops have reported successful repairs from independent repair facilities that have the ability and equipment to repair the PCMs internally and reprogram them to work properly. We don’t have the luxury of this service here in the Midwest, but on the coasts there are technicians in the business.

Toyota/Lexus

RAV4, RX300 series, Corolla, Matrix and Pontiac Vibe are having PCM-induced transmission problems, primarily around the 1999 to 2004 model years. The most-common issues involve the RAV4, and Toyota has issued T-SB-0156-10 that addresses the problem. A revised PCM part number resolves the shifting issues. The primary concerns involve the 2-3 shift with a bind-up, or a spin-up with a double bump. Lately we have seen several Lexus RX300-series vehicles with this same concern, but no published technical-information documents from Lexus address it. It doesn’t take very many shift cycles to damage the direct clutch in the transmission, and eventually the clutch fails. Replacing the PCM seems to be the answer, similar to the Toyota repair.

Jim Stokes is a warranty technician with Certified Transmission. He has been a service writer and diagnostician, has helped run stores and has been a part of the warranty team for almost 10 years.

You May Also Like

Dealing with the increasingly common pin-fit problem

I want to talk a little bit about a common diagnostic misstep or overlooked problem that is prevalent in the automotive repair industry and seems to be on the rise. Pin-fit or tension can deal us a fit sometimes (pun intended), especially if we do not have the proper tools to determine if this mode

RR-Tech-September-FIG-1-1400

I want to talk a little bit about a common diagnostic misstep or overlooked problem that is prevalent in the automotive repair industry and seems to be on the rise. Pin-fit or tension can deal us a fit sometimes (pun intended), especially if we do not have the proper tools to determine if this mode of failure might be the cause. I have a couple of case studies to share that I have seen recently, and will share some testing protocols that I have used over the years to attempt to correctly diagnose a related issue or a code. 

Watch: Replacing a transmission and components

Dave Hritsko and the team have already removed a full transmission in a previous video. This time, see an in-depth explanation of the parts, components, and steps in how they make the upgrade with a remanufactured transmission along with new aftermarket components with the help of students from Ohio Technical College. Related Articles – AMN

Removing-a-Transmission-with-Dave-from-Transtar-1400
Watch: How to remove a transmission

Watch Dave Hritsko from Transtar and team members from Ohio Technical College as they remove an old transmission and replace it with a newly remanufactured transmission. Related Articles – Watch: CVT modules and programming – Watch: CVT fluid diagnostics – Watch: CVT electric and communication codes

Back to square one: When a transmission replacement doesn’t fix the problem

The subject of this article is a 2002 Ford Ranger with a 3.0L V6 engine and 5R44E transmission. There were 191,622 miles on the vehicle when it arrived at our shop. The owner said that the transmission was not shifting correctly and the OD lamp was flashing. Related Articles – Shift of the shaft: Diagnosing

RRfeature-1400
The technician’s duty to the customer

I want to talk about some of the recent trends of particular cars and trucks that we see showing up at repair shops for work to be done. It seems to be a perfect storm of high used car prices, lack of new car inventory, and a bit of economic uncertainty that brings us to

rr-feature-1400

Other Posts

Diving into electrical testing and wiring with the 948TE

We had a 2014 Jeep Cherokee come into our Bellevue, Neb. facility with a transmission that would not shift. This all-wheel drive vehicle was equipped with a 3.2L engine and a 948TE nine-speed transmission. Related Articles – Diagnosing Ford 10R60, 10R80 and 10R140 series speed sensor issues – Jatco JF613E transmission quick reference material – Complete

RR-Tech-June-FIG-1-1400
Potential causes of an overheated transmission: It’s not always what you think

If a transmission starts overheating, the root cause must be something to do with the transmission itself, right? Not always. The following are a few examples where the transmission was not to blame. Related Articles – Think pink: Curtis Price strikes out on his own and has Liberty Transmission and Auto Care stand out from

A mysterious shudder: Locating a problem with no fault codes

It was a dark stormy night… well, not really; it was just an ordinary Tuesday. Related Articles – Spotting different 68RFE designs through the years to avoid issues – Valve body and component suppliers: A comprehensive list – Shift Pointers: Failures caused by incorrect tire sizes On that ordinary Tuesday, a customer came into our

RRfeature-April-23
TCM trouble and the importance of being certain about parts replacement

It’s a tale as old as time. A vehicle comes in and, despite having been recently repaired by another shop, the vehicle owner’s concern is still present. In the case of this story, the vehicle came from a local shop we work closely with. The truck in question is a 66,000-mile 2006 Chevrolet Silverado 2500

RR-Tech-March-FIG-1-1400