Volvo Archives - Transmission Digest
TF80SC Gen 1 2-3 flared shift

The complaint A 2005 Volvo XC90 equipped with the TF80SC Gen 1 transmission has a complaint of a 2-3 flared shift. During the overhaul process a brand-new valve body from the dealer was installed, only to find on the initial road test that a 2-3 flared shift still existed. The adaption procedures were performed but

Volvo I-Shift Gearbox Actuator Service Kit

The gearbox actuator kit from TransTec services the Volvo I-Shift (Generation A-F) Gear Changing System Lip Seals. This kit includes the Lip Seals to service the Range Cylinder, Cylinder 1/R, Cylinder 3/2, and Split Cylinder. Popular Volvo gearboxes covered include AT2412C/D, AT/ATO2512C, AT/ATO2612C/D, AT2812C/D, and ATO3112C/D.

Volvo I-Shift Gearbox Actuator Service Kit

This new kit from TransTec services the Volvo I-Shift (Generation A-F) Gear Changing System Lip Seals. This kit includes the Lip Seals to service the Range Cylinder, Cylinder 1/R, Cylinder 3/2, and Split Cylinder. Kit #49425348 is in stock and ready for immediate shipment, says the company.

Testing the Speed Sensors in the AW55-50SN Transmission

A 2002 Volvo S60 arrived at our shop with two codes in the TCM: 0023 “Transmission input shaft speed sensor signal missing” and 0089 Transmission input speed sensor, signal too low.” The vehicle was in “limp-home mode,” which allows the transmission to be operated in 3rd and 4th gears only and with high line pressure. The customer had bought the vehicle with these conditions and did not know its history. Visual observation showed that someone had spliced into the speed sensors (Figure 1) and had replaced the transmission with a used one.

The Importance of Proper Testing

We can all agree that testing today’s transmissions can be more complicated then it was 20 years ago. We have to deal with more electronics and hydraulic design, not to mention programming of the transmission control module by the design engineers. Proper testing procedure and testing equipment become a necessity.


The ASM Handbook on Fatigue and Fracture (Figure 1) defines fretting as: “A special wear process that occurs at the contact area between two materials under load and subject to minute relative motion by vibration or some other force.”

Fretting wear is usually associated with electrical contacts rather than non-electrical things, but fretting and fretting wear occur with both.

Included in the Quote

Let’s look at an example of what I’ve discussed. Let’s say that you were working on a 2001 Volvo V70 XC AWD, with an AW55-50SN transmission, and the vehicle had been towed in because it suddenly quit moving. You discovered that the transmission had a problem in the final-drive area but you found no other issues. All the clutches were like new, and there was no obvious wear in the valve body etc. That being said, the transmission was probably operating normally just before the final-drive component failed.

Adjusting Clutch-Control Valves on the Aisin FWD 6-Speeds

Have you ever installed a TF80, TF81 or TF60 after overhaul and it has had harsh shifts or engagements, or maybe there has been a flare/bump upshift or harsh coast-down clunks? Most times, clearing the shift adapts and driving the vehicle to relearn the shifts will correct these annoying problems. After a good, long test drive to relearn the shift adapts, sometimes a shifting or engagement problem remains. Assuming that there is not excessive wear in the valve body and the linear solenoids are good, the clutch-control valves on the valve body can be adjusted to correct these problems.

Understanding the AW 55-50 Neutral Control

A 2001 Volvo S60 come into or shop with a smoked AW 55-50 transmission that needed to be replaced.

The AW 55-50 transmission has a feature that Volvo calls “Neutral Control.” What is “Neutral Control” and what is its function? To tell you the truth, I wasn’t really sure, but below is what I was able to both find and figure out about it.

Let’s Talk about Adaptive Shift Strategy

The 604 was the first American computer-controlled transmission with adaptive shift strategy. The relearn process was not much different from what it is for today’s transmissions. For those of you who were not in the transmission industry back then, there was no quick-learn procedure for the 604. The quick-learn feature was not available until the mid-’90s. You actually had to drive the car at different throttle openings to relearn the shift adapts, and it could take 30 minutes or more of driving time to get it right.

4T65-E Valve-Body and Channel-Plate Identification

Let’s start with the valve body. Unfortunately, there are no casting numbers on the 4T65-E valve body for quick identification. The four most-common 4T65-E valve bodies are the early GM, late GM, early Volvo and late Volvo. There are more than four variations, and they can be found during the crossover years of 2002 and 2003. There are four questions that you need to answer to properly identify the valve body.

AW55-50: No Reverse; 09G/09K/09M: No Movement

I recently received a phone call from a shop that was working on a 2001 Volvo with an AW 55-50 transmission. The vehicle would not move when shifted from Park to Reverse. If the selector was first put into Drive then moved to Reverse, engagement was normal. The manual linkage was checked, confirming that the manual valve was in the reverse position.