Looking ‘Outside the Box’
My first encounter with a Nissan CVT was an interesting experience. Our wholesale customer had diagnosed the transmission as being bad, so the transmission was then replaced. After replacement, the vehicle owner said the car would not accelerate beyond 40 mph. Since the installed transmission was purchased from us, it then became our responsibility to find the root cause of the problem and get the transmission working properly. We verified the customer’s complaint with the initial road test and then began diagnosing the cause.
Information, Equipment & Experience
When a vehicle comes into your shop for repair you need to determine whether you have access to service information, the equipment needed to make the repair and the experience to repair it. As you read this article you will see just how challenging a transmission replacement sometimes can be. In this particular situation the service information was misleading and special equipment was needed to make the repair. This was one job that turned into yet another learning experience for me.
Saturn VT25-E Ratio Error
A 2005 Saturn Vue experiences erratic ratio control (gear position) and ultimately sets a trouble code P1882. Once the code is cleared, the transmission starts to shift again, for a short time. The code then reappears and the unit returns to a fixed gear position.
After it was determined that the issue was not computer related or valve-body/solenoid related, the transmission was removed and disassembled. Damage was found in the drive variator (pulley), and there also was seal damage.
CFT30 Variator Repair
Today’s CVTs are a fact of life because of the number of them on the street. In addition, the flavors (variety) of CVTs have also increased.
One of the more popular CVTs being rebuilt today is in a now-defunct vehicle, Saturn, whereas other CVTs are used by Nissan in vehicles like the Murano. The Nissan CVTs are produced by Jatco, which is the dominant CVT manufacturer in the marketplace today. Jatco has recently released a variation of a CVT that actually has an auxiliary gearbox, making it a partial step-type trans. It almost seems like a “step” backward from a pure CVT.
CVTs – Do I Rebuild Them or not?
The question of whether to rebuild a continuously variable transmission (CVT) has increased dramatically this past year on our technical hotline, and I thought I might risk making a few comments about this subject.
The call comes to our technical hotline a few different ways. The question has been: “Why are people saying you cannot rebuild CVTs?” or, “Is it worth trying to rebuild one of these” or, “What am I getting myself into if I try to rebuild one? What tools do I need?”
My answers to these questions follow.
01J CVT: Diagnosing and Repairing Code 17090
A 2003 Audi A4 with an 01J continuously variable transmission (CVT) came to our shop. The customer complained that the vehicle was sluggish in forward and had no reverse and that this would take place only when all the lights in the gear indicator “lighted up and flashed.”
The Bucking Audi
The continuously variable transmission (CVT) used in Audi’s A4 and A6 vehicles, called the 01J or Multitronic, could show up in your shop with a bucking complaint. This style of CVT (see Figure 1) does not use a fluid coupling as a pass-through device for engine torque input. This means that when the vehicle is engaged or comes to a stop in gear, the forward or reverse clutch must slip. When the brake is released and the throttle is depressed, the clutch applies and the drive and driven pulleys begin to move in relation to each other to provide gear ratios.
It’s an Inside Job
The 2003-and-up Audi A4 and the 2002-and-up A6 with a 1.8- or 3.0-liter engine use a continuously variable automatic transmission known as the Multitronic® 01J (see Figure 1) and also referred to as the VL300. The core of this article is not that this transmission is a CVT. The focus is on what’s inside the transmission other than the drive- and driven-pulley set.
