| You are driving down the interstate on the way to | | | | torque converter. |
| visit an old friend. While you're listening to the radio | | | | Here's the nuts and bolts technical explanation of the |
| and enjoying the open highway you suddenly feel | | | | root causes: ZF and Audi's original converter design |
| something a little strange, perhaps like a slight engine | | | | utilized two rubber seals inside of the torque |
| surge. It does not happen again over the next half | | | | converter that were of questionable quality. |
| hour or so- you dismiss it as your imagination. | | | | The two seals are responsible for sealing the |
| A little further along in your journey, you feel it again- | | | | hydraulic pressure that allows the torque converter |
| this time it is accompanied by your check engine light | | | | clutch to engage and hold. One of the seals is a "lip" |
| illuminating. You feel a bit concerned, but the car isn't | | | | type that seals on the transmission input shaft and |
| driving too badly, it just has this very occasional odd | | | | the other "o" ring type seal seals against the piston. |
| engine surge. Naturally, you decide to have it checked | | | | The material originally used was not up to the task |
| as soon as you get to where you are going. Here's | | | | when it came to dealing with the tremendous heat |
| what may be found... | | | | and pressure that occurs inside of a torque |
| As Audi's A4 and A6 models are starting to become | | | | converter. Although Audi did release a second design |
| a few years old, there are few problems that are | | | | input shaft lip seal, failures have been observed with |
| being experienced with their transmissions. By far, the | | | | those as well. |
| most common problem that is being seen at this | | | | When the hydraulic pressure that is required to allow |
| point in time is an issue with the transmission's torque | | | | converter clutch application cannot be contained |
| converter. | | | | because of the faulty seals, the clutch will start to |
| The problem typically starts with a check engine light | | | | slip and usually destroy itself before too long. |
| coming on. While sometimes the actual drivability | | | | When looking for a replacement converter to |
| symptom is subtle, your vehicle's computer is able to | | | | purchase from a remanufacturer, it is often helpful to |
| detect it by comparing engine RPM with transmission | | | | ask them a few questions about their rebuilding |
| input shaft RPM. | | | | procedures. |
| Often times, in addition to the light coming on, one | | | | First off, you will want to find out if they are installing |
| will also notice an increase or fluctuation of RPM's at | | | | the latest design level seals as part of their torque |
| speeds above 45 miles per hour or so. | | | | converter rebuild- using original type seals will work |
| If access to a scan toll is available, either a VAG or | | | | for a while but will eventually lead to another |
| Snap-on type with the correct European vehicle | | | | premature failure. There now aftermarket |
| software, codes can be retrieved from the vehicle's | | | | replacements for these components that seem to be |
| computer in most cases. | | | | far superior to the factory parts. |
| Some of the codes that are normally found in the | | | | Secondly, you will surely want to ask if the clutch |
| system include a code 18032 which is a MIL light | | | | itself is getting replaced. Believe it or not, this is not a |
| request. This code simply means that the vehicle's | | | | given with some suppliers. The clutches in these |
| computer has detected a problem and has illuminated | | | | particular units are of a multi-disk configuration. |
| the malfunction indicator light to let the driver know | | | | Replacing this entire multi disk set up is quite labor |
| that something is amiss. This is a not so subtle | | | | intensive and requires not only special tools but also a |
| warning to get the vehicle checked out. | | | | high level of skill- make sure your converter rebuilding |
| The next two codes give a better indication of what | | | | company has both! |
| the problem actually is. The first code that is often | | | | Naturally you will also want your rebuilder to replace |
| seen is a code 17125- torque converter clutch circuit | | | | any other components that normally wear out such |
| performance. This code is set by the computer | | | | as washers, bearings, one way clutches, and spline |
| commanding converter clutch application but not | | | | inserts. Most of the quality converter manufacturers |
| seeing the appropriate drop in RPM that is associated | | | | will also pressure test and dynamically balance the |
| with proper converter apply. Quite simply, the torque | | | | unit once it is in the final stage of the rebuilding |
| converter's clutch is slipping. | | | | process. |
| The second code that is usually observed is an OBD | | | | Taking the time to find out that the job is getting |
| P0741- torque converter clutch stuck off. Similar to | | | | done correctly is absolutely critical. As with any type |
| the previous code, excessive converter slippage is | | | | of rebuilt or remanufactured automotive component, |
| seen by the vehicle's computer. This code, however, | | | | there can be varying levels of quality. With over 11 |
| usually results in the computer disabling the converter | | | | hours of labor involved in removing and reinstalling |
| clutch's application altogether in an attempt to | | | | your A4 or A6's ZF5HP19 FLA transmission to replace |
| protect the transmission from further damage. All of | | | | the converter, it is surely a job that you will not |
| this is usually going to require replacement of the | | | | want to do or have done more than once. |