cj.surr
Well-known member
I have had an AHU TDI swapped into a Volvo 240 for about 3 years now. I have tried several flywheel/clutch/transmission combinations without any great results. The main source of the problems seem to be a very strong harmonic resonation/vibration in the 1850-2150 rpm range (as well as lower RPM). It gets worse as load is increased, but is still noticeable on decel. It does not occur when free-revving the engine. It gets worse with increasing gear, with 5th gear being the worst by far. It is not at all a normal diesel vibration, it tries to shake the car apart, and you would not be able to hear the passenger talking at its worst point.
I'll go through the sequence of attempts.
Volvo M47 5 speed transmission with custom adapter (To be fair, the transmission pilot alignment was probably not within spec for this transmission)
Single mass flywheel + sprung hub clutch - Vibration is very pronounced
1.8t Dual mass flywheel + solid hub clutch- Vibration is mostly subdued (still noticeable), but dual mass flywheels do not last. All 3 (new) flywheels that I tried failed in less than 3k miles of gentle driving.
Toyota W56 transmission with DCS adapter plate (I chose this transmission because people have had good luck with it in Toyota trucks)
Single mass flywheel + Sprung hub clutch - Vibration is still very pronounced, no change from Volvo transmission
Tremec T5 transmission with custom adapter bellhousing (I checked transmission pilot alignment and it was within spec)
Euro market Sachs Dual mass for AHU 1.9t Audi A4 + solid hub clutch
- Vibrations similar to 1.8t dual mass. This flywheel has pretty much failed after 100 miles of somewhat hard testing/driving (spending a lot of time in the RPM trouble area)
This last attempt is really what has me baffled, since this dual mass was specified for my exact engine as it came in an A4. I feel that it must be an engine issue that is killing the flywheels since it is the only common denominator. Compression test looked fine. The engine has been running fine and I have put about 60k miles on this swap (mostly with single mass flywheels and avoiding the RPM zone that has issues). It has been getting good mileage and driveability is otherwise fine. I don't think the vibration has gotten worse at all over the course of 60k miles. The engine drove fine and smooth in the donor car before swapping it.
Compression test is fine
Cam looks fine
Other parts I have tried replacing without change:
Injectors
Driveshaft
Harmonic balancer (also tried fluid damper)
Engine mounts (currently using BMW M42 mounts, but I have tried a mk3 tdi rear mount without much change)
I have a spare very high mileage engine that I am considering swapping in just to try, but I have little hope for that effort. I am wondering if anyone has any ideas at this point, because I’m all out. Thanks for reading.
Here is a video of the excessive axial play on the A4 dual mass after 100 miles
https://www.youtube.com/watch?v=FRdsGXdXimU&feature=youtu.be
I'll go through the sequence of attempts.
Volvo M47 5 speed transmission with custom adapter (To be fair, the transmission pilot alignment was probably not within spec for this transmission)
Single mass flywheel + sprung hub clutch - Vibration is very pronounced
1.8t Dual mass flywheel + solid hub clutch- Vibration is mostly subdued (still noticeable), but dual mass flywheels do not last. All 3 (new) flywheels that I tried failed in less than 3k miles of gentle driving.
Toyota W56 transmission with DCS adapter plate (I chose this transmission because people have had good luck with it in Toyota trucks)
Single mass flywheel + Sprung hub clutch - Vibration is still very pronounced, no change from Volvo transmission
Tremec T5 transmission with custom adapter bellhousing (I checked transmission pilot alignment and it was within spec)
Euro market Sachs Dual mass for AHU 1.9t Audi A4 + solid hub clutch
- Vibrations similar to 1.8t dual mass. This flywheel has pretty much failed after 100 miles of somewhat hard testing/driving (spending a lot of time in the RPM trouble area)
This last attempt is really what has me baffled, since this dual mass was specified for my exact engine as it came in an A4. I feel that it must be an engine issue that is killing the flywheels since it is the only common denominator. Compression test looked fine. The engine has been running fine and I have put about 60k miles on this swap (mostly with single mass flywheels and avoiding the RPM zone that has issues). It has been getting good mileage and driveability is otherwise fine. I don't think the vibration has gotten worse at all over the course of 60k miles. The engine drove fine and smooth in the donor car before swapping it.
Compression test is fine
Cam looks fine
Other parts I have tried replacing without change:
Injectors
Driveshaft
Harmonic balancer (also tried fluid damper)
Engine mounts (currently using BMW M42 mounts, but I have tried a mk3 tdi rear mount without much change)
I have a spare very high mileage engine that I am considering swapping in just to try, but I have little hope for that effort. I am wondering if anyone has any ideas at this point, because I’m all out. Thanks for reading.
Here is a video of the excessive axial play on the A4 dual mass after 100 miles
https://www.youtube.com/watch?v=FRdsGXdXimU&feature=youtu.be