Hapy Engine-Transaxle Dropped

Around the concrete work, I ordered a replacement flywheel, clutch and pressure plate from Kennedy Engineering for Hapy (TDI-powered 1972 VW camperbus). The flywheel entered fabrication early last week, so I spent part of the Independence Day weekend dropping and separating the engine and transaxle not-in-a-shop for hopefully the last time. Today's post covers the drop and separation; it took 10 hours spread across 2 days.

 

How Did We Get Here

hockey player smile

I have been queuing this most recent engine drop for over a year. Recall all of the starter swaps I have made in hopes of solving the intermittent starting issue. And, I replaced the starter adapter hoping that was the issue. Nope and nope. The flywheel had suffered sufficient incomplete meshing of the starter gear with the flywheel's ring gear, chipping teeth and wearing down others. During my research, I learned that oftentimes (not always) engines will tend to stop running at the same spot in their rotation. So, if the circle is 360 degrees, the engine will stop most of the time at the same point. I know that seems counter-intuitive when you assume an engine is a well-balanced smooth machine, but the 4 cylinders and the 4 steps in the combustion cycle create a frequency, if you will, that for some engines means that when you kill power it will naturally stop at the same point. In those cases, you would think having a complete ring gear is unnecessary, right? I mean, if you only ever use 15 degrees of gear, why have 360? Ok, in re-reading this, obviously you need an entire gear for the starter to spin the engine. LOL.

 

I found on my flywheel there was one spot in particular which was especially bad and 3 other spots which looked like there was wear, but not so much that the starter was really having trouble. This would explain why all the other times I looked at the flywheel I could not see an issue. The starter was not on the really bad spot, just one of the not-so-great spots. When I was unable to get the engine to start on the first try, but I got the gear-on-gear sound, I think I was starting on one of those spots. Inevitably, the engine would eventually land on the really bad one, and the sound would change from gear-on-gear to gear-in-the-air. 

 

Continuing this nonsensical thread, the TDI engine's flywheel can only fit on the engine one way, based on the bolt pattern. If there were any way I could have retained the flywheel and simply removed and re-installed it so that the really bad spot was in one of the zones where the teeth are never facing the starter at dead-stop... I would have. I mean, this flywheel has lasted 15 years of starting issues and abuse and for the most part it's fine. Well, fine except for the 1 big chunk that's missing and some other kinda-worn spots.

 

Getting Down

So, we enter Saturday, July 5th, the traditional first day Pacific NorthWest summer, tools in hand, blues festival on the radio, ready to get after the engine drop. To prepare, I re-read the last engine drop I can remember doing on this bus: to swap the transaxle from the original 002 to the AA Transaxle (Seattle) 1975 CM 002 transaxle. I did that on Labor Day 2012 in my real estate agent's driveway (See Transaxle Transition). It took 1 day to get the engine/transaxle out and separated. It took 1-1/2 days to get the new transaxle mated and the whole operation installed. I figured I would have a similar path, but my real estate agent's driveway was flat and smooth. The square of concrete outside my tiny garage is neither flat nor smooth. Quite the opposite, actually, it slopes away from the garage slightly and it has massive deep cracks in it. Like 2 or 3 inches deep cracks where blocks of concrete are lower/higher than the section next to it. This makes moving an engine on a jack much harder.

 

air disconnected

High level, my plan was to not raise the bus, and to only remove that which was necessary to allow me to separate the transaxle from the engine (and the bus) so I could do a clutch service with a flywheel swap out. So, I chocked the front tires and got after it. I started with the easier stuff: disconnect the air side first (cold air/filter to intake, unplugging the AFM and a vacuum line, then removed the charged air from turbo to intercooler). Then, the 13mm nut/bolts on the exhaust side of the turbo and removed the exhaust. Since I did not have to really move the engine other than up and down, I chose to leave the coolant related systems alone other than disconnecting the overflow bottle to prevent tension on the hoses. I made the same decision wit the fueling system, and chose to only disconnect the large filter, again to eliminate potential tension on the fuel hose. Last thing on the engine was to disconnect the battery and the 12V exciter from the alternator.

 

Shifting to the transaxle, I set a small jack under the center of the ribs and started removing things. First, I removed the CV joints and stuffed the greasy bits into plastic bags held on with rubber bands. The clutch cable and the mount for the bowden tube were next. Once free, I disconnected the shifter at the front of the transaxle, the grounding strap near the front and finished with the nose mount. At this point, the only things connected to the engine/transaxle I needed to address were the rear engine mount and the main carrier mounts.

 

simple coolant solve

I located and set the engine cradle on the ATV jack and supported the engine while I removed the rear mount and the tower between the support bar and the mount. With the engine supported, I removed the 2 bolts which attach the top of the bellhousing to the main center carrier.

 

Well, Now Its Down

This was all I thought I had to do to drop the engine. When I read the old steps, this was how far I had to go. Since then, however, I added the rear sway bar and it was set such that removing and then re-installing the transaxle was going to be more difficult. I removed the 4 14mm nuts that held the middle of the bar to the frame and it swung down far enough for the transaxle nose to clear. But there was not enough room for the shifter linkage above the side-to-side main support to clear. The engine needed to move backwards a couple of inches. So, I removed the rear engine support bar. In retrospect, I realized that I had removed that bar last time too. Now, I could pull the engine far enough back to get the transaxle off of the engine, rotated and then onto the ground. Sitting on cardboard, I pulled the transaxle out the driver side. I regret not taking a picture of the inside of the bellhousing, but it had so many little metal flakes (from the flywheel). I shot the bellhousing with brake cleaner and then, after I had wrapped the cv-joint mount points with plastic film, I shot the whole transaxle with de-greaser. I hosed it off and let it dry in the sun. While I had the de-greaser out, I cleaned the rear engine support bar too.

 

Pressure Plate and Flywheel

jack on crack

Now, I was basically ready for a clutch job. The pressure plate came off with little fanfare. It looks like its in great shape. The clutch still has most of it's friction material, so in a pinch I could probably reuse them. I got new replacements for both, so I may retain them for an emergency. Honestly, after 12 years of running this clutch and still have that much friction material left, I figure I may not have to replace this clutch ever again. I did notice a couple of spots on the flywheel which had a slight blue-ish hue, though. That's usually a sign that the clutch got hot and sticky. Something to think about. Maybe going with the stage 1 clutch this time rather than the stock pre-1972 VW bus clutch was the right call after-all, and the old clutch/pressure plate are not worth keeping.

 

Last, I had to pull the flywheel. Fortunately, I have a flywheel lock for old VW's and since this is a 200mm flywheel designed to fit inside a 002 transaxle, the lock fit. I could not get good leverage lying on my back under the bus so I smacked a rubber mallet against the end of a ratchet to pop the torqued bolt. All 6 came out without too much trouble. Applying a torque wrench on install will be interesting. Because of how snug the flywheel mates to the engine output, I needed to work the flywheel off with a small prybar. Once on the ground, I could more clearly identify the really badly worn spot (pictured above), but the other spots did not look as bad. Perhaps, once I have the new one to compare, the damage on this flywheel will be more apparent.

 

Conclusion

no downhill roll please

That's as far I've been able to get. I am still waiting for the flywheel, clutch, pressure place, throw-out bearing, etc. It took me most of 2 days to get to this point, so I expect the re-install will be similarly extended from 1-1/2 days to maybe 3. It is interesting to see how an uneven surface and 12 years of personal aging can slow a process down. The sway bar and engine support bars each represented maybe an hour of extra work, so I can't attribute it to them. This is probably really about me getting slower and the work location making everything that little bit harder.

 

For those tracking on the shop construction, we may be falling onto their schedule as early as the end of next week. Fingers crossed, I may have a structure before I have Hapy back in one piece. 

 

Anyway, that's it for today. Thanks, as always, for following along-