It started with some oil leakage …
We already knew that our 42 year old camper leaked here and there. Lately it got a bit out of hand and with a view to the upcoming APK (periodic vehicle inspection), it seemed wise to solve this. The gaskets we ordered straight from the U.S. Once on the bridge, My friend Decio (a hell of a mechanic), started to dismount a few things. Decio owns a garage with his expertise in USA cars. His bridge has 7.5 lifting capacity. Because most leaks were already localized, the job seemed not that big.
But then it came… one leak had to be checked and for this the main pully disc, had to be removed. We were shocked when we noticed that the pully could be moved back and forth, even tough everything was still attached to the crankshaft. This was bad news!!! There was axial play in the crankshaft. This in itself does’nt have to be problematic, however >4mm is way to much. The block had to be removed so that we could see what caused the play.
There are various ways to get a V8 engine out of a GMC, but believe me … in all cases its a hellish job. Decio opted for a somewhat unconventional method. After I had covered the interior with plastic, he removed the engine, the transmission and the differential.
Soon it emerged that the crankshaft could not be saved. There were too deep grooves worn in to the vertical contra weights, so the middle bearing could no longer hold the crankshaft in place. We ordered all new U.S. parts again. A complete crankshaft kit, camshaft, piston rings, gaskets, various bearings (also for the transmission and the differential). I kept myself busy with cleaning everything and took every part inside out. I cleaned all housings of the engine block, incl. heads, exhaust manifolds and the differential and sand blasted all outside surfaces. Everything came out as new so I sprayed several layers of heat-resistant transparent clearcoat on them. Decio was involved in assembling and reassembling all parts.
After a while everything was ready to be put back under the GMC.
We placed a provisional hoisting bar with hoist inside the GMC above the hatch. This was a huge help during the replacement of the approximately 350 kg heavy engine. After everything was back in place, we still had 2 days to test. We let the engine run for about 6 hours to see if everything was tight and right. That night I slept in our coach at the garage yard, after working until 02:00 to get the motorhome ready for inspection.