So I tore down the engine completely in my 1980 X with less than 40k original miles because of a deep gouge on the block surface on the head gasket sealing surface of cylinder #3. When I started pulling it apart I found half of the thrust ring wedged in a small portion of its groove in the crankshaft (I found the other half in the oil pan in remarkably good condition).
I laid everything out in order in the following pictures, so here's the quiz:
What is wrong with the main bearing caps in this first picture?
Still stumped? Here's another clue, look at the main bearing journals in the block (labeled in order of the caps)
Okay, if you haven't figured it out by now, if you look closely at the picture of the main bearing caps, laid out in the order they came off, you'll see that some intrepid Fiat engine assembler, probably anxious to get home on Friday, REVERSED the main bearing caps #4 and #5. (If you look REAL closely, you can even see the 4 dimples on the #5 main bearing cap) This left nothing to hold the lower half of the thrust ring in place, causing it to fall into the oil pan, with the upper half of the thrust ring rotating around and almost falling out with just a tiny bit of it still in its groove in the crank. If you look at the crank journal pictures (and the main bearing cap pictures) you'll see there was no wear on the thrust ring area of the block nor the incorrect main bearing cap. Instead, the crank moved forward everytime the clutch was pushed in and rode the back portion of the #1 and #2 main bearing journals and caps. I have all the paperwork from the original owner and this must have been a problem almost immediately because they had the car in within the first 1000miles complaining of a low clutch pedal which was fixed by what the dealership described as a clutch actuating rod extension. Thankfully, this answers alot of my questions of this strange piece on my clutch actuator rod that I need to use to adjust the clutch and also the noticible drop in RPMs when the clutch is depressed. The good news is all the main and rod bearings, as well as the cylinders and pistons look in good shape with little wear. I'm going to Plastigage them tomorrow to verify before I take the block to the machine shop to have it decked. Wow, it's a good thing I decided to tear down the block!
Dave
I laid everything out in order in the following pictures, so here's the quiz:
What is wrong with the main bearing caps in this first picture?
Still stumped? Here's another clue, look at the main bearing journals in the block (labeled in order of the caps)
Okay, if you haven't figured it out by now, if you look closely at the picture of the main bearing caps, laid out in the order they came off, you'll see that some intrepid Fiat engine assembler, probably anxious to get home on Friday, REVERSED the main bearing caps #4 and #5. (If you look REAL closely, you can even see the 4 dimples on the #5 main bearing cap) This left nothing to hold the lower half of the thrust ring in place, causing it to fall into the oil pan, with the upper half of the thrust ring rotating around and almost falling out with just a tiny bit of it still in its groove in the crank. If you look at the crank journal pictures (and the main bearing cap pictures) you'll see there was no wear on the thrust ring area of the block nor the incorrect main bearing cap. Instead, the crank moved forward everytime the clutch was pushed in and rode the back portion of the #1 and #2 main bearing journals and caps. I have all the paperwork from the original owner and this must have been a problem almost immediately because they had the car in within the first 1000miles complaining of a low clutch pedal which was fixed by what the dealership described as a clutch actuating rod extension. Thankfully, this answers alot of my questions of this strange piece on my clutch actuator rod that I need to use to adjust the clutch and also the noticible drop in RPMs when the clutch is depressed. The good news is all the main and rod bearings, as well as the cylinders and pistons look in good shape with little wear. I'm going to Plastigage them tomorrow to verify before I take the block to the machine shop to have it decked. Wow, it's a good thing I decided to tear down the block!
Dave
Last edited:
