Went ahead and stripped the 6.0 block all the way down today. Checked the crank, and it had about 1/8" of longitudinal movement, pulled all the main caps out and found that the thrust bearings had worn pretty well on one side. Also found that one of the #4 main bearings didn't look so good. Problem solved I guess....I'll take some pics later.


BTW....any trick to getting the timing gear off the crank snout?

 

Getting that damn gear off is a PITA. What use is a two jaw puller that I ground the back of the jaws so it could slip in between the gear and block and use a propane torch to heat the sleeve up to help come off easier.

 

that's one of the easier ways to do it. if you have an acetylene torch you can heat the snout up pretty good and tap it off with a ball pin hammer too. or you could just buy a new timing gear lol

 

that's how i lost my 5.3 thunder...thrust bearing. 1/8" of play. Ran like a champ 3 days of the week, like holy hell another 4 days. Finally it ran like crap all 7 days. Found the shavings finally, pulled the pan, hello balance blocks hitting the walls. ugh. A local trans guy figured it out, i kept loosing trans pumps and then took it to a different trans guy.

 

What causes it?

Here's some pics. The good side of the thrust bearing vs the bad side, and a pic of the front counterweight on the crank, looks like it hit the front wall too. Also the #4 bearing looking pretty crappy.

 

I am glad that you found out what it was. I just hope mine will last me some time. I do not have the money to build me something. But i am wondering if I have something going around in the crank as well. So now that you found out what it was, what do you think caused it?

There are two scenarios were I think mine started doing this I ran a little to much timing or it was when i switched to synthetic. I am really leaning to the synthetic. I would definatly consider this since you said that you switched to it and not long after you started to have problems.

 

That might be it, but why would running synthetic cause a problem like this?

 

Well from what I understand synthetic likes to clean the inside of and engine. and if an engine has sludge built in it it will tighten things in their if you will. This usually happens with regular oil at least that is what we think.... But when you run synthetic it likes to clean areas and it makes things come loose. So now you have a rotating assembly that is not as well torqued as it once was.

I really dont know the whole idea of this oil but it seems that this is on belief, idea, thought or whatever you want to call it to make people not use it. I personally am not going to use it again. I am sticking to the regular old stuff. There is a guy on here that said he use to work for craftsman trucks series and all they ever ran was regular oil and nothing fancy. Hell if they do I will do it.

No more synthetic for me.

 

Interesting....I probably won't run it again either then.

You gonna be around on the 15th & 16th or 22nd & 23rd? I think I'll be down building the motor one of those weekends.

 

Well that would explain why some of the pieces looked like brg material and some didn't but were magnetic. The hard backing was eaten into as well. Well at least you know. When you start producing serious power the thrust brg geats a larger amount of load. If you did some agressive driving while towing something heavy it would accelerate the wear on the thrust brg. Also, just a thought, I know you've had the tranny out before there could possibly have been a dimension issue with the converter being too long (I guess you would say) and pushing forward against the flywheel and crank. Sometimes the centering collar (on the torque conv) that goes into the rear of the crank is kind of tight. Maybe it was too tight on yours and never fully seated and was pushing forward on the crank?