Hello all,
Just discovered the crankshaft in my 1970 FJ40 is broken. Heres the background:
1975 2F swapped in before I bought the truck five years ago. Previous owner said engine had been rebuilt recently. I had no reason to doubt him. Engine was very clean, ran great, and didn't leak or burn oil. Then I put in an SM465 and new clutch about two years ago. Probably put 20k miles on it in total, with 7-8k of that with the SM465. No problems...until a few weeks ago. Had started to notice a very faint ticking/tapping that was rpm dependant. Noise was coming from transmission tunnel area. Was so faint I couldn't tell if it was actually a noise or just my imagination. Got ever so slightly louder, but still not loud enough for my car-ignorant wife to notice. At first I thought throw out bearing was riding on clutch fingers all the time and making noise. That wasn't the prob. Stayed same volume for a week or so, then got louder, and definitely noticeable one day on way home from work. At that point I knew something was wrong, not just a throw out bearing or something similar. Close to home, pulling away from a stop light, I hear/feel a terrible sound like Godzilla gargling metal bowling balls. I shut motor off immediately and coast into parking lot. Call wife and have her tow me home with our FJ62.
Once home, I pull clutch cover and look/feel around. All clutch stuff looks fine. Then I grab the flywheel. I can rotate it back and forth a degree or so. At this point I'm thinking loose flywheel bolts. Remove trans/tcase and clutch expecting to find partially-backed out flywheel bolts. Nope, solid as the day I torqued them when I installed the new clutch. I all but know the real problem now. Drop oil pan, rear main cap, and rod #6 cap. There it is, big, nasty break, right through rod #6 journal. #6 rod bearing is all chewed up. I cut the oil filter open and the upstream side is dusted with non-magnetic bearing debris, as is the bottom of the oil pan.
Now I have a few questions. First and most obvious, what caused the break? I drove it gently and kept clean oil in it. One might expect this from a race engine, but not a gently driven 2F. I'd hate to replace crank then it break in another three years. However, I know there are a ton of 2Fs around with a ton of miles on them so this must be pretty uncommon.
Does SM465 have something to do with it? Wouldn't think so.
Now shopping for 2F crankshafts. What year range of cranks fit? Are any 2F crankshafts different than any other years?
Guess I know my project for the next few weeks/months.
Stephan
Just discovered the crankshaft in my 1970 FJ40 is broken. Heres the background:
1975 2F swapped in before I bought the truck five years ago. Previous owner said engine had been rebuilt recently. I had no reason to doubt him. Engine was very clean, ran great, and didn't leak or burn oil. Then I put in an SM465 and new clutch about two years ago. Probably put 20k miles on it in total, with 7-8k of that with the SM465. No problems...until a few weeks ago. Had started to notice a very faint ticking/tapping that was rpm dependant. Noise was coming from transmission tunnel area. Was so faint I couldn't tell if it was actually a noise or just my imagination. Got ever so slightly louder, but still not loud enough for my car-ignorant wife to notice. At first I thought throw out bearing was riding on clutch fingers all the time and making noise. That wasn't the prob. Stayed same volume for a week or so, then got louder, and definitely noticeable one day on way home from work. At that point I knew something was wrong, not just a throw out bearing or something similar. Close to home, pulling away from a stop light, I hear/feel a terrible sound like Godzilla gargling metal bowling balls. I shut motor off immediately and coast into parking lot. Call wife and have her tow me home with our FJ62.
Once home, I pull clutch cover and look/feel around. All clutch stuff looks fine. Then I grab the flywheel. I can rotate it back and forth a degree or so. At this point I'm thinking loose flywheel bolts. Remove trans/tcase and clutch expecting to find partially-backed out flywheel bolts. Nope, solid as the day I torqued them when I installed the new clutch. I all but know the real problem now. Drop oil pan, rear main cap, and rod #6 cap. There it is, big, nasty break, right through rod #6 journal. #6 rod bearing is all chewed up. I cut the oil filter open and the upstream side is dusted with non-magnetic bearing debris, as is the bottom of the oil pan.
Now I have a few questions. First and most obvious, what caused the break? I drove it gently and kept clean oil in it. One might expect this from a race engine, but not a gently driven 2F. I'd hate to replace crank then it break in another three years. However, I know there are a ton of 2Fs around with a ton of miles on them so this must be pretty uncommon.
Does SM465 have something to do with it? Wouldn't think so.
Now shopping for 2F crankshafts. What year range of cranks fit? Are any 2F crankshafts different than any other years?
Guess I know my project for the next few weeks/months.
Stephan
