My 1HDT has about 250k miles on it. I've put about 55k of that on it. In that time I have run 3 sets of BEBs on the truck. Always the same pattern: The bottom halves look fine and the top halves are hammered out a bit.
It took me until I just put the 4th set on to be absolutely sure that the fresh ones are always DEAD silent. But within maybe a thousand miles or so they start to click noticeable. Not a knock, but subtle click in the right rpm range (about 1750-2250). It's worst around 2000rpm, like catching a resonance. After they reach their peak clicking volume at a couple thousand miles, they stay at that volume and never get worse. I had one set in for about 35k miles and it wasn't any louder at the end than after 2000mi.
First set I put on were Taiho STD one-size. I plastigauged those going in (dry with the engine out of the truck) and they were in spec. Several thousand miles after they went in, I had an issue where my injection pump was over fueling slightly and I ended up checking the BEBs and they were now on the wide end of spec. So I swapped them with OEM numbers matched to the crank/cap. Plastigauged those (possibly not with the crank journals SUPER clean of oil, but wiped at least) and they were all in spec.
After that it got another set of OEM matched numbers. I didn't Plasti these. I didn't see the point. Last month I put in a set of ACL Race (STD one-size) and they went from DEAD quiet to just starting to make some light clicking now. So now I'm positive that this is what that clicking is. The last few times I did so much other maintenance at the same time that I couldn't be sure what changed the noise exactly.
So what now? I'm at a bit of a loss here. I am debating getting a set of 0.025mm ACL bearings and Plastigauging them to make sure they're not too tight. I'm not in a position to pull the whole crank to mic the caps with them closed and the bearings in them.
Thoughts? Advice?
Below is a pic of the last set that I took out (OEM crank matched with 15k miles on them,. Cyl 1/2/3 shown, 4/5/6 were the same).
It took me until I just put the 4th set on to be absolutely sure that the fresh ones are always DEAD silent. But within maybe a thousand miles or so they start to click noticeable. Not a knock, but subtle click in the right rpm range (about 1750-2250). It's worst around 2000rpm, like catching a resonance. After they reach their peak clicking volume at a couple thousand miles, they stay at that volume and never get worse. I had one set in for about 35k miles and it wasn't any louder at the end than after 2000mi.
First set I put on were Taiho STD one-size. I plastigauged those going in (dry with the engine out of the truck) and they were in spec. Several thousand miles after they went in, I had an issue where my injection pump was over fueling slightly and I ended up checking the BEBs and they were now on the wide end of spec. So I swapped them with OEM numbers matched to the crank/cap. Plastigauged those (possibly not with the crank journals SUPER clean of oil, but wiped at least) and they were all in spec.
After that it got another set of OEM matched numbers. I didn't Plasti these. I didn't see the point. Last month I put in a set of ACL Race (STD one-size) and they went from DEAD quiet to just starting to make some light clicking now. So now I'm positive that this is what that clicking is. The last few times I did so much other maintenance at the same time that I couldn't be sure what changed the noise exactly.
So what now? I'm at a bit of a loss here. I am debating getting a set of 0.025mm ACL bearings and Plastigauging them to make sure they're not too tight. I'm not in a position to pull the whole crank to mic the caps with them closed and the bearings in them.
Thoughts? Advice?
Below is a pic of the last set that I took out (OEM crank matched with 15k miles on them,. Cyl 1/2/3 shown, 4/5/6 were the same).
