When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Very green to the Ls word, and engine rebuilding, I’m in the process of tearing down a 5.3 for small inspection, and I’ve removed the front cover to replace the front main seal, I noticed that the bolts to the cam sprocket were backed off, and Insanely loose, I also noticed there was no dowel in the camshaft, do all cams come with this dowel ? The bolts backed off indicated to me that there was no locktite used. But a missing dowel seems suspicious as I personally never seen a cam without a dowel, based off you guys knowledge and experience what could this mean ? And what does the science state?
Yes. Use a magnet and see if you can locate/retrieve the pin. It might be difficult to locate another cam dowel pin….camshaft companies might bail you out here.
Tap it back in the cam with a tiny dab of red loctite on it. Clean the pin and the hole with brake parts cleaner and a Q-Tip. Must be clean for loctite to bind. Re-install the bolts with a dab (tiny drop) of blue loctite. 22 ft lbs on your torque wrench. Are the threads on the cam bolts beat up, from running while loose?
Yes. Use a magnet and see if you can locate/retrieve the pin. It might be difficult to locate another cam dowel pin….camshaft companies might bail you out here.
Tap it back in the cam with a tiny dab of red loctite on it. Clean the pin and the hole with brake parts cleaner and a Q-Tip. Must be clean for loctite to bind. Re-install the bolts with a dab (tiny drop) of blue loctite. 22 ft lbs on your torque wrench. Are the threads on the cam bolts beat up, from running while loose?
The dowel must be in the oil pan, I’ve ordered a new oil pan as I planned to put this engine in a 1997 obs GMC Sierra and lower it, I will look for the dowel pin, the cam bolts didn’t look terrible, they do thread pretty smoothly and still tighten, so I’ll use them or possibly use new ones!
The dowel must be in the oil pan, I’ve ordered a new oil pan as I planned to put this engine in a 1997 obs GMC Sierra and lower it, I will look for the dowel pin, the cam bolts didn’t look terrible, they do thread pretty smoothly and still tighten, so I’ll use them or possibly use new ones!
Find out the size of the pin, and you could pick one up at any local Grainger or McMaster-Carr..
I just measured an LS1 pin at .246”. Those things are precision made. I don’t think it’s a std .250” pin. Possibly metric? Everything else is….
With the bolts loose, all the stress is on the pin. They are press fit, and hard as hell. My guess would be the hole in the cam is now oversized a bit.
You will know if you find the missing pin and try to put it back in. Cam gear hole may be wallowed out as well.
I just measured an LS1 pin at .246”. Those things are precision made. I don’t think it’s a std .250” pin. Possibly metric? Everything else is….
With the bolts loose, all the stress is on the pin. They are press fit, and hard as hell. My guess would be the hole in the cam is now oversized a bit.
You will know if you find the missing pin and try to put it back in. Cam gear hole may be wallowed out as well.
By all means use new bolts.
I agree Ron. .246" would be a 6.25mm, so it's certainly not a standard pin. IDK if it's a special 6.25mm pin, or a .250" pin ground .004" undersize. I'm thinking you're right about the cam gear hole being out of round/worn, too, and I don't remember what's what with the cam, but I'm thinking the cam itself may have wear in the cam dowels I.D. IIRC, the pin is supposed to be pressed into the cam. Almost sounds like at some point the bolts loosened slightly and the dowel was forced to help drive the cam. Sure, it couldn't take much pressure, but there has to be a reason why it came out. The back and forth of the timing gear probably loosened it eventually..
02-05-2023, 01:20 PM
Camshaft “Dowel Pin” 
