Before I swap my engine, there are a few things I would like to replace. These include the oil pump, timing gear, cam retainer plate, and the front and rear gaskets/seals. I've heard people here say on SEVERAL occasions that Loctite MUST be used on all these fasteners OR ELSE! Honestly, I have NEVER used Loctite on ANY engine (mostly Japanese imports) I have ever worked on. And I have NEVER had a bolt that is tightened to factory torque specs back off. Is there REALLY something different about the LS in this respect? Is factory torque simply not enough to keep bolts from backing out?

 

Any bolts holding rotating equipment or subject to vibration should be done in my opinion.. it's a cheap precaution.. and from what I've read it is possible for bolts to come loose, so I wouldn't chance it for an extra $5 and 5 minutes worth of effort..

 

Loctite is about useless unless the fasteners and threaded holes are clean and dry from any oil. I personally use it on everything oil free, sometimes under load things seat or move a bit and before you know it something is loose.

I was working on a dare I say it a ha ha ha Honda once and torqued the cam gears to spec NO LOCTITE, 10 thous miles later the engine failed because the bolts came loose. AND I was really careful to tighten them to spec because I didn't like not using Loctite but it was just about impossible to clean the oil off in that situation.

 

use the purple loctite 243. works on somewhat oily surfaces.

i like the 242, acetone in a squirt bottle and compressed air prior to.

 

I don't know if I buy that 100%.

The red loctite expands as well when it drys. Ive used it on oily cam gear bolts many times with little more than a wipe down. The bolts are always a bastard coming out, or going back in with the loctite/loctite-remnants on them. I do try to wipe my bolts down before assembly, but I don't go all out with the acetone. Not that it won't work better clean, but it's working to some degree either way in my experience.

 

Sounds like maybe it might be best if you run a chaser on those threads before reassembly in order to remove old thread locker.

 

I usually opt with "if it came from the factory with it." If i pull a bolt and it has it on there, i clean it and reapply when re-installing. Otherwise just follow torque specs.

 

I do with the more critical parts. The small bolts for the oil pump pickup and cover, as well as the lifter tray bolts get blue loctite. Cam retainer plate and cam gear bolts get either green or red loctite.

When I worked an a shop for marine engines, EVERYTHING got loctite. There was too much vibration to just trust the torque specs. Never had a fastener come loose.

 

DO use it on flywheel and flex plate bolts if you're using ARP bolts. it's recommended by ARP and I found out first hand, crankcase pressure pushes oil through the bolt holes of your crank flange, oil Starts collecting behind the flywheel and it then looks like a leaking rear main. Loctite on the threads, moly lube under the head of the bolts.

 

How long do you want your engine to last? Loctite is absolutely NOT needed for the first few miles. After that well...?

 

I use it on everything