Generation III Internal Engine 1997-2006 LS1 | LS6
Sponsored by:
Sponsored by:

Loctite - Is it REALLY necessary?

Thread Tools
 
Search this Thread
 
Old 10-02-2016, 08:25 AM
  #1  
Launching!
Thread Starter
 
StorminMatt's Avatar
 
Join Date: Jun 2016
Posts: 253
Received 44 Likes on 38 Posts
Default Loctite - Is it REALLY necessary?

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?
Old 10-02-2016, 08:35 AM
  #2  
TECH Fanatic
iTrader: (25)
 
RollinSScamaro's Avatar
 
Join Date: Oct 2003
Location: Frankenmuth, MI
Posts: 1,164
Received 2 Likes on 2 Posts

Default

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..
Old 10-02-2016, 08:42 AM
  #3  
TECH Addict
 
RockinWs6's Avatar
 
Join Date: Mar 2013
Posts: 2,628
Likes: 0
Received 27 Likes on 21 Posts
Default

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.
Old 10-02-2016, 10:34 AM
  #4  
TECH Senior Member
iTrader: (25)
 
truckdoug's Avatar
 
Join Date: Nov 2013
Location: Portlandia
Posts: 6,330
Received 526 Likes on 356 Posts

Default

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

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

Last edited by truckdoug; 10-02-2016 at 10:34 AM. Reason: 242 is the correct number for the blue stuff i like
Old 10-05-2016, 01:03 PM
  #5  
8 Second Club
iTrader: (4)
 
Forcefed86's Avatar
 
Join Date: May 2011
Location: Wichita, KS
Posts: 7,858
Received 677 Likes on 500 Posts

Default

Originally Posted by RockinWs6
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 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.
Old 10-05-2016, 04:23 PM
  #6  
Launching!
Thread Starter
 
StorminMatt's Avatar
 
Join Date: Jun 2016
Posts: 253
Received 44 Likes on 38 Posts
Default

Originally Posted by Forcefed86
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.
Sounds like maybe it might be best if you run a chaser on those threads before reassembly in order to remove old thread locker.
Old 10-05-2016, 05:31 PM
  #7  
TECH Enthusiast
iTrader: (2)
 
99SSJarhead's Avatar
 
Join Date: May 2010
Location: Deloit IA
Posts: 549
Likes: 0
Received 1 Like on 1 Post
Default

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.
Old 10-06-2016, 08:15 AM
  #8  
KCS
Moderator
iTrader: (20)
 
KCS's Avatar
 
Join Date: Mar 2005
Location: Conroe, TX
Posts: 8,848
Received 307 Likes on 207 Posts

Default

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.
Old 10-06-2016, 07:33 PM
  #9  
TECH Fanatic
iTrader: (5)
 
64post's Avatar
 
Join Date: Nov 2011
Location: Sonoma Co. Ca.
Posts: 1,686
Received 226 Likes on 179 Posts

Default

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.
Old 10-07-2016, 08:06 PM
  #10  
TECH Veteran
iTrader: (1)
 
gametech's Avatar
 
Join Date: Sep 2004
Location: Stockbridge GA
Posts: 4,068
Likes: 0
Received 432 Likes on 307 Posts

Default

Originally Posted by StorminMatt
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?
How long do you want your engine to last? Loctite is absolutely NOT needed for the first few miles. After that well...?
Old 10-08-2016, 10:22 PM
  #11  
TECH Addict
iTrader: (7)
 
BrntWS6's Avatar
 
Join Date: Feb 2005
Location: Land of the FOID
Posts: 2,005
Likes: 0
Received 10 Likes on 10 Posts

Default

I use it on everything



Quick Reply: Loctite - Is it REALLY necessary?



All times are GMT -5. The time now is 02:50 PM.