Loctite 518 gasket maker?

YotaAtieToo

YotaAtieToo

Thick skull
Joined
May 19, 2020
Messages
15,534
Loc
Bonners Ferry, ID
Anyone ever use this stuff?

I just replaced a damaged final drive cover on an excavator, and this is what they gave me for sealing. Similar to threadlocker, it sets up in a o2 free environment, so the tube doesn't dry out easily after you open it.

The final drive is just 2 flat surfaces and a bunch of bolts, similar to a diff cover, so I'd don't see why it wouldn't work?

Maybe the rtv is better for a crawler where the cover sees impacts?

20260410_183938.jpg
 
Yes, havent done a diff cover but any flat flange. transmition /tcase, use it on the outside of a seal ( think pinion seal). Skidoo uses it for the 2stroke case haves. it seams pliable like it would work for a good diff cover but it dose have thickness limits
 
M92PV4U said:
Use it on chevy rear bearing caps.
Click to expand...

Why that specifically?
BUCKWILD said:
Yes, havent done a diff cover but any flat flange. transmition /tcase, use it on the outside of a seal ( think pinion seal). Skidoo uses it for the 2stroke case haves. it seams pliable like it would work for a good diff cover but it dose have thickness limits
Click to expand...

The description says rigid flanges. So I wonder if like you're saying, the thickness it might be on an old warped stamped steel cover would be too much for it to set up.

Just thought it might good for some **** we do where it sits in the tool box for 6 months or whatever.
 
That 516 is designed for close fit tolerances to fill any micro gaps between the steel or whatever parts. Even if "flat" and "smooth", at a microscopic level there are canyons of ridges and stuff. This fills that.

Using typical RTV sealer will actually inhibit a flush and close fit. It is not designed to be thin at that level of fit so it can actually hold the parts away from each other, even at torque spec, and allow vibration which in turn will lead to failure on heavy use parts.
 
Flange sealant is good for a nice machined finish flange, I wouldn't use it on a diff cover that is almost always not flat or rigid enough to achieve the kind of tolerance that stuff requires to set and seal. The only place I've used 518 on a truck was the oil pump cover on the transfer case of a 4x4 Freightliner, if I hadn't been concerned about clearance I'd have used RTV instead of the same sealer that was already leaking.

I stick to Permtex Ultra Grey or Ultra Black for diffs especially in a wheeler where you're going to be blasting the bottom edge of the cover into stuff.
 
Last edited:
TrikeKid said:
Flange sealant is good for a nice machined finish flange, I wouldn't use it on a diff cover that is almost always not flat or rigid enough to achieve the kind of tolerance that stuff requires to set and seal. The only place I've used 518 on a truck was the oil pump cover on the transfer case of a 4x4 Freightliner, if I hadn't been concerned about clearance I'd have used RTV instead of the same sealer that was already leaking.

I stick to Permtex Ultra Grey or Ultra Black for diffs especially in a wheeler where you're going to be blasting the bottom edge of the cover into stuff.
Click to expand...

Im a Permatex Right Stuff gray/black snob. Its all I carry on my service truck and its all I personally use at home. When I reseal something I dont want or expect it to ever leak again. Ain't nobody got tome to reaseal **** twice because of a ****ty silicon choice...
 
Funny story about Permatex Right Stuff.....

I changed the water pump on my old race car and used Right Stuff on both sides of the SBC water pump gaskets before I installed them. Several races later we decided to do a cam swap and the water pump had to come off. Pulled all 4 bolts and it wouldn't move!?!?!?!? Had another guy try to pull it off and nothing. I finally climbed in the engine compartment on top of the chassis and stomped the water pump off the front of the engine and to my suprise the Right Stuff was still stuck to the block and pump and the gasket had literally torn in half thickness wise to separate from the engine. We joked about being able to run the pump without bolts next time to save weight. :laughing:
 
TrikeKid said:
That's exactly why I don't use right stuff. We get whatever the Loctite equivalent of ultra-grey is at work, it seals but it does clean up easy if you do need to disassemble something next service.
Click to expand...

I put Right Stuff back on the water pump gaskets as soon as we were finished with the cam swap. I never worried about a DNF due to a leak unless something physically had a hole in it. Another trick was to Right Stuff the thick cork valve cover gaskets we used to the valve cover and apply anti seize to the other side so they don't stick to the rails on the head with heat cycling. We could run the valves after every race and use the same valve cover gaskets all season.


Anything I service regularly at work has an O-ring seal. I use Right Stuff for things like the top plates on rotary table gear cases and final drive covers where pieces only get taken apart once every 5-10 years unless they leak from that sealing surface.....
 
I should have taken pictures...... I have been chasing rotary leaks on a rental micropile rig ever since I went back to work in October. Every place it leaked from is where the factory calls for anaerobic sealer and where it was reused after the shop in RI rebuild it about a year and a half ago. It came back to my shop off rent last week and the rotary was leaving puddles of gear oil on the body work. I gave it a good power washing and determined it was leaking along the back of the top cover and that I needed to disassemble a bunch of it to fix the leak. I reused all the old shaft seals, skim coated the top of the case with Right Stuff and bolted it all back together. It sat laid back and on its side for days and doesn't leak a single drop now. :smokin:
 
SLOWPOKE693 said:
Thats called anaerobic sealer. The factory uses it on some surfaces of rigs I work on and that **** always manages to leak at some point for no reason. I replace it with a thin layer of Right Stuff and have never had a problem or another leak. **** anaerobic sealers.


Btw..... Did you get the primer?
Click to expand...
No, I saw the mention of primer in the instructions, but they didn't give me any. I'm at a remote mine in AK, it's 3+ days to order parts.

I do like right stuff as well, not sure I've ever had it leak. Iirc, they used to advertise you could pull the bolts on a diff cover after it set up :laughing:

But ya, sometimes it's a total bitch to get apart.
 
YotaAtieToo said:
No, I saw the mention of primer in the instructions, but they didn't give me any. I'm at a remote mine in AK, it's 3+ days to order parts.

I do like right stuff as well, not sure I've ever had it leak. Iirc, they used to advertise you could pull the bolts on a diff cover after it set up :laughing:

But ya, sometimes it's a total bitch to get apart.
Click to expand...

It doesn't work good without primer. Not like it works all that well with it either...
 
We had 4 pieces from them

Dozer showed up with 10k hours, a sizeable coolant leak and no ice grousers(so it was useless) has had Def issues the whole time and has barely been useable.

Excavator went into limp mode over Def freezing while it was running, was whole fiasco to get parts.

Water truck showed up ready for a socal dirt job, nothing remotely winter proofed. Wiring has been a constant issue on it.

Forklift had a jug bailing wired to the ccv since apparently it has tons of blow by.

On top of all that, the rental place has provided zero service. Totally refuse to come fix thier garbage.
 
Use it on all face mounting gearboxes on Fanuc robots. What the service manual calls for.

Agree with almost everything said in this thread besides the primer. Its not needed. It does reduce cure times. Yes there are specified cure times before filling with fluid or grease that the 518 is sealing. You fill before that time, it can leak. Again, the primer just makes that cure time less.
 
YotaAtieToo said:
Why that specifically?


The description says rigid flanges. So I wonder if like you're saying, the thickness it might be on an old warped stamped steel cover would be too much for it to set up.

Just thought it might good for some **** we do where it sits in the tool box for 6 months or whatever.
Click to expand...
yes, an old stamped cover is NOT what 518 is meant for.

use normal RTV
 
YotaAtieToo said:
I do like right stuff as well, not sure I've ever had it leak. Iirc, they used to advertise you could pull the bolts on a diff cover after it set up :laughing:
Click to expand...

BTDT. I cleaned the diff w acetone and scotchbrite, glued it on, filled it up.
A year later, I went to take it off. Took the bolts out, jacked the truck up by the cover lip, nothing. I eventually had to hammer a scraper in to make it let go.

AKnate said:
I swear that **** can glue on a **** on a snowman in July
Click to expand...
:laughing:
 
You must log in or register to reply here.
Top Back Refresh