Anti-Seize Compound
- Thread starter Tanner SC
- Start date
rotorwrench
Well-known member
I would use a thread sealant going into a water jacket or an oil pressure port. That alone would act as an anti-seize.
As a General Note:
Ford Axle tapers weren't the best fit even when new. The taper is a part of the design that acts to center the hub on the shaft. The key is what keep it from turning. If the keyways have loosness then the joint will move under hard accelleration and heavy braking action. As many folks expressed in this thread, any lubricant on the taper can and will aid in slippage of the tapers. If the key joint is not up to specs it can and will shear under these circumstances. Many of the tapers are worn pretty badly over the years of abuse. Hell, some folks even use taper shims in there due to this. Engineering finally came into the 20th century when they changed to splined axles. In the aviation industry about the only thing that still uses a taper with a key is a magneto drive and the book on them says to use anti-seize. Obviously a magneto drive is not subjected to near the torque of a rear axle so there is no real comparison there. Where we use tapers on helicopters is where the main rotor is mounted on the shaft with tapered collets. All of these joints use splines as the lock and tapers to center it up. A much more reliable fit thank God.
If using anti-seize on a high torque application make sure all parts have a very snug fit and don't slather the stuff on. You should be able to see metal through the film you apply. Really all you are doing is filling the pores and minute imperfections on the metal surface. The joint will squeeze out what it doesn't need. If you don't trust it DON'T USE IT. Worn and loose parts will do better without.
As a General Note:
Ford Axle tapers weren't the best fit even when new. The taper is a part of the design that acts to center the hub on the shaft. The key is what keep it from turning. If the keyways have loosness then the joint will move under hard accelleration and heavy braking action. As many folks expressed in this thread, any lubricant on the taper can and will aid in slippage of the tapers. If the key joint is not up to specs it can and will shear under these circumstances. Many of the tapers are worn pretty badly over the years of abuse. Hell, some folks even use taper shims in there due to this. Engineering finally came into the 20th century when they changed to splined axles. In the aviation industry about the only thing that still uses a taper with a key is a magneto drive and the book on them says to use anti-seize. Obviously a magneto drive is not subjected to near the torque of a rear axle so there is no real comparison there. Where we use tapers on helicopters is where the main rotor is mounted on the shaft with tapered collets. All of these joints use splines as the lock and tapers to center it up. A much more reliable fit thank God.
If using anti-seize on a high torque application make sure all parts have a very snug fit and don't slather the stuff on. You should be able to see metal through the film you apply. Really all you are doing is filling the pores and minute imperfections on the metal surface. The joint will squeeze out what it doesn't need. If you don't trust it DON'T USE IT. Worn and loose parts will do better without.
Last edited:
All: Thanks much for this informative discussion. Many replies fit my past experiences, such as bi-metal applications, and different types of anti-seize.
After fighting some out of a block, I was wondering particularly about valve guides but did not see a specific answer on this, tho' I can't think of a reason not to use it here.
About 60 years ago, a senior-level engineer often referred to corrosion/rust as "nature's lockwasher" which sure seems to apply for these!
Some replies mentioned things I hadn't thought about. Because of lubrication effects, my rule of thumb has always been not to use anti-seize on surfaces that carry or help carry torque by friction between the parts. Years ago I had fastener torque charts giving different values for dry and for lightly oiled joints to get the intended bolt stretching for preload. In either case all threads had to be very clean.
We manufactured many hydraulic products and thin liquid thread sealers worked well for extra insurance where sealing was critical --even on dryseal-type (NPTF) fittings.
They did not put small particles into the system like the teflon-based sealers did.
We found red or the high-strength green Loctite could be easily loosened after a bit of direct heat. We never used plain tapered pipe threads (NPT) in our products.
Thanks again!
After fighting some out of a block, I was wondering particularly about valve guides but did not see a specific answer on this, tho' I can't think of a reason not to use it here.
About 60 years ago, a senior-level engineer often referred to corrosion/rust as "nature's lockwasher" which sure seems to apply for these!
Some replies mentioned things I hadn't thought about. Because of lubrication effects, my rule of thumb has always been not to use anti-seize on surfaces that carry or help carry torque by friction between the parts. Years ago I had fastener torque charts giving different values for dry and for lightly oiled joints to get the intended bolt stretching for preload. In either case all threads had to be very clean.
We manufactured many hydraulic products and thin liquid thread sealers worked well for extra insurance where sealing was critical --even on dryseal-type (NPTF) fittings.
They did not put small particles into the system like the teflon-based sealers did.
We found red or the high-strength green Loctite could be easily loosened after a bit of direct heat. We never used plain tapered pipe threads (NPT) in our products.
Thanks again!
rotorwrench
Well-known member
That green Loctite 680 has to be heated up pretty well to get it to fracture. I've heated big Timken bearings and applied cold water to the joint two or three times to get the stuff to break loose. When you can see the water boiling out of the joint its ready to pull. The heat applied never got above 275* F.
I don't see any reason anti-seize couldn't be used on L-head valve guides. It would keep corrosion minimal and act as a fretting inhibitor. After 30-years they would probably still be a bear to get out though.
I don't see any reason anti-seize couldn't be used on L-head valve guides. It would keep corrosion minimal and act as a fretting inhibitor. After 30-years they would probably still be a bear to get out though.
Thanks rotorwrench for the valve guide comment!
10 years and 80,000 miles after my re-build using anti-seize, with a socket wrench and no heat application, I had no trouble removing exhaust manifold bolts from a Mustang engine while it was still in the car. Previously, after 100,000 miles and 13 years, I had a bear of a time getting them out even with the engine out of the car. This made me a believer!
My experience with the 600 series Loctites was in much smaller applications than yours. We would hit small fittings or parts, which were often brass or aluminum or stainless steel, with a propane torch, then loosen the fitting or whatever while the Loctite still seemed to be soft. We didn't quench the joint. We used 1000 to 1500 psi hydraulic systems and our components were small --for example, fittings were always either 1/8 or 1/4 inch NPTF.
10 years and 80,000 miles after my re-build using anti-seize, with a socket wrench and no heat application, I had no trouble removing exhaust manifold bolts from a Mustang engine while it was still in the car. Previously, after 100,000 miles and 13 years, I had a bear of a time getting them out even with the engine out of the car. This made me a believer!
My experience with the 600 series Loctites was in much smaller applications than yours. We would hit small fittings or parts, which were often brass or aluminum or stainless steel, with a propane torch, then loosen the fitting or whatever while the Loctite still seemed to be soft. We didn't quench the joint. We used 1000 to 1500 psi hydraulic systems and our components were small --for example, fittings were always either 1/8 or 1/4 inch NPTF.
Rocketsled
Senior Member
On valve guides and lifters, I use Molykote G-N Assembly Paste. A little on the valve stems, too. This is the same MoS2 paste that comes with new cams to provide boundry lubrication before oil flow takes over, and for good wear-in of parts. M0S2 anti-friction coatings are applied to new engine parts and is mainly responsable for the long life modern engines get. To properly apply a paste, rub a little in with a clean cloth until it dissapears. Repeat. MoS2 works into the surface of steel and changes it so that the surface acts like a lubricant. I use a little of a M0S2 dispersion in oil called Molykote M-Gear Oil Additive: 2 oz. in the non-synthetic engine oil; 5-10% by volume in banjo rear ends, transmissions and steering boxes. I found a better product for transmissions and steering boxes, that I have been using for 2 years now with no leakage, namely Molykote Longterm 00, a fluid grease with MoS2.