Diff and gearbox filler and drain plug thread sealing recommendations.

[uninformed]

Teflon tape on a tapered iron plug can cause cracking, esp. in aluminium, it (Teflon) allows the plug to be overtightened and can cause the alloy to split.
I have never used anything on the threads of iron tapered plugs into alloy housings and have never had one loosen/fall out/leak, just nip it up tight, Regards Frank.

I guess if you are controlling that environment its a good way, but what if other heavy handers buggers have made their way in there at some point.......

[rick130]

Frank's right, but I still use a few wraps of yellow (gas) thread tape on BSP taper plugs.
It's me tightening them up, so I know how far to go

On the diff/gearbox/t-case plugs I use spray on Hylomar.

[Dave_S]

I have never used anything on the threads of iron tapered plugs into alloy housings and have never had one loosen/fall out/leak, just nip it up tight, Regards Frank.

On a slightly different tangent, on one of my swivel housings the filler plug will simply screw all the way through the housing. It doesn't tighten at all. I''ve tried other plugs with the same result. It's a small problem that's one of the last 50 items on my rebuild list, but it's time to fix it.

I really don't want to replace the swivel housing - any other ideas?

[Utemad]

Teflon tape on a tapered iron plug can cause cracking, esp. in aluminium, it (Teflon) allows the plug to be overtightened and can cause the alloy to split.
I have never used anything on the threads of iron tapered plugs into alloy housings and have never had one loosen/fall out/leak, just nip it up tight, Regards Frank.

I've never used anything on these plugs either and no leaks.

I recently bought a new magnetic sump plug for my transfer case but should have specified Disco1 as it turns out Disco2 and Disco1 have different plugs. Disco2 being the same as a diff drain plug.
Anyway I recently fitted it to my rear diff instead and noticed it had that preapplied thread sealant on it like an air fitting.

[Bearman]

On a slightly different tangent, on one of my swivel housings the filler plug will simply screw all the way through the housing. It doesn't tighten at all. I''ve tried other plugs with the same result. It's a small problem that's one of the last 50 items on my rebuild list, but it's time to fix it.

I really don't want to replace the swivel housing - any other ideas?

I'd go with the Loctite 567 as Blkusnightus recommends, Dave. Just apply and screw in to the depth you want and leave it there. While it is not a hard cure it will seal and not unscrew itself.

[clubagreenie]

Just try to replace the plastic filler plugs on the diffs with brass ones, they should be about $8- each. And can be reused unlike the self destruct plastic.

Utemad, did you want to move the D2 magnetic plug onto a D2?

[Utemad]

Utemad, did you want to move the D2 magnetic plug onto a D2?

No thanks. I just used it in the rear diff instead to help keep the metal bits out of the locker and bearings.