Using anti-seize on transmission/diff plugs?

[byez]

I recently did a double drain & fill on my RX8 manual transmission. I used some copper anti-seize paste on the plug threads and on the second drain & fill I noticed some copper flakes/particles in the drained fluid.

Is it usually not recommended to use anti-seize for this purpose? I can't see this being good for the longevity of the transmission.

 

[Quest]

Why on-earth would you try to contaminate your MTF with antiseize compound on the drain plug thread? Why?

Isn't a compressible copper/alu washer good enough for you?

Q.

 

[byez]

Wasn't trying to contaminate, I was trying to prevent thread seizing. I am sure we have all made some automotive mistakes.

Do you think I should do one more drain? How much damage could this really have caused, if any?

 

[tom slick]

I wouldn't worry about it.

 

[Quest]

byez-

Treads typically do not seize unless (a) you use a high torque impact gun/wrench and just "gun" it, or (b) you overtorqued it.

Either way, if you have genuine concerns, consider getting a torque wrench and follow the specifications outlined by your factory service manual. typically, transmission drain bolt torque rarely goes beyond 25ft/lbs (can go as low as 8~12ft/lbs on some alloy pans.

Use a crush washer next time. If you need a specific id (internal diameter), drop me a line and I may get you some.

Q.

 

[c3po]

My pipe plug for the differential on my 1983 Chevrolet El Camino was a pain too get out. So I hit it with some PB Blaster and let it soak, it then came out.

I noticed something interesting on the pipe plug. The threads of the pipe plug that were not exactly in the differential cover had a lot of junk on it. This is what I did:

1) I got a new pipe plug
2) I let it sit for a few minutes in differential gear lube
3) I then put the pipe plug in
4) Cleaned the outside of the plug
5) I got some RTV Silicone and covered the outside threads that did not exactly go into the cover.

My thinking was that with the outside threads, which were 1 or 2, this would keep any grime from binding onto the plug, and the next time I go to take the plug out it would be easier.

When I looked at my old pipe plug, you could see a difference in the threads that were solidly in the differential hole and those 1 or 2 that were slightly exposed.

 

[pemdas]

A crush washer will keep the threads from getting contaminated by the outside elements. If the crush washer seals properly there will be no leaks hence the threads are protected as well. Plus you are plugging a drain hole which holds lubricant which will keep the threads lubed.

 

[SubLGT]

Originally Posted By: byez
.........Is it usually not recommended to use anti-seize for this purpose? I can't see this being good for the longevity of the transmission.



The plugs on my rear diff are tapered thread, and I use Permatex thread sealant (not thread locker or anti-seize), and tighten with a torque wrench. No problems with frozen plugs.

 

[Pablo]

I would not worry about it in the least. I even doubt the copper was "moving around" in the MTF, it probably washed out of the threads when draining. You don't need much to do the job on tapered threads, just don't over do it on the torque - but tiny amount of copper and other stuff in Coppaslip won't ruin a MT.

And there are other reasons thread seize, such as metallurgical bonding which happens very fast on my Honda Ody fill plug, and that's NOT a tapered plug and it has an Al washer! So I use solid stick Al anti-seize on the plug threads. Works great.

 

[Kestas]

For tapered threads on diff plugs I use either a light coating of antiseize or teflon tape. Used sparingly, I don't think antiseize is a big deal.

Recently, I've read many posts about people finding copper flakes in diff fluid. Ferrous metal flakes have a copper hue to them when they're in diff fluid. I noticed this last month when I drained the fluid in my diff and saw millimeter-sized flakes in the fluid. You should always verify the composition of the flakes with a magnet. Just looking at them isn't good enough. The metal flakes in antiseize are so small, I'm surprised you could determine the color of the flakes in the fluid.

 

[mechtech2]

Drain plugs can strip or stick from being cross threaded, but I've never seen a seized one.
And I've seen a few drain plugs over the years!
You didn't hurt a thing, but on a drain plug it is not necessary. Actually, a differential tapered pipe thread plug would benefit from anti seize, so there are exceptions.
But I wonder how much you slathered on to be able to see copper in the drained fluid!

 

[Gary Allan]

It doesn't happen often, but I've heard of a few cases cracking in Al trans cases that have hex drive plugs. No washer to them ....there's some galvanic action there (as Pab's mentioned).

 

[[RT] ProjUltraZ]

anti-seize can be nice or it can be dangerous. i think it's all in the amount used, and where. there's just some places it shouldn't be used

by nature (easier to come off) it's much less forgiving than locktite and it depends how much you use. i recently helped/watched an experienced suspension man put my new rear axle in. he used just the smallest dab of locktite on the major suspension parts. didn't see any anti-seize anywhere, and those suspension parts are prone to rust being under the car and close to the road

 

[99]

No need to use anything on drain plug bolts. Install them dry.

 

[Eddie]

I use Permatex non-hardening thread sealent.

 

[tdi-rick]

I use Hylomar spayed onto the threads, purely to stop a leak path on the drain and fill taper plugs.

 

[Al]

Originally Posted By: 99
No need to use anything on drain plug bolts. Install them dry.

I error on the side of caution and make sure there is a little oil on the threads. But I have yet to use/need anything on the threads except oil. If you want to use something on the tapered plug, I'd go with Teflon tape.

Maybe the Hylomar stuff is better. Don't know anything about it.

 

[1sttruck]

I was using the white automotive hi-temp sealant, Permatex as I recall, but have been using teflon plumbing pipe sealant as it seems to be about the same stuff for something like 1/10 the price. Works well, gets semi-hard, also seems to keep stuff like drain plugs from seizing.

 

[PT1]

Originally Posted By: SubLGT
Originally Posted By: byez
.........Is it usually not recommended to use anti-seize for this purpose? I can't see this being good for the longevity of the transmission.



The plugs on my rear diff are tapered thread, and I use Permatex thread sealant (not thread locker or anti-seize), and tighten with a torque wrench. No problems with frozen plugs.


+1 white permatex works very well for me too! I use it on everything

 

[Kestas]

To summarize the thread so far, the following works on pipe thread drain (and fill) plugs:

- antiseize
- teflon tape
- Permatex thread sealant
- teflon plumbing pipe sealant
- Hylomar

Really anything but installing them dry. Anybody who's busted knuckles or tools trying to remove these plugs can appreciate the importance of prepping the threads for the next service.