.Leaky front diff drain plug/bolt. Solution?

[stenerson]

Did my front diff fluid change today. First time, 160K (yeah I know, I'm a slacker)...The fluid looked brand new. But I guess you can't judge condition by appearance.
Anyhow, after draining I hand tightened plug, then torqued to spec. Filled it with amsoil ss severe gear 75w90.
Noticing a tiny, almost imperceptible leak from the bottom of that plug/bolt. I then tightened a little for for good measure but still noticing that leak. I sprayed area with brake cleaner wiped down and carefully watched. Sure enough a very small leak. If I wait 10 minutes a small drop will develop and fall.
These plugs got no o-ring or crush washer. Should I use some kind of RTV on the threads?

 

[BLUKTY2]

I would try some teflon tape.

 

[Atcer2018]

I’ve used the stuff pictured below on transmission drain plugs with good results. Wouldn’t hesitate to try it on a transfer case or differential plug. It’s like liquid teflon tape.

 

[BenchTest]

+1 on Teflon or something like Gasoila thread sealer. Gasoila stays soft/pliable and is made for petroleum based products.

 

[BenchTest]

Gasoila® Soft-Set Thread Sealant with PTFE

fedpro.com

Here is the product I referenced. Small tubes are available cheap. Probably can source from many different vendors. I have about 25 years of experience with the product. It's the gold standard in thread sealing. Or Teflon tape works too

 

[DILLIGAF]

I use Loctite thread sealant , I do live in gas and oil county so its available everywhere... lol..

 

[18CrewDually]

Sounds like you may of dropped the o-ring. There is an oring that seals and goes around the bolt for the front diff plugs on a 2018 1500.

 

[18CrewDually]

I found a video for you and he mentioned the o- ring. I'd double check.

2011-2018 Dodge Ram 1500 Front Differential Fluid Change Easy DIY

This 2015 Ram 1500 is getting new front differential fluid.😎If this video has been helpful consider supporting us with a cup of coffee! 🙂https://www.buymea...

youtu.be

 

[stenerson]

I found a video for you and he mentioned the o- ring. I'd double check.

2011-2018 Dodge Ram 1500 Front Differential Fluid Change Easy DIY

This 2015 Ram 1500 is getting new front differential fluid.😎If this video has been helpful consider supporting us with a cup of coffee! 🙂https://www.buymea...

youtu.be

Interesting. I inspected carefully both bolts when I pulled them and the surface they mate with. Saw no O-rings. But I got a box full of an assortment of green o-rings. And I got plenty of teflon tape. I'll use both. Thanks!

 

[WY-Dave]

works great as a pan gasket too!!!

 

[BenchTest]

Interesting. I inspected carefully both bolts when I pulled them and the surface they mate with. Saw no O-rings. But I got a box full of an assortment of green o-rings. And I got plenty of teflon tape. I'll use both. Thanks!

I've serviced my diffs several times, no o-rings on any of it. Maybe @18CrewDually has different style diffs. Mine are basically pipe plugs. No place for an o-ring or crush washer.

 

[stenerson]

I've serviced my diffs several times, no o-rings on any of it. Maybe @18CrewDually has different style diffs. Mine are basically pipe plugs. No place for an o-ring or crush washer.

Yeah I definitely had none on mine. I inspected both closely when I unscrewed them.
I had to drain and refill today. Added an o-ring and teflon tape, took care of that little leak. But the head on mine does have room for a 0-ring. It's the same as the video shown above. Mine just had no o-ring, or they disintegrated somehow. video

 

[BenchTest]

Yeah I definitely had none on mine. I inspected both closely when I unscrewed them.
I had to drain and refill today. Added an o-ring and teflon tape, took care of that little leak. But the head on mine does have room for a 0-ring. It's the same as the video shown above. Mine just had no o-ring, or they disintegrated somehow. video

Is yours a ZF differential? I can't imagine that you have a different diff than me (you show 3.6 on your info). Guess it's possible though.

 

[stenerson]

Is yours a ZF differential? I can't imagine that you have a different diff than me (you show 3.6 on your info). Guess it's possible though.

I got a zf transmision. The bolt is almost like a pipe bolt but has some head area for an o-ring. Check out the bolt in this video. You don't have to watch the whole thing I have it time marked to show the drain bolt. That's the one I have. Click here, time marked video showing my front diff drain bolt

 

[stenerson]

 

[BenchTest]

I got a zf transmision. The bolt is almost like a pipe bolt but has some head area for an o-ring. Check out the bolt in this video. You don't have to watch the whole thing I have it time marked to show the drain bolt. That's the one I have. Click here, time marked video showing my front diff drain bolt

Interesting. I have a ZF built front diff. It does NOT have a magnetic drain plug, nor does it have an o-ring boss to locate an o-ring. Mine is a 3.55 ratio. I wonder if for some reason they put different drain/fill plugs in the 3.21 or other variants? I don't know why it'd be different. Mine is basically a pipe plug with an Allen key recess machined into it. At the 2:15 mark on this video, this is what I have:

Ram 1500 Front Differential Fluid Gear Oil Change DIY (2012-2026)

Our Blauparts step-by-step video shows how to change the Ram 1500 front differential fluid on 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 202...

www.youtube.com

 

[EdGs]

Looks like the OP's bolt is a straight pipe thread instead of a tapered pipe thread.

Needing an o-ring or seal washer would make sense if a straight pipe thread.

 

[stenerson]

Interesting. I have a ZF built front diff. It does NOT have a magnetic drain plug, nor does it have an o-ring boss to locate an o-ring. Mine is a 3.55 ratio. I wonder if for some reason they put different drain/fill plugs in the 3.21 or other variants? I don't know why it'd be different. Mine is basically a pipe plug with an Allen key recess machined into it. At the 2:15 mark on this video, this is what I have:

Ram 1500 Front Differential Fluid Gear Oil Change DIY (2012-2026)

Our Blauparts step-by-step video shows how to change the Ram 1500 front differential fluid on 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 202...

www.youtube.com

Yeah that one looks the same as mine, except I saw no remnants of sealant or 0-ring on mine.

 

[Joseph Godvin]

This style plug uses a O-Ring, it's a small thin o-ring. without it......it's gonna leak !!!!