Sunday, March 26, 2023


Video and article: Best grease for lubricating trailer plug?

Dear Mike,
Can you recommend a grease that can be used on a 5-way trailer plug?  My connector is a bit tight and hard to engage sometimes. I have some dielectric grease but I’m not sure if I should use it, or if there’s a product made specifically for this purpose.

Thanks. Doug M.

Dear Doug,

I know a couple of ways that don’t work, and a few that work great. So here’s what to avoid. DO NOT use the original WD-40 spray on your trailer plug. My dad did this for years, and all of his trailer plugs would swell up and fall apart. The original petroleum-based WD-40 spray will often attack rubber parts and cause them to deteriorate.

And don’t use Vaseline for much the same reason. It’s petroleum based, which will eventually break down the rubberized parts of your plug.    

In this case silicone lubricant is your friend, and you can use it several ways. If your dielectric grease says it’s silicone based on the label, then it should be safe to use.

You can use a contact cleaner that contains silicone-based lubricant such as MG Electronics Contact Cleaner with Silicone. The advantage is that the contact cleaner will remove any built-up grunge and oxide on your connections, and the silicon lubricant will allow easy plugging and unplugging as well as protect the contacts from future oxidation.

You can also use straight silicone spray from companies such as CRC. Just remember silicone spray by itself won’t clean oxidation from your contacts, only protect them if they’re not already corroded.

Hope this information helps…

Let’s play safe out there….


Mike Sokol is an electrical and professional sound expert with 40 years in the industry. Visit for more electrical safety tips. His excellent book RV Electrical Safety is available at For more info on Mike’s qualifications as an electrical expert, click here.



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Jeff Arthur
4 years ago

De-oxit Gold is And has been my go to for any electrical connection. Tri-flow was also used in the past with good results.

Angela Krause
4 years ago

Love your retro video intro ditty.

RV'in Guy Georgia
4 years ago

Great tips Mike, thank you. As a new RV owner, i see the plug starting to accumulate corrosion, so the timing of this is perfect. My order will be placed so i can remove and protect the corrosion from my plugs.

Thomas Becher
4 years ago

How about nolox inhibitor that we use for aluminum wife termination. I have been using it for years on my boat trailer plug. Messy if gotten on clothes

4 years ago
Reply to  Thomas Becher

Yes, you may want to terminate your “aluminum wife”, and replace her with a real, human one. The human ones are a bit nicer to ‘snuggle up’ to. haha

4 years ago

De-Oxit for cleaning contacts.I found some grease at Harbor Freight with silicone in it. It’s a small grey tube…cost around $6.00,but it lasts a long time.

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