Epoxy your diff: ghetto or legit?

This came up in a facebook group for E36s. This guy is claiming to fill his differential with epoxy instead of welding it. He claims its not as harsh since the epoxy keeps it locked yet still allows a bit of flex.

I can't imagine this lasting very long, especially with some really sticky tires. Plus, $150 per diff seems like a fantastic ripoff. I figured I would post here and just see what you guys thought. You should have seen the hilarity that ensued on the facebook page.

Heres a pic from the FB post:

I... uhhh... no. Are you sure it wasn't the Audi guy?

http://www.audiforums.com/forum/off-topic-5/hey-guys-please-help-my-mods-gone-wrong-80267/

Uh epoxy cures hard.... Doesn't give. Will shatter however. Pure BS.

if you already have your diff out im almost positive any welding shop won't cost you $150 to weld it up.

and he says it doesnt drag a tire when you turn... if its not dragging a tire in a turn its not a locked diff

Picture's broken, but seriously bad idea. The epoxy won't allow anything more than a degree or so difference even if he used something that was more like urethane, and there's a real danger of it shattering and coming loose inside the differential and damaging the ring and pinion.

April 1 is still two weeks away...

This idea is fantastic, but I think expanding foam will work better!

edizzle89 wrote: if you already have your diff out im almost positive any welding shop won't cost you $150 to weld it up.

If you don't want to take the diff out can't you just pour the epoxy in the fill hole?

In reply to EvanB:

My god,,, can you imagine. First we take a group of spoiled turd kids that want to be hellasfrush but aren't interested in cars enough to learn because they are glued to faceballs and then we let them buy grandpa's 325 to cut the springs (like they saw on a YouTube channel) next, we feed them a ton of bad ideas. When everything goes wrong they move on to a bro-dozer and roll coal till the EPA shuts them down. This is great, and makes me feel smarter than the 99%.

That's certainly an interesting idea.

Don't they know you lock a diff with Concrete. Also the added rear weight helps handling.

It wouldn't shatter. I had a cracked housing on a dump truck diff that I epoxied to stop the leak. It would last about a year and then soften and peel off. The oil eventually breaks it down. But in this application I suspect it would work fine.

I have also heard of molten lead being used for the same reasons.

Oh boy, thanks for this. I really needed a good laugh this afternoon

Looks like he made a poor man's Phantom Grip...and the real thing is questionable enough.

Doesnt work, i tried jb weld on a diff that i had tried welding 3 times already and the housing was already cracked. Yeah its probably my worse automotive ideas but i was about to crush the car anyways so i didnt have much to lose. 2 miles is what it lasted, didnt even get to see if it would hold.

Moral of the story? Use a 220v welder and preheat the piss out of it. Bolts and junk jammed in the spider gears help so you use less rods/wire but ideally you pretty much want to fill the inside of the diff with welds, not just a couple beads on the spider gears.

I wasnt the hella drift type i just wanted two tires to spin instead of my usually one mile long single tire fire. Go ahead and get your laughs out at my expense its okay. Haha

Epoxying your diff is absolute bullE36 M3. You need to use superglue. Everyone knows that. y0.

this is almost as good as the welded diff troll on pirate4x4

Man, and I thought the solution to killing diffs in my Camaro was going to have to be something drastic like swapping the 10-bolt for a 9-inch. Thanks, Internet!

Dr. Hess wrote: Epoxying your diff is absolute bullE36 M3. You need to use superglue. Everyone knows that. y0.

Duct tape.

There aren't enough facepalm memes on the internet to adequate express how I feel.

The picture doesn't look like epoxy, it looks like a industrial strength silicone sealant. That stuff is so tough you can't cut it with a razor blade. It is just flexible enough to allow a little play but not enough to turn without problems.

How come it looks like hot melt glue?

An aquantance of mine once shared a story of his father's DIY locked diff, allegedly used in a mid-seventies IMSA racer in one of the smaller engine classes. He said that he packed the inside of the diff with lead birdshot, then tack welded sheet metal over the openings to keep it inside. The Idea, so he said, was that it would act like a tight LSD until all the shot got pulverized, usually near the end of a race weekend, and if he got a post race inspection, it would be loose enough that the scrutineers wouldn't think they needed to tear it down.

I have no idea if this story is true, but I do know that his father was a legit privateer racer in the late sixties through the seventies, and known for interpreting all of life's rules loosely.

The best part is the dude is charging $150 for a half tube of glue hes probably stealing from work.

I have an epoxied/locked diff in an e30........ Remote controlled car.