Diff breather mod issues?

As the title says I’ve been having trouble with what I’ve heard is a relatively simple and helpful mod. For some reason I cannot find a single union to thread into the diff apart from the oem one way valve, I have tried four different unions with no luck, is the threading different on Limited slip differentials compared to rear locking ones? Any info is helpful.

 

https://www.tacomaworld.com/threads/cheap-free-mods.4838/page-3#post-45989

 

Thank you for the thread link, but as you can see by my photo I have tried the part number listed and it does not thread into the diff.

 

I just did mine yesterday and used this -

$7 Toyota 90404-51026 Intake Air Control Valve Union

https://www.amazon.com/dp/B01H79JUQQ?ref=ppx_yo2_dt_b_product_details

 

I’ll give that one a try, I tried a similar one in the picture but again no luck, seeing as you also have an LSD this should hopefully help will respond with updates as soon as that comes in.

 

Crap..
Knowing them they changed it again..
Got no way to confirm that anymore…
Sorry ..

 

Did ya booger the threads up while taking it out? Or is the OD/ID the wrong size?

 

Yeah... check the threads in the pumpkin to make sure they're not galled up with the original breather. When I removed mine, it was in there pretty damn tight so factory overtightened mine and the silver union threaded in without issues.

From reading many prior posts, the thread pattern is some kind of a British pipe thread and not very close to any standard US npt. Check the original breather threads and make sure none are missing or chewed up. Again, no issues doing this with the silver toyota union PN on my 2020 OR.

 

The threads seem okay they seem a little flatter I guess on the oem than the the other options, I figured it could have been overtightened or maybe weirdly cross threaded but the oem breather always threads back in with 1-2 hand twists , the others will just spin and never even thread in a little

 

What happens when u compare OD and thread pitch? Do they fall in together?

 

It’s really hard to tell, I’ve since put the oem one back in. They look incredibly close out of the diff, probably why everyone else seems to have no trouble using the commonly recommended ones. It almost looks/feels like it was made too thin, and the oem one was kinda jammed in there while somehow not affecting the threading

 

I can’t answer your question, but I can point out one clarification. None of the 3rd gens have a limited slip differential. There is a locking diff found on the OR and Pro and an open diff on the other trims. There are also two different size diffs, but my knowledge gets a bit foggy. I’ve heard the manual transmission trims get the larger diff.

 

Interesting. I'd bet the start of the threads on top of the axle are a lil joed up. How carefully did you try rethreading the new one?

 

I haven’t tried messing with any sort of rethreading, I’ve bought all the ones in the above picture and none of them seem to thread in

 

Sorry, I meant restarting the new union. Lots of down pressure and turning counterclockwise until it clicks, then clockwise?

 

I just installed the silver union. It did not thread in as easy as I thought it would. I was able to start the first thread by hand, but then I had to really wrench on it to get it in.
The factory one was also hard to remove. I looked at the threads and they seemed. fine

 

That was part of my issue as well, I’ve tried using some significant force to get it there but still no dice, I am also worried about really jamming it in there because I’ve read some horror stories about damaging the threads and having to rethread the diff

 

https://www.threadtoolsupply.com/thread-checker.html

OP, pick one of these gizmos up to check the threads of both fittings to make sure they are the same. You could also pick up a thread chaser to make sure the threads in the diff are good.

 

Mine did go in smoothly or else I would have stopped. There is some comfort knowing the replacement is aluminum and would get stripped before the diff threads would.
I did read another post where they had the same problem and watched a YouTube vid where it looked like the guy had to use some force to get it in. I chalked it up to using a smaller wrench and being under the truck while turning it.
So much for quick and easy mod. Good luck with yours.

 

My 2019 Sport factory breather was on really tight also but it finally loosened and I used the Amazon silver breather and it threaded in just fine. Maybe the 2020 Sport changed it?
/gg Toyota