Rear diff. breather mod

I ordered part #

$8 90404-51319 Toyota Union - 90404-51319

90404-51319 (union fitting) to do the above mod, but just wanted to confirm that it'll work first. Depending on which write-up you read, that part or part#

$7 90404-51026 Intake Air Control Valve Union

90404-51026 is required. Are the two interchangeable, or specific to certain years of truck? Mine is an '09.

 

The Union is what threads into your axle tube. So, the only important aspect of either of those part numbers is that the *threads* are correct to screw into your axle tube. You could probably go down to the local auto store or hardware store and find a similar union type fitting with the same threads that'll work.

Don't worry about the two different part numbers. If you read somewhere that it worked for one person, then chances are....it'll work. Both part numbers probably have the same threads but a different design. As long as its the proper size for the hose you plan on using, that's all thats important.

I did that mod on my 96 truck years ago. I haven't done it on my 07.

 

Thanks Janster. I'll give 'er a go this afternoon.

 

So it's all done. I'm a bit worried about the union fittin screwing into the diff housing though... With the Teflon tape I put on the threads, I found it a bit more difficult to gauge how tight to screw it in, just aired on the side of caution in the end. Hopefully it's tight enough, I certainly can't unscrew it (or tighten it further) by hand, and with the Teflon tape the seal should be good enough. What do you guys think, I know it's difficult to tell without turning the wrench yourselves, and I don't know exactly what my question is, I'm just voicing my concern with tightening it further and feeling it go loose... Then yelling every curse word under the sun and feeling sick.

 

You've done your homework with research, so I would assume the threads on the union are what you needed to screw into the axle tube.

If you screwed the union in there halfway (for instance) and it 'wobbles' - then you've got the wrong size. It shouldn't wobble.

If you screw it in there and you feel a lot of resistance, either means the threads are dirty or you have the wrong threads or too large of a union. Teflon tape will add some resistance, but not all that much.

Hard to explain. If you tightened it by hand, grab a wrench and give it a half turn tighter and see how it feels and go from there. Then - in a couple days, feel free to check it. If its coming loose, then you need to tighten it down more.

Nice work!!

 

Right on Janster, thanks for the reply. I will check it in a couple of days, and even after my 300 km trip home this evening. I checked the thread pitch against the stock breather and the two threads meshed nicely. I think the Teflon tape is throwing my feeling off when I tightened it down. Well see when I check it. Oh, and I was looking around on here and discovered that my front tow hook was on upside down, so I promptly flipped it.

 

Keep wrechin'!!!

It's kinda like.... a wrench a day will keep the garage boys at bay.

 

Haha that's correct, until I strip the threads and need a new rear diff I just took it off and re-installed it for piece of mind, the threads seem ok, but I'll monitor it for a while. It's funny, as an electrical guy electrons don't phase me (i.e. I know how far I can push them ), but when it comes to important mechanical things like this I'm scared to death. I feel far better having taken the Teflon tape off and felt the bite of the thread. I guess it's not the right part to be expecting 100 pounds of torque anyway

 

thread size is 1/8"-27tpi National Pipe Thread.

 

I believe you but what does that dimension (1/8") represent? Just curious, since the outside diameter of the thread is more that 1/8", and the length of the threaded portion of the union fitting is also longer than 1/8".