Futo Fab Subaru Stub Shafts not fitting into R180 properly

[geob415]

Hey Everyone, 

 

I seem to be running into a problem with the Futofab Stub Shafts for my 240Z. The Stub shafts seem to be too long for my Subaru R180 Mechanical LSD. If you look at the photo here you'll see that it's sitting way too far out in order to hold diff fluid. Am I not putting these in right or did Futofab sell me the wrong stubs? I was wondering if anyone else has ran into this issue. I counted the splines and they are 27 on the stubs. They also turn the diff too if I move it. It's just way too far out.

 

Thank you in advance!

 

Photo of stub:

https://imgur.com/a/cDYnBLphttps://imgur.com/a/cDYnBLp

 

Photo of mechanical 3.9 STI Diff:

https://imgur.com/a/whb84QW

[thisismatt]

Are you trying to user circlip stubs with a bolt-in diff?  Pull the stubs and look into the diff...does it have something in the middle with a threaded hole in it?

[iceman510]

None of the later Subaru R180s should have the bolt-in stubs, but no telling if someone changed something.  I think you have to really push those in to get the circlips to engage, so don't do it unless you have a method to remove them. 

 

Measure the depth in the diff to the circlip and the insertion length and see if that is what is impeding full insertion. 

 

I don't think you would have the wrong parts, as there is really only one version of these out on the market that I know of (not necessarily one maker, but they should all be the same). 

Edited February 16, 2022 by iceman510

[geob415]

Hey Fellas, I'l take a look into the advice with the circlips. I think that's where the issue is. I took the Diff cover off and confirmed its an 05 STI Mechanical Diff. Here's a video of me trying to push them in. I think you guys are aright with the clips. I'll see how that goes. I'll post updated photos and videos. Here's a clip before I mounted the diff.

 

 

[geob415]

Here’s another video where I use a mallet on the stub, it’s lined up where it’s supposed to.

 

 

[Jesse C.]

Well, I installed my stubs by making sure the clips inside the LSD where pretty well centered inside and not sticking to much to one side or the other. Then I greased the end of the stub, pushed it in as far as I could by hand, and then used a Dead Blow hammer. Best to place the diff on its side or against a strong backing, like a solid wood against the wall or a the leg of the bench. It took  a few hits before they finally went in, and they seem to be working just fine. 

 

And don't forget to install the studs before you install them. 

[geob415]

Should I be concerned with these marks on my stub shaft. It appears that th esplines on my diff are hitting the stub shaft. If you look closely in the purple circle you can see where the marks are hitting. Perhaps my clips aren't all the way in?

https://imgur.com/gallery/wd8eHqf

[Jesse C.]

19 hours ago, geob415 said:

Should I be concerned with these marks on my stub shaft. It appears that th esplines on my diff are hitting the stub shaft. If you look closely in the purple circle you can see where the marks are hitting. Perhaps my clips aren't all the way in?

https://imgur.com/gallery/wd8eHqf

 

That almost appears as if they have gone in too far. But apparently they have not. My stubs came from Williams Machine in California, I have no idea where FUTOFAB gets theirs done. 

 

My stubs could be pushed in all the way to the clip, and then I had to use the dead blow to finish driving them in. But I never had marks like that on my stubs when I first tried pushing them in. 

Edited February 19, 2022 by Jesse C.

[iceman510]

Interestingly, the two stubs look different.  Jesse's show that the spline grooves continue onto the second step of the shaft slightly, matching the splined section.  The parts in your Imgur photo don't seem to have that portion machined as they came to you. 

 

My question is- are they marks from insertion or rotation?  If there is no rotational interference it may not matter.  Are they getting marked from making contact with the mating spline structure when inserted?  Might need a slight relief cut.

Edited February 21, 2022 by iceman510
correction

[thisismatt]

2 hours ago, iceman510 said:

Interestingly, the two stubs look different.  Jesse's show that the spline grooves continue onto the second step of the shaft slightly, matching the splined section.  The parts in your Imgur photo don't seem to have that portion machined as they came to you. 

 

My question is- are they marks from insertion or rotation?  If there is no rotational interference it may not matter.  Are they getting marked from making contact with the mating spline structure when inserted?  Might need a slight relief cut.

 

Good catch.  Seems like they're maybe bottoming out on the side gears before inserting fully...?

[SupDoc]

On 2/15/2022 at 2:43 PM, geob415 said:

Hey Everyone, 

 

I seem to be running into a problem with the Futofab Stub Shafts for my 240Z. The Stub shafts seem to be too long for my Subaru R180 Mechanical LSD. If you look at the photo here you'll see that it's sitting way too far out in order to hold diff fluid. Am I not putting these in right or did Futofab sell me the wrong stubs? I was wondering if anyone else has ran into this issue. I counted the splines and they are 27 on the stubs. They also turn the diff too if I move it. It's just way too far out.

 

Thank you in advance!

 

https://imgur.com/a/cDYnBLphttps://imgur.com/a/cDYnBLp

 

Did you ever get this issue resolved? I need to buy a set of conversion stub axles, too.

[geob415]

On 3/5/2022 at 8:52 AM, SupDoc said:

 

Did you ever get this issue resolved? I need to buy a set of conversion stub axles, too.

Unfortunately no, I went onto the Datsun Facebook Forums and found an old post from John Williams, he is currently making more stubs so I will be giving him my business. It sucks that I paid almost $600 for a part that doesn't work. Luckily I've bought some products from John Williams before and I will be happy to wait for him to manufacture new stubs for my diff.

[iceman510]

Talk to Dave Patten at Futofab.  I think he would be interested in getting this right.

[thisismatt]

@Dime Dave you in here bro?

[carterb]

Dave has gone above and beyond with me in the past as far as customer service goes. 

Hive him a call or send him an e-mail  David Patten <futofab@gsinet.net>

 

--carter

 

[geob415]

On 2/15/2022 at 2:43 PM, geob415 said:

Hey Everyone, 

 

I seem to be running into a problem with the Futofab Stub Shafts for my 240Z. The Stub shafts seem to be too long for my Subaru R180 Mechanical LSD. If you look at the photo here you'll see that it's sitting way too far out in order to hold diff fluid. Am I not putting these in right or did Futofab sell me the wrong stubs? I was wondering if anyone else has ran into this issue. I counted the splines and they are 27 on the stubs. They also turn the diff too if I move it. It's just way too far out.

 

Thank you in advance!

 

Photo of stub:

https://imgur.com/a/cDYnBLphttps://imgur.com/a/cDYnBLp

 

Photo of mechanical 3.9 STI Diff:

https://imgur.com/a/whb84QW

Hey everyone, the Futofab WRX STI Stub axles didn't work but the Williams Machine one did. I wasn't crazy and the stubs from Futofab were bigger than neccesary. the Stub axles I bought from Williams Machine fit in after 3 hammer smacks and are physically smaller stubs. Thank you so much for th einput fellas. The refrence pictures made a big deal. Take a look at the difference on this video here https://www.instagram.com/p/CbV9H--lCU9/