Technical Is my axle shaft too long?

Ford 9" with 31 spline axles:

1) With both axles' bearings and seals nicely seated in the housing ends, the inside gap is only 0.98". Aren't they supposed to be 1.125" apart?


2) Then, with the center differential installed, the pass side seats nicely again, like this:


But the driver's side won't go in all the way, even with a sledgehammer. It's proud by the thickness of 3 washers (about 0.15").


So is the driver's side axle about 0.13" too long?

TIA.

 

Put some clay/putty on the axle end to see if indeed it’s making contact.

 

Put the sledgehammer away.

 

IS MY AXLE SHAFT TOO LONG? I don't know, ask your wife!

 

I had to stop reading after "sledgehammer"

 

Also, the bearing-to-flange distance is the same on both axles.

 

Cut .250 off the one that’s too long and you’re done. I guess I could add this what I did with my Dutchman axles after I had the housing narrowed 5/8”. There was plenty of extra spline to make full engagement.

 

Stock housing or narrowed?

 

I think before I cut axle, I’d want to know what’s bottoming out. If it’s the end of the axle, fine, whack some off.
But if the splines-where they meet the axle-are bottoming out, no cutting will help you.

Ie dummy up your differential. Slide axles in. Easier to see with an open drive, not easy with a posi.

 

Narrowed.

 

Gary, I had to cut one of mine. The putty trick told the story.

 

Gary yr third member , what are you using ?
Is 3rd member spline straight through no step up? If no step ( smaller after splines ) that gap in between axle would be fine 1 inch. Little bet of
Burr/ grit can case axle not to seat all the way ,
Pic of ,
Is the pocket on bearing same depth side to side(LvsR) axle tube .
& are both bearings same thickness?
Before you cut ,is this pic with 3rd member in?
Swap Axle & see if other one will seat with no washers / spacers

 

The putty trick is the way to go but to get a starting point I use a graphite driver shaft (due to length) and I use it as a dept gauge (could call it a feeler gauge too if you prefer).
Remember that the bearing ‘crushes’ inward so measure from max depth of splines in the rear end to the inner bearing ridge of the flange.
PS: looks like you have lots of spline length to work with.

Couple snaps from the Currie site.

 

Fellas, where do you put the clay to check the clearance, but can remove it afterwards?

-It's all Ford with trac-lock and Moser axles.
-I confirmed no burrs or grit.
-Housing ends' bearing pockets are identical.
-Bearings are both the same thickness.
-yes, the picture with the washers is with the third member installed.
-with the third member removed, I swapped axles side-for-side, and they both seated in the housing ends correctly.

 

I cleaned the end of the shaft with laquer thinner and stuck it on.

 

^^^^^ This. Just a little ball will do. Lube up spider pinion for non stick. Hell, “Pam” it.

 

I would measure the length of the axle splines on both axles. Then I would insert each axle into the 3rd member with it setting on the bench (no housing) then I would measure exposed splines on each shaft.

This would tell you exactly how much spline engagement you have. I would check Moser and see what their recommendation is (minimum 1" IF I remember correctly) then IF I am well within that recommendation I'd just cut or grind the axle and be done with it.

But that's just me.....


...

 

That works as well.

 

I wonder if there is a preferred shortening method? You might want to ask Dutchman before proceeding.

Easiest just to drop an axle in a chop saw but maybe a liquid cooled horizontal band saw would create less heat which might be recommended as it may help preserve any existing heat treating. I dunno, just thinking out loud

 

Like @lostone said also , just slide axle in 3rd member on bench,
Since pic with spacers are with 3rd member ,cut 1/4 -1/2 off , use cut off wheel , hacksaw , chop ext, then hit the splines with file just to tapper where splines where cut ,,,
All the axle that I have where/ are cut to fit .

So sounds like there a step in 3rd member / not splined all threw

 

This made me grimace in shame. Two days ago I was working on the FED, bolting the driveshaft cover to the rear of the shortie 'Glide. Pulled the five cad-plated bolts that came from the transmission shop, and installed fancy ARP ones. Space is tight, can't get a socket or ratchet wrench in, so normal wrench, 1/32th of a turn at a time.

Bolts bottom out. Too long methinks. Reverse out all the bolts, 1/32th of a turn at a time.

I put the fancy, expensive ARP bolt into the vice soft jaws and was halfway through cutting it shorter, my head noodling away. It dawned on me that mebbe the threads were bottoming out. Checked, and yep, bolts were the correct length, threads not deep enough. Glad I realised on the first bolt... you have to mortgage both kidneys for the ARP stuff.

Cheers,
Harv

 

Gary, does the axle go into the center section (on the bench) as deep as the splines are long?

Aren't there inner and outer splines in a posi axle? Perhaps they aren't lined up properly.

 

Have you tried rotating the axle when it’s installed? To line up the side gear and the splined plate? If the axle is too long it could be contacting the long cross pin.

 

What 57 heap said is super important! Must engage both sets of splines on the long axle.

 

With 1 inch gap between axles ,
I am sure its in both set of splines ,
Even before the .150 thoe of
spacer /shim

 

What 57 said is important as there are two sets of splines (on one side) that need to be aligned for the axle splines to fully engage. I assumed that you had already done this (my bad if not done) as you’re just a few thou off on your depth.
Here’s a story to help explain where I’m coming from.
I chased a problem like you are having a while back on a coupe project. It had a new 9” just installed and I would always get an axle seal leak on one side. I messed with trying to reseal it several times. Finally got pissed and pulled the whole dam rear end out and put it on my bench. Once I checked the lengths of both axles myself and found the axles were both trimmed to recommended length, I checked the housing.
Result: Found the 56” unit (wms to wms) was actually a bit shorter. Whoever built the housing had shortened and welded it up (done well) and had made it 50.875 (so 55.875” wms/wms). Long story short, I reassembled, used the method I described above and ended up knocking ~1/8” off the end of the axle in question. Resealed it and never had a leak again. Since then I check the housings a little more carefully before I start to assemble.
*** The housing wasn’t a Currie unit like yours, but found out it was sourced from a reputable vendor (lmfao).

 

The housing is 55 1/2" wide.


You guys were right; when inserting the long pass side axle, I felt a slight "step" about an inch before it came to a complete stop.

Here are the axles bottomed out in the center differential:


That resulted in 55 3/8" between the bearings' outter edges.


I think all this confirms my driver's side axle needs to be shortened 1/8" ( or a bit more for wiggle room).
Right?

 

I’m not sure that left axle is in all the way. Can you hold the right axle with someone helping you with a big prybar and try turning the left axle until it is aligned. I believe that is the side with the clutches and it has to engage the clutch hub as well as the axle gear. I was mistaken when I said the long axle. It’s actually the shorter one. If you pull that axle out and look in there, you should be able to see the two sets of spines. See if they are lined up.

 

Yes- the left (short, driver's side) is all the way in. The diff is 3" deep and the splines are about 3 1/8" long.


Yes- that side's two sets of splines are aligned.


Thanks for the step-by-step analysis.

 

Perfect.
Now when pumpkin is installed, use a depth gauge (like a shaft from a golf club) and insert until it touches that inner ring (see pic) and measure to where the inside of the bearing will ride (2nd pic). Then measure your axle from spline end to the inside of the bearing. I bet you’ll find your axle measurement is ~1/8” longer. Trim as necessary and Bob’s your uncle.