Front Axle Replacement

[Brian_B]

tl;dr --
How the F*** do you get the new axle in the differential to lock in? Mine is about an inch away from fully seated, but I can't get it to back out or push in. It was very difficult to get out.


Long Story --

So, about a week after I replaced the shocks I took it out on a new trail. It ended up being a bit gnarly, but made it back ok.

About a week later - noticed I had a blown drivers side outboard CV boot. As soon as I noticed it was blown, I also noticed it would start to click at full steering while backing up. So I don't know if I dorked it up while doing the shocks, or if it was something on the trail, but it happened. So I'm gonna fix it.

Looking it up - it appeared just as well to replace the axle as to try to repair the boot, and since it was starting to click, I figured it was probably a bit more involved than just "new boot".

So, I ordered a new axle. Watched a couple of youtube videos. Searched around here and couldn't find much, other than a post by @Snacktime saying he did it plus the RC rack bushings in about an hour.

I think "Hey that's a good idea since I'm in there" so I order those too.

I figure - ok, I'm no mechanic, so longer than an hour, but it doesn't look too complicated so maybe an afternoon?

I started today around 1pm. First issue was I couldn't get the LCA off the knuckle; it wouldn't budge at all... so, I just took the back camber adjustment nuts and bolts off like I did for the shocks - that let me get half the axle out. The diff side would not budge. I had to pry and beat it about an inch and a half before it finally broke loose and pulled out. That took... 3 hours. (told you I was no mechanic)

Ok, so with the axle out, I cleaned up the mess from the blown boot, got the RC bushing in place (that wasn't terrible), and go to put the new axle back in.

Twist and push, twist and push, I finally get it to start to seat in the diff, it slid in about 1.5 inches from fully seated. But it's stuck, won't pull back out, won't push in any further. I tried beating on it semi-gently, but it has so much play that's hard to do to any effect. I got it in about another half inch, but I'm still an inch from being fully seated.

I kinda stopped here, after mangling the first few threads on the axle (did get that fixed) and getting just stuck without going and getting a bigger hammer. And the mosquitos were coming out in force. So figured I'd call out for some help.

Any advice?

Sponsored

 

[Snacktime]

Sounds like you had a fight with the drivers side, the M190 has galling issues due to the cast iron carrier. Makes the job much harder than it should be. Long as you put the shorter one in on the drivers side you are probable fighting the carrier.

Need to verify correct parts, then you might need some emery cloth.

https://www.bronco6g.com/forum/threads/front-differential-discussion.79723/page-3 has some photo that may help.

 

[Brian_B]

Yup. Drivers side.

Need to verify correct parts,

This is a good question. I looked at both but didn't lay them side by side before I started installing.

Engineering number on the original is MB3W-3A428-DB
Engineering number on the new is MB3W-3A428-AB

Part number I ordered was MB3Z-3A427-A

According to this post, it should be correct?
https://www.bronco6g.com/forum/threads/half-shaft-part-question.73979/post-1933402

Although reading that post down a bit further:
https://www.bronco6g.com/forum/threads/half-shaft-part-question.73979/post-1933416
Maybe I should have ordered MB3Z-3A427-B (Big Bend) and I have the wrong shaft.

 

[Ducati1098]

Yup. Drivers side.

This is a good question. I looked at both but didn't lay them side by side before I started installing.

Engineering number on the original is MB3W-3A428-DB
Engineering number on the new is MB3W-3A428-AB

Part number I ordered was MB3Z-3A427-A

According to this post, it should be correct?
https://www.bronco6g.com/forum/threads/half-shaft-part-question.73979/post-1933402

Although reading that post down a bit further:
https://www.bronco6g.com/forum/threads/half-shaft-part-question.73979/post-1933416
Maybe I should have ordered MB3Z-3A427-B (Big Bend) and I have the wrong shaft.

MB3Z-3A427-B is the correct part number for your original engineering number.

 

[Brian_B]

MB3Z-3A427-B is the correct part number for your original engineering number.

Thank you. Ordered the right part. Will chime back in with results.

 

[Brian_B]

@Snacktime got it in 1

Thank you @Ducati1098 for the part confirmation too!

 

[Snacktime]

That is a m210 driver side one! The passenger side m190 and m210 cv have the same length/spline counts which is why you didn't have an issue on that side.

 

[Brian_B]

That is a m210 driver side one! The passenger side m190 and m210 cv have the same length/spline counts which is why you didn't have an issue on that side.

Huh. Somehow it was cheaper than the m190 one and shipped same day. I suppose my google-fu needs a bit more work looking up part numbers.

 

[Brian_B]

A minor miracle - United States Post Office came through and delivered! The correct axle came in, 2 hours later all buttoned up and cleaned up. The new axle slid right in, a little turning and a push was all it took to get it fully seated and locked in.

If I had been able to get the LCA out of the knuckle, the install would have been done there, but since I didn't and had to drop the LCA from back at the camber adjustment, in combination with my lack of foresight before sliding the new axle home into the FDU, I had to pull the caliper off to get the new axle on the correct side of the brake line. So that ate up a few minutes of wasted time right there, but didn't really add any difficulty to it. Live and learn.

Sponsored