Fixing Yesterday's Mistakes - Replacing Front Drive Shaft and CV Axle

[Godzilla2y]

Howdy again, ExplorerForum.

As I've mentioned in a few previous posts, I made a mistake several years ago--I trusted someone else's judgement on these Explorers.

In 2020, when trying to get The Archbishop running again, my FIL believed there was an issue with the front end. When on the lift (wheels fully extended), the driver's side wheel would only turn a small amount before hitting a lock and not turning any further. I now know that some of the front differentials are just made that way--I could have verified this by compressing the suspension slightly and trying to rotate the wheel again.

My FIL's solution to this (to get it back on the road quickly) was to cannibalize the front CV shaft, leaving only the far end of it (the piece of the spline that passes through the wheel bearing), so the wheel bearing didn't immediately collapse. He told me that the front diff would be fine, and that I wouldn't have to worry about any fluid leaks.

This was coupled with my uncle losing one of the bolts that holds the front drive shaft into place. Our solution to that was to pull the front drive shaft.

4 years and a few hundred miles later, here we are.

I found some new bolts for the front drive shaft (from front drive shaft to the front diff; the ones that hold the u-joints in via the little brackets): 1/4 28, for any future readers trying to find the same thing.

I have a few questions, though, guys.

1. Will regular hardware store bolts be okay for these? Do I need to get them in a certain grade?
2. We did not mark either the transfer case or the front axle for where specifically the front drive shaft is supposed to go in--how boned am I?
3. I've ordered a new cv axle and seal for the driver's side--is there anything else I should consider replacing related to the cv axle/front diff?
4. Anything I'm forgetting? Any pointers so I don't rip my hair out?

Thanks in advance, all

 

[C420sailor]

Me, I’d probably run stainless hardware down there for corrosion resistance. I don’t believe those bolts are under any real tensile or shear stress—those brackets simply keep the u-joint engaged against the bearing surface of the yoke—which bears the brunt of the load.

 

[Godzilla2y]

After getting the old seal out, it looks like the outer bearing got a little rusty, too. Debating if it's even worth replacing. Seems to be mostly surface rust.

Regarding my "not marking the drive shaft" question, after some research, it looks like I should be okay. The driveshafts themselves are balanced externally. Marking driveshafts, from what I've gathered (and what makes logical sense) is to make sure you install them in the proper orientation (ie making sure you don't stick the end that was on the rear diff onto the tail end of the transmission). It's not really possible to do that with this truck, so I should be in the money.

I've looked around some more underneath the truck, and it looks like my rear driver's side axle seal is leaking way too much, and the seal at the front of the rear diff is leaking a little. The driver's side seal, I'm pretty sure, is OE, so that's no surprise. But the one connected to the driveshaft, I replaced in 2020. Any idea what I did wrong so that I can prevent it from happening again? Maybe a binding u-joint?

 

[Godzilla2y]

Tonight I'm nursing my office worker muscles that aren't used to doing all this stuff, and figured I should post an update. I worked on The Archbishop pretty much nonstop from 5pm-10pm Friday. Then again from probably 10AM to 6PM on Saturday. And again from 10AM to 6PM today. I get so wrapped up in this stuff that I've been eating very little; my waistline is loving this, man. My wife appreciates the rougher hands, too.

To save a little face from my initial post in this thread, I'd like to clarify that I haven't driven the truck much with the removed cv shaft--less than 1000 miles, I'd reckon. Considering that's ove the course of 4 years, maybe that makes me look worse in terms of this truck.

Anyways. Onto the updates.

I replaced the upper control arms on both the driver and passenger side, and got the new seal and new CV shaft into the front driver's side. Try as I might, I could not get that seal in there properly. It's 100% seated on the left (front of the truck) and gets worse starting at about 1 o'clock and ending at about 5 o'clock on the seal, being only about 80% seated at 3 o'clock. I figured a new seal and a plugged hole is better than what I ran 4 years ago, so I made an executive decision and said "**** it, ship it". Stuck the CV shaft in there.

The CV shaft went in mostly without a hitch. I say "mostly" because that's the first CV shaft I've done solo in over a decade. I spent hours trying to slide the shaft in to no avail on Friday night (story of my life), finally got dinner, then did some Googling to figure out my major malfunction. The internet suggests making sure the opening of the circle clip on the cv shaft faces DOWN when trying to get it in the diff, packing a little grease around the circle clip to make sure it stays in place before it gets where it needs to go, keeping the shaft as straight as possible during insertion (we all know how important that is), greasing the splines and shaft for smoother movement, and then whacking the hell out of the end once you know it's all lined up properly inside (hold your laughs, please).

So I tried it all again Saturday morning (positioning and greasing the circle clip, smacking it with a rubber mallet, etc.) and got the cv shaft in in basically no time.

During test drives, there was a whining sound coming from the front end. And a clunk when going from D to R or from R to D. The internet said this could be anything from failing auto hubs to bad CV shafts.

Sunday morning, I realized the front diff was probably low. Got the truck on the lift, had of a hell of a time getting that fill plug out, and then filled it up. Checked rotation of the wheels, tried shaking the hell out of anything I could get my hands on, and it all seemed stiff. Off the lift, back and forth in the driveway, and it's still clunking.

I figured there were bad lower ball joints. Had a 3-year-old helper try to turn the wheel while I looked underneath, and noticed a shudder when it got turned to the right. I figured bad lower ball joints, maybe?

Back on the lift and back up in the air. Took everything apart except busting the steering knuckle free from the lower ball joint, when I saw it: loose bolt on the passenger side upper control arm.

I still have the two-piece passenger control arm assembly. Nowadays, manufacturers offer either the single-piece replacement that Ford now recommends OR they sell the lower part of the two-part assembly. I bought the lower assembly part, and then busted the camber adjustment bolt trying to remove it when I changed the parts. I learned after breaking it that I did not need to remove it. This adjustment bolt also helps prevent the wheel from moving forwards or backwards if the other bolts aren't tight enough. If they're NOT tight enough, that control arm can move left and right pretty freely, producing a nice loud clunk when you turn the wheels.

Tightened those control arm bolts like my life depends on it. Put it all back together. Took it off the lift.

The clunk is gone! But the whining sound still exists. This one has me a little stumped. Sometimes it'll suddenly stop, sometimes it'll suddenly get much louder. If I leave the truck parked for even a few seconds, then go to take off, the sound will not be there for 20-50 feet. I thought putting a couple miles on it might get the new gear oil spread around enough to quiet everything out, but 5 miles did not seem to do it.

Finally, I tried putting it into 4 Auto and driving to see if it changed. The shafts seemed to bind up, turning out of the driveway. The sound seemed quieter. Hitting a railroad crossing a little ways past my house, the 4WD lights started flashing, and ended with the 4WD light turning off. Pulled into a driveway shortly after. Cycling through the switch didn't change anything. The lights would flash occasionally. Limped it home in I guess what was 2wd.

Shut it off when I got back home, then restarted the truck.Foot on the brake in park, put it into 4Auto. Seemed to shif into it. Light came on. Shfted to neutral and then 4Low, heard what I'm guessing is the hubs clicking, light switched to 4Low. Backed up and down the driveway 20 feet or so. No binding, no growling, much quieter whining. Park, 4Auto, forwards and backwards, same thing. Park, 2WD, whining came back.

I shut the truck off and called it a night after that. I needed dinner and a beer. I was sore and sweaty and filthy.

Any ideas, forum? What should I check next? I have a new AC compressor coming Tuesday, so it's not like I'm done wrenching on this thing.

 

[Godzilla2y]

Wife ran some errands with the Explorer today to get some more miles on it. It seems to be squealing less now. I'll keep driving it in 2wd this week to see how it does. Maybe things just needed more lubrication. It doesn't look like there's much of anything leaking anywhere, either.

 

[C420sailor]

How loud is the whine? I had a very slight whine/whistle after replacing front diff seals. I think it was the dust seal lip rubbing against the CV. It eventually went away. Not sure if it’s the same thing.

 

[Godzilla2y]

Not loud enough that one could hear it over the phone. The road noise overcomes it by 35 or 40, at least to my ears. It's high-pitched. Is the dust lip seal the metal bit that sits along the outside face of the diff?

 

[410Fortune]

Tonight I'm nursing my office worker muscles that aren't used to doing all this stuff, and figured I should post an update. I worked on The Archbishop pretty much nonstop from 5pm-10pm Friday. Then again from probably 10AM to 6PM on Saturday. And again from 10AM to 6PM today. I get so wrapped up in this stuff that I've been eating very little; my waistline is loving this, man. My wife appreciates the rougher hands, too.

Thank you for that! As somebody who designs elevators for the worlds tallest buildings (basically a glorified auto cad operator that draws boxes all day for the last 30 years “flying a desk”) this paragraph about made my day

Get out of the office and into the shop! Your body and your wife will thank you for it

 

[Godzilla2y]

Did another ~10 mile trip today. Squealing is, again, better--it disappears once you get above 40mph or so, and doesn't return until you get much slower. It's still there, though.

Still no major leaks or clunks or anything, even after intentionally hitting some bumps to test it all. I'll update if any more progress is made.