Rear propshaft upgrade

[Ben Rover]

Well the shaft and the u-joints do have grease nipples and I was planning on greasing em up before the install but how do I know, short of taking them apart, if they're greased properly?

[antichrist]

Originally Posted by Ben Rover

Well the shaft and the u-joints do have grease nipples and I was planning on greasing em up before the install but how do I know, short of taking them apart, if they're greased properly?

Like I said, purge the old grease, meaning you see it (the fresh grease) coming out from around the seals. This is the only way to know that all 4 journals are getting new grease, and that the old "dirty" grease is out.
If it's not coming from around all 4 seals one or more grease passages are blocked. For as cheap as the u-joints are, if that's the case, I would just replace it.
I'm attaching the relevant section from the Spicer manual on greasing them. (I've seen a lot of misinformation about it on various forums)
You'll notice that it says every 5-8,000 miles, but I tell people "every oil change" so it just becomes habit, rather than having to remember, or take notes, when you did it last. Obviously, if you're off-roading a lot in water or muck, you want to do it more often.
One last thing, you must lube them. If you don't do it properly, you're better off with sealed u-joints.

[p76rangie]

Originally Posted by antichrist

You want grease to come out from around all 4 seals on the joint.
grease them well (grease coming from all for seals) after installation.

There is a little difference between grease coming out the seals and it being visible. The spicer instructions are telling you to STOP once you get SIGHT of any grease. They are not telling you to blow the seals by forcing grease out. You stated that you use to be a mechanic, what bullshit.

Why not just pull the seals off before you fit the joint.

[texaninmass]

What is the reason in general for this conversion?

[Ben Rover]

The reason I'm doing the conversion is because of the lift. I'm running about 5" right now and proably more like 6" by the end of the summer. A u-joint will help with the driveline angle and the rotoflex can get damaged on the trail more easily that a u-joint propshaft.

Other than that, no real reason. Most Discos, even with 2-3" lifts go their whole lives with the rubber donut on their rear ends and live long, happy lives

[texaninmass]

Ahh I see. Thanks Anthony

[antichrist]

Originally Posted by Ben Rover

The reason I'm doing the conversion is because of the lift. I'm running about 5" right now and proably more like 6" by the end of the summer. A u-joint will help with the driveline angle and the rotoflex can get damaged on the trail more easily that a u-joint propshaft.

I didn't realize you had that much lift. I don't know how much research you've done, but quite a few people report excessive driveline vibe with that much lift without going to a GBR or TW double cardan propshaft. YMMV

[Ben Rover]

Oddly enough, I've gotten no vibration whatsoever from the lift versus when the truck was stock. I was prepared for the worst and I gotta say I'm pleasantly surprised by the way it handles. I'm still going ahead with the prop shaft change and eventually the radius and trailing arm upgrades since this is a dedicated trail truck

[antichrist]

Originally Posted by Ben Rover

Oddly enough, I've gotten no vibration whatsoever from the lift versus when the truck was stock. I was prepared for the worst and I gotta say I'm pleasantly surprised by the way it handles. I'm still going ahead with the prop shaft change and eventually the radius and trailing arm upgrades since this is a dedicated trail truck

Well, if there're no vibes, and it isn't squirely driving, and tracks properly, I guess that's what matters. Yeah, from what I've been told, a rotoflex wouldn't last too long with that much lift.
Where are you located?

[Ben Rover]

I live in Montreal

Status update: Prop shaft is removed, now I'm struggling to get the 3 bolt flange out. Gonna have to build some kinda too to get it out

And it's getting dark...

[Ben Rover]

Tragedy! The bolt I had in the flange broke in it...

Any idea how to get this out? I read on an old Discoweb thread to hack it out

[antichrist]

Originally Posted by Ben Rover

Tragedy! The bolt I had in the flange broke in it...

Any idea how to get this out? I read on an old Discoweb thread to hack it out

Do you mean a bolt you had screwed in to the centering peg at the red line? The sruface indicated by the "62" is coated with loc-tite.
You might try a screw extractor. But if you were using a hardened bolt you might have a hard time drilling it out for the screw extractor.
I've found the best extractors are the type shown below (I think I got mine from Matco Tools)
If you get the bolt out, most people find the centering peg comes out better after applying heat.

[Ben Rover]

Yeah, that's where it broke. Luckily it broke because I apparently had some crappy old bolts mixed in with my good one, I should be able to extract it.

And I think you're right on the heating part, I just read in the manual that the part is supposed to be covered in Loctite before being jammed in there. A little heat might budge it good.

If not, the grinder will

[antichrist]

Always a good idea to look at a bolt head before you use it. I've found grade 5's, and even grade 2's, mixed in with grade 8's at the hardware store. Mostly I get them at a bolt supply house by the box, so it's not as much of an issue.
Some people say they got the peg out without heat, but I didn't even try on mine. I applied heat and it popped right out. It's been so long I can't remember if I used a slide hammer or not, which is what a lot of people use.

[Ben Rover]

Finally got the conversion done, took two days... this is what's left of the old drive flange.