Front pinion and driveshaft angles issues (3.4 degrees) after HP30 upgrade

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TexasTJ2004

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High Folks, I have upgraded my front axle to HP30 from XJ.
I measured the driveshaft angles VS pinion angles,
And I see the following:
Driveshaft at 0.4 degrees
Pinion at 3.8 degrees
That gives delta of 3.4 degrees.
I suspect that it is too much of an angle for a front driveshaft.
If I understand it correctly, it is supposed to be like 0 degrees difference, not 3.4.
The reason I started to dig into it, is that I see too much of a play in the yoke and the pinion seal is leaking.
Do you guys think that this could be related to bad driveshaft angles? I am thinking that after upgrading to HP30 I did not change anything in control arms etc.


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Any way you can get a side picture of the driveshaft and pinion from further away? It’s hard to tell from that up close video. And yes the center axis of the pinion should* be right in line with the axis of the driveshaft. What matters though is that you don’t have vibrations on the highway. Some people find that up or down 1 degree does the trick of eliminating vibrations. 3.4 does seem like a lot but it’s impossible for us to see it without a further back side picture.
 
HornedToad said:
Any way you can get a side picture of the driveshaft and pinion from further away? It’s hard to tell from that up close video. And yes the center axis of the pinion should* be right in line with the axis of the driveshaft. What matters though is that you don’t have vibrations on the highway. Some people find that up or down 1 degree does the trick of eliminating vibrations. 3.4 does seem like a lot but it’s impossible for us to see it without a further back side picture.
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I will take a picture from side. However, the 3.4 angle difference is something that will be very to see.
I measured 0.4 degrees on the driveshaft and 3.8 on the pinion. I measured the pinion from the front of the diff.
 
TexasTJ2004 said:
High Folks, I have upgraded my front axle to HP30 from XJ.
I measured the driveshaft angles VS pinion angles,
And I see the following:
Driveshaft at 0.4 degrees
Pinion at 3.8 degrees
That gives delta of 3.4 degrees.
I suspect that it is too much of an angle for a front driveshaft.
If I understand it correctly, it is supposed to be like 0 degrees difference, not 3.4.
The reason I started to dig into it, is that I see too much of a play in the yoke and the pinion seal is leaking.
Do you guys think that this could be related to bad driveshaft angles? I am thinking that after upgrading to HP30 I did not change anything in control arms etc.
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The leak is not related to the pinion angle. Remove the driveshaft and check the yoke to see if you have any play. Check the nut also.
You will have to replace the seal most likely .
The pinion angle should be adjusted also.
 
NskLJ said:
The leak is not related to the pinion angle. Remove the driveshaft and check the yoke to see if you have any play. Check the nut also.
You will have to replace the seal most likely .
The pinion angle should be adjusted also.
Click to expand...

Can you clarify how the yoke play check would be different with or w/o driveshaft?
Trying to understand why to remove the driveshaft to check the play.
 
Opened the diff to check any gear damage, didn’t find any. Gears seems to be perfectly fine.
However, the diff fluid looks horrible. I have replaced it it 5K miles ago, how did it to such a dirty state in just 5K miles?

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Looks as though a water crossing may have occurred and the gear lube was not changed.
Have you checked with a magnet to verify there are not metal particles in the slurry.... ?
You will need to thoroughly spray out the inside with Brakleen or some other cleaner to remove as much of that slurry as possible.
Driving with that slurry could and would affect the carrier and pinion bearings over time.
 
TexasTJ2004 said:
Can you clarify how the yoke play check would be different with or w/o driveshaft?
Trying to understand why to remove the driveshaft to check the play.
Click to expand...

You can do it either way, I prefer to pull the driveshaft so I can inspect just the pinion preload. . If the seal is leaking the shaft needs to come out to fix it any way.
 
CharlesHS said:
Looks as though a water crossing may have occurred and the gear lube was not changed.
Have you checked with a magnet to verify there are not metal particles in the slurry.... ?
You will need to thoroughly spray out the inside with Brakleen or some other cleaner to remove as much of that slurry as possible.
Driving with that slurry could and would affect the carrier and pinion bearings over time.
Click to expand...

Do you think that putting fresh oil and then driving little and replacing the oil again will work?
I think that in order to properly clean everything I will need to remove the carrier, no?
 
TexasTJ2004 said:
Do you think that putting fresh oil and then driving little and replacing the oil again will work?
I think that in order to properly clean everything I will need to remove the carrier, no?
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I think you'd be fine spraying it down with brake cleaner, spin the carrier around as you go so you can hit it from every side. Empty a whole can or two if that's what it takes to clean it out. Let it sit for a few hours so everything can run to the bottom and the cleaner can fully evaporate out, wipe out the bottom of the pumpkin with some shop towels and button it back up.

The FSM actually recommends just pouring motor oil into it to flush it out, which wouldn't be anywhere near as effective as brake cleaner.

I bought some magnetic fill plugs for mine. I'm not sure how much it protects anything but it at least gives me a quick health check by pulling the plug and seeing what's there.
 
freedom_in_4low said:
I think you'd be fine spraying it down with brake cleaner, spin the carrier around as you go so you can hit it from every side. Empty a whole can or two if that's what it takes to clean it out. Let it sit for a few hours so everything can run to the bottom and the cleaner can fully evaporate out, wipe out the bottom of the pumpkin with some shop towels and button it back up.

The FSM actually recommends just pouring motor oil into it to flush it out, which wouldn't be anywhere near as effective as brake cleaner.

I bought some magnetic fill plugs for mine. I'm not sure how much it protects anything but it at least gives me a quick health check by pulling the plug and seeing what's there.
Click to expand...

Do you remember by chance which PN you used?
 
TexasTJ2004 said:
Do you remember by chance which PN you used?
Click to expand...

TexasTJ2004 said:
I mean for the magnetic plug? Sounds like a great idea.
Click to expand...

This is what I have in my Amazon order history. It doesn't say anything at all about being magnetic...it's been almost 4 years but I seem to recall going through dormans catalog to find whether they were magnetic before I ordered. Also you'll have extras because all I found at the time was a 5 pack. I'd offer you my extras if I hadn't moved 3 times since then and had put eyes on them at any point in recent history.

Dorman 090-100 Pipe Plug C.S. Square 1/2-14 Npt, Head Size 3/8 In., 5 Pack https://www.amazon.com/dp/B000DCNR3W/?tag=wranglerorg-20
 
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freedom_in_4low said:
I think you'd be fine spraying it down with brake cleaner, spin the carrier around as you go so you can hit it from every side. Empty a whole can or two if that's what it takes to clean it out. Let it sit for a few hours so everything can run to the bottom and the cleaner can fully evaporate out, wipe out the bottom of the pumpkin with some shop towels and button it back up.

The FSM actually recommends just pouring motor oil into it to flush it out, which wouldn't be anywhere near as effective as brake cleaner.

I bought some magnetic fill plugs for mine. I'm not sure how much it protects anything but it at least gives me a quick health check by pulling the plug and seeing what's there.
Click to expand...

I do see unexpectedly to much play in the pinion. Tile there is some movement in and out, meaning pinion moves in and out into the diff and also it goes little bit up and down. Like it is not sitting tight enough in it’s place. Could it be a damage from this bad fluid? I might have driven like this for 3K miles.
 
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