Front axles (1 Viewer)

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Oct 16, 2016
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Trinidad
I have a leaking front diff oil through axles seal problem that 4 pairs of new seals have not resolved. mech has advised that the axles are looking a little worn around the point where seal sits.. weird that a rubber will wear axle..

so i am looking for replacement axles for my 1991 HDJ81 and i see Longfield has 24 and 30 spline... how to know which to buy short of pulling down to count?
 

NLXTACY

Wits' End
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Yeah there are two possibilities: the scoring on the axle journal is significant enough that the oil seals fail right away or the knuckle shims were not installed correctly from the last rebuild and the axle shaft isn’t true center the housing. Actually dealt with both over the past month.

The tool over drives the seal 2mm to a fresh spot on the journal.
 
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Joined
Nov 9, 2012
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Olathe, KS, USA
Linking the other thread for reference.

@NLXTACY is also very correct. I'll bet the shafts are very worn where the seals ride and you need new axles. If you cannot get new axles, there is a thing called a "Speedi-Sleeve" that you could drive on there, but I'm not sure that's readily available in Trinidad.

 
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Trinidad
well the 80 series doesn't have any adjustment for shaft alignment. the brass sleeve on spindle was thinner than the replacement however I am not sure if it was thinner at install or if it was worn. so we changed and redid axles. I used trail gears axle seal

will tray OEM and over drivign it if it continues to leak
 
Joined
Nov 9, 2012
Messages
11,268
Location
Olathe, KS, USA
well the 80 series doesn't have any adjustment for shaft alignment. the brass sleeve on spindle was thinner than the replacement however I am not sure if it was thinner at install or if it was worn. so we changed and redid axles. I used trail gears axle seal

will tray OEM and over drivign it if it continues to leak
Well, the shims that are under the trunnion caps are what are used to get the correct alignment of the knuckle housing with the axle shaft. If someone removed the shims and they weren't supposed to, then your alignment of the shaft center to the spindle center is not correct.

If your housing is bent, it can cause the same effect. Have you been jumping your truck?
 
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Sep 15, 2016
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Chattanooga, TN
You should also make sure that your axle housing vent is not clogged. If it is clogged pressure will build when things heat up and could be pushing gear oil out past the seal(s). You can pretty easily remove/clean and confirm that no part of the vent system is clogged, including the elbow that screws into the housing.

Besides vertically aligning your shaft the shims also set the preload on your knuckle/trunion bearings. If you are in doubt of the state of these shims you can use the preload check as one way to see if you are shimmed correctly though it requires disconnecting steering/tie rods and possibly removing the wiper seals. From memory I think I read somewhere that the 80 axles typically didn't ship with a lower shim and that shims were added/removed from the upper trunion bearing cap to set preload. I wouldn't trust that 100% (since it's from memory) but you may be able to research and verify the typical shim arrangement and adjustment procedure on the forum and in the FSM if you need to get more deeply into it.
 

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