Used gears with like new preload

kameronkales

kameronkales

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I have a mostly stock LJ. Bought from original owner who hardly drove it / never used 4wd.

Recently tested out preload on the Dana 30. I don’t have the “most” accurate tools but preload read at 12. That’s basically new. iirc spec is 12-14 inch lbs

Is that spec possible with a 18 year old vehicle or were gears/something in diff changed out?

It has 3.73s in it so if it was changed it was changed with stock gears.

PO “can’t remember” if anything in front diff was changed.
 
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kameronkales said:
I have a mostly stock LJ. Bought from original owner who hardly drove it / never used 4wd.

Recently tested out preload on the Dana 30. I don’t have the “most” accurate tools but preload read at 12. That’s basically new. iirc spec is 12-14

Is that spec possible with a 18 year old vehicle or were gears/something in diff changed out?

It has 3.73s in it so if it was changed it was changed with stock gears.

PO “can’t remember” if anything in front diff was changed.
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Are you asking about the preload on the pinion bearing? Did you take your measurement with the ring gear/ carrier removed? So just an empty housing aside from the pinion gear/ bearings.
 
SvtLdr said:
Are you asking about the preload on the pinion bearing? Did you take your measurement with the ring gear/ carrier removed? So just an empty housing aside from the pinion gear/ bearings.
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No. Full housing. My understanding was I could do this, given I’m not counting the breakaway it takes to get started.
Also it’s entirely possible I used the wrong terms. I’m learning.
 
Unfortunately you're not getting an accurate idea of the pinion preload the way you're doing it. You're measurement is also including the drag caused by the ring gear and carrier bearings (which also have preload on them.) No worries, this is how we learn!

What is your concern with the differential? What are you after here? Maybe there's another way to accomplish the goal.
 
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SvtLdr said:
Unfortunately you're not getting an accurate idea of the pinion preload the way you're doing it. You're measurement is also including the drag caused by the ring gear and carrier bearings (which also have preload on them.) No worries, this is how we learn!

What is your concern with the differential? What are you after here? Maybe there's another way to accomplish the goal.
Click to expand...

I don’t have any concern with it. I have seen YouTube videos where people do this exact procedure. Full housing and all. So I was curious what mine would read. Everything works fine.

Sounds like I need to only watch @hosejockey61 videos from now on.
 
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SvtLdr said:
The best way to know what's inside is to pull the cover and snap some photos for us.
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It’s got stock gear ratio in it. Open diff. I know that. When I read 12 after watching a YouTube video saying you could do that, I got suspicious.
 
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kameronkales said:
I don’t have any concern with it. I have seen YouTube videos where people do this exact procedure. Full housing and all. So I was curious what mine would read. Everything works fine.
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I would do what you are doing if i was going to remove the pinion nut to change a pinion seal. Otherwise I wouldnt worry about it.
 
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kameronkales said:
Right. But it sounds like even doing that you’d be getting an inaccurate reading?
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The spec is with just the pinion installed. Since you have the axle fully together, you do not follow spec. The only time you would do this is if you wanted to change the pinion seal. You take a measurement, replace the seal, and make sure you set the preload back to your initial measurement.
 
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Lou said:
The spec is with just the pinion installed. Since you have the axle fully together, you do not follow spec. The only time you would do this is if you wanted to change the pinion seal. You take a measurement, replace the seal, and make sure you set the preload back to your initial measurement.
Click to expand...
Nice! That’s what I missed. Thanks for the help.
 
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Ya I'm just learning that lesson the hard way. I pulled the pinion and seal without realizing that it needed a preload torque measurement. so I will be pulling my axles and and setting the pinion preload tomorrow. but as it turns out it was a good thing I took it apart because a previous someone had changed the seal with out a crush sleeve so its assumed that it had not been done correctly. but it appears my gears are in decent repair.
lesson learned

Most expensive thing I've ever paid for was ignorance.
 
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