Jeff09

Hi Everyone,

I am in the middle of swapping out driveshafts, and I have run into a bit of a snag.

I can't remove the pinion nut for the front differential. (It is the first one I have tried.) I have tried the impact gun that came with my Craftsman compressor (from what I have read it is capable of 300 ft-lbs). I have also tried a breaker bar with an extension. (I get enough leverage with the breaker bar, with the front tires on the ground, and the rear axle on jack stands to move the JK a few inches.)

I am considering the following options:

1. Purchasing an impact gun with a higher torque output.

2. Building a flange wrench to hold the flange while I use either the impact gun or the breaker bar.

And for a "Mr. Obvious" question, I would like to confirm that the pinion nuts are standard right hand thread (turning counter-clockwise should loosen the nut).

Any input would be appreciated. I also want to make sure I don't screw up the pinion bearing, so if I am doing something improper, please feel free to correct me.

I find the Chrysler service manual to be pretty comical. It shows an illustration of a guy with a 1/2 drive ratchet and a flange wrench effortlessly removing his pinion nut. Pretty hilarious.

Thanks for any help.

Jeff

BlackNorthernJK

Ah yes...the god forsaken pinion nut....
First...you really really really need to do this procedure properly...or you'll regret it.
By removing the pinion nut you are destroying the pinion bearing preload....there is a crush collar that is squeezed between the inner and outter pinion bearings that retains the proper pinion bearing preload...it can take up to 400ft/lbs to crush that thing....next, the second you back that nut off you have completely eliminated pinion bearing preload which may lead to bearing failure, and ultimately gear failure...no joke.
You can get around this problem however by taking a dab of paint to mark the position of the pinion nut on the pinion so when you re-install your pinion nut with the new pinion flange, you can re-align the two marks...BUT, not only must you re-align the marks...you must now turn the nut PAST the mark slightly...about an 1/8" would probably suffice...this is to get your pinion bearing preload back....don't go TOO far or you'll place TOO much preload on the bearings and they will burn out faster....keep in mind that the pinion nut is really only designed to be used one time, the threads will not hold torque generally a second time...so use a generous amount of red locktite.....and as you've discovered...it's gonna take a HELL-ALOT of torque to even crush that crush sleeve again that little bit....your best bet is to construct a tool out of some heavy duty iron or steel to bolt to the new flange to hold everything steady...it's gonna have to stand up to substantial torque...if you can do all of that you'll be ok....but whatever you do...don't resort to a heavy duty impact gun, you'll blow that pinion preload outta the water and regret it.
Have a look at my adventure in re-gearing and crushing this sleeve https://www.jk-forum.com/forums/modified-jk-tech-2/begins-78112/

RedneckJeep

I always use a chisel to mark the pinion nut and end of the pinion shaft. Paint can come off. I've had it happen.

BlackNorthernJK

great point

edwin907

My front was incredibly tight as well.
I used the floor jack pushing up on the breaker bar to loosen it.

Re-installed the new yokes (front and rear) at 165 ftlbs with red loctite, zero problems after thousands of miles, no metal on the ARB differential cover magnets. Maybe I was lucky.


I've got a TRE that won't come out of the pitman arm right now.
Was finally getting around to the RK draglink that's been in my signature for months. Yeah, I know, disgusting.
Not even with the pitman arm sitting in my vise on the workbench will it come out!
Puller, pickle fork, BFH, heat, don't matter!
Some of you guys know how much fun it is to remove the pitman arm, well that wasn't much of a problem with the proper puller.
But this factory TRE is in there!
It'll be heading to my friend's machine shop tomorrow.

Jeff09

Hi Everyone,

Thanks for the suggestions.

I will go back to the breaker bar in the morning (with a cheater) in hopes that it will let go. I will chock the wheels, too.

I marked the pinion nut/shaft earlier (there was another post I read some time ago that also suggested this).

I hope this isn't a stupid question; but, I'll ask it anyway. In order to use the alignment marks as reference should I be concerned with the new yoke dimensions? In other words, will the alignment marks be the same if there is a difference between the two yokes? (I can see where the marks would be a great reference with the same yoke; but, I guess I'm wondering about the replacement yokes.)

One installer has suggested that I use red Loctite, with some silicone sealant on the mating surface of the nut, and then use an impact gun with the regulator at its lowest setting to drive the nut back on. Supposedly there won't be enough torque to crush the sleeve any further. I know this isn't really an approved method, and it probably won't crush the sleeve any further; but, at least I won't over-crush it.

I am planning on re-gearing in a year or so anyway when I get bigger tires, so if I screw this up, I'll be doing that sooner rather than later.

Thanks again for all your advice. I can't really understand why that front nut is so tight; but, I'll get after it again in the morning.

Jeff

nangulator

I usually use my 3/4 inch drive impact gun to remove the pinion nut.

BlackNorthernJK

Are you holding the pinion flange with something?? I didn't have much of a problem busting either pinion nut with my electric impact gun, at best I think it puts out about 150ft/lbs...but that's holding the pinion rock steady with that wrench of mine.

TINMAN080

there can be no movement of the nut or flange, in other words no ''slack'' while you are trying to bust the nut loose with an impact. Any slack will cause the nut to vibrate back and forth, causing the biggest part of the impacts torque to be absorbed without loosening anything....

RedneckJeep

Search Ebay for this: "1/2" Ingersoll Super Duty" and buy one. A good seller will have them right around a hundred bucks including shipping. That is the baddeest ass 1/2" impact wrench you will ever own. They will deliver 425 LB FT of torque @ 102 PSI. Most shops run air pressure over 150, so do the math. The Ingersolls have a "double hammer" design that kills the competition. I have one that's probably off the first run. It's over 25 years old. I got it when they first came out. It's probably a little stronger than it ever was cause it's been rebuilt numerous times and has gotten looser with time. It'a a bad mofo.