THE SEAL ON BACK OF THE FRONT DIFF. TO FRONT D-SHAFT HOW HARD IS THAT TO REPLACE? IT LEAKS A LITTLE. I HAVENT MOVED THE TRUCK IN THREE MONTHS. BUT I DONT KNOW IF I SHOULD CHANGE IT OR NOT.  

With a little mechanical ability a Pinion seal is easy to replace.

To the best of my knowledge all it takes is 1)Remove the driveshaft 2)Pry out the old seal 3) Tap in the new seal 4)Reattach driveshaft

*Disclaimer... that is just a general synopsis of replacing a pinion seal. Be sure and consult with your repair manual before attempting.  

FourWheeler Web Editor:
With a little mechanical ability a Pinion seal is easy to replace.

To the best of my knowledge all it takes is 1)Remove the driveshaft 2)Pry out the old seal 3) Tap in the new seal 4)Reattach driveshaft

*Disclaimer... that is just a general synopsis of replacing a pinion seal. Be sure and consult with your repair manual before attempting.

You left out you will need a big breaker bar or vary serious impact wrench to remove pinion yoke. Before you remove pinion nut though you want to scribe a line on it and nut to mark its position so you can put nut back in same position afterwards to restore proper preload. (this is VERY important!)  

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You left out you



Like I said...

*Disclaimer... that is just a general synopsis of replacing a pinion seal. Be sure and consult with your repair manual before attempting.  

SOUNDS EASY ENOUGH. I HOPE.  

CHEVYGURL87:
SOUNDS EASY ENOUGH. I HOPE.

The hardest part is breaking nut loose but a 3/4 impact would make short work of it. DO NOT forget to scribe a line on pinion and nut before you remove it as stated above because if you do not get the preload right, you can have problems.  

or you could do it correctly and use a torque wrench as it could have loosened up.  

joshjansen:
or you could do it correctly and use a torque wrench as it could have loosened up.

No, you do not want to change ANYTHING here. Whatever preload it has, stays and that is why you mark the nut and shaft.  A change in preload at this stage can shorten bearing life and/or change mesh pattern enough to cause bit of noise. Also even if you want to check preload rotational torque you would have to remove carrier from truck and pull diff from it. I have seen problems for not restoring preload to same state.  

Also need to check the yoke for any signs of wear near the area that the seal lips ride.  If you can catch it with your fingernail the new seal will eventually leak.  Possible fix would be a speedi sleeve or installing the new seal in a slightly different spot if that is possible.  Also bearing preload here is very important.  Check the shaft for any signs of it being loose by wiggling on it. And make sure that you do mark the nut to your shaft before you remove it so you can put it in its same place.  With old bearings it is not a good idea to be changing your preload from what you were already running. Plus while you have the seal out you can visually inspect the outer bearing. Bearing failure is a good cause of a leak to occur.  More than likely your problem is just an old seal.  

I have to disagree on the bearing failure causing leak. I have seen a lot of seals fail with age and mileage issues on rear axles that had no bearing issues at all.  

You are right. A bearing does not have to fail to cause a leak.  But if you do have a leaky seal it could be a warning sign that your bearing is starting to fail or has already.  

You are right. A bearing does not have to fail to for a leak to occur. But if you do have a leaky seal it could be a warning sign that your bearing is starting to fail or has already.  Snoman probably didn't read my last sentence.