[chanman3]

I have a 2005 Big Bear 400 with a leak at the seal where the drive shaft enters the front differential. Wondering what replacing this will entail and what the easiest route would be? Would like to leave diff on machine if possible. Anybody done one of these? I've included a picture and also a schematic of my diff. (Picture needs to be rotated)

 

[reogem]

Hey...chanman3..Welcome to GC from Wisconsin.

You will not have remove the diff to repair the seal.

 

[dezz]

Reogem is correct above. The diff must be removed to replace the pinion seal.

You need to move the diff forward in the frame to separate the front driveshaft splines. The diff is essentially out at that point.
Then you need to remove the u-joint in order to gain access to yoke retaining nut. Then remove the yoke. Replace the seal and put it all back together.
I recommend you get a new u-joint when ordering parts. Many times u-joints get damaged or needle bearings lost when removing them. Additionally, for the work load involved to replace it, you might as well do it now since it's already out and on the bench.

 

[chanman3]

Gotcha. I am only confused as to why I would need to unbolt the differential and slide it forward. Could i not just disconnect the u-joint and swing the drive shaft to the side to gain access to the yoke retaining nut? Then I could remove the yoke and replace the seal without ever moving the differential? I'm sure I'm missing something here, just trying to fully understand

 

[reogem]

.......You will not have remove the diff to repair the seal.

Reogem is correct above. The diff must be removed to replace the pinion seal.

You need to move the diff forward in the frame to separate the front driveshaft splines. The diff is essentially out at that point.
Then you need to remove the u-joint in order to gain access to yoke retaining nut. Then remove the yoke. Replace the seal and put it all back together.
I recommend you get a new u-joint when ordering parts. Many times u-joints get damaged or needle bearings lost when removing them. Additionally, for the work load involved to replace it, you might as well do it now since it's already out and on the bench.

Dezz.. you must have meant in-correct..eace:

What I meant was that the diff can be slide forward to pull the driveshaft and replace the seal. I should have provided a better explaination.

To me removing the diff involves much more work..to get the diff to the bench means pulling the knuckles, one end of the tire rods pulling the axles. If there is a winch that may need to pull out.

However if there is more damage as you explained then completely removing the diff is required.

 

[dezz]

Dezz.. you must have meant in-correct..eace:

What I meant was that the diff can be slide forward to pull the driveshaft and replace the seal. I should have provided a better explaination.

To me removing the diff involves much more work..to get the diff to the bench means pulling the knuckles, one end of the tire rods pulling the axles. If there is a winch that may need to pull out.

However if there is more damage as you explained then completely removing the diff is required.

Lol....I was tired....still am.

Yes the seal can be done in the frame. The u-joint can be taken apart where it sits. I have done it both ways. I don't find removing the diff completely any harder than just doing it in the frame. Actually, I find it easier as you have much more control an less chance of f-ing up. I just remove the bottom ball joint of the knuckle and remove axles from diff. This is why I say to remove the diff to do a u-joint style driveshaft.

On a CV joint style driveshaft (like in the 660's), I always leave the diff in the frame. That's just an easy one to do.

 

[chanman3]

Reogem is correct above. The diff must be removed to replace the pinion seal.

You need to move the diff forward in the frame to separate the front driveshaft splines. The diff is essentially out at that point.
Then you need to remove the u-joint in order to gain access to yoke retaining nut. Then remove the yoke. Replace the seal and put it all back together.
I recommend you get a new u-joint when ordering parts. Many times u-joints get damaged or needle bearings lost when removing them. Additionally, for the work load involved to replace it, you might as well do it now since it's already out and on the bench.

Gotcha. I am only confused as to why I would need to unbolt the differential and slide it forward. Could i not just disconnect the u-joint and swing the drive shaft to the side to gain access to the yoke retaining nut? Then I could remove the yoke and replace the seal without ever moving the differential? I'm sure I'm missing something here, just trying to fully understand