Front axle u joint replacement

[b3uhbp]

I have an 84 CJ7 with Dana 30 front axle and I’m finally getting around to replacing the front axle u joints but I have two questions. 1st, will the axle shafts just pull out? And 2nd, will I loose gear lube when I pull the shafts? In other words, do I have to remove the diff cover and drain the oil? Thanks

 

[mriplaybass]

I have seen the D30s set up 2 ways. Some of them allow differential oil to flow to the wheel bearings for lubrication. On these, if you pull the axle shaft, oil can leak out. Usually not too much since the oil level is not that far above the axle shaft. Other D30s have the wheel bearings lubricated by packing with axle grease, a much better set up in my opinion. These have a seal inside the axle tube near the differential housing to prevent the gear oil from entering the axle tube.
Once you remove the rotor and caliper, remove the bearing housing retaining bolts and then the housing. You should be able to pull the axles out.

 

[jp360cj]

I have seen the D30s set up 2 ways. Some of them allow differential oil to flow to the wheel bearings for lubrication. On these, if you pull the axle shaft, oil can leak out. Usually not too much since the oil level is not that far above the axle shaft. Other D30s have the wheel bearings lubricated by packing with axle grease, a much better set up in my opinion. These have a seal inside the axle tube near the differential housing to prevent the gear oil from entering the axle tube.
Once you remove the rotor and caliper, remove the bearing housing retaining bolts and then the housing. You should be able to pull the axles out.

You are thinking about the AMC20 rear axle.

On the front axles, the oil seals are on the differential side of the axle tube.

OP, you'll have to remove the tires, brakes, hubs, and spindles, and then the axle shaft will just pull out. If any oil comes out, it will be very minimal as long the axle is level. While you have it apart, go ahead and change the spindle bearings (the ones inside the spindle where the axle shaft rides).

 

[Kane]

Whenever I did this job I did one side at a time and jacked up the side I was working to be higher than the other side so no fluid would leak out.

 

[mriplaybass]

You are thinking about the AMC20 rear axle.

On the front axles, the oil seals are on the differential side of the axle tube.

OP, you'll have to remove the tires, brakes, hubs, and spindles, and then the axle shaft will just pull out. If any oil comes out, it will be very minimal as long the axle is level. While you have it apart, go ahead and change the spindle bearings (the ones inside the spindle where the axle shaft rides).

I agree, that's what I thought, but when I rebuilt the Dana 30 front axles on our CJ5 and CJ7 , there was no seal in the axle tube, and the gear oil was lubricating the wheel bearings. I changed it to the right way. Seal in the axle tube, grease packed wheel bearings. I guess both Jeeps were the victims of PO's!

 

[jp360cj]

I agree, that's what I thought, but when I rebuilt the Dana 30 front axles on our CJ5 and CJ7 , there was no seal in the axle tube, and the gear oil was lubricating the wheel bearings. I changed it to the right way. Seal in the axle tube, grease packed wheel bearings. I guess both Jeeps were the victims of PO's!

Not possible...There's no connection from the tube to the front wheel bearings, the oil would have just ran on the ground. Did you remove the carrier to install the seals?

 

[Posi]

Bass knows the difference must be a typo or thinking rear axle.
Yes, the carrier has to be removed for all inner seal installs.

 

[mriplaybass]

Duh! You are both right! I am thinking rear axle. I guess I need to get on the forum a little more frequently, and engage the brain before posting!
What I was thinking of is when I installed an additional seal near the outer end of the Dana 30 axle tube to keep crud out of the tube. I know that the seals won't last a long time since there is no lubrication for the rubber, but I greased up the shaft and so far no seal failure in 5 years. Sorry for the confusion!

 

[jay59l]

I need to replace my front seals as well (got a leaky driver's side). Any thought about the aftermarket outer seals? Worth the cost?

 

[b3uhbp]

I need to replace my front seals as well (got a leaky driver's side). Any thought about the aftermarket outer seals? Worth the cost?

Thanks all. I completed the job with no issues. U joints are always a pain. I also replaced the ball joints with moog greaseable joints. They weren’t worn out but very dry. Now the Jeep returns to center for the first time in the 6 years I’ve owned it. Yippee!