Advice on replacing front axles

[98TxTJ]

If you check out my signature, you'll see I've R&R'd practically everything on my TJ. The one big thing I haven't done yet is the front u-joints and axles.

The PO was a college kid that did stuff on the cheap. To be fair, he also did it, or had it done, poorly. He was running 35 x 12.5s on stock 3.73 gears and stock axles with a 6 inch RC lift. I have a feeling the TJ saw some rough use.

I downsized to 33s, regeared to 4.56, and changed to a 3.5" Rock Krawler lift.

I needed to do rear axle seals so I went ahead and changed out the rear axles with Revolution units in 1541H.

New u-joints will be a given. The question is, how much risk is there that with the gear ratio and tire size he was running, the front axles are ticking time bombs and should be replaced with new units in 4340 alloy? Unless they were replaced in the past, they have 217k miles on them.

It's a daily driver and vacation vehicle. It isn't likely to see more than moderate off-roading. I care about reliability though as we've taken it to some pretty remote areas.

Thanks in advance.

 

[rasband]

It seems like you answered yourself there by the end.

I was on 4.10 and 33s and had the ears widen a bit and toast the front stubby, only after a few trips. I’d go for a little overkill if it were me.

If it’s just moderate usage you could be fine with the revolution discovery series and save a little on the cost. They’re not quite as strong, shorter warranty, and manufactured overseas (I believe).

 

[Goatman]

The Ujoint will see the most wear and tear on them. If the axle isn't exhibiting any problems now then as long as the ears (which you can check ahead of time) look good you are probably safe with the current shafts. If you were planning hard core trips then my answer would be different. A daily driver type Jeep will rarely see 4hi let alone 4lo where the torque on the shafts is multiplied. I would have some reserve cash set aside incase when you pull the shafts you see an issue, but would feel safe in just replacing the Ujoints. If new shafts are needed you can just pull the new Ujoints and move them to the new shafts. Or get new shafts already put together and save the old ones as an emergency part that you will likely never need.

 

[rasband]

save the old ones as an emergency part that you will likely never need.

This is a nice side affect of replacing shafts before they're toast. I have a single stubbie (since the passenger side of mine was ruined) and both inners to be able to have a spare on either side for me or anyone we run with that has the 30spline 44.

 

[Lou]

If the axle doesn’t have a locker the stock shafts will be more than adequate for you.

 

[CharlesHS]

When I replaced the front axle U joints in the stock axles I had the inner surface of the ears cut at a machine shop so that I could install full circle clips instead of the C clips. This modification provides more support for the U joint cups and they will not move under load. A few years later I won a set of alloy axles which already had the full circle clips installed so I kept the stock modified axles as spares.

 

[98TxTJ]

If the axle doesn’t have a locker the stock shafts will be more than adequate for you.

The front is still an open differential; the rear was converted to limited slip when I regeared.

My concern has always been hidden damage from before with 35s on the stock axles. But with 3.73 gears then and the open dif, I wonder if my concern is unwarranted.

 

[98TxTJ]

It seems like you answered yourself there by the end.

I was on 4.10 and 33s and had the ears widen a bit and toast the front stubby, only after a few trips. I’d go for a little overkill if it were me.

If it’s just moderate usage you could be fine with the revolution discovery series and save a little on the cost. They’re not quite as strong, shorter warranty, and manufactured overseas (I believe).

If I replace them, Revolution or Yukon? Revolution is made in U.S. Yukon, maybe not. Both have limited lifetime warranties. I've got Yukon gears in both diffs, Revolution axles in the rear. Between the two brands, is there a clear winner?

 

[rasband]

If I replace them, Revolution or Yukon? Revolution is made in U.S. Yukon, maybe not. Both have limited lifetime warranties. I've got Yukon gears in both diffs, Revolution axles in the rear. Between the two brands, is there a clear winner?

I don’t have any strong reason for either, though I did Revolution. I’ve heard good things about 10 factory as another option.

 

[Irun]

The front is still an open differential; the rear was converted to limited slip when I regeared.

My concern has always been hidden damage from before with 35s on the stock axles.

Best to pull them and see. This is what I found when I pulled a pair. A break waiting to happen!

 

[Lou]

If the splines aren’t twisted and the ears are fine I wouldn’t trip out about running 33’s on an open dana 30 in your environment with the stock shafts. If you want to upgrade you would be fine with any reputable axle company.

I see no point for you to run RGA USA axles. They are like double the cost of other good options.