Anyone know...
 

I really want a taller lift than 2.5" so I can get some 37's under there...but at what height do people recommend switching out the drive shafts? I have read and heard and researched and get a million different answers. SO what is it? 3" and up? 3.5"

Thanks.

At 3" on my 2 door the front shaft went in a few years. The rear was still good when it was replaced.

37s will fit with 2.5" and flat fenders. Might need some trimming in the rear well just to be safe.

Generally above 3" you need to start thinking about that DS, but there's no hard and fast on that. Had a buddy with a 2.5" budget boost and his DS went after 25k miles, with about 20 of those miles being off the pavement. LOL. Honestly, it's just one of those things that you should plan on at some point if you're going to lift and head off road. My front went at about 25k miles on 3.5" lift. Different buddy's went at 15k miles on 3.5".

This is a good read... courtesy of Planman

https://www.jk-forum.com/forums/jk-w...8/#post3375491

At 2.5" I replaced mine, not because they were "broken", just because that was the next phase of my build.
I was shocked at how much smoother the rig was at highway speeds. I did not realize how much "harmonic vibration" (I think that's the term) I had been living with.
So, needed? No. Better? Absolutely.

The best looking rigs I see tend to be 2.5" lift, 37's and flat fenders. I run 37's on a 2dr at 3.5" with flats and could easily run 2.5" and be happier. What are you looking to get out of the 3.5" vs the 2.5" besides the number itself?

Maybe at least shoot for 3" so you can really dial back in the steering geometry and run the DL flipped / raised TB. That's what I'm doing anyway with 3.5" being the highest I'll go with 37s and cut fenders.






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Generally 3.5" is the limit that you can stretch the factory driveshafts while keeping them reliable, and even then generally you're reducing their useable life. Driveshafts are never a bad idea on a JK regardless.

I installed a MC 3.5" lift and my front driveshaft started to spit grease less than a month later. Only two mild wheeling trips and maybe 1k miles at most. Granted... my actual lift height ended up being closer to 4"s.

When I installed my 2.5", I found mine started spitting grease too. It was the Rzeppa joint, the boot around the joint gets creased and tears. Replacing it is pretty easy. I replaced mine with an aftermarket Terraflex high angle joint and have been happy.