Topic: RCV vs Chromoly shafts

[stan98tj]

Need some advice here guys.
This weekend i DETONATED, GRENADED my driverside u-joint when my wheel fell between 2 rocks and I turned slightly while the locker was engaged. Basically the u-joint failed and then since I was still moving backwards, the axle shaft ears bit into one another and mangled. Now, I wasn't running high performance u-joints, they were Autozone's most expensive model but instead of failing at the caps as most do, it split right down the middle.

Basically, I want to beef up things on the axle end. I'm between getting a set of chromoly shafts with high grade u-joints or just going big and getting RCV shafts. RCV claims their cv joints are indestructable, but my concern is that I will effectively shift the weak links to a different place along the axle. With reg chromoly shafts, you still run u-joints. The u-joint (even a high grade one) can fail. If it doesn't fail, the next thing to fail is the shaft. Both of these aren't a terribly concerning thing as you can still repair on the trail if you carry spare shafts. But with the RCV, if the cv doesn't fail and the shaft doesn't perhaps the weak link ends up being your differential and THAT would basically mean game over.

What do you guys think about this? Am I being paranoid, should I go for the RCV or are chromoly shafts a safer deal?

[aw12345]

Either will work, RCV's are a good product but expensive. A good set up chromemolly shafts with spicer U joints and full circle clips will do you well also for a bit less money. I personally would go for the Superior EVO ones if you can find them expect to spend around 600 bucks for those. If I am not mistaken RCV's are in the 1000 bucks neighborhood. You were lucky it didn't rip the balljoints out.
Even if the weak point travels to the ring and pinion it isn't the end of the world.
You pull the carrier out and take the ring gear of put it back together and drive home. We have done one of those on the trail had it done and moving again in about 45 mins. easier yet save the stub shafts and just run those so you can drive home.

[sharpxmen]

problem with RCV is that they wear and you end up spending another pile of money compared to replacing a u-joint and even the beefed up ones are cheap compared to RCV.

on the other hand like he ^ said the chromoly ones are expensive, so maybe axle upgrade instead?

[stan98tj]

problem with RCV is that they wear and you end up spending another pile of money compared to replacing a u-joint and even the beefed up ones are cheap compared to RCV.

on the other hand like he ^ said the chromoly ones are expensive, so maybe axle upgrade instead?

I guess I need to do a bit more research on RCV. I was under the impression that they were fairly maintenance free with the cv being the only thing that needed greasing. My overall fear is to build it so strong it blows the ring/pinion which would be nore tedious to trail fix than an axle shaft or u-joint. Is this an even reasonable fear?

[neale_rs]

Went through the same decision a while back.  Finally got some Alloy USA shafts with their X-joints (included).  I've been on three trail rides since then with front locker use with no problems.   Based on reading and local experience, stock shafts are actually not that bad as long as the u-joint is a Spicer or stronger and you keep the caps in place (tack weld).

Having said that, the original plan was to get RCV shafts.  That idea was scrapped due to the high cost. For me this was because the local shops don't get discounts from RCV but they do from their usual vendors.  The next choice was Superior Evolution shafts (lifetime warranty like the RCVs) with Spicer u-joints.  I waited several months for those shafts but eventually lost patience and got the Alloy USA stuff.  It was also cheaper than the other two options.

According to the Jeep shop owner, a very respected fabricator and wheeler around here, the u-joints break first in the great majority of cases, so the brand of alloy shaft doesn't really matter too much (it might matter if you run CTM u-joints or similar). He also said that 30 vs 27 spline is a moot point since the u-joints are what break anyway.

A friend of mine runs a D30 in a JK with RCV shafts and an ARB.  He is heavily into the skinny pedal but rarely breaks anything.  However, when it does break it's the ring and pinion, so that does end up being the weak link.  And that is a high pinion D30, a TJ D30 is a bit weaker.

Overall, since the shafts have good warranties and the R&P does not, it is better to avoid making the R&P the weak link.

[sharpxmen]

I guess I need to do a bit more research on RCV. I was under the impression that they were fairly maintenance free with the cv being the only thing that needed greasing. My overall fear is to build it so strong it blows the ring/pinion which would be nore tedious to trail fix than an axle shaft or u-joint. Is this an even reasonable fear?

neale just mentioned they have lifetime warranty so i guess replacement cost isn't a factor.

[aw12345]

Here is some food for thought Stan, my yellow Jeep has seen a ton of trail abuse over a 4 year period the Superior shafts with Spicer U joints have been very good to me. Those have been in there since my first Moab trip, same U joints cups haven't spun yet. I did swap in a high pinion housing for several reasons. On the stock shafts, when I put 35's on after 2 runs the U joint cups started spinning, which is why I bought the Superior shafts. Haven't regretted that choice yet.  If you would kill the ring and pinion which is somewhat likely to happen anyway. Then you have 2 courses of action pull the shafts and stick a pair of stub shafts to keep the wheelbearings together which isn't a hard thing to do. Or take the ring gear off, little harder but also not that hard to accomplish. If you run lockers it doesn't hurt to carry something to knock the broken shaft stub out of the diff carrier.
 

[chardrc]

even with a lifetime warranty on the RCV, its useless when you are day 1 of a week long trip and one goes bad. I would rather have a quality u-joint that can be replaced. just my $0.02

[stan98tj]

Lots of really great points here guys. I'm starting to re-think the RCV shafts. I think I'm gonna look into the Superior shafts and a high grade u-joint to run. It's kind of a let down as the RCV shafts were so tempting given the reviews I've read. But, parts will fail and I'd rather it be easy to access and allow me to continue (as in swapping a shaft) then having the ring + pinion grenade given that neither I nor any of my fellow wheelers can handle that kind of a trail fix.

[Bounty Hunter]

Another thing to consider is that a standard ujoint it weakest when the joint is bent, the shafts try to work against each other to spit the ujoint out.  An RCV joint has the same strength at any angle so it doesn't have the Achilles Heel the standard ujoint does.

[stan98tj]

I actually spent some time on the phone with RCV and East Coast Gear Supply today and I ran them through the concerns I was having with the RCV shafts. I must admit, the techs were really helpful and super nice. Maintenance on the RCV shaft is bascally greasing every 6 months, and then rebuilding the cv every 3-4 years depending on how heavy you wheel. The rebuild costs $125. As for my concern with blowing the ring and pinion, they were both receptive to the concern but neither had experienced customers informing them that they had blown ring and pinions since the install of th RCV shafts. The benefits seemed pretty good too, better strength, ability to deal with stress from more angles than the traditional u-joint. One thing I will def do is sleeve my axle. The sleeves can be purchased from ECGS for about $100 and would get me on the track of readiness if I ever wanted to step up to 35s.

[sharpxmen]

I actually spent some time on the phone with RCV and East Coast Gear Supply today and I ran them through the concerns I was having with the RCV shafts. I must admit, the techs were really helpful and super nice. Maintenance on the RCV shaft is bascally greasing every 6 months, and then rebuilding the cv every 3-4 years depending on how heavy you wheel. The rebuild costs $125.

so what do the lifetime warranty apply to - that's what i meant that they wear out, not sure what they mean by rebuilding them as they usually wear in the inner and outer sphere where the balls are located so do you have to send them in for a rebuild? is the cost of $125 for each side or total, if its for each side then at $250 you're better off going with x-joints and cromoly shafts, after the first RCV rebuild you'd be at 1/2 price even repacing the u-joints once or twice.

my opinion anyway.

i've seen double cardan CV axle shafts before (not on a Jeep) and i honestly think that would be the better alternative but i have no idea if there's enough room and if they're even available for the D30.

[neale_rs]

Didn't know about the rebuild cost.  That's a lot to pay without something actually breaking!   

But then again, premium u-joints like CTM and others can cost even more. 
Just keep in mind that without locking hubs it is not recommended to use u-joints without needle bearings.  Although I have read about CTMs being used this way and not wearing out too fast.

[chardrc]

Just keep in mind that without locking hubs it is not recommended to use u-joints without needle bearings. 

U-joints without needle bearings? never seen that unless they are pounded out and missing. what Sharp said about the rebuild was exactly my thoughts. Our Willys came with the RVC type joints out front and when they wear out its the socket where the ball bearings ride on that wear out.

[neale_rs]

U-joints without needle bearings? never seen that unless they are pounded out and missing. what Sharp said about the rebuild was exactly my thoughts. Our Willys came with the RVC type joints out front and when they wear out its the socket where the ball bearings ride on that wear out.

CTMs have bushings, no needle bearings.  Several other super tough u-joints also use just bushings.