Baystate Jeepers

For my 06 Rubicon with 4" RE lift and 35" tires, Barrett has prepared a detailed quote and I'm looking to pull the trigger on some upgrades including:

- Vanco big brake kit
- 4:88 gear swap
- Currie Tie rod/drag link
- new timken unit bearings an spicer ball joints
- teraflex oil pan skid
- lower control arm skids

I'm thinking about replacing the stock 27 spline outer front axle with a Alloy USA 30-SPLINE UNIT BEARING&OUTER AXLE SHAFT KIT while I have it in the shop. I'll run the rear axle stock. Have you found the stock Dana 44's up to the task when wheeling blues and occasional blacks around here of should i pull the trigger on the front axle upgrade? I have no desire to turn this rig into a rock crawler and hit reds all day long.

On my TJ I spanked a number of Chromoly axles shafts. I was running a TJ rubicon and when you broke shafts they were hard to find. I was very happy when I went to RCVs and stopped breaking axle shafts. I have only heard of one person breaking RCVs (Marky ?) and they were replaced under warranty. I ran 35s and was a little rough on the TJ...

I’m running an 05 rubicon with stock d44’s with 33’s. No issues yet, going on 4 years with this tire size. Another member here with an LJ rubicon has broken ujoints on his axle shaft.

My eventual goal is to truss the axles and run chromolys on 35’s with 4.56 or 4.88. RCVs look awesome but is spendy upfront, but stand the rest of time. Take it easy on the throttle and avoid applying full torque at full lock and you’ll have a better shot no matter what.

I have wheeled a TJ axle pretty hard. Never had an axle shaft issue. (Did have chromoly) Like Dan said you need to be conscious of what your doing. Sometimes I watch people and say that shaft is going to break and low and behold it does hopping and binding isn't friendly no matter what your running. Nothing is bullet proof. U joints are maintanance items that most people don't change until they break and take out the ears on shafts.

There are plenty of companies that offer great warranties on Chromoly axles. You get what you pay for just because says chromoly doesn't mean they are all equal. Lately I have seen a lot of RCV issues. The weak link in the rubicon axle is the locker.

I lost two right side stock Rubicon shafts in 10+ years on the LJ. Upgraded to CM with full circlips and haven't had an issue since.

Going to 30 spline outers will make it more difficult to get a wheel bearing and an outer shaft in a pinch. The TJ d44 outer is the same as a d30 so you can find a replacement easily. My d44’s have survived many years on 35’s, and I only had one ujoint fail on the highway coming home from Rausch.

Thanks guys for the feedback. I'll pay careful attention to not apply full torque with the wheels cranked. I'll have Barrette inspect the U joints and run the stock axles for now. With only 34K easy miles, at least I know I'm not dealing with a setup that's been run hard.

Look into the inner C trusses or gussets . I think the TJs still had strong 44s so you may not even need them. Ive wheeled a D30 for 15 years and just this year Ive managed to explode a u-joint. Use you head and get through the day , its not a race. You also have a winch. Do the gears and be happy ! FjR68

Modeler wrote: ↑Thu May 28, 2020 7:06 pm I lost two right side stock Rubicon shafts in 10+ years on the LJ. Upgraded to CM with full circlips and haven't had an issue since.

BTW, only one was catastrophic, the other was worn ears and caused the caps to be loose.

Liv2Ryd wrote:For my 06 Rubicon with 4" RE lift and 35" tires, Barrett has prepared a detailed quote and I'm looking to pull the trigger on some upgrades including:

- Vanco big brake kit
- 4:88 gear swap
- Currie Tie rod/drag link
- new timken unit bearings an spicer ball joints
- teraflex oil pan skid
- lower control arm skids

I'm thinking about replacing the stock 27 spline outer front axle with a Alloy USA 30-SPLINE UNIT BEARING&OUTER AXLE SHAFT KIT while I have it in the shop. I'll run the rear axle stock. Have you found the stock Dana 44's up to the task when wheeling blues and occasional blacks around here of should i pull the trigger on the front axle upgrade? I have no desire to turn this rig into a rock crawler and hit reds all day long.

Take a look at the Savvy steering setup instead. It’s the same as curry but with a solid aluminum tie rod. Is about $50 more IIRC but won’t bend.

Some people may say that it’s better for the tie rod to bend than for something more serious to break upstream. In my experience though, once a tie rod bends, it will bend regularly. That gets old fast.

My experience with axles has been the the U-joint is typically the fuse that goes. The only axles I’ve had to replace were related to the carnage from a u-joint failure.

I run Yukon superjoints now (got a killer deal, would not pay MSRP) so my axles might be the weak point again even though they are cromoly.


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Hoodoo Man wrote: ↑Thu May 28, 2020 4:40 pm On my TJ I spanked a number of Chromoly axles shafts. I was running a TJ rubicon and when you broke shafts they were hard to find. I was very happy when I went to RCVs and stopped breaking axle shafts. I have only heard of one person breaking RCVs (Marky ?) and they were replaced under warranty. I ran 35s and was a little rough on the TJ...

Not me, but J twisted the splines on his when it still had the D30.

I'm leaning towards the Savvy steering kit now. Thanks for the feedback.

Boy those Superjoints are pricey.

So my TJ is off to Barrette Fab today. I ended up going with a revolution 5:38 gear swap and Savvy steering setup. When talking to Blaine at Vanco about the mods I was doing, he asked why I was doing 4:88's? I told him that's what other suggested and he offered to run a gear calculation for me based on my tires, tranny, motor etc...

After going thru a list of questions on what I'm looking for from my TJR (not a daily driver, blue/black wheeling). Here are the numbers he came up with:

4:88 in 4th gear @65 mph = 2130 rpm
5:38 in 4th gear @65mph = 2350 rpm

Right now my motor lugs pretty bad virtually all the time with the stock 42RLE tranny. Blaine explained that the 4.0L motor is best when run in the mid 2k rpm range. Better performance, less strain and even better gas mpg. I'll let you know how it works out but I'm really excited to start testing the new setup.

I'm also getting a big brake kit, UFC alum engine skid, lower control arm skids, diff cover guards and adj lower control arms to fix my caster.

Given that my TJR is a 6spd manual, my experience with gear ratio will be different then yours. Of the two other people I know with TJR's, I believe they both run (or did run) 4.56 gears on 35's. I've heard that with the auto, you'll want a little deeper, the 4.88 gearing. But if you don't actually daily drive it, it doesn't hurt to go to 5.38, you'll just end up closer to 2800-3000 rpm at 7-75.

Try out this calculator at the link below. Enter the information that you currently have, such as your transmission, transfercase and axle ratio, then compare it to the change you want to make. Use your current setup as an example, and plan for any upgrades like tire size. My guess is 5.38 will be the choice.
http://www.grimmjeeper.com/gears.html

Not a TJR, just a lowly TJ, but with a 3spd auto. Yes the 4spd would help but 35s on 4:88s just will not highway well for me. To get over 60 your at or neat 3k RPM and I can watch the gas gauge drop after that. With that said it isnt horrid milage when kept in the mid to lower 2k rpm range. As an example I took all backroads to yesterdays event, wheeled all day and same roads home. 42 miles each way keeping it around 40-45 or so used about 6.2 gal. Tire pressure could play a part, I could tell on the way home they were not perfect after the fill up from wheeling.

As for the axles, I run stock shafts as well as the stock rubi locker in a rubi D44. It was pointed out to me by some of our well experienced members that there is ALWAYS a weak spot in the setup, decide where you want it. After a discussion around that, I stuck with the stock shafts and am letting those be the weak point for now in order to protect the gears and locker. Yes they could still break, however the ears on the stock shaft should go first.