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WhiteRhino's Latest Mods

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317K views 2K replies 189 participants last post by  whiterhino 
#1 ·
Sometime late last summer I was talking to Jim about modding his jeep and it snowballed and somehow I got in the middle of it. before I knew what was going on I agreed to build his jeep over again pretty much. The goal was lots of strength and a nice cushy ride while providing clearance for 40's in the future.

The entire build/arguing/problem solving thread is here: http://www.misfitoffroad.com/phpbb/viewtopic.php?t=8991&start=0

it will be completely finished and wheelable in the next couple weeks.
here are a few pictures of the build:
 

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#1,024 ·
I've always understood that a locker will let the outside radius tire spin faster but not slower, which is why axles with lockers are far less likely to chirp when going around tight corners. If that is not the case, why do lockers work, especially in the front end? My Detroit never binds up on sharp turns on pavement & I've been running drive flanges for years. I can tell you that when I ran the spool up front for about 6 months....... it sucked.

I can't say that I have anything to complain about. This gearset and axles have been in since 2007 and I have been running the stickies for 3 or 4 years. Who knows how long the axle has been twisted, maybe since before the stickies.... Same with the chipped tooth. It is not a fresh break.
 
#1,030 · (Edited)
I've always understood that a locker will let the outside radius tire spin faster but not slower, which is why axles with lockers are far less likely to chirp when going around tight corners. If that is not the case, why do lockers work, especially in the front end? My Detroit never binds up on sharp turns on pavement & I've been running drive flanges for years. I can tell you that when I ran the spool up front for about 6 months....... it sucked.
Lockers will only unlock when there is less than X amount of torque on the drive shaft in either acceleration or deceleration. The X amount of torque depends on the springs and ramps in the locker, and tire diameter plays a part in how the locker reacts too. It doesn't take much torque for the locker to lock and stay locked. The faster spinning tire theory is under acceleration with very low torque on the D shaft, it reacts opposite under decel conditions. When running it in the front end and in 2 wheel drive, theoretically the locker never locks and your rig will drive fine, even with flanges. Put it in 4x4 and now it doesn't turn, it will act like a spool even when a spool is in two wheel drive.
 
#1,025 · (Edited)
My understanding is that with no power applied, a tire can spin faster and the clutch/gear allows this "slip". When power is applied, it "locks" and prevents any difference in tire speed. If you've ever turned a long sweeping corner with a rear locker you either coast the turn or power through, if you do a mix it pops and jerks throuh the corner.

My opinion is the same as green's, I think some nice low pinion dana 60's are the solution!
 
#1,028 ·
My understanding is that with no power applied, a tire can spin faster and the clutch/gear allows this "slip". When power is applied, it "locks" and prevents any difference in tire speed. If you've ever turned a long sweeping corner with a rear locker you either coast the turn or power through, if you do a mix it pops and jerks through the corner.

My opinion is the same as green's, I think some nice low pinion dana 60's are the solution!
I don't know about you but I am not always under power when driving on pavement. Typically when turning a tight corner, I am decelerating. Not always but most of the time. If the locker will allow "some" movement and eliminate torsional bind, in addition to being aware of it, I believe the risk is greatly reduced. Ever since I figured out what twisted my driveshaft, I have been much more conscious of tight turns on pavement and have done my best to not make extremely tight turns. I don't believe the issue is on a highway type radius, but rather a tight one when like pulling into a parking space. (that's when I twisted the driveshaft) Maybe I can drive like Tim Cameron and constantly blip the throttle to keep it unloaded. :d:

Why would I want a low pinion 60? Low pinion sucks, the 60 is no stronger than the Hi-9 and the axle shafts are no bigger. Plus, it just adds a bunch of work for no gain. I've wheeled this setup all over the country in some of the most extreme trails available for several years without a failure. Finding a potential problem during routine maintenance is no reason to rush into major changes.

The shaft has been yielded, the torsional strength has been severely compromised. The shaft has failed. That being said if I did not have the cash to replace it, id run it. As long as it wont destroy the locker when it decides to fracture.

Ring and pinion on the other hand is not usable. Pinion is probably chewed and deflected out of spec. Ring gear is trash, but hey it cant hurt much to run it.

If you are going to a new locker I would replace those shafts.

What third do you have? High strength one? If not put that on the christmas list too...nevermind I just read what you have...hi-9

dare I say 14bolt?
You are absolutely right about the shaft. I don't even know why I posed the question. Thankfully only one side is twisted but I don't know if Moser will sell an individual. (website sells in pairs) I didn't even consider reusing the ring gear.


There is a arb for 35 spline 9" on here for 800$
I saw that. Problem #1, the Grizzly locker is already purchased. Problem #2, I'm running out of cash.
 
#1,026 · (Edited)
The shaft has been yielded, the torsional strength has been severely compromised. The shaft has failed. That being said if I did not have the cash to replace it, id run it. As long as it wont destroy the locker when it decides to fracture.

Ring and pinion on the other hand is not usable. Pinion is probably chewed and deflected out of spec. Ring gear is trash, but hey it cant hurt much to run it.

If you are going to a new locker I would replace those shafts.

What third do you have? High strength one? If not put that on the christmas list too...nevermind I just read what you have...hi-9

dare I say 14bolt?
 
#1,031 ·
Understood on all the acel, decel theory. BUT......... it does unlock in some circumstances. Are you saying that in the parking lot scenario that it "WILL NOT HELP, guaranteed 100%" or "MAY NOT HELP & may be a waste of money"? Remember, no failure in 6 years with the current setup, just a fatigue & chipped tooth. With a better awareness, plus the locker, I believe the risk is reduced.

True on the front being in 2wd. But I have noticed a difference offroad wheeling too. Tight & twisty stuff is much easier with the Detroit than with the spool. Like night & day.
 
#1,034 ·
The locker will help the parking lot situation for sure, as long as you are coasting (not on throttle, not engine braking). The locker works better in the trails because when you lift off the throttle (even for a moment) while going thru tight turns, it can allow the axle shafts to "reset" and the tires to spin independently, where you get zero forgiveness from a spool. My only point was that if the axle shaft twisted due to your parking lot maneuver with the spool, it will most likely happen again with the locker, but it sounds like it may just have been time (fatigue life) for those shafts to fail. Route55 is pretty much correct on the drive shaft issue, but a spool could put a little more stress on the drive shaft just because the engine is still trying to get the slower tire to slip while a locker could eliminate that extra torque required to make it slip / move the jeep.
 
#1,033 ·
Wait wait wait. Hold the boat here.

I just reread back a couple pages. Jim, you are saying you twisted a driveshaft in the parking lot, not an axleshaft? Am I reading right?

If that is the case I believe that had nothing to do with your rear being locked, unlocked, spooled, etc. The only "stressfull" torsional torque should be on the axleshafts, as they are being forced to attempt to turn the different speeds whilst turning (the twisted axleshaft).

The only extra stress the driveshaft would be under would be the torque required to physically get the axle to get your "sticky" tires to skip a bit around a corner.

Now how would this be any more stress than say doing a burnout in a drag car, where you are breaking loose both tires, or even the torque required on rocks, or pulling someone on the trail?

I honestly think the broken driveshaft was a complete coincidence in this equation. Something else must have gone wrong, or it was already damaged/binding somehow. Same goes for the chipped ring gear (which indicates probable setup issues)

I could be totally wrong, but thats my two cents.
 
#1,036 ·
There is a certain amount of torque required to lock it up, so the torque converter might "coast" under that amount of torque required. I always had a manual with my lockers. I have not yet had lockers in my auto rig so I am not sure. Even with front lockers, my rig was a bitch to turn in tight turns running 40" Iroks and I have never had stickies.
 
#1,038 ·
Jim

My advice is to get a new R&P and get better shafts. Those shafts have no neckdown so they are twisting right at the splines. A properly made axle shaft will have a necked down section that is slightly smaller then the splines are cut into the shaft. That is why stock 14B shafts work pretty good with the neckdown in the 1.35" range. A good axle shaft has to be designed to twist in the right spot.

my 2 cents
 
#1,045 ·
I agree. If the entire axle shaft is the OD of the spline, the weakest point is the pitch diameter of the spline. Since the pitch diameter (in this case) is only about 3" long, all torsional windup must happen in that area. If it is longer, there is less chance of the shaft yielding. I have used long bolts in some designs for this same reason. What (good quality) manufacturer does this? I'm not stuck on Moser.
 
#1,047 ·
I've ran a full detroit in the back of two daily driven TJ's, once with an auto, and once with a stick.

With the auto it was absolutely smooth as silk, I really had no issues with it, and I could take someone for a ride and they'd never know it was locked.

The stick was a slightly different story, it was more noticeable, but I wouldn't call it terrible.

Point being is that I drove these things daily, I could make turns, pull out into traffic, accelerate in turns etc. With that said however, it was all based on the throttle - if I jammed on the gas while making a turn, it would lock up and squeal a tire.

I don't know much about the grizzly, but if it's anything like a Detroit I think you will really be pleased - it has to be ten times better than a full spool - both off and on road.
 
#1,050 ·
That Jantz thread is interesting, as all of his threads are. The thing is, he is an engineer's engineer and is pushing to the extremes; which is good for advancing the sport and building the ultimate gizmo, but not always great on the pocket book.

Moser (and many other custom shaft makers) that are selling to sportsman and hobbyists build shafts by cutting splines and polishing a bearing surface. The main thing they are trying to do is keep costs down by doing as little rework to a blank as possible. They go for strength using brute force.

Jantz, Trophy truck teams, and other well heeled individuals go the extra step and build shafts with proper length rolled/hobbed splines, and turn down the shaft to the minor diameter and produce beautiful machined pieces with rolled edges, blah blah blah to maximize strength vs weight; and in some cases like the story about the Ivan Stewart truck, provide desired amounts of cushioning to the drive line to make the axle shaft the fuse to protect other components.

Since OEMs build by the 1000s, they can also afford to build shafts "the right way" since they can spread the cost over many parts.

Given that you've gotten 6 years out a set of shafts, I'd say brute force is working for you. If you manage to destroy these in short order, then it might be time to call up Jantz.

And don't they have a lifetime warranty of Moser 35-spline shafts? I thought my 40-spline stuff (even more brute force) did.
 
#1,051 ·
All good points John. No, Moser will not warranty an off road application, only drag racing. Go figure. I would also be more concerned if both splines were twisted, and since only one has moved, it's another good indicator that I don't have a design problem.

I just got through cleaning the ring gear up. It is definitely not just a chip, it's into the wear pattern & about half the tooth is gone in one spot. I talked to Hi-9 today and sent them a pic, they felt it was a shock load break. I have no idea where the "event" could have happened other than my parking lot episode. My only other major catastrophic issue has been my broken link in Cali, but I don't think that should have stressed the gears.

Hi-9 used to not sell gear sets because they wanted to assure they were set up properly in the beginning. Now they sell them outright so it looks like I will be tapping Dale on the shoulder for his expertise.
 
#1,053 ·
I have to disagree. Yes, I haven't been running the stickies that long, but I have been running them for 3-4 years. And, as in any engineering failure, you look for events if possible, rather than not knowing what caused a problem. I can pinpoint a very specific event that had enough torque on my driveshaft to twist a heavy duty Tom Woods spline. As debated over and over above, maybe the locker will solve that problem, maybe it won't, but I am making one specific move to change the dynamics.

I am also much more aware of the potential problem and can hopefully drive around it some. Noting the Jantz thread, no one has offered up any super duper shafts that aren't expensive custom made like Eric Miller is running.

Back to the Moser concept of bigger is better, I have mixed feelings about it. We make induction hardened shafts that have splines on the ends and I am very familiar with the heat treatment and processes. I also have first hand experience with a longer torsional shaft versus a shorter one. But, if the Moser tests are correct that a smaller diameter shaft "IS" weaker than the minor diameter of a spline, eventually it can fail too. And, it makes sense. Yes it can torsionally wind up more than the spline, but once it meets its yield point, either it will fail or the spline will fail.

One other note, the Moser tech told me that a spline has not failed if it has not twisted more than 1-1/2 spline teeth. I find this questionable but he told me most splines will move some. I am not the expert on this and I feel comfortable with the answers from Moser.
 
#1,054 · (Edited)
One other note, the Moser tech told me that a spline has not failed if it has not twisted more than 1-1/2 spline teeth. I find this questionable but he told me most splines will move some. I am not the expert on this and I feel comfortable with the answers from Moser.
I hope they mean over the length of the entire shaft and not the pictured spline....

Edit...I just looked again and I agree that yours is still probably "good". Thinking of another picture that had the twist in about a quarter inch section.

Stress relieve it?
 
#1,055 · (Edited)
I guess I didn't pin him down but to me, it's stressed more than it should be and from a metallurgical standpoint, there's no fixing it. Not knowing the specifics the material & heat treat, we don't know specifically what temps to stress relieve it at. But in most cases, stress relieving causes distortion in other areas. So, it gets stored as a spare.
 
#1,056 ·
The new Grizzly locker is in thanks to Dale @ Ironman. Thanks Dale for setting up my gears. :thumb: My first reaction is wow, is that thing noisy. :sonicjay: It sure goes clickety clack. But it works. I find that it releases when coasting around a corner with no problem. I did a whole bunch of playing around on an asphalt parking lot doing tight turns both directions, forward and reverse. It released without any effort. It also releases when under power when I am just maintaining speed. Give the throttle a blip and it locks in. I'm guessing it's going to take some getting used to but it seems to do what I was hoping for.
 
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