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Jeep-Short Wheelbase All discussion of short wheelbase Jeeps: CJ, TJ, YJ and JK

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post #1 of (permalink) Old 07-21-2009, 07:39 PM Thread Starter
 
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Question tutelage

ok, so i need an explanation. i took my jeep up a bank at a slight angle (left side lower than right) and my front right wheel (red arrow) got into the air. as soon as this happened my right rear (blue arrow) started spinning in the dry sand and digging in. It lifted the front right wheel more and it was feeling like it would tip. Why did this happen and what is the best adjustment (in addition to driving skill) to get out of these situations? Locking diffs?
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post #2 of (permalink) Old 07-21-2009, 09:00 PM
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Ah, you've learned the "secret" of open diffs! 1 tire spinning on each axle really equates to 2 wheeldrive!

Yes, lockers would have either drug you up the slope or gotten far enough off-camber to flop

A couple things...

Did you disconnect the front sway bar?
What did you air the tires down to?

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post #3 of (permalink) Old 07-22-2009, 05:24 AM
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Quote:
soon as this happened my right rear (blue arrow)
Uh, the blue arrow points to your left-rear tire.

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post #4 of (permalink) Old 07-22-2009, 09:32 AM Thread Starter
 
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left-right-its all the same!
yeah pay attention to the arrows not the words....
i didn't disconnect sway bar.
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post #5 of (permalink) Old 07-22-2009, 01:18 PM
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Quote:
Originally Posted by dlloydj View Post
i didn't disconnect sway bar.
Not sure what's involved to disconnect it (never had one ), just that MOST folks add that ability. It *will* help the front axle (both tires) stay in contact with the ground better... and reduce the teetering effect from the suspension.

Airing down (from street pressure to maybe 15#) to create a larger contact patch will aid traction, especially in the sand...

Or, there's always the slippery slope of traction devices! Spend money, drive harder stuff than you could open, break, spend more money upgrading, drive, break, spend... never ending cycle!

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post #6 of (permalink) Old 09-06-2009, 06:11 AM
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Yup, adjusting the driving technique is the cheapest. Your situation in that photo has the most vehicle weight on opposite corners, so the two wheels with the least weight on them (therefore the least traction) are on different axles. Without lockers, or perhaps even limited slip, those un-weighted tires spin and you have zero wheel drive.

Disconnecting the sway bar(s) will give your suspension a little more movement and might have been all you needed for that situation. I haven't gotten around to that modification, and have only wished for it a couple of times over several years of trails.

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post #7 of (permalink) Old 09-08-2009, 01:45 PM
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Originally Posted by dlloydj View Post
Locking diffs?
Yup, just put a lock right in the rear axle and you will be amazed what you can do.

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post #8 of (permalink) Old 09-12-2009, 01:25 PM
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Quote:
Originally Posted by dlloydj View Post
ok, so i need an explanation. i took my jeep up a bank at a slight angle (left side lower than right) and my front right wheel (red arrow) got into the air. as soon as this happened my right rear (blue arrow) started spinning in the dry sand and digging in. It lifted the front right wheel more and it was feeling like it would tip. Why did this happen and what is the best adjustment (in addition to driving skill) to get out of these situations? Locking diffs?
First off,
Your suspension was too stiff to keep the right front in contact with the ground.
Once the right front lifted, 50% of your traction went out the window.

If you had disconnected the sway bar and/or had softer springs, the right front would have stayed in contact with the ground and you wouldn't have lost traction as easily.

Secondly,
When the right front lifted, that lost 50% of your traction,
SO,
All engine torque (torque is what actually MOVES the vehicle and does the work) was transfered to the rear axle.

Since you have an 'Open' differential in the rear, all engine torque was transfered to the wheel with the LEAST traction.
In this case, The 'LEFT' rear,
And the tire simply didn't have enough traction to keep from spinning.

-----------------------------------------

What you can do to stop this in the future,

1. Disconnect sway bar(s), stay way from 'Hard' springs so the suspension can 'Flex' with terrain.

Sway bar disconnects are cheap and easy to install,
Nothing but common tools to install, and don't require any critical measuring or opening the differentials.

2. You can use your emergency brake pulled on slightly to keep the rear axle from spinning only one wheel.
The added drag to the wheels with LESS traction will help apply power to the wheel that DOES have traction.

When you successfully get all four on the ground again, or get over the obstacle, you can release the brake and go on your merry way...

This is hard on rear brake pads/shoes, but off roading is an expensive sport, and this is just the price you pay sometimes...
And this only works if you know how to adjust your brakes.

3. *IF*...
You have front lock outs on your hubs,

(NOT a good idea of you don't have lockouts or have full time transfer case)
You might consider a front 'Lunch Box' locker in that D-30 Axle. ($200-$250 before install)

This WILL require you to take the carrier out of the differential and have some pretty specific measuring equipment to make sure the clearances are proper.

Since this is a 'Full Time' locker, and you can't control when it 'Connects' or 'Disconnects' the front axles,
It's a REAL GOOD idea to have lockouts on your hubs to disconnect the wheels from the locker,
And a transfer case with '2 wheel drive' so you can disconnect the transfer case from the locker on highway/hard pack roads, and when trying to make sharp corners.
(lockers don't like to turn corners)

4. Consider a rear locker CAREFULLY...

A 'Full Time' rear locker is a real pain in the butt!
Snaps, Pops, Cracks, Jumps, and unpredictable highway/hard pack/gravel operation are the rule of the day.

Then consider actual strength.
'Lunch Box' lockers are Cheap, but not very strong and are CONSTANTLY needing new center pins, ect.

Full size lockers are around $800 and need another $250 to install since you have to reset the ring and pinion,
And most of the full size 'FULL TIME' lockers STILL do strange things in the rain, on gravel, on pavement, and make all sorts of noise.

For me, the ONLY acceptable choices for the back are:
SELECTABLE LOCKERS you can connect and disconnect from the drivers seat so you don't have to put up with the sudden (sometimes dangerous) jerks and noise from the locker when you are on highway/roads,

OR,
Detroit TrueTrac Limited Slip Differential.
You will not know a TrueTrac is back there until you need the extra traction!
Works great, no stupid selector switch, and never given me a minute of problem.

This is NOT the limited slip that is virtually helpless when on ice or gravel,
And many people use them in the front since you can still STEER with both axles pulling!
(you can't do that with a full time locker! If it's 'Locked', it's not going to steer worth a darn!)

I don't like putting money in a Dana 30 front, so I run a Aussie that I can turn 'Off' at the hubs and transfer case,
And a TrueTrac in the back, and I can go virtually everywhere the guys with full size lockers in both ends can go!

5. Consider a 'Long Arm' kit for your TJ.

This will increase your suspension travel, keeping your wheels in contact with the ground better.

This option is more expensive than a SINGLE locker,
But about the same cost at TWO lockers, and you can normally install without specialized tools.

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Last edited by TeamRush; 09-12-2009 at 02:01 PM.
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post #9 of (permalink) Old 09-14-2009, 10:52 AM
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'Lunch Box' lockers are Cheap, but not very strong and are CONSTANTLY needing new center pins, ect.
I have over 40k miles on the lockright in my YJ that has been in there for 3 years now. I also have a pair of lockers in my CJ that have been in since August of 2000. Neither have had any problems. The CJ does have some wandering on the street but the YJ's locker is very rarely noticeable. I suspect the CJ's problem is the frame flexes too much. Just the engine idling rough makes the frame rails move up and down and side to side. I need to built another crossmember for under the engine.

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post #10 of (permalink) Old 09-14-2009, 07:52 PM
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Quote:
Originally Posted by WILL View Post
I have over 40k miles on the lockright in my YJ that has been in there for 3 years now. I also have a pair of lockers in my CJ that have been in since August of 2000. Neither have had any problems. The CJ does have some wandering on the street but the YJ's locker is very rarely noticeable. I suspect the CJ's problem is the frame flexes too much. Just the engine idling rough makes the frame rails move up and down and side to side. I need to built another crossmember for under the engine.
Yup!
I think you mean to say you have 40,000 on the jeep since you installed the locker,
Not 40,000 on the locker it's self.
Since the locker is only 'ON' when you are wheeling...

I've never seen ANY KIND of locker live under 40,000 Miles of CONTINUOUS USE...

If you do have 40,000 miles CONTINUOUS USE on a lunchbox locker,
I'd SURE LIKE TO KNOW WHAT BRAND!

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