Author Topic: Some thoughts Mods  (Read 4627 times)

Offline R3

  • Member 2020
  • *
  • Posts: 1261
Some thoughts Mods
« on: July 02, 2019, 11:20:03 AM »
My thought  in starting this thread is to try to pool some information learned thru my build process.  It is my intent to  let other learn from my mistakes, research and application.  I would hope that  others would chime in on other models
 and things they have learned from their builds.  I wrote this not to  suggest one manufacture or brand over another  but  just present some of the information I have learned and gathered  thru my process. We all have opinions i have done my best to present facts and lessons I have learned.  drive you rig first and foremost  then look at where you want to go with your build. Yes that goal will evolve over time, try to keep that in mind.  Build it for you not to keep up with "the Jones". A daily Driver is much different from a Dedicated trail rig so are the capabilities to each.

People join the forum to learn and share their experiences and knowledge in their Jeep journey. From my build I have learned a lot in a short amount of time.  As briefly discussed in my Rig Build  I would like to share some thoughts and lessons learned in my JKURR build.  In the interest of  not promoting one brand over another I will do my best to present facts and information not brand hype. I will say  you can buy cheap and replace it again and again or  spend a little  more and buy it once.

Background: I bought my first Jeep in 1976 a 1954  CJ5 4 cylinder  3 speed rig.  It needed work a lot of work and by the time it was "done" the little CJ  had a Commando  drive train installed and huge 31 inch tires. That silly thing went everywhere. Built on a budget with limited  resources and no real specialty equipment  it was a great way to get out into the woods and have fun.  This was preceded by many a Jeep, Bronco, Scout, and F series truck over the years.   My current Jeep is the first Jeep I bought new.

Question most often heard is what should I do(Modify)  to my Jeep first?  My answer is  Drive it! Wheel it !  Find out what works for you and what doesn't.  My first ride with the Black Goats was at AOAA in a cold February day. I had the good fortune to run with another JKUR that was completely stock. While it was frowned on to "build a road" to climb obstacles the rig was spotted and  driven thru some challenge  areas without damage.  Fast forward a year and in  come  this little black JK. Stock street tires, no suspension. We wheeled  for a whole day thru lots of cool stuff and much to my surprise the bone stock Jeep  hung in there and made each challenge with careful driving a some spotting.   The lesson I learned was Drive you Jeep. Find out what works for you and what doesn't.  Learn  a bit about your rig and what you would like to do with it. Set  a goal and a budget for attaining that goal.  Remember it is your Goal and there will always be some one with a more capable rig and more money to build that capability.

I also Hear that Jeeps  handle  like crap, agricultural machines, with poor road manners.  My stock Jeep exhibited these tendencies from Day one.  Being a Mechanic and  an engineer  plus having fallen into the  "Can't leave well enough alone" puddle I started to look at  the mechanics of the JKUR.  Stock the Rubicon is a pretty good vehicle from the factory, but as usual the OEM  takes some liberties with production and is constrained by  Cost control and profit.
Some of the things I have found to be short of the mark:

1) Factory Ball joints. The wear material is Plastic, from day one my Rubicon wandered all of the road. Dealer replaced  right side Ball joints at no charge but not the left 4000 miles on my NEW Jeep at this point. The left were "within tolerance". Another 500 miles later they were no longer within tolerance and needed replacing. Factory Ball joints  are worthless with stock tires and rims.  I replaced then with high quality  Ball joints and have not had a issue  since.  You pay for what you get. Yes you can just keep replacing  cheap ball joints every year or buy a good quality set  once and service ( read grease) at recommended intervals. Why buy a $500.00+ set of ball joints  I can get them for much less and I will just replace then every couple of years?  You certainly can do that, you time and labor  is a cost  and if you factor that in you are actually spending more money  than  buying a good quality component up front once.  

2) Tie rod, Drag link and track bars.   Tie rod and drag link use the same design  join as the ball joints. The plastic material allow for movement and wears quickly.  This  joint movement  coupled to Ball joint movement  all adds up to  the dreaded Death Wobble  that folks chase down.   OEM ( Factory)  steering gear is made as cheap as possible to constrain overall cost and maximize  corporate profit.  The factory Tie Rod, Drag link and track bars all flex under load.  this movement adds up to the loose  wandering feeling  driving the OEM Jeep.   Track bars Look into a forged type track bar.  Steering components ( drag link and Tie rod)  there are a variety of  good  manufactures out there. I have recently found the the 7075  Aluminum  components are extremely strong.

3) Steering box. the stock box has a flaw in it , it doesn't hold up to high heat and loading very well. The combination of the two stresses the selector shaft and  breaks.  Larger than stock tire and wheel loads contribute the the high loading as well as  tough off road conditions.  There are a couple of ways to go here; Go big with an oversize steering box  or go with a hydraulic ram and a ported  OEM box.  Both approaches net the same end result a strong steering  system with the higher than stock loading and abuses of off-roading.

Tires and lifts!

This opens up a huge can or worms.  Yes it is "cool" to have big tires and huge lift and if that is the direction you want to go in  Go for it!  However, ( pause for effect) understand the suspension geometry and how it  affects you handling. If the rig is a trailer queen and will never see the street  than the  next paragraph is a mute point.  Like most of us we do drive our rigs  Handling is an issue.  I will say this  you get what you pay for and  cheap  has  both Pros and Cons in most cases the Cons out weight the Pros in terms of drivability.

Short arm vs Long arm. It is All about the geometry here. Terms like  Axle steer, Anti Squat and roll center are important terms to understand if handling and performance are the goal.  If  the short arm lift relocates the frame side  pivot points  your OEM geometry is retained but  ground clearance is compromised.   If the lift is based on stock pivot point locations (Short arm) , Axle steer is induced. In short  as the suspension cycles up or down the axle strays from the 90 degree orientation to the frame and effectively points the the front or rear  in a direction other than straight.  To keep the vehicle going straight you have to add steering input to counter.  A Short arm kit is easy to install and can be done in your garage with simple hand tools.
A long arm Suspension  the arch that the axle move thru  while cycling is much larger in radius,  the amount of steer induced by  up/down travel is reduced. The down side is  Long arm kits are a bit more involved to install and often involve  cutting old (OEM) mounts off to make way for the new  mounting points on the frame.

Geometry there is a huge  amount of math in suspension design.  Google has some great explanation of the terms Anti Squat and Roll center.  In short  ever wonder why some jeeps can get up that hill and other can't? Why some bounce  when  climbing and other do not?  It is all about  the set up. The rear suspension should drive the vehicle forward not jack or walk under the rig.  It should not squat under acceleration either. If the rear suspension  exhibits these tendencies the geometry is not right.  there is much written on this subject and it could take hours and many pages to fully explain. In short your suspension should  drive you forward  and drive over  the terrain not bounce you over it.  if this is done correctly  you can have a rig  that rides like a luxury car  on the road and climbs like a goat off road.

Tires... face it most of us spend 80% of our time on the black top and tires are expensive.  Here everything is a trade off. A super aggressive tire will work well  in gooey mud will handle poorly on the street. A great  AT tire  on the street might not handle  the  mud as well.  I  would say that  how you  tame the off road adventure working thru the problems presented is part of the challenge. Big tires  present  huge loads on  suspension components.  just going to a 37 from a 31  puts a huge strain on Gears and axle shafts.  If you are going to run  big tires  you will need to address Gearing and at some point axle shafts. Sure you can wheel on a D30 with 40s and 3.21 gears  if you drive careful but performance will suffer and in the end you will break something  in the drive train.
 
General rule of thumb 4.56 gears for 35 inch tires, 4.88 for 37s and 5.38 for 40s.  A stock Dana 30 axle will be ok if you drive smart  for a 35 inch tire a D44 is better. At the 37 inch mark  a Dana 44 would be my recommendation and  if 40s are in your future  high end axle shafts on a 44 will work  but a Dana 60 or better  will live longer.  Something of note  as ring and pinion strength goes down as the ration goes up  (3.21 to 4.11)   the weak link on  D30 and D44 are the pinions.  on the D44 5.13:1 is  about the limit in strength Pinion shafts are just getting too small and ring gear teeth are also getting smaller.  The Larger  axle D44, D60, D80  gives you a larger thicker ring gear and a larger  pinion shaft.

Stock drive shafts   on the JK/JKUR carry either a 1330 U-joint or a CV type  joint.  If you upgrade , up grade! 1310 are not an upgrade as they are a physically smaller  joint. If you can't run the stock Drive shaft  look a the 1350 style  to provide  the capability needed to run big rubber.

Brakes... I never found the OEM brakes to be comforting with the stock 32 inch tires. Going to 37s I needed  a bit more braking to slow the beast down.  Several companies make  "big brake kits"  it is a worthwhile investment in safety.

So the reality check ....   to put on a set of 35/37 inch tires and wheel  you are looking at
1) tire and wheels $4000-$5000
2) re-gearing $2000
3) Big Brake $1000+
Total          $7000.00- $8000.00 give or take



Skid plates.... Get them at some point  if you get into serious  trails. if you are just a casual trail rider the OEM units are fine. You can always upgrade as you confidence builds.


Last note , upgrades to your Jeep add weight   one of these  fully built rig can easily weight upwards of 7500lbs.  Weight  adds to the workload you drive train as to deal with each time your drive.  This needs to be part of the consideration in the build  strategy.

I leave you with this. This is  just my experiences  I have learned  in building my JKURR and working on other rigs and listening to the questions I field each time I talk to Jeep folks.  I am not an expert but I do like a good performing machine and for me, I have no extra/second or third income to  dip into to buy Jeep  upgrades.   My rig is a daily driver and my only  all weather vehicle.  It is a compromise in  capability  to achieve  the goal of  reliable daily driver and capable off road machine.

Cheers
Rob


« Last Edit: July 18, 2019, 07:40:55 AM by R3 »
Cheers

17 JKURR
2013 Victory XCT hot rod.


"Talent hits a target no one else can hit; Genius hits a target no one else can see"

Offline Gr8Dain

  • BOD
  • *
  • Posts: 12287
  • I HATE RUST!!!!!
Re: Some thoughts Mods
« Reply #1 on: July 02, 2019, 12:18:51 PM »
That is a lot of good information there Rob. Thanks.

Did you learn anything from the old CJ? 

My approach for the Scrambler has been the “I am a cheapskate” model. Well, until I (with you and Garner helping a lot) installed the Sniper EFI kit. That was by far the best mod I have done for my CJ. I have yet to do many major mods. Mostly repairs other than the 4”  lift and 33” tires. I did swap to 3.31 gears but did it by swapping the whole axles when I did the frame swap.

I have recently purchased a rebuilt dana 300 with 4 to 1 ratio and twin stick. Hopefully the ratio will help keep me from crawling into everyone’s rear ends on the trails.

After that install, the next step will be lockers. Still researching those.
Dain

1984 CJ-8 Scrambler
3.5" lift
DD and trail toy

1949 CJ 3a - Stock - Garage queen

Offline R3

  • Member 2020
  • *
  • Posts: 1261
Re: Some thoughts Mods
« Reply #2 on: July 02, 2019, 12:51:53 PM »
Dain,
My  old CJ5 was an 81 with the 304. I found the old girl to be pretty bullet proof with a few exceptions.
 
Carbs suck.  Since the advent of  all in one fuel injection  that is the way to go off road. Manages a lot of the fuel related issues.  HEI type  ignition is also another  game changer  for the old technology and most times a drop in and go.  hook the two together and  you can have a powerful system that is infinity tunable. The new systems are digital  and so much more reliable than anything pre-dating.

AMC 20 rear... splines are a weak point. Sheared off a hub/axle on a Off road romp in Spain... tough place to find AMC parts in the 80s. Curry flange type axles  are the bomb back then.

Leaf springs are, well harsh. Did the shackle flip  up front, moving the shackle to the rear and improved the ride and handling a bunch. This also provided a small lift that had to be compensated  by arching the rear springs.  

You can use a 360 Crank in the 304 to build a low buck stroker. Can't remember if we used the stock 304 pistons or  did an aftermarket. That woke up the old  iron block.

The aluminum Case 4 speed ... we  that will not handle the abuse that I threw at it. I was lucky to  have a friend  with an Isuzu truck company that was able to adapt the 5 ton 5 speed and T case into my  CJ... truly a one of a kind. Yes lots of machine work was involved but at that time  a US dollar  went a very , very long way.  1 USD =230 Spanish.... the whole Trans swap cost me about $2000.
« Last Edit: July 03, 2019, 08:05:14 AM by R3 »
Cheers

17 JKURR
2013 Victory XCT hot rod.


"Talent hits a target no one else can hit; Genius hits a target no one else can see"

Offline R3

  • Member 2020
  • *
  • Posts: 1261
Re: Some thoughts Mods
« Reply #3 on: July 02, 2019, 12:57:20 PM »
That is a lot of good information there Rob. Thanks.

Did you learn anything from the old CJ? 

My approach for the Scrambler has been the “I am a cheapskate” model. Well, until I (with you and Garner helping a lot) installed the Sniper EFI kit. That was by far the best mod I have done for my CJ. I have yet to do many major mods. Mostly repairs other than the 4”  lift and 33” tires. I did swap to 3.31 gears but did it by swapping the whole axles when I did the frame swap.

I have recently purchased a rebuilt dana 300 with 4 to 1 ratio and twin stick. Hopefully the ratio will help keep me from crawling into everyone’s rear ends on the trails.

After that install, the next step will be lockers. Still researching those.

Lockers, Selectable are the way to go. With your  "long wheel base"  the ability to deselect  the front or rear or both  will aid in maneuverability. ARB is the leader here but requires a Compressor. The E-lockers  just require power and wires.  the Air lockers and compressor give you the ability to have live on board air for tires and accessories like air beds at camp. either way  you are going to part with some coin. average is $1000 per end and $500 if going ARB.
Cheers

17 JKURR
2013 Victory XCT hot rod.


"Talent hits a target no one else can hit; Genius hits a target no one else can see"

Offline highlandercj-7

  • Forum User
  • Posts: 1687
Re: Some thoughts Mods
« Reply #4 on: July 02, 2019, 01:00:31 PM »
IMHO, putting a selectable into a Dana 30 is pissing money away. Lockrite it (or other lunchbox style) and call it good. When you decide to upgrade to a D44 or greater then add a selectable.
HighlanderCJ-7

Offline Gr8Dain

  • BOD
  • *
  • Posts: 12287
  • I HATE RUST!!!!!
Re: Some thoughts Mods
« Reply #5 on: July 02, 2019, 01:03:47 PM »
IMHO, putting a selectable into a Dana 30 is pissing money away. Lockrite it (or other lunchbox style) and call it good. When you decide to upgrade to a D44 or greater then add a selectable.

Can you elaborate? 
I have a lunchbox locker sitting on my shelf, but am hesitant on installing it in case I go with different gears or bite the bullet on selectable lockers.
Dain

1984 CJ-8 Scrambler
3.5" lift
DD and trail toy

1949 CJ 3a - Stock - Garage queen

Offline R3

  • Member 2020
  • *
  • Posts: 1261
Re: Some thoughts Mods
« Reply #6 on: July 02, 2019, 01:13:08 PM »
Everything is a trade off. I hear this  everyday. "D 30 are junk  don't bother building" it etc.  True is if you don't beat you rig  and are not running  huge tires or power the D 30 will hold up fine.. Like everything Abuse it and it will break. Quality components are the key to longevity.



 
Cheers

17 JKURR
2013 Victory XCT hot rod.


"Talent hits a target no one else can hit; Genius hits a target no one else can see"

Offline R3

  • Member 2020
  • *
  • Posts: 1261
Re: Some thoughts Mods
« Reply #7 on: July 02, 2019, 01:16:13 PM »
IMHO, putting a selectable into a Dana 30 is pissing money away. Lockrite it (or other lunchbox style) and call it good. When you decide to upgrade to a D44 or greater then add a selectable.

Can you elaborate? 
I have a lunchbox locker sitting on my shelf, but am hesitant on installing it in case I go with different gears or bite the bullet on selectable lockers.

Dain what is the goal of your build?

I know  Garner has a Lunchbox locker in his CJ and it works well for him.  perhaps he will chime in at some point.
Cheers

17 JKURR
2013 Victory XCT hot rod.


"Talent hits a target no one else can hit; Genius hits a target no one else can see"

Offline Gr8Dain

  • BOD
  • *
  • Posts: 12287
  • I HATE RUST!!!!!
Re: Some thoughts Mods
« Reply #8 on: July 02, 2019, 01:19:08 PM »
For now it is a DD that I can drive comfortable on the highways, yet handle blues (maybe some blacks) about 4 times a year.

Down the road if I get a truck that can be my DD and tow pig, I might go crazier with the Scrambler. But for now, it needs to be a good daily and be street legal.
Dain

1984 CJ-8 Scrambler
3.5" lift
DD and trail toy

1949 CJ 3a - Stock - Garage queen

Offline R3

  • Member 2020
  • *
  • Posts: 1261
Re: Some thoughts Mods
« Reply #9 on: July 02, 2019, 01:27:01 PM »
The Locking front end in the snow might give you control issues  steering.  Chat with Rattletrap55 he has one and does drive it to wok now and again.
Cheers

17 JKURR
2013 Victory XCT hot rod.


"Talent hits a target no one else can hit; Genius hits a target no one else can see"

Offline highlandercj-7

  • Forum User
  • Posts: 1687
Re: Some thoughts Mods
« Reply #10 on: July 02, 2019, 02:55:48 PM »
I hit a Dana 30 with a 400 HP 360 running 35's, 410 gears and a Lockrite locker. Yes, CJ Dana 30s are reliable provided you drive like you have a Dana 30 and not like you have a Dana 60. That said, it does not matter what gears or open carrier you run with it Dain, They are all the same. So put that locker in there and go, especially if you already own it. I put around 60K-70K miles on my CJ with this set up, daily driving it year round, and running 4wd on the highway in the snow. It worked just fine and I had zero issues. 90% of the time you are going to have the lock out hubs unlocked anyway.

If you are not locked in the rear, and are open back there, I would also get a lunchbox for the rear axle too. I have run several versions of rear lockers since 1995: trac-loks, Full Detroit Lockers and Lock rites in the rear 20.
My thoughts:
I HATE the trac-loc, they fail miserably off road and/or when needed the most.
The lock rite was great for the $ spent and I had no issues with it.
I prefer the Full Detroit for the case strength and reliability especially when you need to change the carrier in a re-gear.
 :cheers
HighlanderCJ-7

Offline RFH_98TJ

  • Forum User
  • Posts: 1449
Re: Some thoughts Mods
« Reply #11 on: July 03, 2019, 02:45:05 PM »
I have a lunchbox locker sitting on my shelf, but am hesitant on installing it in case I go with different gears or bite the bullet on selectable lockers.

I would just install it if it fits your current carrier.  It's probably no more than a 2-3 hour job (haha) and requires no special tools except a torque wrench.  You will need to remove the carrier and clean it down good.  You may need to remove the ring gear - so mark it to put it back the same.  As for drive-ability, it only engages in 4-wheel.  I do hear mine clicking in the parking lot in a real tight turn, but other than that, you don't know its there until you need it.  If I recall on Garner's, the time consuming part was just removing the hubs.  It's a perfect time to maintain them and a gear oil change too.
98 TJ 4.0 Sport 5-speed - 4" lift on 35s, 4.56 on D30 with Lock Right and Ford 8.8 LS, Lots of welding

- Frank

Offline Gr8Dain

  • BOD
  • *
  • Posts: 12287
  • I HATE RUST!!!!!
Re: Some thoughts Mods
« Reply #12 on: July 03, 2019, 04:37:47 PM »
I have a lunchbox locker sitting on my shelf, but am hesitant on installing it in case I go with different gears or bite the bullet on selectable lockers.

I would just install it if it fits your current carrier.  It's probably no more than a 2-3 hour job (haha) and requires no special tools except a torque wrench.  You will need to remove the carrier and clean it down good.  You may need to remove the ring gear - so mark it to put it back the same.  As for drive-ability, it only engages in 4-wheel.  I do hear mine clicking in the parking lot in a real tight turn, but other than that, you don't know its there until you need it.  If I recall on Garner's, the time consuming part was just removing the hubs.  It's a perfect time to maintain them and a gear oil change too.

Yeah. I need to make sure it will fir my carrier. I know it is supposed to work with my 3.31 gears. But can’t remember if it matters between the AMC 20 or Dana 30.
Dain

1984 CJ-8 Scrambler
3.5" lift
DD and trail toy

1949 CJ 3a - Stock - Garage queen

Offline R3

  • Member 2020
  • *
  • Posts: 1261
Re: Some thoughts Mods
« Reply #13 on: August 06, 2019, 01:04:55 PM »
Something  I am learning about the  Lunch box locker,  it is hard on the drive train.  In  recent trip to the playground in PA, the ole CJ7 has eaten a couple  hubs. First was shattered, ( OEM Stock) the second  broke mounting bolts.  Not a High HP rig or running  huge tires, the tires are really not aggressive at all.  Listening to the front end  turning there is a loud  metallic clacking sound... this is the Lunchbox  skipping teeth or  locking and unlocking. This is harsh on the front end components and as Murphy's Law dictated  it will find the weak link.  In this case it was the  locking hubs mounting bolts. previously  in an aggressive mud hole we heard a pop, the OEM case hug exploded. Again the front end locking and unlocking creating a shock load thru the drive train.

Now it may be the imbalance  between the front and rear as the rear axle is a LS type and the front is this brutal  Lunch box type.  Perhaps a locker int eh rear axle would take off some of the loading on the front hubs.

Just some observations from the cheap seats.
Cheers

17 JKURR
2013 Victory XCT hot rod.


"Talent hits a target no one else can hit; Genius hits a target no one else can see"

Offline sjalkian

  • Member 2020
  • *
  • Posts: 294
Re: Some thoughts Mods
« Reply #14 on: August 08, 2019, 11:09:53 AM »
I've been running an Aussie on the front of my TJ and have been very pleased.  I will say though that I am running a HP D30 which has a stronger ring and pinion than the standard LP D30 that comes on TJs standard.  I do have a rear locker now as well, but I've run trails both locked and un-locked in the rear and the Aussie has been great and not noisy at all.  Front reading on the interwebs, the lunhbox seems like a solid option in the front, not as much in the rear.  Also, as others have stated its a pretty straight forward install.  I had to take off the ring gear to install mine and it wasn't as scary as it seems.  My $0.02

Sarkis
Freebird - 2000 TJ SE
5" total lift (3.75" SL and 1.25"BL)
35's Cooper SST Pro's
Rear D44 with ARB locker and 33 spline chromo shafts and 4.88 gears
Front HP D30 with Aussie Locker and 4.88 gears
UCF Tummy Tuck
X20 10K Synthetic Winch

 

Officers:

President: Stephen Clough (overhead) | Vice President: Donnie Herrity (Jeepin_Donnie) | Secretary: Robyn Alley (sticksout)
Treasurer: Danille Wilson (TJ Girl) | Member-at-large: Brit Nora (rebel4sale)

Board of Directors:
Dave Plummer (HAWAIICJ) | Sean McCready (Unl1mtd)
Jeff Wilson (jwilson2598) | Aaron Thomson (Jeep Freak) | Dain Wilson (Gr8Dain)

Founding Fathers:
 Jason Markvart (LNDSRK)  | Steve Scott (Islander90) | Josh Storer (Jastor)| Mike Finelli (BiggMike) | John Harper (Opie) | Andrew Harvin (HarvinJeep)

Disclaimer Statement:
All images from NoVaJeepers.net are exclusive to the Northern Virginia
Jeepers Association. Any reproduction of exclusive Northern Virginia
Jeepers Association material is strictly prohibited without written
consent of the Northern Virginia Jeepers Association. Jeep,
Wrangler, Cherokee, Commander, Compass, Patriot, Liberty, Unlimited,
Rubicon, SRT, HEMI and Grand Cherokee are copyrighted and trademarked
to Chrysler LLC. NoVaJeepers.com, Northern Virginia Jeepers Association
is not in any way associated with the Chrysler LLC.