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Extending rear differential backwards

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Extending rear differential backwards
« on: March 17, 2018, 06:45:12 PM »
Who has pushed the rear differential back am inch?do the brake lines need to be lengthened? Does anything other than the suspension parts need modified?

I have built the upper link spacer, two inches down and one inch back.  I am extending the lower arms next.  I am extending a new set of lower arms.

I have the rear differential assembly from my wrecked rig.  It was rebuilt before the wreck, from end to end.  I plan to have all the parts ready to install, before I pull the existing parts.

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Offline JollyZuk

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Re: Extending rear differential backwards
« Reply #1 on: March 19, 2018, 07:44:18 PM »
Do you know if there is anything different about the Sport rear diff and suspension?  I am thinking aloud that maybe the upper shock mount may need to be pushed back, because I think I read someone had trouble with springs and shocks making contact with each other, and pushing back may make that worse.
Are you planning on rotating the diff any when you move it back?
1995 Sidekick JLX
16v 5 spd, milled head, LROR Stage 2 clutch
2" Spacer lift, XL7 rear springs,  2nd Gen front springs, W-Body GM Struts on front
OEM ROOF RACK!!!

Re: Extending rear differential backwards
« Reply #2 on: March 30, 2018, 09:18:42 AM »
I don't think the Sport is different in the rear. The shocks will be closer to vertical with the axle pushed back an inch. I will look at it when I get back. The push backwards will help with drive angle. I won't rotate the axle, until I do am axle swap to the 8.8.

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Offline JollyZuk

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Re: Extending rear differential backwards
« Reply #3 on: March 30, 2018, 08:35:54 PM »
Ok, brain fart happening. Were you the one that had the DT shocks made with the lower mount point offset?  That item there is what is making me think the shocks might be a problem...
1995 Sidekick JLX
16v 5 spd, milled head, LROR Stage 2 clutch
2" Spacer lift, XL7 rear springs,  2nd Gen front springs, W-Body GM Struts on front
OEM ROOF RACK!!!

Re: Extending rear differential backwards
« Reply #4 on: April 01, 2018, 06:35:46 AM »
That's me.  The shock has bump stops and a wider body.  Without the offset, the shock body would contact with the axle tube.

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Offline JollyZuk

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Re: Extending rear differential backwards
« Reply #5 on: April 01, 2018, 05:34:59 PM »
If you keep the shock mounts wher they are currently, do you get close to having that contact again?
1995 Sidekick JLX
16v 5 spd, milled head, LROR Stage 2 clutch
2" Spacer lift, XL7 rear springs,  2nd Gen front springs, W-Body GM Struts on front
OEM ROOF RACK!!!

Re: Extending rear differential backwards
« Reply #6 on: April 20, 2018, 04:03:03 PM »
I won't likely move the upper mount back for a while.  I am looking at a possible coil-over conversion and a 8.8 rear differential.
« Last Edit: June 01, 2018, 07:44:14 PM by Ridjobradi »

Re: Extending rear differential backwards
« Reply #7 on: June 01, 2018, 04:39:54 PM »
Well the plan has changed, yet again.  I am keeping the Sidekick rear axle for a while.  I am also going to extend the rear diff back an inch or so.  The decision I need to make is whether to just extend the factory trailing arms or to cut the differential end off and replace it with a forged poly joint and a threaded tube insert. 

I can purchase or fab offset coil spring pads that will help with the spring angle issue, when pushing the axle back.  The shock mounts will be replaced or relocated at the same time.  I have my rebuilt rear Sidekick axle from the wreck, so I can paint it and mount all the new parts to it first.  I thought about rotating the rear diff to improve the drive line angle, but I keep reading conflicting information about drive-line phase, etc. 

The reason for going back to a previous plan was that I was able to pick up a 5.85 front ring and pinion set, in Phoenix.  The gear set the one from 4xFourArt out of Turkey.  It was a good price and I didn't have to pay the shipping from Turkey.  I was researching parts for my planned 8.8 rear diff, but I haven't found a 5.8X ring and pinion set for the 8.8.  What I can get is a matching rear set for the Sidekick differential or a switch to a Ford 9 inch.  The Ford 9 inch has lots of options available, like LSD, posi, lockers, etc.  I can also get it in a matching 5x5.5 bolt pattern.  The hard part is waiting to find Ford 9 inch in the width I want, instead of the wider F150 widths that are commonly available. 

Does anyone have any input on using the forged poly joint on the axle end of the trailing arm, please chime in.  I would like to do something like BRD HNTR, but I will wait to build a true four link until / if I get a Ford 9 inch to build up.
http://www.barnes4wd.com/1-14-Forged-Poly-Joint_p_419.html


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Offline JollyZuk

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Re: Extending rear differential backwards
« Reply #8 on: June 02, 2018, 08:29:39 PM »
If you are going Ford 9”, you might try getting a unit from like a 61-64 f100.  They are much narrower than the later units.  I don’t know if it would cause an issue, but they do have an offset center section.
Nice snag on the front R&P though.  Are you going to relocate your front mounts and lengthen your arms forward?  You could use the arms off your parts rig and splice them with the arms on the current ride to make longer arms.  The idea with the threaded rod end is good if you want adjustability, if it is worth the trade off of harsher ride if you give up the rubber bushing.
1995 Sidekick JLX
16v 5 spd, milled head, LROR Stage 2 clutch
2" Spacer lift, XL7 rear springs,  2nd Gen front springs, W-Body GM Struts on front
OEM ROOF RACK!!!

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Offline BRD HNTR

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Re: Extending rear differential backwards
« Reply #9 on: June 03, 2018, 07:16:15 AM »
I really like my 4 link suspension.  I have ended up welding the threaded bungs and Heim joints, making them solid non adjustable links.  I have had the joints and bungs strip to the point I could feel the a gap by pushing and pulling by hand.  I replaced the stripped bungs & heim joints and then had it happen again, so I welded them solid.  These were supposed to be manufactured by one of the leading Off Road parts suppliers, but not bought from them, so I figured they were good quality.  I have not heard of others having this problem, but there are a lot of forces on the links.  Having adjustable links is definitely a plus when setting them up.  Get your bungs & joints from a reputable dealer (even though they will cost you more.
93 Tracker,XL7 springs & 1" raised spring pads in front with YJ springs in back, home built bumpers rear & front (w/winch), 2" x 4" rock tubes,  ARB front & rear, converted Sami rear to IFS, 33x12.5x15  aluminum rims, roll cage, 2.7L w/5 speed auto.

Re: Extending rear differential backwards
« Reply #10 on: June 06, 2018, 05:54:22 PM »
JollyZuk - I am looking for the F100 rear or an early Bronco 9 inch to get the width closer. I  running 1.25" spacers all the way around, to keep my tires from rubbing the shock mounts. I can go with a later model 9 inch and shorten / center it also. If I center the rear from a later model, I can use early model axle shafts.  I can do the work, but I don't have the $450 arbor that makes the job relatively easy. .  If I go with threaded bushings, they will only be on the axle end of the trailing arm. I can keep a stock bushing on the frame side to keep from transferring any harshness from the road.

The Sport front lower arms are cast, not stamped. The current plan is to copy BRD HNTR using non Sport 1st Gen front lowers, when I move the front wheels forward.

BRD HNTR - I would like to do a rear 4 link with 30+" trailing arms, but I am not real comfortable with such a big mod. I can make anything, but the dimensions and lack of prior experience cause some heaitation. I will start with my factory rear axle and 1" extended trailing arms.  I am hoping I can build the Ford 9 inch and new 4 link later.
« Last Edit: June 06, 2018, 06:05:54 PM by Ridjobradi »

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Offline BRD HNTR

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Re: Extending rear differential backwards
« Reply #11 on: June 11, 2018, 10:09:03 AM »
JollyZuk - I am looking for the F100 rear or an early Bronco 9 inch to get the width closer. I  running 1.25" spacers all the way around, to keep my tires from rubbing the shock mounts. I can go with a later model 9 inch and shorten / center it also. If I center the rear from a later model, I can use early model axle shafts.  I can do the work, but I don't have the $450 arbor that makes the job relatively easy. .  If I go with threaded bushings, they will only be on the axle end of the trailing arm. I can keep a stock bushing on the frame side to keep from transferring any harshness from the road.

The Sport front lower arms are cast, not stamped. The current plan is to copy BRD HNTR using non Sport 1st Gen front lowers, when I move the front wheels forward.

BRD HNTR - I would like to do a rear 4 link with 30+" trailing arms, but I am not real comfortable with such a big mod. I can make anything, but the dimensions and lack of prior experience cause some heaitation. I will start with my factory rear axle and 1" extended trailing arms.  I am hoping I can build the Ford 9 inch and new 4 link later.

I used stock bushings on the axle end of my 4 links, with Johnny joints on the frame end.  My first 4 link set up had my lower links going outside the frame and lower links were 26".  The longer outside the frame the lower links are the straighter they will be.  4 link's use the differences in upper/lower link angles for stability and control of the axle.  Kris & I did a lot of comparison programing with a 4-Link Calculator for what we considered doable.  I have 4 positions on all my links attachment points, and I really can not tell the differences in traction or handling when changing them (but the calculator has very different potentials).

While my front A arms are not cast, I am not sure they will interchange with yours.  I thought your frame is 4" wider than mine (making a motor swap easier)but don't know on the actual a-arm dimensions.
93 Tracker,XL7 springs & 1" raised spring pads in front with YJ springs in back, home built bumpers rear & front (w/winch), 2" x 4" rock tubes,  ARB front & rear, converted Sami rear to IFS, 33x12.5x15  aluminum rims, roll cage, 2.7L w/5 speed auto.

Re: Extending rear differential backwards
« Reply #12 on: June 11, 2018, 03:27:10 PM »
While my front A arms are not cast, I am not sure they will interchange with yours.  I thought your frame is 4" wider than mine (making a motor swap easier)but don't know on the actual a-arm dimensions.

I always thought the A arms were not compatible, until Matt did his coil-over install.  i believe that he compared all the parts and the A arms were the same dimensions.  I don't think his install / build log is stall on the forum, but that is how I remember it.  I would prefer to get some used A arms, from someone to try this with, but I will most likely order an A arm and a ball joint.  If f the mounting points are the same, I should be good to go.  If the old style arms are longer, all the better.

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Offline JollyZuk

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Re: Extending rear differential backwards
« Reply #13 on: June 26, 2018, 09:30:20 PM »
So to throw some more fodder for figurin’.  Been looking at parts on Rock auto, and comparing things.  What is the difference in front diff mounting on a Sport?  Looking at part specs, I am inclined to think it sits slightly more to the drivers side in a Sport.  The left half shaft for a Sport is shorter than a standard ‘Kick, and the Passenger side longer.  So if you are widening things, you might look at a non Sport left half shaft.  I think the difference was over an inch on the left shaft, and minimal on the right.
1995 Sidekick JLX
16v 5 spd, milled head, LROR Stage 2 clutch
2" Spacer lift, XL7 rear springs,  2nd Gen front springs, W-Body GM Struts on front
OEM ROOF RACK!!!

Re: Extending rear differential backwards
« Reply #14 on: June 26, 2018, 10:19:18 PM »
Thanks for the information.  I haven't seen or heard about the shaft dimensions being different.