Lower ball joints - need to remove the control arm and torsion bar?

[MaddieCycle]

Hello. FSM, Haynes, and Chiltons all say to remove the LCA, which includes pulling the torsion bars, to replace the lower ball joints. There has to be a way to do this without pulling the LCAs.  I am sure the LCA bushings could stand to be replaced, but I have no interest in tackling that job for what I use this truck for. Upper ball joint boots are both intact, so I am going to leave those alone.

 

Thanks.

[datzenmike]

I would think that if you raise the truck, loosen off the tension anchor bolt on the rear of the torsion bar, unbolt the sway bar and shock absorber the LCA should be capable of dropping downward. Unbolt the ball joint and maybe jack the hub and upper control arm upward you should have plenty of room.

[Charlie69]

Are the ball joints bolted in or are they pressed in.  If they are bolted then you should be able to replace them with out removing the lower control arm.  D21s (Hardbodies) went to pressed in ball joints. I prefer the bolt in ball joints.

[matrophy]

There's a good tutorial here. No need to disconnect torsion arm. Whatever you do, don't lose control of the tension rod. Ask me how I know

 

https://720nissantrucks.weebly.com/

[datzenmike]

I've had tension rods off before and didn't have any problems.

[Charlie69]

The only time I have had a problem getting tension rods back on was on my 85 KIng Cab 2wd ST and that was on the drivers side.  THe frame was bent is why I had the problem lining up the tension rod.  I have done tension rod bushings on 520, 521, 620, & & 720s with out any problems except when the frame was bent.  Note These were all 2wd trucks.

[MaddieCycle]

On 6/27/2020 at 8:51 PM, matrophy said:

There's a good tutorial here. No need to disconnect torsion arm. Whatever you do, don't lose control of the tension rod. Ask me how I know

 

https://720nissantrucks.weebly.com/

This is a great writeup, I have a 4wd so I can't just take my spindle off like that without getting involved with removing the outer CV joint/drive axle.

 

I am trying to pre-plan pain points on this job, which I am planning to do tomorrow.  The only major problem I see is that it does not look like there is enough clearance to lift out the lower joint from the spindle without the joint hitting the outer CV boot/joint.

 

Pic:

 

https://drive.google.com/file/d/1cI5qkfpAyMm1fQmhRRuO-8uY663w2qJ5/view?usp=sharing

 

[MaddieCycle]

Ok so I did (most) of the passenger side front end today.

The short answer is that you DO have to back out the outer CV joint from the spindle in order to have enough room to pull out the lower ball joint.  You don't have to take it all the way out. It was actually pretty easy. Pull off the auto-lock hub via 6 hex bolts, remove the circlip on the axle splined shaft, pivot the spindle around a bit and you can get the lower ball joint out/in.

 

I did have to slack out the torsion bar, so that will be lots of fun fitting it back in/measuring etc...  I do have a question - how in the heck do two 12mm bolts maintain the tension that holds up 25% of this truck's weight? Crazy. Nuts, in fact!

 

A couple of other observations: The upper ball joint is press-fit into the control arm (in addition to 4 bolts), so now I am off to Auto Zone to rent a Ball Joint press tool.  Also, the tension rod was pretty easy to put back in, lining up the holes was not too bad, with the torsion bar off I was able to jack the lower control arm up and down to jimmy the rod into position and line up the holes.

 

The Monomax shocks I bought did not come with a compression wrap on them so I had to jerry-rig something with a clamp and some zip ties. Tomorrow the new tie rods, shock, and upper ball joint go in, re-tension the torsion rod, and then torque everything.  Then I have to find the time to do the other side one day!  The idler arm and steering damper were easy-peasy.

 

This was an exhausting job but satisfying and probably would cost thousands at a shop.

[MaddieCycle]

Everything is bolted up and done.  A couple of other observations: The upper ball joint needed to be pressed out by a machine shop. The underside of the upper control arm is an irregular shape and there was nowhere for the portable ball joint press to clamp down on.  It took them 10 minutes and cost me $35 so no harm done.  Putting the torsion rod back in was a little bit of a pain, even with a full clean-out and regrease of the splines, it did not fully slide in easily.  I had to worry it forward about 1/2" to allow the adjuster arm to fit properly on the frame boss.  To do this, I set up two jack stands along the length of the rod to support it and catch it in case it fell out.  Then I just whacked on the adjuster arm end with a mallet until I got it in.  This was a nervewracking experience because I was convinced I was going to cross-thread the splines and render my entire truck useless, since replacement torsion rods for an '86 4x4 are unobtanium. But it all came together and nothing was more of a relief to lower the jack and see the truck sitting supported on the tire.

Edited July 31, 2020 by MaddieCycle

[captain720]

Compression wrap on shock? I just put them in fully extended, maybe I missed something are your shocks fancy?

[MaddieCycle]

29 minutes ago, captain720 said:

Compression wrap on shock? I just put them in fully extended, maybe I missed something are your shocks fancy?

I installed Monomax shocks.  With the LCA in the lowest possible position (torsion bar disconnected), the shock was too long to fit between the upper and lower shock mounts. I used a large clamp to compress the shock, then used a series of zip ties to hold it in compression, fit it into position and fastened the lower bolt, and then cut the zip ties and the shock expanded right up into the upper mounting hole.

[captain720]

Maybe I need to upgrade my shock experiance 😂 are they better when they are that long? I never get the best quality ones and just blow up my driver's side one every 6 months or so

[MaddieCycle]

31 minutes ago, captain720 said:

Maybe I need to upgrade my shock experiance 😂 are they better when they are that long? I never get the best quality ones and just blow up my driver's side one every 6 months or so

Lolz these are are KYB Monomaxes, I got them at Rock Auto for 50 bucks a piece, they are pretty good shocks.  The ones I took out were totally shot and probably the original ones. I was able to compress them by hand and there was zero rebound, they just stayed compressed.

[captain720]

15 minutes ago, MaddieCycle said:

Lolz these are are KYB Monomaxes, I got them at Rock Auto for 50 bucks a piece, they are pretty good shocks.  The ones I took out were totally shot and probably the original ones. I was able to compress them by hand and there was zero rebound, they just stayed compressed.

Once every six months or so I take a brand new shock from perfectly functioning with quick rebound to no rebound and the oil leaked out 😂 I have had good luck with the KYB excel G Black editions on my 2wd but havn't wanted to try an expensive shock on the 4WD with how fast I blow them up.

[datzenmike]

2 hours ago, MaddieCycle said:

Lolz these are are KYB Monomaxes, I got them at Rock Auto for 50 bucks a piece, they are pretty good shocks.  The ones I took out were totally shot and probably the original ones. I was able to compress them by hand and there was zero rebound, they just stayed compressed.

 

They would only extend by themselves if gas charged. Ask Charlie but I doubt 720s had them 35 years ago.

 

Rebound is how fast or slow the shock allows the spring back to rest position after it has been compressed going over a bump. It's a dampening effect controlled by the rebound side of the valving inside. Some are externally adjustable, the average ones are not and it's just built in.

[Charlie69]

The original shocks on all 720 were not gas filled just the same design as cars and trucks have used they were oil filled hydraulic shocks.

 

I run the KYB gas adjust silver in color on my 2wd.  On the 4x4 I would use the KYB Mono max red in color.

Edited August 1, 2020 by Charlie69