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Cardinal Grammeter

74 620: Suspension: LF Loud Creaking Stiff Binding

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I'm hoping this is my FINAL PROBLEM to solve with this project! 

 

And I confess, "How hard could finding a stuff suspension piece be?  But I've been working 12 hours today cleaning black and green mold and mouse piss and shit from a car I just bot.  And I'm draggin'...   Maybe someone will say, "Oh yeah, <this part> typically fails and binds up the suspension!"

 

Anyhow, here is what's up in all its Gory Detail:

 

When I greased the front end, it was in pretty bad shape:  stripped and broken off zerks and plugs.

 

KNOWN ISSUES:

  1. The LF Upper King Pin bushing took grease and I popped the top Welch plug out a bit while trying to get grease to flow out the bottom of the bushing.  Unfortunately, you can see red rust around the bottom.  That is never a good sign with king pins.  Only good thing was that the grease did come out the top.
  2. The Upper Inner Rear Control Arm Bushing would not take grease.
  3. When I bounce the suspension by pushing on the front fenders, the LF is clearly stiffer and the bounce frequency is higher.  Something is binding.

NOTE:  Of the 6 tie rod ends, I think only 1 had a boot.  And that boot was as hard as coal.  I thought there were more boots but it was only Petrified Grease.  I'm tempted to get hand fulls of grease and make "grease snow balls" around each of these ends.  (this is funny but not a joke!)

 

THE CREAKING:

 

U can hear it when the LF suspension works.  I can feel it strongly with my hand on the shock tower - which is near Issue #2.

 

HOW TO PROCEED:  (not knowing what part is the problem)

 

Disconnect Sway Bar:  This will free up the suspension and make it easier to move and diagnose.

 

Tighten all bolts.

 

Break all grease type bushings loose (as if replacing) hopefully finding the problem one.  (1-1/4" socket works!  way cool!)

 

Could it be a SHOCK ABSORBER?

 

Thanks in advance,

Tom

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Won't be a king pin (but you know that) but it will need work.  You can try heating the kink pin with a torch so the grease melts and flows. (done that on my 521) Not a fix. What about the other 3 grease fittings on the king pins?

 

Try a new grease fitting any where grease would not go in.

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The other 3 king pin zerks flowed nicely.

 

I had the Left Outer Tie Rod End not flow - took a center punch and pushed the little ball in and it took the grease.

 

Maybe the first thing to do is break free that non-flowing Upper Inner Rear Bushing and see if it is it.  (there is NO rust around that bushing.)

 

Maybe just break them all free and tighten all bolts.

 

... damn, its 9PM and I'm heading back out to work on it....

 

QUESTION:  Wonder if it would make sense get spares of all suspension pieces?  That would be a chunk of change, but what happens if suspension pieces become NLA???

 

________________

 

EDIT:  EUREKA!

 

Jacking it up, it Creaks like crazy.  (And check this out:  I raise the jack 1-2 inches and its creaking, so I figure "Hey, I'll let it down and it'll Creak on the way down.  NOT!  It is so frozen, suspension DID NOT GO DOWN.

 

But HOW TO? 

 

ANSWER = STETHOSCOPE!  Totally nailed it - NO doubt whatsoever - clear as a "bell." 

 

Now I hope I can get a breaker bar on it.

 

(Finally, a little good news today!   I have to laugh, I decided not to take my morning shower but do it when I was done working.  Little did I realize how wise a decision that was.)

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When My 521 got all stiff and squeaky I would take it for a night of mud bogging and drinking.

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Oh Man, I cringe at mud bogging.  I bot a Paxton supercharger setup from this kid that had a 3/4 ton Ford that he had to put a water pump on.  This truck was solid mud - like the kid never cleaned it.  We were trying to find the bolts to the pump and it was a nightmare.  No water.  No pressure washer.  Oh, and it was Ohio clay which is like Poor Man's Concrete.

 

Unexpected Result:  Leading up to this, I was feeling all kinds of engine vibe that was rotational unbalance and it was causing a loud vibration in the dash - it was the defroster nozzles.  I could reach up under the dash and just touching it would silence it.

 

Now that I've freed up this control arm, the dash vibration is gone!

 

This is very interesting because I'm an engineer that specialized in stress and vibration analysis - specifically jet engine turbine and compressor blades for Pratt & Whitney.   So I'm wondering if Nissan actually designed this system of rubber motor and body mounts, spring stiffnesses, etc. because it could lead to much quieter cab environment.  I would have thought that level of engineering would not be present back in the early 70's.  But who knows...

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Ha!  after about 10-15 miles, it started creaking again, getting worse the more I drive it (maybe 20 miles).

 

Nowhere as bad, but suspension is stiffening up again (and dash is vibrating (!) )

 

I'm wondering if the threaded bushing is bottoming on the threaded shaft?  or maybe I just need to keep greasing it to work the grease into the worn areas?

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You probably have rust in the joint.  Take the time to disassemble, clean, and grease things.  Replace bushings and be done with it.  I think you can still buy them at Rockauto for about $1 each.  

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I checked RockAuto and all they have a rubber bushings.  I called Advance and they only show rubber too.  The ones in the parts manual and on my truck are the solid steel threaded ones with zerk fittings.

 

Is this more Unobtanium I wonder?

 

 

 

EDIT:  I just called the local Nissan Dealer:

 

The king pin threaded bushing  54507-B0100 is $70.99 and according to them fits "73-79 620's"

The ball joint rubber bushing  54506-B9500 is $26.99 and according to them fits "73-79 620's"

 

Online I've seen the B0100 for $34 which is still a pile of quan.

 

Therefore, all the more reason to clean out the one I have and hope it's not too loose.

 

EDIT.2:  ebay KENTIGO in Mexico is selling the complete "Upper Arm Spindle" for $70 shipped.  (shows in Completed auctions, none current at this time)

 

s-l500.jpg

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UPDATE:

 

This is the 3rd time I've wound the nut out, greasing each turn with wrench both ways.

 

It stays free for maybe 30 minutes and then stiffens up again.  Creaking basically doesn't happen anymore.

 

I was going to wind the bushing off completely but after maybe 1/8" out, it was like I hit a shoulder.  I'm assuming it is a simple bushing with internal and external threads.  The FSM does everything with words and no pictures to define the part names. 

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You are doing the final tightening of parts with the suspension in it's on the wheels at rest position, right? With the wheel off, set it down on a 6" block of wood to simulate the tire. This includes the bottom bolt on the shock absorber.

 

There is also a bushing where the LCA bolts to the frame. The rear of it has the torsion bar mounted into it.

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It never occured to me - Duh!  You are absolutely correct - the extension bumper is on the upper control arm which means when hanging, that bushing has a bunch of load on it. 

 

But I found those 2 radial grease holes inboard of the arms on the bushing - they flow grease evenly after I pushed a bunch of grease through.  I'm keeping my fingers crossed because I am now getting grease flow through both holes.

 

I know for sure this is the creaking bushing.  It was the only one that didn't take grease (it's taking grease good now) and was also clearly confirmed with a stethoscope - I could cause it to creak when jacking so I was able to probe the area completely.  The original creaking was so strong that you could feel it with your hand on the shock tower.  Very obvious.

 

The weather has just turned major crappy here and I've done about all I'm going to do for winter.   I want to put some weight over the RR tire and haven't decided what to use. 

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RE:  Freeing up the kingpin bushing that flows grease only out the top:

 

I was thinking if I could pump oil into it, it might work its way through the rusty end.

 

I just tried pumping oil with a grease gun and ha, it works, but the oil blows by the big rubber piston and makes a complete mess.  I have to be quick since the oil leaks out of the GG so fast.

 

SOLUTION:  PORTA-POWER!   This should work awesome.  Now wile I can hold the top king pin "freeze plug" in with a large c-clamp, I'd like to use something more rigid - like .....  eureka!    A could cheap coil spring compressors just might do the trick.     (I wsa thinking of a couple bars of steel and 2 pcs of all-thread which still would be the most robust.

 

The thought of taking it apart  - I don't have the time or interest.

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