620 floating around

[metalmonkey47]

Trucks a '76 620 with 720 4x4 leafs, stock shackles, and 2'' blocks.

 

I've been getting this weird problem ever since putting in 2'' lowering blocks on my 620. Every once in a while when I take my foot of the gas to coast or slow down, I've noticed the truck pulls from left to right rather hard (but most of the time rather mild.) It feels almost as if the rear diff is just floating around under the truck. I checked everything and it seems to be pretty tight, so I'm not sure why I'd be getting this sensation.

 

 

Things I've noticed in particular:

• It doesn't pull directly to any side in particular.
  
• If I jump back on the gas, it straightens out.
  
• It LITERALLY feels like the rear of the truck is floating around.
  
• It's very inconsistent and seems to get worse after hitting a bump HARD.
  

I know my passenger rear brake is dragging very lightly (trying to figure that out still) but I don't feel that's related since it doesn't just pull to the right.

[I'm BLUE]

ur leaf spring brackets/locaters in good condition ? springs themselves can fracture... bushings any goood ?

[wayno]

I would check the front upper spindles/mounts, also the kingpins/balljoints, I can't remember what year the change over was.

When ever I used my brakes on my 521, the thing would take off in some direction, the upper spindle was almost ready to fall out of the bushing.

[datzenmike]

Does it do this when braking?

 

See if the front spring mount is broken from the frame. Use a pry bar to lever down on the spring.

[metalmonkey47]

It's not any different when braking and doesn't pull from side to side. No mount tabs are broke/bent/cracked, but I did notice one thing that I'm going to post pictures of that may help.

 

Theres no play in the kingpins or any suspension components for that matter...

 

Except my leaf bushings are literally gone.

 

 

 

Needless to say, herp derp Datsun drama.

[I'm BLUE]

Get those leaf spring bushings ordered ! That is def a lot of "un-tensioned" play in any direction

 

:)

[metalmonkey47]

Got them already ;) You'll see tomorrow why I haven't changed them yet :sneaky:

[datzenmike]

Except my leaf bushings are literally gone.

 

 

Well that might do it. If the rear end can cock sideways even a small amount it's like having rear steering.

[odmanjohnson]

Rear end moving around for sure. Double and tripple check u-bolts, and for sure replace spring bushings. Make sure centering pins on springs arent broken.