"79" 620 KC ball joints & Torsion Bar

[Seeker > 620 KC]

I had some loud noises like someone hammering on the frame with a ball peen hammer. It sounded like it was coming from the front end and from mid section of my newly purchased 1979 620 KC. :( I never found the mid section noises, but could feel one if I put my hand under the FR lower control arm. Based on advice from a 510 owner, I jacked up the truck under the frame and shook the tire from side to side and up and down. All tight. Did some research and realized I should have jacked up under the control arm in order to isolate and inspect ball joints...shot!

 

 

 

 

The odometer says 48k that had an outside chance of being accurate, but seeing the play in the ball joints I'm sure that is 148k and I ordered new upper and lower ball joints and control arm bushings, bearings, steering parts, and new wheel bearings figuring that would cover any front suspension noises. I got everything off the right side and was about to figure out how and where to mark the torsion bar and remove it in order to remove the lower control arm bushing. (Can it come off by removing the front lower control arm bolt from the front without removing the torsion bar ???)

 

 

 

 

That is when I found a lot of movement in the torsion bar. :blink: Is this play normal? And if so what takes up this play when everything goes back together? It sounds just like the hammering noise I couldn't locate from mid vehicle. I'd sure like to know the torsion bar is not the source of this noise and how to identify if it is damaged or not. The manual doesn't show pics or explain what keeps the torsion bar from slopping around under load. Is it possible the play at the torsion bar is allowing it to hammer due to the front looseness in the ball joints and control arm bushings?

 

 

 

 

 

According to the Nissan service manual the truck vehicle height appeared to be set a couple inches higher than stock which may have contributed to wearing out the front end & steering so drastically?

 

This is my first time posting video, hope the links work. :unsure:

[]2eDeYe]

The play seems about right. The weight of the truck removes most of that play when the truck is on the ground.

 

You will have to remove the torsion springs to install the control arm bushing as the bolt is held in by the torsion spring. The anchors are held in with a c-clip. There is a good post in the FAQ (see my sig) showing the clips.

 

A bad carrier bearing (on the driveshaft) will make a bit of a racket near the middle of the truck as well.

[yello620]

2eDeYe' date='13 February 2012 - 01:28 PM' timestamp='1329168519' post='633946']

A bad carrier bearing (on the driveshaft) will make a bit of a racket near the middle of the truck as well.

 

 

Carrier bearing was the source of the noise in the middle of my truck a few years ago too. Fixed now.

[Seeker > 620 KC]

Will the carrier bearing make noise at a stand-still if you're jumping up and down in the bed?

[yello620]

Will the carrier bearing make noise at a stand-still if you're jumping up and down in the bed?

 

Possibly. If the parking brake is not set and the vehicle rolling movement is resisted by the driveline/transmission being in gear. It could cause a bad carrier bearing bushing to make noise. I think it would have to be awfully bad to do it this way, but possible.