Lowering my 1979 620

[dplrbruno]

I have a previous post called (1979 Datsun/Nissan 620 pickup) in that post are photos of how the truck sits empty. I would like to lower the front about 1 1/2" and the back to make the truck level. 

I have read that adjusting the torsion bars in the front will work but I'm not sure what to do for the back.

Two questions: 1. How are the torsion bars adjusted?

                         2. What hardware do I need to lower the back?

 

[Jersey]

1) Loosen the torsion bar bolts to lower it.

 

2) You'll need a lowering kit for the back (longer u bolts and blocks), I believe they come in: 1,2,3, and 4" kits.

[datzenmike]

 

Two inches would be about as far as I would go unless you are under 25 and don't give a shit about the ride quality. Lower than that the suspension doesn't have enough travel to sufficiently absorb bumps. To avoid bottoming out you have to increase the spring rate but few do. Carried to an extreme the rubber bump stop is cut to allow more droop and the torsion bars indexed to go lower. By now there is no suspension and you are riding on the air in the tires and the camber is way past excessive.

 

As mentioned the backs are as easy as adding a 2" spacer between the leaf spring and the axle. Keep in mind that lowering upsets the U joint angles and vibration will increase the lower you go. Also the lower you go the stiffer your springs should be to reduce bottoming out. For only 2" you're probably ok if not hauling loads.

 

 

 

For the fronts You may get what you want by searching out D-21 Hardbody drop spindles. Not sure if you have to swap the brakes or not. Something to search for the information.

 

To lower by adjusting the torsion bars find where the rear of the torsion bars mount on the crossmember behind the transmission.

 

 

Loosen the top lock nut sufficiently and then loosen the adjusting nut below it and the truck will lower. Lower both side the same amount and bounce the front end before measuring the bumper height. All lowering or raiding will change the alignment settings of toe and camber. The suspension is designed to run in a narrow range and once you exceed this, proper camber cannot be adjusted out although toe can be. Toe in WILL increase when lowering so get that sorted out as this totally affects the handling and WILL wear your tires away. Again 2" is probably within camber adjustment but once all the shims are removed, all future adjustment stops.

 

Re-aim your headlamps.

[dplrbruno]

Thanks to everyone's replies.

I don't want to make the truck a really rough ride. Just want to make it look better than the going down hill look it has now. Really just wanted to make it level. Probably only take the front down an inch and the back to make it level.

Thanks again.

[banzai510(hainz)]

ride should not chamge as your just reposition the bar/ clocking it off a few degress. the bar is heat threated and will not change.

I don't know wht people say they ride different. Only the rubber travel stop if its riding on that before it hits the frame will affect this and you can revove this also to give more room.

 

buy new shocks for rockauto.. If you buy a gas shock set up the bushings on the shock but the lower on then cut the tiewrap and when shock extends point thru the hole and then cap the upper bushing and nut.

[datzenmike]

If on the bump stop, or near it, it will hit and bottom out the suspension travel on a bump. The suspension stops moving downward so the vehicle weight comes down on the tire and it compresses and rebounds like a beach ball. As I said a couple of inches will be fine.

[hobospyder]

Do rear first and match the front to it. A lot easier than trying to match rear to front

[Stoffregen Motorsports]

ride should not chamge as your just reposition the bar/ clocking it off a few degress. the bar is heat threated and will not change.

I don't know wht people say they ride different. Only the rubber travel stop if its riding on that before it hits the frame will affect this and you can revove this also to give more room.

 

Because of the bump stop. That's why.

 

I say remove the bumpstop, notch the frame or re profile the control arm and slam it!

[robrizzo]

I was thinking of going 3 inches in the front. Is is possible without changing spindles?  Do you think it will really be way to much over 2 inches? 

I have 15 inch wheels with same offset as what is on the truck now. What size tires would be best? I don't want low profile because of ride quality and I like the full tire look to fill the wheel well.  235/65/15 Good?    205/75/15 Better?    advice.

I have a 1971   521    thank you  

 

[Crashtd420]

Being a 521 I dont belive we have drop spindles available to use due to the king pins.... 

I'm Pretty sure you can due 3" all around with no real issue.... probably just need shorter bump stops....

 

As for tires I run 195/60r15..... i have no idea how lowered I am because I have no idea what the stock ride height should have been.... I should be around 2 1/2 to 3".....

 

 

I can measure from the ground up to the bottom of the fenders if you wanna compare....

 

Any one know what stock ride height measured to the bottom of the fender should be?

 

[Crashtd420]

2 hours ago, robrizzo said:

 

I have a 1971   521    thank you  

 

Just realized your in the 620 section asking this.....