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521 one torsion bolt shorter than the other?


d.p

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Couple things trying to lower it via torsion bolts and 3" blocks.  I couldn't break the rear u-bolts loose to save my life (no breaker bar or torch) so I gave up on it.  Will try again with the right tools.  When I looked at lowering the front the driver side bolt was way shorter than the passenger side bolt.  Looks like the driver side broke at some point. Not sure what to do with the fronts, anyone know?

 

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It just means they were each lowered a different amount. Generally you would lower them evenly and measure each side of the frame to ensure the front is even height side to side. Probably if you adjusted them even, there would be no difference.

 

Looks like the torsion bars are already lowered. If you want to go lower you will run out of adjustment so... Type "Indexing Torsion Bars" into our search engine and read....

 

http://www.bleachgarage.com/620tech_spn.html

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your torsion bars might be badly indexed already

 

Makes perfect sense. Bars, for what ever reason, were turned the other direction.

 

 

 

The upshot is... doesn't matter what you have, it's where you are going and how to get there. Mark the spline, loosen the bars, move to the rear slightly to disengage the front spline, turn one tooth and put back in. One tooth will probably bring you back to stock settings. You may want to try two teeth to get lower again.

 

To lower, turn driver's side counter clockwise as viewed from the rear and turn passenger's side clockwise as seen from the rear.

 

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Keep in mind that any altering of the ride height will alter the steering toe in. Lowering below or raising above the stock ride position will add toe in. The truck will grind away the tires but worse, it becomes more unstable to steer. I found on sharp in town turns  that half way into the turn the truck would begin to pull to that side all by itself. If one wheel hits a puddle and looses traction the other one becomes dominant and you very suddenly end up in the other lane or the road shoulder. Don't let this happen.  

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It's not missing a tooth, there could be 20 teeth, I don't remember anymore.

In the past a former owner could have re-indexed them already, and got one side a tooth or two off, so that could be the issue, a former owner also could have weighed a lot and they adjusted one of the torsion bars so that it would be level when the driver was in it.

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Keep in mind that any altering of the ride height will alter the steering toe in. Lowering below or raising above the stock ride position will add toe in. The truck will grind away the tires but worse, it becomes more unstable to steer. I found on sharp in town turns  that half way into the turn the truck would begin to pull to that side all by itself. If one wheel hits a puddle and looses traction the other one becomes dominant and you very suddenly end up in the other lane or the road shoulder. Don't let this happen.  

 

Understood.  One more question after watching that video..I pull the torsion bar back, jack up the axel to the desired height, then turn the torsion bar up (1 or 2 notches) and slide it back in?  

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It's not missing a tooth, there could be 20 teeth, I don't remember anymore.

In the past a former owner could have re-indexed them already, and got one side a tooth or two off, so that could be the issue, a former owner also could have weighed a lot and they adjusted one of the torsion bars so that it would be level when the driver was in it.

 

 

Lol who knows whats up with it.  I assumed that the torsion bolts needed to be equal otherwise the front of the truck would be lopsided which it isn't.

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Understood.  One more question after watching that video..I pull the torsion bar back, jack up the axel to the desired height, then turn the torsion bar up (1 or 2 notches) and slide it back in?  Two questions, is there a c clip on a 521? 

 

I guess, or try one tooth and see what you get. Add as needed.

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Which direction do the rear angle blocks go in? Angle up towards the front of the truck or towards the back? Have the taller towards the back but can't seem to get a solid fit between the block and the leaf spring.

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In my case after 2" blocks were installed I notices a bass rumble vibration. I measured the angle at the transmission and at the differential U joints and added a 1/8"shim at the rear. This would tilt the differential downward at the driveshaft and as luck would have it, perfectly matched these two angles.... vibration is completely gone.

 

 

Don't read a lot into this picture below. The two angles just have to be the same to cancel induced vibration. Make sure you measure the angles with the vehicle sitting on it's wheels. Optionally you could fill the gas tank and have someone in the driver's seat.336028d1327182643-lq4-into-3rd-gen-1972-

A 1/8" shim about 3" from the axle will move the nose of the differential, which is probably close to a foot from the center of the axle, about 4 times or 1 inch.

 

If you have angled blocks, and because this is a guess on the part of the manufacturer, you should do the actual measuring yourself and see how close it really is.

 

 

Got the pass side on. It know the driver side won't line up with the axle. Looks like the axle rolled forward a little and I can't get it to roll back to line up. Anyone know how to fix this?

 

Got the pass side on. It know the driver side won't line up with the axle. Looks like the axle rolled forward a little and I can't get it to roll back to line up. Anyone know how to fix this?

 

 

Loosen the passenger side U bolts completely. You may have the axle slightly cocked when the U bolts were tightened and now are forcing against them. With the pass side loose the drivers side will be easier to move. Tighten both sides together.

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Yeah I was going to do that but was able to get it lined up with my brother's help.  He just massaged the driver leaf into place which worked just fine, if that didn't work next step was to loosen the passenger side.  I do have the 3" angled blocks so once I am said and done with the fronts I will check whether I need a shim.  Tried to do the fronts but didn't have the right tools (again) so will revisit those soon.  

 

Not my best pics, but you get the idea.  Almost looks like the passenger front is higher than the drivers side. 

 

Ground to fender after (didnt measure before)

Rear:  26"

Front: 27 1/2"

 

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