What castor angle are you running?

[LiftedLimo]

So I installed 6" skyjacker springs, moved my shackle to the bottom of the frame to get a good shackle angle so now the truck rides like heaven(in the front at least). The stock shackle angle with the lift springs and wedge rode like holy hell; very bouncy and stiff. Horribly compared to my stock saggy leafs. And as I rotate my castor angle more and more the truck keeps driving better and better! I dont know where I should stop.

No, I have not taken it to an alignment shop to get laser exact measurement on what the angle is at, but it looks around 4 degrees positive by my electric angle finder, versus 4 degrees negative castor with the skyjacker 6" springs with the stock shackle location.

What castor angles are you guys running on your dana 60's to make them drive like a dream? My truck drives so well now that Ill actually let my friends and family drive it. But I think I can do better:-laf

 

[Ctdchris]

By negative castor you mean pointing 4 degrees below horizontal right, like pointing towards the ground?

 

[LiftedLimo]

Let me clarify. Right now differential is pointing farther tword the ground then before. If you take a measurement off the machined flat surface on the top kingpin the axle is rotated up 4 degrees positive. Before it was rotated down 4 degrees negative and driving erratically because the wheels did not track. When I took a stock measurement it was about 2 degrees positive.

 

[LiftedLimo]

#ad

 

[BSMcCauley]

I had castor on mine set at 4. 5* positive about 6-8 years ago and had to sign a liability release with the shop to get them to agree to do it. However, it made a significant improvement in how straight the truck tracks. Had been a bit like hearding cats previously. I have experienced no ill effects nor the short ball joint life that the alignment shop had warned me about -- even with about 450# of iron wrapped around the front. :-laf

 

[Ctdchris]

It has always been my understanding that you want 2-4* negative caster. That's how we set them up when we do spring over axle conversions anyway. I believe if you get too much angle you'll blow through tires, that's the warning I always got for going too far.



Chris

 

[cerberusiam]

With the bigger tires and the weight in the front end 4-6 degrees of positive caster to get them to drive civilized. Less than that and its like herding a shopping cart down the road.



The problem you will now run into is the pinion angle is going the wrong way and you start to have problems. Running that much caster does put more stress on the ball joints but no more than the big tires. You do scrub the tires more on turns but thats just the nature of lifts and big tires.

 

[Moab4x4]

Skyjacker doesn't know caster...

My alignment shop says 0-3. 5 positive is original spec.



I have a 4" skyjacker softride in the front. The wedges that came on it were 4 degree and made of aluminum. That took my alignment to 2 degrees negative caster to keep pinion angle to a minumum. That truck was scary!!

All over the road at random moments, The truck steered when the turbo kicked in. #@$%!

I took out the wedges and it ran much better but my yoke would bind just a hair under extreme articulation. I could have ground the yoke a little but decided not to.

BTW I do not have a stock front driveshaft. I have a custom 1350 front driveshaft from Tom Woods so the stocker will be a little different. IIRC the stock 7260? and 7290? yokes actually flex more than the bigger 1350.



Anyway, I installed a set of 2 degree steel wedges and lengthened the rear shackles by . 5". This did two things. It kept the spring from hitting the frame all the time and in the end I ended up with . 5 degree positive caster. I can now live with the compromise of handling and pinion angle. Oh yeah, reinstalling the sway bar helps on the highway too.



Another peeve, check the diameter of the springpack bolt head compared to the matching hole in the spring perch. I had to install a bolt with a bigger head to make it center better.



Pics here:

RamchargerCentral. Com - Moab Rocktruck, 92 CTD W350 daily driver



Ken

 

[Ctdchris]

After staring at that picture for about 10 minutes I see why you guys are right. If i was standing next to the truck I could tell you, but pictures and talking about it confuses the crap out of me #@$%!



When we do our spring over axle conversions we point the pinion towards the transfercase, then adjust the caster to compensate for the tilting of the pinion. That way we can avoid running CV's or binding drivelines.



Glad you guys got it figured out.



Chris