The 80 is high!!!

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Correct me if I'm wrong, but, with a lift, the more caster correction one does, the bigger the front diff pinion angle. Stock driveshaft won't work anymore, transfer case and front diff exits being parallel. Christo Slee told me that his caster plates alone on J springs will cure caster problems, but create front driveshaft ones. All right, my explanation esuckes, but you get the idea. Is a front (and rear) double CV a must for Jsprings lift? Looks so to me.
 
After much thought and searching, I have come to the conclusion that I will not be doing any camber correction other than the OME bushings. Yes, castor causes handling issues. However, this thing drives so much better than any other wheeler I've owned so I don't care. It's not worth the extra time and money. (FYI- other 4x4 I've owned: 81 GMC K15, 89 Chev K1500, 95 Nissan p/u, 87 4Runner, 85 4Runner, 77 Jeep J20, 01 Jeep Wrangler, 85 Toy p/u, 78 CJ-5, 73 CJ-5, etc.)
 
As long as it's safe, and you're comfortable with the handling, you can do what every you please. Be whatever shade of grey you want :)
 
Walking Eagle said:
As long as it's safe, and you're comfortable with the handling, you can do what every you please. Be whatever shade of grey you want :)
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LOL! Well, I figure it really doesn't bother me. I'm single, no kids, nobody else drives the thing... Why spend the $?
 
Romanknight said:
Correct me if I'm wrong, but, with a lift, the more caster correction one does, the bigger the front diff pinion angle. Stock driveshaft won't work anymore, transfer case and front diff exits being parallel. Christo Slee told me that his caster plates alone on J springs will cure caster problems, but create front driveshaft ones. All right, my explanation esuckes, but you get the idea. Is a front (and rear) double CV a must for Jsprings lift? Looks so to me.
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Depends on how you correct the caster. One advantage to drop brackets, the axle is not turned - except for whatever delta there may be from the drop to the actual sping height gain from spring variation (ala clown_midget). So the pinion should still be pointing at the same angle.
 
I did J's with 4 OME trim packers (2 each side = 20mm) in the front. I am also running Christo's caster plates as I wanted more caster than stock. I did have to have the front shaft rebuilt and balanced but I have no drive line vibration's now. DC shafts like to see one misalignment (ie. pinion pointed towards T-case,( T-case on crankshaft plane of course). Regular shafts with u-j's at each end are better for multi misalignments. I did try a DC shaft from Christo at first but vibration was much worse than with my worn front shaft. I love my truck on and off highway! It drives/rides excellent in both environments!
 
"Depends on how you correct the caster. One advantage to drop brackets, the axle is not turned - except for whatever delta there may be from the drop to the actual sping height gain from spring variation (ala clown_midget). So the pinion should still be pointing at the same angle."
Yes, but the axle is 3 to 4 (or more) inches lower than stock. Does THAT make a difference?
 
Romanknight said:
"Depends on how you correct the caster. One advantage to drop brackets, the axle is not turned - except for whatever delta there may be from the drop to the actual sping height gain from spring variation (ala clown_midget). So the pinion should still be pointing at the same angle."
Yes, but the axle is 3 to 4 (or more) inches lower than stock. Does THAT make a difference?
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It puts the drive shaft at a greater angle, but it doesn't change the pinion angle like caster plates do. With any lift the u-joints will be running at a steeper angle, with drop brackets the angle on pinnion and transfer case increase the same amount, with caster plates, it increases more at the axle.
 
Romanknight said:
"Depends on how you correct the caster. One advantage to drop brackets, the axle is not turned - except for whatever delta there may be from the drop to the actual sping height gain from spring variation (ala clown_midget). So the pinion should still be pointing at the same angle."
Yes, but the axle is 3 to 4 (or more) inches lower than stock. Does THAT make a difference?
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EDIT: I hope we are talking about the front axle only here....
Not trying to make a huge wave here, and maybe I am not understanding you, clown_midget, and Walking Eagle, but this theoretical BS seems to be just that.

Lets assume for a moment the degree of caster correction is equal amung all options; bushings, caster plates, drop brackets...Caster plates, bushings, or control arm drop brackets the pinion angle is altered, the agle at the transfr flange is constant relative to the vehicle. So conversely, the pinion flange is the variable. So whatever the option plates, bushings, drop brackets the "physical" axle goes from \ to --.

Stealing Christo's technical diagram expertise...

Lift, no caster correction.


P\/|T

Caster Bushings & plates


P|/|T

Drop Brackets


P| / |T (notice the increase in distance from T to P flange)

Maybe I am envisioning a different animal than is being discussed. But I am not quite sure what this stement; "One advantage to drop brackets, the axle is not turned" is trying to describe. I think it is important to add... relative to what??? Because in fact the axle "is" turned with drop brackets, it is not turned (assuming bracket drop exactly equals lift height) relative to the stock axle rotation-but relative to its "uncorrected" lifted rotation-yes it is "turned"/rotated. Furthermore, speaking in terms of the axle housings rotation only-this can be achieved with all alternative caster correction options.

True, drop brackets would result in the axle postion, relative to the vehcile (back/forward), remaining constant with respect to its stock postion and independant of lift (and as before assuming drop bracketry exactly matches lift height). Which would thereby decrease the u-joint angles at the Trnsfr output and pinion flanges (relative to other caster options) -but I would envision this decrease to be minimal (i.e. not make up the difference to eliminate the need for a CV shaft-in such an instance where one is found to be required..er...wanted).

IMO saying; "One advantage to drop brackets, the axle is not turned" is like saying "Diet Dr. Pepper tastes more like regular Dr. Pepper." As opposed to what!? Lemonade? - I would hope :D :flipoff2:

And as far as the point about correcting caster resulting in more lift from removal of spring "bow" and thereby needing additonal caster correction. I would like to see this-really! I know someone is aching to hop on to CAD.. how many people have "witnessed" an increase in lift height after caster correction? How much lift did you see vs. lift spring height/spacer height??? I can't imaging the alteration is going to make or break the effectiveness of the chosen caster correction option....
 
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Seems like it would just be easier and cheaper to volvo portal axles
 
fj803fe said:
True, drop brackets would result in the axle postion, relative to the vehcile (back/forward), remaining constant with respect to its stock postion and independant of lift (and as before assuming drop bracketry exactly matches lift height). Which would thereby decrease the u-joint angles at the Trnsfr output and pinion flanges (relative to other caster options) -but I would envision this decrease to be minimal (i.e. not make up the difference to eliminate the need for a CV shaft-in such an instance where one is found to be required..er...wanted).
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The ujoint angle at the transfer case isn't decreased with drop brackets relative to caster plates, it's decreased at the pinion flange. And more importantly, the two angles remain equal.
 
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Romanknight said:
Correct me if I'm wrong, but, with a lift, the more caster correction one does, the bigger the front diff pinion angle. Stock driveshaft won't work anymore, transfer case and front diff exits being parallel. Christo Slee told me that his caster plates alone on J springs will cure caster problems, but create front driveshaft ones. All right, my explanation esuckes, but you get the idea. Is a front (and rear) double CV a must for Jsprings lift? Looks so to me.
Click to expand...


Actually the more caster correction decreases the pinion angle. That is why the stock shaft begins to vibrate. A Double Cardon shaft requires 0* pinion angle as it's the 2 U-Joints at the transfer case that cancel each other out and the one at the front diff is supposed to be neutral. On my truck it would take 6 or 7 degrees of correction to get within the designs specs of the DC shaft. I only did 5* but still don't have any vibrations.
 
Walking Eagle said:
The ujoint angle at the transfer case isn't decreased with drop brackets relative to caster plates, it's decreased at the pinion flange. And more importantly, the two angles remain equal.
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I don't get your drawing at all. At any given height with the same caster reading the axles position is the same. What changes the drive shaft angle is the fact that by dropping the rear bracket you will maintain the axle in the wheel wells center position (vertically) which would be slightly forward from where the axle would be by attaching the rear arm to the stock position.
 
landtank said:
Go take a few dozen tylenol and lie down in a dark room. This arguement will still be here after the migraine passes.
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Thanks for the advice. I took a speedball of tylenol, asprin, mountain dew, and a few other things I can't pronounce. At least I can see straight now.

I don't think the arguement will still be here. At least not the part about caster and pinion angle and dropped arms vs. caster plate. The theoretical BS doesn't lie if you actually draw it right - so if I agree that you're right, we don't have to argue anymore right?

I'm stopping to get Turbo CAD on the way home, I can't stand not having CAD on my work putter or home putter, but can't afford a $1,000 program. Should give me something to do while avoiding the in-laws at Christmas, and hopefully I won't screw up stuff like when I'm trying to use paint to draw stuff :)
 
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