how high can i get

BRKLYN1

 
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May 23, 2005
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I run 850-Js and a 1" spacer in the front. I have not noticed any vibrations or noise, at what point might I expect to get an efect that will cause me to need to plop the replacement front (double cardan)drive shaft cash down? :confused: thanks
 

MTNRAT

 
 
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Oh and this from another thread.
From what I can figure and been told, it seems that 80 series front axles are not all alike with respect to caster. The only explanation is that when they are built, the knuckles are not all welded in the same position. The result is factory caster that seems to range from 1.5 degrees to 4.5 degrees. Those with more positive castor respond to lifting better, and those with less factory caster respond to lifting poorly.
Just a few thoughts to ponder.
Cheers,
Sean
 

Cruiserdrew

On the way there
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The real concern is safety at the margin. If your caster is off, your steering will be twitchy in emergency braking situations. It will also tend to follow groves in the pavement, and be very sensitive to the crown in the road.

Vibrations are not due to caster problems. They are do to inproper alignment of the t-case output flange and the differential companion flange. The two good places to be are absolutely parrallel, or the diff pointing exactly at the output flange on the t-case. In the first instance a standard two joint driveshaft should be free of the vibes. In the second instance a double cardan will prevent vibrations.

Everything else is a crapshoot.
 

BRKLYN1

 
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would a two inch spacer be out of the question? I have castor corected for the curent lift I dont think i will get more out of the OME bushings. at the moument the steering is not twitchy under hard braking. my main fear-question is about the drive shaft vibration.
 

Cruiserdrew

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You need to talk to Slee Offroad. You are headed down an unsafe path. Here is what I would reccomend.

2.5 inch lift-Caster correction bushings
4 inch lift-Caster plates
6 inch lift-new leading arms with proper caster built in.

There are other possible custom solutions as well. I'm suprized no one has done an 80 series cut and turn, or maybe they have and kept it quiet. That Australian method of mounting the leading arms on top looked cool as well.
 
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Cut and turn: basically, you cut the knuckles away from the housing and turn them several degrees to correct your castor, then reweld the sleeves into the housing.
 

BRKLYN1

 
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May 23, 2005
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MTNRAT said:
Oh and this from another thread.
From what I can figure and been told, it seems that 80 series front axles are not all alike with respect to caster. The only explanation is that when they are built, the knuckles are not all welded in the same position. The result is factory caster that seems to range from 1.5 degrees to 4.5 degrees. Those with more positive castor respond to lifting better, and those with less factory caster respond to lifting poorly.
Just a few thoughts to ponder.
Cheers,
Sean

It seems crazy that there is a 3 deg range in manufacturing? Is that something indicated in the codes of the axle or something that you have observed? If that is the case how can one take a measurement of an axle’s castor position or disposition?
 

Junk

 
 
 
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BRKLYN1 - lift before dshaft issues varies by truck as mentioned above. I ran J springs + 20mm worth of packers on all 4 corners - never needed to replace the front driveshaft. Some others with that setup have had to ... just lift it and wait and see. If you then need it, get it - seems to be the best approach.
 

MTNRAT

 
 
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The theory of the difference in stock caster is more of an observation derived from how the same suspension modifications on different trucks give a seemingly vast array of results with respect to driveability. It would be very interesting if everyone here who's 80 is still stock had the caster measured and reported back. That would give us an idea of the actual starting point.
Cheers,
Sean
 

e9999

You want to do what...?
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MTNRAT said:
The theory of the difference in stock caster is more of an observation derived from how the same suspension modifications on different trucks give a seemingly vast array of results with respect to driveability. It would be very interesting if everyone here who's 80 is still stock had the caster measured and reported back. That would give us an idea of the actual starting point.
Cheers,
Sean
I believe I did report someplace that my completely stock (as best as I can tell) suspension in excellent condition was showing slighly under the low end of the published specs range. IIRC it was something like 1.5 and/or 1.75 deg. Drives perfectly.
 
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