Delta VS Radius Arms (1 Viewer)

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I think you are measuring the rear pinion angle? If so great just buy som upper or lower adj arms and match that number at the transfer case to avoid rear vibes. If the ds angle at the transfer is over 10* you’ll need a rear dc shaft.
As for the caster just go get an alignment as it sits now. You can’t measure off the rad arm mount. You can get close my taking an angle at the knuckle top and bottom studs but the real number comes from the caster sweep from the alignment machine.
At this point you might want to start a dedicated thread to your situation.
All measurements were up front. I think that an alignment shop is definitely the way to go at this point.
 
What he means is, are you at a 2.25” lift as measured from coh to bof? Then yes the math would be around 4* positive caster. What is your front panhard axle bolt to frame bolt measurement? And do you have actual caster numbers from an alignment?
Also hard to believe that you don’t have driveline vibes at a lift under 2.5” and caster around 4*
But lucky you I guess!

I'm simply subtracting the stock value to my lift value to get 2.25" per landtank's guide and others in this very thread.

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I get my alignment checked at least once a year by a professional that I trust, so yes, this isn't some type of backyard garage eye test value.

I also run landtank's DC shaft matched with a bought new OEM rear prop shaft. This combo has served me well for many years now + tens of thousands of miles. Buttery smooth, zero noise on 37s.

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Handful of folks have been waiting far too long for radius arms, many apologies for that. Won't bother anyone with excuses, a whole bunch went out over the last few days, whole bunch more will be going out again in the near future.

Recently came across a smoking deal on a 6-axis robot welder to augment the house built robot welder we have been using for radius arms. This machine will increase our through-put and overwhelm the powdercoat shop even more.

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Handful of folks have been waiting far too long for radius arms, many apologies for that. Won't bother anyone with excuses, a whole bunch went out over the last few days, whole bunch more will be going out again in the near future.

Recently came across a smoking deal on a 6-axis robot welder to augment the house built robot welder we have been using for radius arms. This machine will increase our through-put and overwhelm the powdercoat shop even more.

View attachment 3181357
Drooling and jealous! Nice!
 
@Somebodyelse5 - (I'm Not Dave, but might be able to help)

5" Arms provide 9.9 deg of Caster correction.
What's your lift height from wheel hub to top of fender?
 
@Somebodyelse5 - (I'm Not Dave, but might be able to help)

5" Arms provide 9.9 deg of Caster correction.
What's your lift height from wheel hub to top of fender?
Thanks buddy,

I am right around 4" of lift (Measure around 23.5"-24" hub to fender).

9.9 degrees?! Maybe I need the 3L arms then.
 
Thanks buddy,

I am right around 4" of lift (Measure around 23.5"-24" hub to fender).

9.9 degrees?! Maybe I need the 3L arms then.

@CJK @Delta VS

So... for 4" lift... which arms? I know for sure that my caster is at -.7 deg right now, with no correct.
 
@CJK @Delta VS

So... for 4" lift... which arms? I know for sure that my caster is at -.7 deg right now, with no correct.

Sorry, busy work week.

So if you’re measuring 23.5-24” Hub-to-Center, you’re at 3” - 3.5” of lift. If you’re measuring -0.7 deg of Caster, that means you’ve lost 3.7 deg of Caster

According the Dave’s tech drawing for the arms, a 3” lift loses 5.3 deg of caster. The 3” arms provide (lost amount) + (1.1) = 6.4 deg of caster.

For you, 6.4 deg + (-3.7) = 2.7 deg of caster

5” arms provide 9.9 deg, so that would put you at 6.2 deg of caster

Clear as mud?
 
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Thanks buddy,

I am right around 4" of lift (Measure around 23.5"-24" hub to fender).

9.9 degrees?! Maybe I need the 3L arms then.
Your a bit more lift than me. I had the 4 arms and was slight -caster still. Went with the 5L and haven't had it at the alignment shop but pretty sure its over spec now and handles great with 37's even. Pretty sure 3L would get you nowhere near where you need to be. Best to error on the + side from what I have experienced.
 
Your a bit more lift than me. I had the 4 arms and was slight -caster still. Went with the 5L and haven't had it at the alignment shop but pretty sure its over spec now and handles great with 37's even. Pretty sure 3L would get you nowhere near where you need to be. Best to error on the + side from what I have experienced.

Curious though, if 6.2 deg of caster is just way too much...

@CJK @Delta VS
Do you guys have people running 6 degrees of caster? Curious what the target caster numbers for your arms are, maybe 6 deg is where I want to be and I just don't know it! I have been shooting to get back to yota spec of 3deg +/- 1 deg. Can you share what you are shooting for with these arms?

It looks like you are using caster loss of 1.76 deg / inch + 1.1 deg (for both 5" and 3" arms)

5" Arms = + 9.9 degrees of correction
3" Arms = + 6.4 degrees of correction


Example:

Your stock 80 sitting at 3 degrees of caster
You lift 3", your uncorrected caster = 3 deg - 1.76 deg/inch *3 inch = -2.28 degrees
You install the DeltaVS 3 inch arms, your new corrected caster = -2.28 + 6.4 = 4.12 degrees

Why is that extra 1.1 degrees added in? without it, you would be back at 3.02 degrees (which, I was assuming everyone was after... but maybe we want more castor than spec?)
 
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I’m just an enthusiast so don’t take anything I say as official :)

I was curious about that same question (regarding normal range of caster).

From my googling, >6 degrees of caster is a bit. Seems like 3-5 is normal range.

The main concern I had is that as you increase caster, you are also changing the pinion angle (on opposing side of axle).

Idk how 80 series do at 6 deg of caster (based on others experience) so maybe you can check that out.
 
Just a reminder that Firestone auto has a lifetime alignment that's worth the money. After the first alignment, it pays for itself quickly.
Not all locations have the capacity for 37s and larger. My local store referred me to another store about 10 miles away that could do them.
 
I’m just an enthusiast so don’t take anything I say as official :)

I was curious about that same question (regarding normal range of caster).

From my googling, >6 degrees of caster is a bit. Seems like 3-5 is normal range.

The main concern I had is that as you increase caster, you are also changing the pinion angle (on opposing side of axle).

Idk how 80 series do at 6 deg of caster (based on others experience) so maybe you can check that out.
IIRC, when I had my alignment checked at a dealership years ago, their spec sheet had +2-4 degrees as acceptable. I think excess camber will put more angle on the front ujoint, which would increase the chances of vibration.
 
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IIRC, when I had my alignment checked at a dealership years ago, their spec sheet had +2-4 degrees as acceptable. I think excess camber will put more angle on the front ujoint, which would increase the chances of vibration.
Nice, good to know about the range.

I think you meant “caster”, and yes exactly right. I was trying to say that (regarding the relationship between caster and pinion angle) but stopped halfway 😆
 
Let me know when the 4" radius arms are in stock. I currently have the 6" and need to step down.
If someone has the 4" and would like to swap ,let me know. Mine are practically new. I've had them for about 3 months and only have highway miles.
 

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