What are the options for castor correction for 2.5" lift (not 4",6",etc.)?

[1973Guppie]

I have been running 3 degree blue slee bushings for years now with no problems.

 

[dubyahard]

Here's my experience with the TJM 50mm, along with where I've ended up. Originally I had them with the 2in drop brackets, and replaced my stock control arm bushings with the OEM one's, which was a big upgrade over initially driving around without caster correction. I really wasn't very happy with the way it handled overall though--turn radius wasn't great, unstable and top heavy, hydroplaned a lot, erratic braking pull, tracking every rut in the road, and didn't feel anything close to the stock setup. It slowly started to bug me more and more. I upgraded my front shocks to radflo, I put the metaltech rear uppers and lowers on, I got new tie rod ends, etc. When I did the tie rod ends, I had the truck aligned, and I was at like a 1.3 pos caster.

At that point I started digging into the forum some, as that was obviously out of spec from factory recommended numbers, and I was kind of wondering the same thing that you are. After chatting with some members who'd had a similar experience, I ended up having the slee plates put on, and they made a drastic difference in the way that it drove and handled. It wasn't completely back to stock, but it was a big step up from the drop brackets. Caster went up to like 3.6 pos.

I did have some driveline noise at that point, which went away when I pulled my front shaft. I eventually decided to part time it, although that was probably overkill, as it was time for new u-joints anyway. I did that in the rear and it took care of the little vibes i had there.

My wife has always hated the lift, and we drive the cruiser so much, that I finally agreed to go back to stock height. I put a set of Old man emu stock height heavies on last weekend, removed the slee plates, and the cruiser drives like a whole new vehicle. I know for a lot of you, your use of the rig necessitates the lift, but the OME stock heavies drive fantastic on the road, are progressive springs, and I can still armor the thing down. And no caster correction to fool with. Braking, turn radius, general smoothing out of the ride, cornering, i mean pretty much everything is 100% better now. I wish I'd switched to these a couple of years ago honestly.

Plates were better than the 2in drop brackets, but stock height Emu springs wins the day for how I use my cruiser. Just like tire size, I know everyone will have a different opinion and experience on this. Hope this helps.

What are the item numbers for the stock height "heavies". Can't really figure it out form all the threads on the subject. This sounds like what I want as I'm already running an ARB Deluxe (no winch yet) and RTT with armor plans in the future on 295/75 KO2s. What shocks do you run with it? Thanks.

 

[Beej]

@Dragos80 I have the lift in the garage but haven't installed it yet. I went with the TJM castor correction rubbers but yeah, haven't got it on yet.

 

[Dragos80]

If you just replace the springs it's not hard at all. Most of the time people have some trouble with the top shock nut.
Caster bushings are a different story if you don't have the press.

 

[mtnzorro]

What are the item numbers for the stock height "heavies". Can't really figure it out form all the threads on the subject. This sounds like what I want as I'm already running an ARB Deluxe (no winch yet) and RTT with armor plans in the future on 295/75 KO2s. What shocks do you run with it? Thanks.

https://www.amazon.com/gp/aw/d/B004...=8-1&pi=AC_SX236_SY340_QL65&keywords=arb+2862

https://www.amazon.com/gp/aw/d/B004...=8-1&pi=AC_SX236_SY340_QL65&keywords=arb+2861

They're the 861's and 862's. Got mine from amazon.

I'm running radflo remote resi up front and fox 2.0 rears. Others have said the stock tockikos or bilsteins ride fine with this setup too though.

Hope this helps.

 

[Miguedangel]

Hi
I have the OME 2.5 lift with 295/75 KO2 on my TRD OEM supercharged LX450 and no castor correction....
I had some vibrations starting at around 120kmh (that's around 74.5 mph) so after doing my knuckle kit install (OEM toyota, with Koyo bearings...) I decided to replace the control arms bushings as well, so OEM Toyota got installed....
After that no more vibrations whatsoever, or any other kind of problems (steering or suspensions...)..... Feels very strong and planted even at 145 kmh (90mph)....not that I frequently drive that speed but it's good to know your truck limits.....
So for me with the 2.5 lift there is no need for castor correction....

It is the best answer I read for my configuration ... I also have 295 / 75-16 and I have to install 2.5 "spirals ... which is without the correctors then without fear

Tks

 

[Bambusiero]

Is it correct that 1 inch in lift corresponds to 1 degree in castor correction needed?

No, best practical approximation is 1.75 degrees caster loss per inch of lift above stock.
If you want the actual math, you can plug into the calculator:
CasterLoss[degrees] = ARCSIN(Lift / ArmLength) (degree mode, not radian mode)
or
CasterLoss[degrees] = ARCSIN(Lift["] / 32.68")
Not sure that 32.68" is the absolute best true number for ArmLength but...got it somewhere.

Stock caster target is 3.0 degrees +/- 1 degree.
Higher may be better, but people say above 5 degrees becomes bad, too heavy/slow response.

ARCSIN means the same as SIN raised to -1 power.