Got 80 Series Caster Correction? (1 Viewer)

[Bud_Dude]

So my '97 80 has always felt tender on the highway, especially at speed; where a sneeze can send you into another lane and you don't dare try to change lanes quickly to avoid something in the road for fear of rolling. Basically, oversteer, which makes driving the truck on long drives tiresome. Never had this issue on my old '95 80 with it's 2-3" OME suspension. I've always suspected this was due to the previous owner's installation of the Icon Stage 3 lift and shocks. So today on recommendation from Steve at Alternative Automotive who rebuilt my engine, when looking to see if he did alignment (he doesn't) I took it to Off Road Warehouse, generally not my favorite place, but Steve said the main suspension guy there name Jason (big dude) was the man on Auto Park Way to talk to and all the other alignment shops would be clueless with regard to caster angle on a solid axle truck. Jason was indeed a knowledgeable guy and pleasant. So he did the alignment ($145 for an hour since they can't really do anything but measure what it is and adust toe in...), and indeed the caster measures at -0.4 degrees... that would be axle rolled forward... The spec calls for the caster to be +2 to +4 degrees (or axle rolled backward); and thus the oversteer situation. Yes it does have the offset bushings in the control arms, but those bushings can do only so much.

I see Dobinsons, Slee, Metaltech, and others sell caster correction plates. I'm looking to get some and probably just have a shop install them and re-test the alignment in hopes of improving the manners of the truck on long highway cruises to fun places to wheel. Anyone have experience with using or installing these?

 

[Overlandeffex]

I have plates on my truck and installed them myself. I did not weld them on like some say you need to do

 

[BreckenridgeCruiser]

I've seen a lot of people like @Overlandeffex that have bolted them on and then run them for ever. Not a hard job and you don't even need the alignment. Rotating the axle will push your steering a bit off center (since you were so far past correct caster - I'd target closer to the +4 than the +2) but you can fix that yourself by just adjusting the bar from the steering box to the axle until the steering wheel aligns when driving straight ahead.

 

[Bud_Dude]

I have plates on my truck and installed them myself. I did not weld them on like some say you need to do

I just watched a video from OTRAMM looks pretty easy... Which brand did you install?

which did you install?

 

[Bud_Dude]

So I just spoke with Christo at Slee... He says it gets complicated with these caster correcting mechanisms with regard to the tie-rod behind the differential and drive train vibration from the front drive shaft due increased angle. It appears my radius arms have caster correcting offset bushings installed to correct some of the caster. As the suspension is an Icon Stage 3 system (allegedly 3" lift) and does not sell offset bushings, these may be ARB or other branded bushings. Christo said that if these bushings are installed to not attempt using the caster correcting plates as it will roll the axle too far and result in the tie-rod rubbing on the radius arms...

Lastly he said to measure from the center of the front wheel hubs to the inside edge of the fender flares to establish how much actual lift is installed and that the stock measurement is 19.5-20 inches. My measurement is 23.5", so I come up with 3.5-4" as the lift.

Given that installing plates ($150 from Slee) also means have to replace the bushings (about $500 for a full set, plus shop cost to press them out...) all up I'd be out of pocket about $650++. It almost seems like just putting on replacement caster correcting radius arms may be a better long term fix investment. It seems there are a few options out there for this -
Slee @ $1875++ in stock but damn! $$$$
Delta @ $1550++ apparently long lead times
Blackhawk @ $1200++ seems best, but flakey US distributor...
Superpro @ $1250++ free shipping off the shelf, but only generates 2.5 degrees correction on a 3" lift...
Superior Engineering @ $1800++ same comment as Slee

 

[Overlandeffex]

I have the dyes to push the bushings out and was planning on taking @RET2 20 ton press back to him tomorrow. We can do the pressing easy.

 

[Loober]

When you think of all the mounting points on the axle, must consider what other components rotating the axle will affect, and choose the least impactful. In my opinion the best way is to cut and turn the knuckle balls. This leaves most other things unaffected, only other thing it affects is the rear tie rod clearance on the arms. It may not be a problem, depends on how much caster you are trying to gain. Everything else stays the same, pinion angle is unaffected, and the biggest thing are the axle perch where the spring sits.

All the options you mentioned will alter the perch on the axle in relationship to the bucket on the frame, forcing the spring to sit at an arc. Under compression it will act funny and mess up its spring rate.

 

[Bud_Dude]

When you think of all the mounting points on the axle, must consider what other components rotating the axle will affect, and choose the least impactful. In my opinion the best way is to cut and turn the knuckle balls. This leaves most other things unaffected, only other thing it affects is the rear tie rod clearance on the arms. It may not be a problem, depends on how much caster you are trying to gain. Everything else stays the same, pinion angle is unaffected, and the biggest thing are the axle perch where the spring sits.

All the options you mentioned will alter the perch on the axle in relationship to the bucket on the frame, forcing the spring to sit at an arc. Under compression it will act funny and mess up its spring rate.

Wow! Cutting and turning the knuckle balls is a new one on me! It might be the best way, but also sounds like the most difficult and surely expensive way. I did see that someone was offering offset steering knuckle top and bottom bearings which is interesting, but not an easy install either. I'm aiming to get from a -0.4 degree caster to a +4 degree caster. In the grand scheme of spring rates and such it seems rather small. And given that the factory spec is +2 to +4 degrees, I'd imagine that returning it to that range also returns the spring vertical alignment to what it was prior to installing the Icon Stage 3 lift in the first place since the lift in and of itself is what introduced the misalignment. Right?

 

[Bud_Dude]

I have the dyes to push the bushings out and was planning on taking @RET2 20 ton press back to him tomorrow. We can do the pressing easy.

Hey Jeff, yeah can you delay that return a week or two? I've confirmed (I think) that the truck currently has what appear to be the yellow OME offset bushings installed. So I'm ordering the Slee 4" lift caster caster correction plates today and will get new bushings to replace those currently installed.

 

[Overlandeffex]

Dropped it off this morning.... easy to run up and use it. Let me know when you have the parts

 

[RET2]

Hey Jeff, yeah can you delay that return a week or two? I've confirmed (I think) that the truck currently has what appear to be the yellow OME offset bushings installed. So I'm ordering the Slee 4" lift caster caster correction plates today and will get new bushings to replace those currently installed.

It's available pretty much any time.

 

[Bud_Dude]

It's available pretty much any time.

Thanks Ralph - Correction plates have shipped from Slee, new bushings ordered on Partsouq, and bushing bolts/nuts ordered at Toyota Escondido who rather begrudgingly honored the 33% lower price from Norm Reeves Toyota in SD. FYI - Shane is no longer at the Parts Desk out front, he's in the back in the Wholesale Parts office so if you want the BnT pricing or to get any deal you need to go to Wholesale. Other parts coming in via UPS, hopefully their impending strike won't affect delivery.

 

[Bud_Dude]

Yay all the parts arrived so I’ve got Slee plates, bolts and bushings ready to install. But damn it’s hot out there.

 

[RET2]

Yay all the parts arrived so I’ve got Slee plates, bolts and bushings ready to install. But damn it’s hot out there.

Hey you have an 80, leave the complaining to the 200 crew

 

[Overlandeffex]

Next week work for going up to @RET2 house...early in the day??

 

[RET2]

Next week work for going up to @RET2 house...early in the day??

O-dark-thirty works for me

 

[Bud_Dude]

O-dark-thirty works for me

I'm up for going up any time. I can bring the tools and grinder with cutoff wheel and just do the whole thing while there? Early morning or late night matters not to me... Or I think I can yank both radius arms off here early one morning or evening and just bring them up to press the bushings in. Options, options...

 

[RET2]

I'm up for going up any time. I can bring the tools and grinder with cutoff wheel and just do the whole thing while there? Early morning or late night matters not to me... Or I think I can yank both radius arms off here early one morning or evening and just bring them up to press the bushings in. Options, options...

Y'all know Mr. Murphy right? just take it back to Esco especially since you both can use it. I achieved my task already.

 

[Bud_Dude]

Y'all know Mr. Murphy right? just take it back to Esco especially since you both can use it. I achieved my task already.

Hey Ralph I could just drive up this afternoon if that works then bring it back to ya next week.
I'm assuming it'll fit in the back of my 80...

 

[RET2]

Hey Ralph I could just drive up this afternoon if that works then bring it back to ya next week.

Sure do you have a truck?