Lower trailing arms (1 Viewer)

[sakamo]

Shop just installed an Old Man Emu 4” but the lower trailing arms weren’t available. They kept the stock ones in as the uppers are adjustable. After the suspension settled in a bit, it’s still somewhat unstable. I took it in where they said the longer arms will of course solve the issue as the axle is now tilted even though I have adjustable upper arms. Is this accurate? I was just going to buy some Ironman adjustable lowers but assume I’d have to readjust the uppers again prior to a new alignment. Is my thinking correct? And do I even need lowers as my uppers are adjustable and maybe there’s something else
going on?

 

[efjayatee]

Besides needing caster correction you will also want to level your panhard to avoid wandering of the backend.
Many threads on MUD how to properly mod your 80 when lifting more than 3".
If you have not already done so, you can use caster plates or get a Delta lower control arms to correct the casters. And also longer brake lines to accommodate the lift. Did you also install drop brackets for your rear swaybar? Aswell as the front swaybars?
Your geometry is off after lifting 4" and that is why its driving unstable.

 

[Delta VS]

Shop just installed an Old Man Emu 4” but the lower trailing arms weren’t available. They kept the stock ones in as the uppers are adjustable. After the suspension settled in a bit, it’s still somewhat unstable. I took it in where they said the longer arms will of course solve the issue as the axle is now tilted even though I have adjustable upper arms. Is this accurate? I was just going to buy some Ironman adjustable lowers but assume I’d have to readjust the uppers again prior to a new alignment. Is my thinking correct? And do I even need lowers as my uppers are adjustable and maybe there’s something else
going on?

You're asking about the rear? Uppers should get your pinion angle back in check with that much lift.

As @efjayatee mentioned, addressing panhard and caster should be HIGH on your list. Panhard correction would come from our bolt in panhard bracket or an @eimkeith weld-in solution. Caster for the front axle needs to be address by something other than the caster bushings likely installed. @landtank caster plates, @sleeoffroad caster plates, our radius arms, are just some of the available solutions. But NO caster bushing plates will be sufficient.

First post of this thread addresses why you need a panhard bracket: Delta Vehicle Systems Panhard Lift Bracket, 3" & 5" - https://forum.ih8mud.com/threads/delta-vehicle-systems-panhard-lift-bracket-3-5.1085308/

Caster is a key part of stable driving, must also be addressed.

 

[landtank]

Lifting the truck 4" will shorten your wheel base in the back. Adjusting the upper control arms for pinion angle will further shorten your wheel base. Lengthening the lower Control arms will solve the pinion angle and reclaim the lost wheel base from lifting the truck. I'm not a fan of adjustable control arms and offer an extended length fixed lower control arm. No adjustment of the upper arms are needed.

Plenty of options out there this is just mine.