NBS Front Brake Swap for OBS Trucks

[dave_erald]

Gotta a pic of the setup @GreenChevelleSS ?

 

[GreenChevelleSS]

Only pics i got of it.

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[dave_erald]

Hard to tell from that unfortunately

 

[Brother Al]

Wait, did you put GMT400 or GMT800 LCAs IN????

 

[GreenChevelleSS]

they are the gmt800 arms
"Its an almost identical forging, but the differences are the lower ball joint mounting bore, the shock bracket mounting area has larger bolts on NBS, and they are moved slightly apart. The mounting area is also flatter and kicked off at less of an angle as the OBS control arm. So I just slotted the holes slightly on the old shock mounting bracket, and bent the ears slightly to try to get the angle back a bit. Otherwise, the overall arm's dimensions and appearance are identical."

 

[Brother Al]

Yes, therein are the issues as you noted. Those differences screw up the steering geometry, regardless of "slotting". Itd causing it to bind up. Elsewhere on this site, and possibly in this thread, those problems are noted. It is why the swap posts note the use of the GMT400 A-Arms, not GMT800 lowers. If you want forged lowers, look at '95-'98 8 lug K2500 & K3500's for the forged versions... see my posts elsewhere.

 

[TylerZ281500]

the angle and everything you just said, which im agreeing with al is the exact reason your geometry is messed up.

 

[GreenChevelleSS]

What? steering geometry? did you read what i posted? have you compared the k2500 LCA between the 400s and the 800s? cause i have both and they are identical except what i noted in my previous post which has nothing to do with steering geometry.

 

[TylerZ281500]

at the angle is the shock bracket, well torsoinal stress has relevance, even though you say it was "marked" and lowered, still a potential factor, lowering it affects geometry and could result in bump steer though for sure. is the shock binding?

 

[dfarr67]

Having some trouble finding info for this question, although it was referred to on page 1. Have a '89 K1500 and I have everything from a 2003 Avalanche/suburban f/r disc conversion, the parts have been sitting for a few years, and I'm ready to move ahead- the rear fittings I can deal with but need to have a link or part number to the adapter from the front flex line to the hard line. Or are the banjo fittings compatible at the caliper end.