Zerorates Pls help

[Leper]

Hi all, and thanks in advance for your help.
I am putting a zerorate on the front of my 91 Blazer to move the axle forward to increase my approach angle. I have looked at posts here and elswhere for problems/modifications needed for doing this and still need more detailed info. Like: steering mods needed, turning issues, geometry issues, drive shaft issues.Details of my truck: 91 Blazer 350fi, auto trans w/overdrive, factory 10 bolt ft/rr, 241 tcase,35" bfg mudterrains,Ft 4" tuff country lift, ORD grocery list, Rear 4" shackle flip, greasables, sway bar disconnect, HD ft shackle, Steering box brace, zerorate in stock location just for lift in rear.
After installing the lift I can see splines on my front driveshaft and I think that moving the axle forward will require me to lengthen the ft driveshaft.?.?
What about the link between the steering box and drivers knuckle? Will just turning it in to shorten it be enough? Are there any driving/alignment issues? Will I be able to turn right and left equally? Will it wear susp components faster? Also, finances permitting, I plan to do a crossover steer setup. Hopefully with a dana 60. Any geometry issues if using a 2WD box for crossover with the axle more forward? BTW, trimming of sheetmetal is not a concern. This is my DD most of the time and I don't want to sacrifice reliability/dependability/safety for approach angle.
TIA
Leper

 

[88sub4x4]

Maybe I'm didn't read correctly, but if you are doing it to just lengthen the wheelbase, why don't you just leave the front axle in the stock location, and move the rear axle back? If the splines are showing in the front driveshaft, you will need to lengthen it. I had to make mine 2" longer just to work with the 4" Rough Country lift. I have never moved a front axle forward before, so I can't help you out much more then this. Good luck.

 

[jekbrown]

with stock steering parts i dunno if there is enough adjustability to deal with relocating the axle or not. IMO, you should just wait until you do x-over (post-D60 swap hopefully) and then relocate the axles as much as you want. Its much easier then, I moved my front axle forward an inch... and then 2 more inches later on. Just a matter of adjusting the draglink ends and putting it all back together.

j

 

[Leper]

I am more interested in reclaiming my approach angle in the front than making the wheelbase longer. I have recently installed a winch bumper, and it killed my front angle. I have seen it stated that you only need a winch if your rig is already crazy built. I disagree. Some of the people I wheel with, have stock or mostly stock vehicles. We all push our rigs to see how far they will go and a winch is a needed item. If you know you can get out, go ahead and try that impossible hole in 2wd. See what your skillz are!

 

[jekbrown]

moving the front end forward always helps approach angle... but perhaps what you really need in that regard is a differently designed bumper? Moving the axle forward an inch really doesn't improve the angle THAT much...

j

 

[Leper]

Back to my original question. WHEN I move tha axle forward, what concerns are there in respect to alignment, geometry, turning ability. BTW the bumper is a must have right now.

 

[cegusman]

Back to my original question. WHEN I move tha axle forward, what concerns are there in respect to alignment, geometry, turning ability. BTW the bumper is a must have right now.

I ran my blazer with the axle moved 1.5" farward for a few months, the steering sucked offroad. On the road it steered fine, offroad as soon as the front end started to flex I pretty much had very little steering. If you are going to do this, crossover steering is a must.

 

[Leper]

Thx

Thats what I'm talking about! Can anyone explain why that happens? Is it just a geometry thing?

 

[jekbrown]

its not hard to figure out if you're looking at your factory-style steering set up. With the wheel off, just imagine what happens to the draglink as the wheel droops further and further away from the stock ride-height position. At some point your draglink is approaching near vertical (in theory, it'll never get there) which means you pretty much have no steering capability because the draglink can't push/pull on the steering arm anymore.

j

 

[Leper]

How does moving the axle forward affect that? That happens anyway.

 

[88sub4x4]

By moving the axle forward you lose 1 1/2 " of drag link length. The shorter the drag link, the worse the effects of bump steer and the quicker the steering loss as the axle travels up and down. The idea of the crossover is to get the longest draglink as possible to minimize the effects suspension travel has on steering. I hope this makes sense!

 

[Leper]

Hmmmmm zerorate

Thanks for the reply. I'm starting to see now. When the drivers side of the axle drops, the steering geabox can no longer move the knuckle because the knuckle is now below the gearbox to the point that instead of moving front to back it is now almost stuck because there is no provision for moving up and down. It seems like this scenario would also limit the flex for the drivers side of the axle. It would keep it from dropping.
If I got a different steering arm for the gearbox and kept the draglink the same length, would that help? Do they make a steering arm for the gearbox that has the balljoint mount on the side? Also because of the lift I just installed, the new arm on the knuckle made me lengthen the draglink. Is that of any benefit?
Should I crossover the 10 bolt or wait till the 60. The 60 may be several months down the road and I still want to wheel. Do any of the crossover 10 parts interchange with the 60 setup?
Thanks again guys, you are a big help. The post I have in the ORD forum still has no replies.

 

[jekbrown]

Should I crossover the 10 bolt or wait till the 60. The 60 may be several months down the road and I still want to wheel.

IMO you should wait.. unless you are made of $$$. Of course if you were, you'd have a 60 already.

Do any of the crossover 10 parts interchange with the 60 setup?

not really... the expensive part is the arm(s) and they aren't interchangable. I never measured, but it may be possible to use the same tie rod and/or draglink. I guess it would depend on what steering arms you went with and how much adjustability you had with the TRE/DLEs. The TRE/drag link ends themselves you could carry over... but thats pretty much the cheapest part of the x-over system. Not to much benefit there. You need a 2wd steering box (or 2wd sector shaft) and a drop pitman arm as well... those could be used with either a D60 or 10b.

Thanks again guys, you are a big help. The post I have in the ORD forum still has no replies.

yeah, the Watson crew seems to be pretty busy with filling orders and getting ready for events. Better to ask general questions here, bigger audience.

j

 

[88sub4x4]

I have to agree with jekbrown. Wheel what you got now and do the crossover when you put in the D60. From what I have been reading, when you do a 4" lift the best steering setup to use is the 2" drop pitman arm and stock steering arm. Just using the stock pitman arm and a raised steering arm gives lots of bump steer. I had the problem with my '88 sub, but I sold it before I could change back to the stock arm and get a drop pitman arm. Using the zero rates in the stock position in addition to the 4" springs may yield you less bump steer though. I am interested to see how your truck drives.