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Pulling springs and bump-steer.

Posted: Thu Aug 08, 2013 2:43 pm
by DodgeDirty1963
So I finally got a new job close enough to home that I can give the swepty a rest and pull the front end apart. It has the 2 bottom springs out of the rear packs so I figured I would pull the bottom 2 from the front when it goes back together. Are those the right ones? I'm not going for super low, just to even things out a little. Would I get bump-steer from this?

Re: Pulling springs and bump-steer.

Posted: Thu Aug 08, 2013 7:10 pm
by Hobcobble
You might. There's basically one way to confirm....
John

Re: Pulling springs and bump-steer.

Posted: Thu Aug 08, 2013 9:05 pm
by Dood
:goodpost

I think, as a rule of thumb and all other alignment correct, you will have bump steer if the pitman is not vertical at dead center. Maybe someone else will chime in to tell me I'm wrong, but that hat would seam a pretty strong indicator that you are out of bounds and actually putting suspension load on the steering linkage.

Re: Pulling springs and bump-steer.

Posted: Fri Aug 09, 2013 7:40 am
by Hobcobble
You can think of it this way.....
Automobile manufacturers likely put hundreds of thousands of
miles on vehicles at their testing grounds to make sure things
like steering geometry pass muster. Even then, you hear of the
occasional factory stock vehicle with problems. When people start
dropping out springs, flipping axles, grafting IFS frames, etc., they're
"generally" venturing into uncharted territory. It can be a trial & error
situation. Hopefully, any "errors" don't come at a cost of people getting
injured. :pale You might give thought to putting a bunch of miles on
this truck on some back roads at different speeds, etc., etc. to see
what you've created before mixing into general vehicle traffic. :idea :2cents
John

Re: Pulling springs and bump-steer.

Posted: Fri Aug 09, 2013 10:00 am
by 40YearOldFury
From what I have been reading and discovering about "bumpsteer" is that if you modify a vehicle and wack out the geometry of the steering and suspension you will generate "bumpsteer". Allot of the people I have spoken to have said that the angle of the draglink is what matters. The draglink is the bar that connects the pitman arm to the steering arm. The draglink should be running parallel to the frame if not running slightly downhill from the back to front of the vehicle. There are a couple ways to achieve this. Use a shorter pitman arm, cut down the pitman arm, or bend the steering arm. On my D200 when I took out 3 springs (it came down about 3") I did not get bumpsteer and did not make any other changes. I have recently installed a drop axle and have bad bumpsteer now. I am in the process of shotening my pitman arm and bending the steering arm down a little bit so the dragllink has a better angle. Some have reported bumpsteer at 3". Some people have said there will not be bumpsteer if the drop is at 3" or under. Maybe that's within the designed tolerances from the factory. Wait...need to disclose that I am not an expert and this is just what I have read and learned from different sources. Don't use what I say as gospel.

Re: Pulling springs and bump-steer.

Posted: Fri Aug 09, 2013 11:34 am
by DodgeDirty1963
For what it's worth I may just leave it alone and get the springs I need for the back. I think they look good at stock height too. I was looking at my front springs and even with all six in the pack they are pretty damn flat. So it may drop toooo much even if I pull just 2. If I'm gonna do these king pins and everything else I want it to drive nicely after the $ and effort.

Re: Pulling springs and bump-steer.

Posted: Sat Aug 10, 2013 5:28 pm
by F6866
I have a 71 Uteline with a slant six and 3 speed, and the previous owner pulled the two bottom leaves out of the front and it drives and steers fine.

Re: Pulling springs and bump-steer.

Posted: Tue Aug 20, 2013 9:18 am
by 40YearOldFury
The bumpsteer fix is easy. If you drop it 3+ inches you will most likely have it but just by getting a shorter pitman arm makes the problem go away. I went with a 5 3/4" pitman arm on a 7" drop and all is good! I have a 6 1/4" arm left over is anyone else needs to fix their problem.

Re: Pulling springs and bump-steer.

Posted: Tue Aug 20, 2013 1:17 pm
by StinkFinger
At 5-3/4 dose the threaded end of the tie rod not hit the frame ? Mine did at 6"

Re: Pulling springs and bump-steer.

Posted: Wed Aug 21, 2013 10:14 am
by 40YearOldFury
StinkFinger wrote:At 5-3/4 dose the threaded end of the tie rod not hit the frame ? Mine did at 6"
Did a full lock to lock under normal load and all seems good. I will have to check after I get more miles on it and see. Hmmm? Where does the tie rod end hit the frame? Did you flip your front? Mine doesn't even appear to be close.

Re: Pulling springs and bump-steer.

Posted: Wed Aug 21, 2013 2:30 pm
by StinkFinger
Where the tie rod end protrudes threw the pitman arm there is an indent on my frame shortening the arm made it so that it no longer lined up with the indent and it rubbed the frame. Nothing a little grinding dident solve

Re: Pulling springs and bump-steer.

Posted: Wed Nov 27, 2013 6:27 pm
by AJwestcoast
hey guys, If i'm pulling the 2nd lowest leaf from both the front and rear packs on a 1969 d 200 camper special, what U-Bolts should i buy to have them fit properly?
-thanks AJ

Re: Pulling springs and bump-steer.

Posted: Tue Dec 03, 2013 11:01 am
by 40YearOldFury
AJwestcoast wrote:hey guys, If i'm pulling the 2nd lowest leaf from both the front and rear packs on a 1969 d 200 camper special, what U-Bolts should i buy to have them fit properly?
-thanks AJ
New ones! Always new ones...lol You will have to measure how much thread you will need go to a local trailer or truck shop and get them. Different trucks had a different number of leaves on them so they would need different length u-bolts.

Re: Pulling springs and bump-steer.

Posted: Tue Dec 03, 2013 12:28 pm
by BigG
So, if I decide to raise my sb 66 about 2 " what would I need to do besides build new shackles,and add more length to the pitman arm ? BigG

Re: Pulling springs and bump-steer.

Posted: Fri Dec 06, 2013 1:38 pm
by StinkFinger
If your just going 2" you won't need to mess with your pit man arm

Re: Pulling springs and bump-steer.

Posted: Thu Dec 12, 2013 12:37 pm
by AJwestcoast
"New ones! Always new ones...lol You will have to measure how much thread you will need go to a local trailer or truck shop and get them. Different trucks had a different number of leaves on them so they would need different length u-bolts."

Thanks! i just asked this question in a different thread too, But okay... i know which ones ill have to buy now. Bettz srings in oakland, and fresno and a few other locations is probably your best bet for any custom U-bolts or even having leafsprings made, or anything like that.

So then my next question is, where can i find the centering pin for the leafsprings? im told that i have to get new ones before i pull anything appart...

Could i possibly reuse the old ones? (and the old spring clamps?) or where could i find fresh ones online to get ASAP..
thanks a f*****ing lot!!!!!!

Re: Pulling springs and bump-steer.

Posted: Thu Dec 12, 2013 1:52 pm
by 40YearOldFury
AJwestcoast wrote:"New ones! Always new ones...lol You will have to measure how much thread you will need go to a local trailer or truck shop and get them. Different trucks had a different number of leaves on them so they would need different length u-bolts."

Thanks! i just asked this question in a different thread too, But okay... i know which ones ill have to buy now. Bettz srings in oakland, and fresno and a few other locations is probably your best bet for any custom U-bolts or even having leafsprings made, or anything like that.

So then my next question is, where can i find the centering pin for the leafsprings? im told that i have to get new ones before i pull anything appart...

Could i possibly reuse the old ones? (and the old spring clamps?) or where could i find fresh ones online to get ASAP..
thanks a f*****ing lot!!!!!!
For the centering pins I used socket head screws from HD or Lowes, you know the kind you use an allen wrench/bit for. I can not remember the size though. They look similar to these: http://www.ebay.com/itm/25-PIECES-3-8-1 ... 43c30ed2f2
For other parts I used these guys, I think I even got my U-Bolts from them: http://www.springsnthings.com/

Re: Pulling springs and bump-steer.

Posted: Thu Dec 12, 2013 5:40 pm
by AJwestcoast
perfect, so you used ones LIKE those, but not those exact ones? i just dont want to have any play...
if the HD or lowes worked for you ill totally go buy those bad boys.
do you know of any threads about this topic that has any pics???

im gna go look under the rig now haha