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Old 07-01-2020, 08:49 AM   #1
HeavyHauler
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Anybody else get alot of bumpsteer after lowering your truck? How did you correct it?

I lowered my 1968 Chevy C10 4.5 inches in the front and 6 inches in the rear then had it wheel aligned at a local repair shop.

I am now getting alot of what I think is called bumpsteer. When I hit a bump or pot hole the wheels will want to switch directions on their own without steering input and then I have to man handle it to keep it going straight.

Anybody had this happen and what did you do to correct it?

I used the following parts to lower the truck along with converting to 4 wheel disc brakes.

Front: Early Classics 2.5 Drop Spindle with 2 inch lowering springs from Western chassis. My truck came from the factory with 1 1/16 sway bar but i added poly bushings. I replaced ALL bushings,ball joints,tie rod ends,pitman arm and idler arm with new over the counter auto parts stuff from Oreillys and Autozone. Installed 5 lug front disc brake kit from Early Classics. New shocks from Bell Tech.

Rear: Western Chassis 6 inch drop springs with double adjustable track bar. Installed new 5 lug conversion axles and rear disc brake kit. New shocks from Bell Tech.
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Old 07-01-2020, 09:17 AM   #2
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

Check this post

http://www.67-72chevytrucks.com/vboa....php?p=7953452
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Old 07-01-2020, 09:23 AM   #3
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

Did the shop you had it aligned at give any feedback? Mine's only lowered 2" on the front (cut coil springs, not optimal), but I don't have any bumpsteer issues.

I know excessive toe out can cause issues like that and my first thought was to take it to an alignment shop. Did the alignment shop you took it to have any experience with lowered vehicles?
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Old 07-01-2020, 10:00 AM   #4
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

Yes, happened to me after lowering my truck (4/6 drop using ECE drop spindles & springs). Turned out that I had installed the drag/center link in backwards, which is very easy to do. After I corrected the center link, it was completely resolved.
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Old 07-01-2020, 03:16 PM   #5
68 P.O.S.
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

On mine, when I did a 4-6 drop, I rebuilt the front end with Moog parts as well. That tightened things up and afterwards I added a Moog ssd10 steering stabilizer. It helped out a good bit, but wasn't a 100% cure by any means.
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Last edited by 68 P.O.S.; 07-01-2020 at 04:06 PM.
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Old 07-01-2020, 06:23 PM   #6
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

Here is a link to my repair thread. Post 273 I wrote about my bump steer testing and posted my alignment specs. Now my truck has factory spindles so that should mean it should experience less tie rod angle for any given spring height.
I have seen spring compressors used when checking for bump steer in the down direction and well up is easy.
There are plenty of threads in the suspension section and of course the ever popular "Make it handle" thread where bump steer is discussed and remedies are shown.

https://67-72chevytrucks.com/vboard/...698377&page=11
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The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377
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Old 07-01-2020, 10:38 PM   #7
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

Any chance you also changed wheels and / or tires? In particular, wheels with more negative offset can contribute to bump steer. Wider tires up front (and some tire brands) can cause tramlining, where the tires tend to follow cracks or seams in the pavement. Not quite the same as bump steer, but might make it feel even worse.
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Old 07-02-2020, 01:26 AM   #8
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

I bet the centerlink is on backwards.
The inner tie rod nuts should be on the front side of the centerlink.
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Old 07-02-2020, 08:47 AM   #9
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

In addition to all of the above, adding high amounts of caster will aggravate bump steer..
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Old 07-02-2020, 06:52 PM   #10
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

Several good suggestions worth checking out posted above.

What were the alignment numbers? They should have given you a print-off for your records.
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Old 07-06-2020, 01:47 PM   #11
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

Here is a pic of the passenger side of the centerlink. Hopefully you can tell me if I installed the centerlink correctly from this pic.
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Old 07-06-2020, 01:49 PM   #12
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

Quote:
Originally Posted by jonmc56 View Post
Yes, happened to me after lowering my truck (4/6 drop using ECE drop spindles & springs). Turned out that I had installed the drag/center link in backwards, which is very easy to do. After I corrected the center link, it was completely resolved.
I just posted a pic of mine to see if you guys can let me know if installed correctly.
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Old 07-06-2020, 01:52 PM   #13
HeavyHauler
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

Quote:
Originally Posted by Stocker View Post
Any chance you also changed wheels and / or tires? In particular, wheels with more negative offset can contribute to bump steer. Wider tires up front (and some tire brands) can cause tramlining, where the tires tend to follow cracks or seams in the pavement. Not quite the same as bump steer, but might make it feel even worse.
Yes I have new wheels and tires. On the rear 20x9.5 with 275/45/20 and on the front 20x8 with 255/45/20. They are US MAG Ramblers.
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Old 07-06-2020, 01:54 PM   #14
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

Quote:
Originally Posted by americanmusc1e View Post
Did the shop you had it aligned at give any feedback? Mine's only lowered 2" on the front (cut coil springs, not optimal), but I don't have any bumpsteer issues.

I know excessive toe out can cause issues like that and my first thought was to take it to an alignment shop. Did the alignment shop you took it to have any experience with lowered vehicles?
They gave me a print out but I dont know what the numbers mean as far as how it makes the truck handle.
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Old 07-06-2020, 01:55 PM   #15
HeavyHauler
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

Quote:
Originally Posted by lolife99 View Post
I bet the centerlink is on backwards.
The inner tie rod nuts should be on the front side of the centerlink.
I just posted a pic of how I mounted my centerlink.
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Old 07-06-2020, 03:58 PM   #16
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

Quote:
Originally Posted by HeavyHauler View Post
They gave me a print out but I dont know what the numbers mean as far as how it makes the truck handle.
Take a picture of the alignment printout & post it as an image attachment.
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Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive.
It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar.....

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Old 07-06-2020, 04:41 PM   #17
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Re: Anybody else get alot of bumpsteer after lowering your truck? How did you correct

It looks like your center link is correct but check out this link.
http://67-72chevytrucks.com/vboard/s...d.php?t=400205
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