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PostPosted: March 9, 2018, 9:43 am 
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Joined: August 21, 2017, 7:37 am
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Im build a vehicle using my factor Subaru running gear. But I lowered the seat a bit and therefore lowered the steering wheel a bit. Now i see to have a bind in the steering. Its not major but its noticeable and i'd like to fix it. From my reading, my angles arent terrible and it should work but it doesnt. I also read that its a good idea to keep the eyes of the ujoints inline with each other, but I am using the factory Subaru u-joints and they arent inline. Would redoing the ujoints to be inline help? would trimming the pinion coming out of the rack to lower that joint help?


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PostPosted: March 9, 2018, 12:44 pm 
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Joined: August 11, 2011, 12:38 pm
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Location: Akron, NY
The following is out of the Woodward universal joint catalog. I would guess that Subaru clocked the U joints the way they are because the steering shaft and and the input shaft to the rack are not in the same plane and they were trying to even out the acceleration and deceleration of the two U joints. In by case I used splined shafting between the U joints and tried different positions and picked the best. Form your photos it looks like you may have have to much angle on the lower U joint but it is hard to tell.

Phasing and Clocking of U-joints

Phasing or “clocking” of universal joints for smooth operation is especially
critical when welding u-joints directly to the shaft, since it will be impossible to
reposition them once you’ve done it. Assuming all sections of the steering shaft
lie approximately in the same plane so that the only misalignment is angular
(the most common condition), any back-to-back pair should be aligned like the
ends of a driveshaft, as in the illustration at right. Please study it closely; the
difference is not obvious unless you are looking for it. The greater the angular
misalignment of the steering shaft, the more critical the phasing of the u-joints.
For reference, most stock car steering layouts will tolerate joints 20 degrees
out of phase, but 45 degrees out will cause a noticeable change in rotational
velocity–the steering will actually speed up and slow down within half a turn
of the steering wheel. Shafts with both angular and parallel misalignment may
require special u-joint phasing which can only be found by trial and error. In
the case of weld-on u-joints, this can be done by temporarily holding one of the joints onto the shaft or tube with a small tack weld, and welding it
permanently in place only after you have determined its optimal position. The obvious disadvantage of welding u-joints directly to the shaft or tube
is, of course, that once you’ve welded them they cannot be removed without resorting to a torch, saw, or angle grinder.


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PostPosted: March 9, 2018, 3:27 pm 
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Joined: August 21, 2017, 7:37 am
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I would agree the lower angle is too steep. I'd like to find a way to shorten the shaft. its spline but crudly, i almost think i could replicate the splines with a angle grinder. There only about 12 splines


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PostPosted: March 9, 2018, 5:07 pm 
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Joined: January 14, 2006, 1:06 pm
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Location: Vista (north of San Diego CA)
The angles are tight, but they don't seem over the top. On the other hand it's hard to tell from a photo. You might want to sort out whether it's a problem with u-joint alignment (and the acceleration issues) or actual binding somewhere. Are you sure your shafts are all true? No slop in the u-joint bearings? Maybe try a straight shot to the pinion and turning to see if there is any binding in the rack. Just a thought.

John


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PostPosted: March 9, 2018, 5:57 pm 
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Joined: June 5, 2016, 7:03 am
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Location: ontario
I have done a bit of research about U-joints for similar projects. I believe that the norm is the maximum angle of operation is 30 deg. It is hard to judge what you have on this picture but to me the lower U-joint is borderline. My attitude is that steering is the most vital component of car building. Personally I give myself "zero tolerance" even when it means redoing something. I would fix this linkage if I were you.

A useful read:https://www.speedwaymotors.com/the-toolbox/u-joint-selection-and-design/28638

They state that 35 deg should be max.


Last edited by phil on March 15, 2018, 6:42 am, edited 1 time in total.

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PostPosted: March 12, 2018, 4:17 pm 
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Joined: July 4, 2006, 5:40 pm
Posts: 1905
Location: Novato, CA
The steering on my Locost was a little loose until I added a support bearing to the connector shaft. That doesn't look like the problem here, but I can't see from the photo how well the steering column is supported.


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PostPosted: March 12, 2018, 7:20 pm 
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I don't think column support is an issue. The shafts just don't line up, like if you extended the column and rack pinion shaft they would never touch, not even close. I can't take any new photos for a bit, it's all apart for welding frame.

I think its a combo of mis aligned joints and steep angle on lower joint


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PostPosted: March 13, 2018, 11:59 pm 
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Joined: February 23, 2017, 12:45 pm
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The Chevy trucks of the mid 2000's have a pretty severe steering angle like yours. The rack input is pretty much straight up and down. You might be able to find a joint at the pick and pull and make it work on the cheap.

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PostPosted: March 14, 2018, 7:32 pm 
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Location: Cornholio OR "Where the magic happens"
banzairx7 wrote:
The Chevy trucks of the mid 2000's have a pretty severe steering angle like yours. The rack input is pretty much straight up and down. You might be able to find a joint at the pick and pull and make it work on the cheap.

Attachment:
s-l1600.jpg



What did that joint come off? Never seen one...

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PostPosted: March 14, 2018, 10:29 pm 
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Joined: February 2, 2017, 1:02 am
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Location: Illinois
banzairx7 wrote:
The Chevy trucks of the mid 2000's have a pretty severe steering angle like yours. The rack input is pretty much straight up and down. You might be able to find a joint at the pick and pull and make it work on the cheap.

Attachment:
s-l1600.jpg

Reminds me of a ujoint for a trailblazer. I think the pick ups went to rack and pinion in 05ish? Rack was behind ball joints (rear steer) on trail blazers.


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PostPosted: March 15, 2018, 5:23 pm 
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Joined: February 23, 2017, 12:45 pm
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That was the lower joint(at the rack input connection) from 2010 Silverado. they're still using that style now but new they are kind of pricey at ~$160. The Colorado uses a similar joint also.


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PostPosted: May 5, 2018, 7:24 pm 
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Joined: August 21, 2017, 7:37 am
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Drove car today. Steering needs fixed. The steering column is close to 5/8-36 spline. The rack quill/pinion shaft is Subaru one off not gonna match it 5/8 diameter. I'd like to try and cut lower shaft shorter to decrease and get a weld on x spline shaft to match the upper.

Here's a side shot. The lower joint angle isn't as bad as it looks since it slopes away like it shows in original pic. Probably close to 35 degrees though. My thoughts are cutting that lower fillet weld and phasing the u-joints

https://photos.smugmug.com/Tube-thing/i ... 544-X4.jpg


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PostPosted: May 6, 2018, 8:39 am 
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I've been taking Steering classes at YouTube university last couple days. This video pretty much made everything very clear to me. I think my angles are ok, I just need to rotate my joints until bit ends spin consistently.

https://youtu.be/Idk3BVDVHq4


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PostPosted: May 6, 2018, 2:00 pm 
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Joined: August 21, 2017, 7:37 am
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I phased the joints, it felt the same. Then I rotated it 90 from "stock" and it took away about 90% of the hard spot feel. I'll post some pics tomorrow when I'm back on a pc

"stock" horrible speed change, hard spots

Image

phased with joints inline, same feel as stock

Image

and 90 degrees from "stock", almost perfectly smooth. I called it quits here since grinding around my engine fuel and brake lines, i didnt feel like pressing my luck any further

Image


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