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makeshift slip plates

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Old 07-11-2013, 03:05 AM
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Don Ashe
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Default makeshift slip plates

I needed to do a quick camber adjustment after a ball joint replacement, so I figured I would make some DIY slip plates. I ran across a thread on the subaru owner's forum that suggested 5 or 6 plastic bags under each wheel, so I gave it a try and it worked like a champ!

HTH,
-Don
Old 07-11-2013, 03:15 AM
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rexpontius
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Wow could you elaborate a bit more on the exact procedure? Cheers
Old 07-11-2013, 01:17 PM
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davek9
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Wow, I'll need to give that a try, thanks!
Old 07-12-2013, 02:34 PM
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Don Ashe
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Originally Posted by rexpontius
Wow could you elaborate a bit more on the exact procedure? Cheers
I just placed 6 plastic grocery bags flat on the floor and rolled the front tires onto them.
I followed Earl's camber procedure:
http://members.rennlist.com/captearlg/928aligndiy.html
Since I don't have calibrated turn plates, I followed his advice in step 8,
setting caster by setting the ball joints all the way back.
The camber adjustment was almost effortless, the tires slid so easily on the bags.
The ball joints were steel, but here is what happened:
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Old 07-12-2013, 02:52 PM
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dr bob
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^^^ There's a potential lesson in here someplace. Is there any accident or impact history that might be identified a a possible cause for that failure? And what did the other one look like?

---

There's been a behind-the-scenes discussion lately on DIY alignment techniques. This plastic-bag trick will certaily get added to the next rev of "as the wheels turn", the spellbinding saga of a retired engineer with excessive tire wear, and his efforts at gettting a perfect alignment at home.

So far, I'm still using the laser levels, mounted on an aluminum frame that fits on the face of each rim, secured with bungee cords. I've changed the original measurement technique to null out inaccuracies caused by variations in the laser mountings. It lets you use low-dollar lasers without penalty. I added digital angle gauges to make camber and caster measurement a lot easier. For folks without access to a caster gauge and calibrated turn plates ($$), it works well. There's less than $100 in materials total, putting it in the easy reach of most 928 owners, certainly within local group ownership range. Here locally, there will soon be a serious shortage of those plastic grocery bags. So another workaround will need to be thunked up; it will probably look like a few layers of painter's plastic with a spritz of WD-40 between the layers. I may have to put a safety/spring line under the car to keep it from drifiting off the plastic though. Or just do three wheels and leave that one firm on the floor with the brake set. Lots to play with as time allows.
Old 07-12-2013, 05:00 PM
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Don Ashe
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Originally Posted by dr bob
^^^ There's a potential lesson in here someplace. Is there any accident or impact history that might be identified a a possible cause for that failure? And what did the other one look like?
Yes, it was a lesson for me - don't procrastinate fixing a squeaking ball joint just because it's steel. The boot had torn and water and grit had entered the joint. I drove it like that for a ridiculously long time, I'm afraid. Eventually rust and grit ate the top of the joint and the ball was able to pop out. I was nearly at a stop and hit a big pothole. The other side was kind of wiggly, too.
The joints had around 180,000 miles on them, driven daily for the past 7 years.



Originally Posted by dr bob
Here locally, there will soon be a serious shortage of those plastic grocery bags. So another workaround will need to be thunked up; it will probably look like a few layers of painter's plastic with a spritz of WD-40 between the layers. I may have to put a safety/spring line under the car to keep it from drifiting off the plastic though. Or just do three wheels and leave that one firm on the floor with the brake set. Lots to play with as time allows.
The other tip on that forum was to use old Playboys, with the binding toward the rear of the car. Apparently the gloss coating makes the pages slip...
I'm not sure my wife will buy that one!

-Don
Old 07-12-2013, 10:08 PM
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dr bob
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New or used Playboys?

Old 07-13-2013, 09:04 AM
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Herman K
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Originally Posted by dr bob
New or used Playboys?

and if your wife says no way than the poor man's alignment tools begins with a $20 box of linoleum tiles, a tape measure, some string, and a box of coarse KOSHER salt.
Old 07-13-2013, 05:04 PM
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I'm using some 8x8x0.25 steel plates now, with a smear of Vaseline. They have rubber mat glued to the outside faces, and a couple bolt holes to pin them for drive-on. They work fine, but if the plastic bags do the trick, they are a lot easier to store between uses.

My alignment tools come out maybe twice a year for my car. They've been attached to several visitor/clinic cars in the last couple years, but not since I added the digital angle gauges for camber and caster. Not enough visitor/clinic cars I guess. Might be something to plan for fall sometime, when the temps get more reasonable in the daytime. Or do an early clinic followed by a fun drive... That's the ticket!



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