What do you think of this caster distance?

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Model T Ford Forum: Forum 2014: What do you think of this caster distance?
Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert Poane on Saturday, October 25, 2014 - 11:52 am:

I was having caster difficulty which you helped me with. I watched the video on the front end and read the book.

Last night I tried to make a tool to bend the wishbone, but that failed because the threads broke.

So I rented a four foot wrench. That worked.

Important question: the distance from the top of the axle at the perch area to the ruler is not as far as the distance from the top of the spindle to the ruler. The video said a pencil distance is fine. Chaffins book says 1/8 in the picture on page 10 and 3/8" in words bottom of page 9?

The service manual shows the measurement at the spindle and should be between 1/4 and 5/16

Does it matter where I measure from and how exact it much be to 51/2 degrees rearward?

As Vinny Barbarino used to say in Welcome Back Carter, "I'm so confused!" http://www.youtube.com/watch?v=ll9-jEtEiiI

Thank you in advance.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert Poane on Saturday, October 25, 2014 - 11:54 am:

Her is my home made straightening bar. It needs to be welded to make it strong.
It is four feet long.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Saturday, October 25, 2014 - 12:27 pm:

Bob, using the diagram in Glen's book I checked this on two cars. Measuring at the perch, one was a little under 1/4" and the other was 1/8". That 3/8" seems like a lot to me, so I suspect it's a typo. Probably wouldn't hurt to call Glen and ask him.

I'll be interested to see how the DIY adjusting tool works out. I suspect that even with welding the half inch pipe won't be stout enough.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Saturday, October 25, 2014 - 12:51 pm:

Robert;
I do not think that that black pipe (1/2" or 3/4"?) will even be close to strong enough to stand up, it might crush and bend before the axle does anything. The correct tool is hell for stout. The one I have seen (shop made) was made out of plate about 3/4 to an inch thick and the ears that come up and cradle the axle about 1 1/2 maybe 2 inches wide. The ears coming up to hold the axle look too far apart. If they are too far apart and because the axle does have rounded edges the axle will act like a stationary cam, the more force that is applied the more it will want to remain in place and just force the ears apart. The ears should be just far enough apart to fit the axle.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert Poane on Saturday, October 25, 2014 - 12:52 pm:

Steve you are probably right about the 1/2 pipe; especially since the 4" pipe closest to my hand broke at the threads upon leverage force.

I'll just convert into a bar clamp!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert Poane on Saturday, October 25, 2014 - 12:56 pm:

Mark, you are correct about the 1/2 pipe. I rented a 4' pipe wrench and it worked great.

It cost $15 per day and at this point it was well worth the money. I can now move on to other things needed on the T.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Saturday, October 25, 2014 - 01:02 pm:

Follow the service manual. You need both sides to be the same so that you won't have a pull to one side.
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert Poane on Saturday, October 25, 2014 - 02:38 pm:

Here is the new way that I measured. I am going to go with this measurement.

It still does not make sense to me. The service manual says no more than 5/16 and no less than 1/4 when measured using the right angled ruler, from the top of the spindle bushing. But then it and everyone emphasizes 5 1/2 degrees.

5 1/2 degrees according to the protractor measures about 1/2 inches from the top of the spindle bushing to the right angle ruler.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert Poane on Saturday, October 25, 2014 - 02:42 pm:

missed this pix


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert Poane on Saturday, October 25, 2014 - 02:45 pm:

I'll get it right yet!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dale Peterson College Place, WA on Saturday, October 25, 2014 - 05:41 pm:

Make sure you are measuring correctly. The body of the yoke will not give an accurate measure as the top is not as thick as the bottom. You would need to put a spindle bolt in and measure from that to get an accurate angle.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett - Australia on Saturday, October 25, 2014 - 09:31 pm:

Dale has hit another nail on the head. Using either the axle eyes or the spindle bodies as a reference for making measurements is hit and miss. Machining and forging of both components will show wide variations. The only true register is the kingpin. The machined flanges on the kingpin bushes are also accurate reference points.

I have just finished rebuilding a front axle assembly for my Duncan and Fraser roadster and found some interesting points. My alignment rods showed that one end of the axle was twisted outboard of the perch. This was easily corrected with a 30" crescent wrench.

Then I fitted the perches, facing the opposite way to accommodate an accessory suspension setup. One was way off being correct. Closer inspection revealed that it was the same as the other side, but had been bent to make a "pair". I went back to the parts bin to find a replacement.

All this led to placing a couple of rods in the perch bushing holes to check that they were indeed canted at the same angle. Not so. One was clearly offset more than the other, but which one was the one needing "adjustment"?

I have become a convert to smart phones. My son Anthony's device can be used to measure angles!!
Using the phone against the alignment rods in the
axle eyes, the axle was held in the vice at -1 degree. Placing the phone on the perch rods yielded measurements of +2 degrees and +3.5 degrees. So one perch was at 3 degrees to the kingpin and the other at 4.5. We adjusted the 3 degree one to match the other.

I can see a simple way to accurately set caster in the car using the phone. I need the mathematicians among you to calculate something for me. I need a tool with two registers to rest against the kingpin bush flanges. The top register needs to be longer, "by the thickness of a pencil"? Given the distance between the bushing flanges is 115mm, a right angle at one end and the required 5 degrees of caster at the other end, what is the length of the short side? i.e. How thick is the pencil?

Your homework for the night.

Allan from down under.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Thode Chehalis Washington on Sunday, October 26, 2014 - 12:04 am:

Robert,
You are correct, there is an error in the manual. This is what I came up with:




Jim


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bud Holzschuh - Panama City, FL on Sunday, October 26, 2014 - 08:33 am:

Interesting discussion.

My guess is that the Ford engineers knew that the body of the yoke was not parallel to the spindle bolt.

So the question is: did they allow for that when the manual was written ?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert Poane on Sunday, October 26, 2014 - 12:18 pm:

I used the four foot wrench to caster the axle rearward so what appears as about 5 1/2 degrees measured at the spindle.

I quess that is what works because it rides a whole lot better! Thanks for your help.

Now the timing is off. I never had good success with adjusting the timing rod so I out a True Fire on my last car. Which leads me to the next thread - dare I ask it - is the e-timer relatively easy to put on?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bill Elliott on Sunday, October 26, 2014 - 03:13 pm:

O.k., before I took my engine out I measured the distance from the ruler to the spindle bushing and it was 3/8" on both sides. It sure looks extreme to me, but is it acceptable? If not, can I use a 4' wrench to bring it closer to the 5/16" measurement and can I do this with the motor out and the wishbone just hanging there?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Roger Karlsson, southern Sweden on Sunday, October 26, 2014 - 03:56 pm:

I just measured this distance on my primitive pickup. 0.71" on the RH side and 0.81" on the LH side. The pickup runs great & straight at speeds up to 55 mph on the road with original 5:1 steering - and the steering works fine in reverse too, though at a much lower speed :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert Poane on Sunday, October 26, 2014 - 05:11 pm:

Bill E. I am definitely not the one to answer your question, but I will.

The engine has to be in so the wishbone can be in place. According to the video, the 4 foot wrench (or bending bar)is actually bending the wishbone to make the caster. Someone else please confirm. Thanks.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bill Elliott on Sunday, October 26, 2014 - 05:29 pm:

You know, I thought kinda so - I mean there really isn't much holding things in place once the engine is gone! Just making sure, so thanks! BTW, does 3/8" sound like too much?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert Poane on Sunday, October 26, 2014 - 06:00 pm:

Mine is 1/2 inch. My guess is, caster is very important, but according to this thread, something is better than nothing. I had nothing - axle was straight up once and leaned forward once. Both times it rode horribly. Once I put a caster on it, about 1/2 inch from the top of the spindle bushing to the ruler, it rode better.


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