Adjusting caster on 34v8

[35ragtop]

Hi fellas,
I checked the Caster angle today and its positive 9 degrees + ( limit of gauge). The 34 pickup truck as been lowered. Just wondering about the easiest way to bring it into spec. (+ 4.5 to +7 deg. I believe).
I was thinking of packing the spring down on the top about 1 inch.
Comments please on how you have achieved adjustment.
Thanks Dave h

[51 MERC-CT]

Doubt that lowering would have that much effect on caster angle. Probably bent or deformed wishbone that would require straightening.

[jailhousebob]

Are you running stock or split wishbones? If stock,are they mounted in the stock location or lowered at the ball pivot? (I have seen this done for oil pan clearance) Also,has the stock front cross member been removed,changed or relocated? The angle of the cross member on an early ford helps determine the caster.If it has ever been removed it may have been reinstalled incorrectly.Bob

[35ragtop]

I have had the front axle assembly out to check the various components for wear and noticed that the front cross member had been replaced at some stage. Bolted back in instead of rivets. Cant tell if its wrong though. The stock wishbone appears straight but on the 34 could it be upside down? This would change the angle at the ball. Unlike the 35 it has no spring shackle mounts on the wishbone so looks reversible. The ball is in correct position.
thanks for your comments
Dave

[1931 flamingo]

Is the ball worn??
Paul in CT

[JSeery]

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In the Hot Rod world the normal procedure is to pie-cut the radius rods and weld them back up at the desired castor angle. Just did this on my 33 5-window.

[Fordors]

Can you provide photos with closer views of the front suspension? Pictures are worth a 1000 words, maybe then we can help determine your problem. If your wishbone were flipped over the caster would go to the extreme negative side, so I don't see that as a possibility. Your front crossmember is bolted in but I would expect they used the original rivet holes so I guess that it is mounted in the stock position also. Is it in fact a '34 'member, and also is the '34 X-member under the transmission stock, or has it been cut up to accommodate a later engine/transmission? Is there a particular handling issue you are experiencing, or do you just feel 9° caster is too much?
Going back to the front crossmember, the cant (rearward tilt) built in by the factory was mainly to keep the front spring from getting in a bind caused by the caster angle. If the caster was say 5° and the front 'member straight up then the front spring leafs are trying to be twisted, at least that is the way it was explained to me.

[Tom Walker]

Isn't that gauge for checking camber?

[35ragtop]

Hi guys
first Tom,
Yes it does both, you just use different bubble, selections. there is another in the box that tells you the king pin inclination! ( for what its worth)
Fordors, I have had serious death wobble issues, but gradually as I have listen to advice on here and checked individual suggestions, I have eliminated a few things. A friend offered me the use of this old equipment ( given to him by his Dad (RIP) and it was just an idea to check. And now, after rechecking,I think that it is more like 8 deg, and therefore within spec ( just).
On a previous different thread, Supereal, who has a wealth of information, mentioned that on occasions, front end upsets can be caused by a rear wheel tire bulge or wobble. Having changed the rears to front with no apparent difference, I discounted this idea until today. I jacked the front up and spun the wheels. One tire had no apparent movement and came to rest evenly, however the other side had an obvious bulge on the inside and wobbled. This was previously a rear wheel. So I changed this for a brand new, unused tire which spun evenly.
I took old Clyde for a test run over the same rotten rough roads and had no death wobble!
I am not convinced yet, and will do some more miles tomorrow ( as I have been caught out before) , but it does look promising. Such a simple fix seems too good to be true at this time.
"1931 flamingo" the ball looks fine but I replaced the rubber so I am satisfied that it is tight .
Apart from the reverse eye posi spring and hydraulic brakes, everything else is stock, no chassis mods.
I will let you know how things go tomorrow ( GMT + 10 here).
Dave

[tanner]

Actually, the king pin inclination is what determines caster. Caster is correct when vehicle steers straight and doesn't wander right or left. Good example is front fork of a bicycle which is inclined to make it easier to ride. I corrected death wobble on F1 by replacing tierod ends, worn pitman arm and rebuilding drag link. Proper toe in setting is also needed.

[JSeery]

Originally Posted by 35ragtop

Hi guys
first Tom,
Yes it does both, you just use different bubble, selections. there is another in the box that tells you the king pin inclination! ( for what its worth)
Fordors, I have had serious death wobble issues, but gradually as I have listen to advice on here and checked individual suggestions, I have eliminated a few things. A friend offered me the use of this old equipment ( given to him by his Dad (RIP) and it was just an idea to check. And now, after rechecking,I think that it is more like 8 deg, and therefore within spec ( just).
On a previous different thread, Supereal, who has a wealth of information, mentioned that on occasions, front end upsets can be caused by a rear wheel tire bulge or wobble. Having changed the rears to front with no apparent difference, I discounted this idea until today. I jacked the front up and spun the wheels. One tire had no apparent movement and came to rest evenly, however the other side had an obvious bulge on the inside and wobbled. This was previously a rear wheel. So I changed this for a brand new, unused tire which spun evenly.
I took old Clyde for a test run over the same rotten rough roads and had no death wobble!
I am not convinced yet, and will do some more miles tomorrow ( as I have been caught out before) , but it does look promising. Such a simple fix seems too good to be true at this time.
"1931 flamingo" the ball looks fine but I replaced the rubber so I am satisfied that it is tight .
Apart from the reverse eye posi spring and hydraulic brakes, everything else is stock, no chassis mods.
I will let you know how things go tomorrow ( GMT + 10 here).
Dave

8 degrees is still to much castor for most applications, most find something more in the 4 to 5 degree range better. If you are not wanting to cut and weld the radius rods to correct the castor there are alignment shops that have the equipment to bend the axle ends to correct castor.

[Fordors]

Well that is partly true; when the k/p is tilted back we have positive caster so you might say the k/p has inclination. The definition of k/p inclination is the amount of tilt from 90° between the king pin and the axle stub as viewed from the front. If you draw a line through the centerline of the k/p and one through the centerline of the tire when those lines intersect at the ground you have zero scrub radius. Zero scrub will be the easiest on the tires and wheel bearings. As an example Ford k/p inclination is 8°, but Lincoln spindles are only 4°, they appear to be similar but are not. If you were to fit Lincoln spindles to a Ford axle your camber will not be correct.