My last drive before my new tires arrived was marred by a sudden severe wabble in the front end. I pulled over, tightened things ( spokes, king pins,steering) then increased toe in. A little improvement, but every pothole produced the "wobble of death".
Whilst mounting tires, repairing wheels and split rims I inspected the front end and found the problem: loose king pins and drag link ball.
So I need to do that repair now. I put in new King pins and bushings just 20 years ago. I went to my repair stock and found a 1909-1916 repop set. It has the cool threaded oilers instead of the flip top oilers. My question is: Is there any other king pin differences between pre-16 and 1927 front ends (can I use these parts)?
The drag link is also loose. I have heard of using a penny as a shim to take up wear. It looks like I might be able to grind down the cap to take up the wear. Does anyone know the best way to remove the drag link wear?
The front axles that use one piece spindles also use a slightly different spindle bolt. The difference is the thread at the bottom of the bolt is not quite as long on the 2 piece spindle axles. At the bottom of the yoke where the 1/2x20 thread is the one pice spindle front axles is not relieved for 3/16 of an inch the way the are on two piece spindle axles. Assuming you are not using a one piece spindle front axle, you should be fine.
Another cause of the "Wobble of Death" that is often over looked are the spring shackles and bushings. If one of the shackles is binding or locked in a bushing, this too can produce a shimmy.
Trent, thanks. The parts I have are marked 1909-1916 by Vintage Ford. The spindles are the late 1927 "improved Ford" lowered spindles. I think I still have the spindle reamer I bought to do the job back in the '90's. If I remember correctly my piloted adjustable reamers don't go small enough. Last time I had to face the bushings by hand with a file... this time I have a lathe (ain't life grand?).
I will check the shackles tomorrow. What is interesting is that I oiled them... and all the front end lube points on Sunday, the wobble started on Monday.
Yes, oiling the T caused the wobble. When they were dry, the parts were stiff.Now that they are Limber(that was one of my old T mentors favorite words, usually said with disgust and the subject not Ts)they can really shake it. While you obviously need to do some tightening up, see what the radius ball is like.if you can get a lot of up and down play, your caster is not being held right. I am rusty, so to speak,at this,but there are many threads about caster and shimmy.
You can buy a new round ball and the shims to tighten it up. just don't get it so tight it doesn't move freely.
Grinding down the cap on the drag link too much can weaken it. You may try filing the end of the drag link instead. Check the roundness of the balls - they tend to wear oval. If oval, you can use them for some more time with an Apco spring loaded accessory cap to still get it as tight as possible but avoid binding. If the ball is round, then you can use a cupped copper penny as a shim.
Constantine used a vendor supplied steel shim in his '13 for his african journey - it wore through and locked up the steering. A penny won't do that.
Use a copper penny, not the current copper plated steel ones.
The current pennies are 97.5% zinc and 2.5% copper. The only steel pennies ever issued were in 1943 and unlikely to turn up in circulation these days. You want a cent from 1981 or before, which is 95% copper. Even if you drive a lot and have to change it every year, it's a cheap fix. I dislike the idea of grinding off enough of the cap to make any difference.
Steve, thanks, I was thinking of using a penny. Didn't think of using two however. I was thinking of using my press to pre-curve them... like core plug nickels.
Just thought I bought the car for $5.00. Use 3 nickels as freeze plugs, now 2 pennies... the dang car is worth $5.17 ... I can sell it and retire! Wait, I am retired, AND the car is now re-tired. I guess I will keep it as just another questionable investment.
Bob Bergstadt makes kits with all the shims you need for this operation. For me, I file the caps until I get a good fit. No big deal. As Trent suggested, re-bush the front end, and your problems are over.
I place the penny on a 1/2" drive 5/8" socket. Then place the ball of my small ball peen hammer (the ball is the same size as a steering arm ball) on the penny. Then hit the small hammer with a bigger hammer. Makes a perfectly formed shim.
Today I started to disassemble the front end. Nothing startling pops out, a little radial and axial play in the King pins. The bushings are worn and the pins show a little wear. The ball joints on the drag link were a bit loose, I started to take off the passenger side ball, the nut wouldn't come all the way off before the ball came loose... so I temporarily tightened it back onto the tie rod.... SHEZAM!!! now that it is oriented differently there is almost no play detectable in any direction!
The bushing in the drag link of the spindle on the passenger side is very worn.
There is enough stuff here to have been the problem.
Of course I have read all your comments (even if I didn't respond to yours). So on skimming old shimmy posts I noted several folks have pointed at the castor. I had checked my castor many years ago so it is good to go. Well that was my thinking then. I will be checking it but have to do some work first.
Terry, with your lathe you can make the facing tool needed so same same. If you need a picture of one let me know. us my email or phone 785 432 3993 Jerry
If you haven't pressed in the new bushings into the spindles yet, you may fix them in your lathe in another way..
Use the reamer on the new bushings before they're pressed in so they fit nice on the new king pins. Thread the old bushings and screw in a large bolt so they can be pressed out. Turn down the new bushings so they're a slip fit in the spindle and test fit in the axle - then you know how much to cut from the lower bushing in the lathe. When the spindle with the loose bushings fit in the axle, you can glue the bushings in place with your favorite epoxi - just use the king pins as a guide so they get properly lined up - in place in the axle. Some oil saves the moving parts from being stuck
I've been away and just got back to the front end of my car today. I found little bits of wear on the bushings all over: King pins, drag links, shackles etc. I figure while not really impressive these sloppy joints can add up to produce the "Wobble of Death".
So whilst at it I am going to swap in an axle which actually has threads on both sides. Good time to remove the overload springs and return to a front end like Henry designed.
So on the docket for this afternoon: finish tear down, replace bushings and reassemble. The new axles have even less slop on the existing spindle bushings... whoa, I have found the problem!!! Great, now I can reassemble and I won't replace all the bushings but order the replacement stuff and wait for a time when the weather is cooler to have another go at it.
The problem? Let's revisit what Trent said: "Another cause of the "Wobble of Death" that is often over looked are the spring shackles and bushings. If one of the shackles is binding or locked in a bushing, this too can produce a shimmy." WOW! Why would I even look at anything else once Trent has spoken? I know that is a lesson I will take to heart in future.
My left front shackle is Frozen in my overload spring. Lucky that was where it happened as I cannot get that shackle out. Fortunately I have another shackle on the shelf and it wasn't in the perch as I have no extra perches.
Now that the extra springs are gone I pushed out the perches and then swapped them side for side. Remember to maintain castor (and driving stability) you must swap side to side and not just rotate them 180º!.
The take home lesson bears repeating: