Shake or Wobble at Downhill Stops

Fillinjc

Fillinjc

Member
Hello,

1930 coupe.
I experienced something yesterday that I haven't felt before. Just achieved break-in of my freshly rebuilt engine at the builder's recommendation of 500 miles. Came to the first stop sign which I stop at every time I leave my house. Downhill stop sign and the car produced a rather extreme shake or wobble. I continued on with no issue until braking on the next downhill and got the same wobble. Turned around. Started back home. Couldn't reproduce it so went back to the downhill and wobble. Watching the gear shift lever, it seemed like the drive train was shaking but now I'm thinking that was probably coming from the front cross member. Crawling under the car today I see coolant dripping all over and I had to top off radiator for the first time but I'm guessing that is due to the hoses being jarred.

I took the car out for a short bit tonight without floorboards so I could try to see what is happening but couldn't reproduce it. Honestly I was pretty cocky yesterday after driving 500 miles and thinking that I could now drive it more aggressively. And today back to babying it.

Any thoughts?

Thanks,
Jerry
 
Have someone sit in the car and bump the steering wheel back and forth over and over just enough to just start to move the wheels. Lay underneath and look everything over to see if there is any slop in the steering assembly. Tighten anything loose.
Jack up the front end and grasp the tires and wiggle them top to bottom and side to side to see if you have loose bearings, backing plates or worn king pins.
Pull the wheels and hubs and give the brake system a good look over.
Check your ball on the wish bone to make sure it is adjusted right.
Lots of things it could be.
 
Had that problem the front tires were simply underinflated. Hopefully you just need some good air.
 
Thanks! I will check everything listed above.

One thing I just thought of is that before I took the coupe out yesterday I greased it as a 500 mile service. In doing this I saw that there were broken grease fittings at the top of the front spindles. I pried out the broken fittings, dug out some crud and greased with new fittings. The first time in God knows how long that there is grease there. Might have freed up some worn bearing surface?

Thanks,
Jerry
 
yea, should be space between the 2 pieces that go around the wishbone ball assembly on the bellhousing - no space major slop. or of the bolts are "too long" and nuts bottomed out. Those holes in the soft cast iron get hammered out pretty bad over the years.
 
Fillinjc said:
Thanks! I will check everything listed above.

One thing I just thought of is that before I took the coupe out yesterday I greased it as a 500 mile service. In doing this I saw that there were broken grease fittings at the top of the front spindles. I pried out the broken fittings, dug out some crud and greased with new fittings. The first time in God knows how long that there is grease there. Might have freed up some worn bearing surface?

Thanks,
Jerry
Click to expand...

Badly worn king pins could cause the problem but so could lots of other things. Check everything as was described above and do the search suggested. Loose bolts holding the steering box to the chassis is another cause.
 
The July/August 2015 MAFCA Restorer has a very good article, "Causes and Fixes for Death Wobble in the Model A Ford"
 
I think he drove the 500 miles earlier, and was feeling cocky yesterday.....that's the way I would interpret it.
 
Synchro909 said:
What's wrong with driving 500 miles in a day? I've done 700.
Click to expand...

Nothing, but if you keep "turning around" and "going down the hill" again you are going to sleep well after that day. Or don't sleep at all and keep wobbling in your bed...
 
It sounds like you have the beginning of "Death Wobble"! It doesn't fix itself! Jack up one front wheel at a time and shake, beginning with the left side. Also disassemble the steering balls (Linkage) and make sure they're round (1.000"). This is just a start, almost any worn part in the front end will cause death wobble from a bad steering box to loose king pins, from worn out spring bushings to bad tires and beyond.
Terry
 
Hah, drove it 500 miles this past season to break-in the engine per instructions from Schwalm's. Saturday I put on only about a mile and a half due to the issue. I will check everything I see listed here and search "Death Wobble". I do know that I need to rebuild the steering arms. Balls are not round. I have installed a Mel Gross steering box and everything has been replaced up to the steering arms. They are next for refurb.

Thanks for the help.
Jerry
 
probably kingpins and bushings too...DO NOT put the bandaid fix of a "steering dampner" the parts houses sell...replace your worn out stuff and it will be perfect.
 
I agree, check for undo looseness everywhere, but odds are pretty good that it is kingpins. I did mine a few month back. It is not a difficult job, but it is a heavy job.

Another thing worth checking...if your radius ball was 'upgraded' to the rubber ball type, you may have a worn out rubber ball. If that is the case, I would recommend that you change it back to the original setup.

Good luck,

Ken
 
Why beat around the bush.

Your reply no. 4 is about as informational as opening an Egyptian Tomb that has been sealed for years ..... broken grease fittings, crud ..... King Tut, Julius Caesar, or Christopher Columbus may have been the last guy to grease and maintain your Model A front end.

If it were mine, rather than shimmy and wobble all the way into the front bumper of an oncoming 18 wheeler, I would conduct a thorough Archaeological Investigation on the entire front end.

Rather than considering this reply #4 as a problem ...... consider it a challenge ..... and just get a Frank Buck Hat and start digging.

For life safety's sake, hope this helps.
 
Last edited:
H. L. Chauvin said:
Why beat around the bush.

Your reply no. 4 is about as informational as opening an Egyptian Tomb that has been sealed for years ..... broken grease fittings, crud ..... King Tut, Julius Caesar, or Christopher Columbus may have been the last guy to grease and maintain your Model A front end.

If it were mine, rather than shimmy and wobble all the way into the front bumper of an oncoming 18 wheeler, I would conduct a thorough Archaeological Investigation on the entire front end.

Rather than considering this reply #4 as a problem ...... consider it a challenge ..... and just get a Frank Buck Hat and start digging.

For life safety's sake, hope this helps.
Click to expand...

I couldn't agree more. Do a thorough investigation and fix EVERYTHING that needs attention.
 
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