1930 Coupe front end shimmy
 

I have a friend that owns a 1930 Model A Coupe. I did major brake work on it back in 2009. At that time he mentioned that he had a shimmy problem with the front end.

So while I was working on the brakes I checked out the front end and found some play in the tie rod ends. I installed new Teflon ball seats and new springs. I also had to replace the drag link because it was damaged. I adjusted the toe to factory specs. I didn’t think that the balls were eye shaped too badly—just some minor wear.

When I was performing the brake repair I installed all new brake drums, new front hubs and bearings, new brake shoes, all new brake hardware and new adjusting hardware. The right rear brake rod was bent and it was not even connected to the wheel, so I replaced it with a new rod.

The king pins and front spring shackles seemed to be okay at the time.

I adjusted the steering box per Les Andrews Mechanics Handbook Vol. I.

I did not balance the wheels because I live in a very rural area and I didn’t want to trust anyone to mess with the wheels.

The shimmy is still there. At 35 mph driving downhill my friend says that he has to stop the car because it is so bad that it feels like it will come apart!

At this point I will be rechecking the entire front end again. Oh, one thing that I did not mention, the wish bone has been welded to the front axle some time before I worked on the car. Also, when I was working on the front end I noticed that one of the bushings on the spring perch had moved out of the perch-see photo. And the front spring has 12 leafs plus a 1/4” shim at the top.

I have read some posts on Ford Barn about front end problems and it was mentioned that some axles on the Model A’s are bent, which can cause problems.

I am thinking that I will need to purchase another axle and wishbone to start. Will I be able to check out the axle and wishbone myself or is there some place that I can send it to make sure it is not bent or damaged?

So where do I start?

Re: 1930 Coupe front end shimmy
 

Job one would probably be to balance the wheels since that is where the shimmy problem usually is. Validating the suspension geometry probably needs to be accomplished with wheel alignment equipment. Please advise when the fix is found.

Re: 1930 Coupe front end shimmy
 

What shape is the wish bone ball in?

Re: 1930 Coupe front end shimmy
 

Yes, that front axle is welded up mess, so replace if a good one can be found. I heard one time time, that to check if a front axle is bent, to remove the spring perches and install straight rods a couple feet long that fit the perch holes and see if they line up from the side. If not, the axle is bent. You said that you adjusted the steering box. Often that is the cause of death wobble. And king pins and all the rest of the front assembly is reasonably tight. I would go with Mulletwagon's advise and check the balance of the front wheels.

Re: 1930 Coupe front end shimmy
 

Check your "Private Messages" in the upper right corner of this web page.
Marshall

Re: 1930 Coupe front end shimmy
 

I agree that you have some real problems in that front end.

If it where mine, I would replace front axel, wishbone, and front spring. Than repair all the worn out parts, all of them.

You, I believe, have to many negative issues going on here. The some total, shoot front end.

Maybe I have been lucky, but in 60 years I have never had to balance a front tire on our Model A’s. Have always rebuilt the front end as completely as possible.

Enjoy.

Re: 1930 Coupe front end shimmy
 

The wobble is caused by lack of toe-in, and/or loose tie rods and drag link ends. Most of the time.
Tighten those four ends to snug, reset the toe and the wobble just might go away.
Pitman bushings must be good and tight. Slop here must be repaired.

Re: 1930 Coupe front end shimmy
 

The axle looks crappy but I doubt that is the problem. Wobbble is usually caused by looseness in 1) drag link 2) tie rod ends 3) steering gear. Front end alignment is also critical.

Re: 1930 Coupe front end shimmy
 

I agree with the 'loose' posts. The looseness can be anything from the steering box all the way thru to the wheel bearings, anything along the way. Once thats done, add a bit of toe-in.
Then the axle/spring problems can be addressed when there is time.

Re: 1930 Coupe front end shimmy
 

Toe in has always been the cause of shimmy on my cars ! I set the toe in at one sixteenth and shimmy goes away .

Re: 1930 Coupe front end shimmy
 

My car had a low speed shimmy that was “fixed” with a steering stabilizer. The real fix was a complete steering system rebuild, box, spindles, spindle arms, etc. Set the toe right and chucked the stabilizer in the spare parts bin.

Re: 1930 Coupe front end shimmy
 

That front spring is worn out. The 1/4 inch spacer verifies this, a sagging front end decreases castor causing shimmy. A shopping cart front castors that have been smashed into parking curbs will shimmy. The perch spring bushing can be replaced on the car. I would disassemble the front end and fix what's worn out. The wish bone, perch welded to the axle just maybe ok, other than looking bad. Keep us advised on your work, and have fun !

Re: 1930 Coupe front end shimmy
 

I find that excessive castor can cause a shimmy, rarely, but it happens once in awhile.

Our cars come with 5* castor by design. Thats plenty, more than enough. I cut mine back to about 4* because I prefer the steering wheel to return easier.

Re: 1930 Coupe front end shimmy
 

That front spring shackle concerns me. It may not be the cause of the shimmy but it needs to be addressed. If that is a import they are prone to breakage and by the looks of yours it could be. http://www.fordgarage.com/pages/brokenshackles.htm

Replace them with the USA made ones from Snyder's. They don't look originl but I would rather be safe. https://www.snydersantiqueauto.com/P...earchByKeyword

Here is a picture of one of mine off the rear that I recently replaced.
https://live.staticflickr.com/65535/...8bf72d3e_z.jpg

Re: 1930 Coupe front end shimmy
 

Toe in, balance, and a good 10 leaf spring will help a lot to stop that shimmy. Make everything correct and it won't cause trouble!

Re: 1930 Coupe front end shimmy
 

I moved the 30 Coupe to my shop. I removed the old radius rod rubber ball set-up. The radius rod steel ball looks pretty good as far as I can tell. So I am gong to install the original style radius rod socket set that I purchased from Snyder's (made in USA by the way).

Two questions at this point:

1-Should I install the radius rod ball spacer if the steel ball looks good?

2-How tight should I make the nuts on the socket bolts?

Re: 1930 Coupe front end shimmy
 

This is what I did. Dont use the cup spacer. Tighten the nuts up until they just hit the spring spacers. Install cotter pins. May seem to loose , but my experience, such that it is, led me to believe this was the correct way. My 30 coupe seems to like it. First time I tried it the nuts tightened up but went above cotter pin holes. Ordered new nut, same results, put two washers under nuts, seemed to work, but just didnt seem correct. More research led me to the installation I just described. IMHO

Re: 1930 Coupe front end shimmy
 

Most things have been addressed by previous posts. I agree the suspension should be repaired. The axle and wishbone can also be repaired. Mandrels are needed to check the axle for bending and excessive bore wear. Bores can be rebushed with press fit steel bushings. The wish bone can be weld repaired and machined back to specs. You may find some better parts out there but many OEM parts may be in similar condition to what you already have so shop carefully.

The king pins should be a light push fit if renewing them. If they wiggle at all then they should be refit with new parts.

Tires can be in balance but still have tread separation from the carcass. I remove the wheel assembly and roll it to see if it will roll true. If it immediately wobbles & flops over then there is a tire problem. Old rubber is problematic. A person shouldn't run tires that are well over 5-years old.