VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Shimmy problem on 32 chev roadster

I get a bad shimmy from time to time when I hit an uneven road or bump. It doesn't do it all the time but is getting more frequent. Sometimes I can drive 20 or 30 miles between episodes, but other times It can occur every 5 miles or so. My mechanic says the steering box is the cause. He said that most of the times he has worked on the steering box the problem is a worn sector shaft. Does anyone know where I can find a good sector shaft or an entire steering box? Any help will be appreciated.

I would first adjust tie rod and drag link ends to see if that helps any.

I was hoping that was the problem but he made the adjustments today and believes the problem is in the steering box

Chuick had a problem like this a couple of months ago. His was in the steering box. There are 3 adjustments but you have to do them in the correct order. Maybe he'll log in...Joe

Thanks! I didn't know there were any adjustments that could be made.I hope Chuick logs in. That might be the answer since there seems to be excessive play in the steering box.

I had the same problem with my 1931 coach. I started by making sure everything was tight. I started with the wheel bearings to make sure they weren't loose. Then checked the king pins for looseness. Then I went thru and checked all the tie rod and steering rod and set to specs. That only left the steering gear. I found that there was free play in the steering arm which would not adjust properly. Bob Barkers site 31chevrolet.com has very good articles on the front end alignment steering gear repairs and adjustments. Go to his site and go down the page to Restorations. Then go to steering column and more. There click on Adjustments Instructions. There are three adjustments to be made. On mine I tried to adjust but ended up pulling the steering gear and found that at sometime the sector bushing was replaced and when the bushing was reamed to size they got it crooked and then tried to put a shim to make up the difference. Lucky that I had a good used sector with housing that I saved years ago. After I got everything set up I have not had a shimmy since. Before it was so bad I would have to stop to get it to stop shimmying. If yours is not to bad see if the mechanic done the three adjustments. They are not like the newer cars where there is just one adjustment. Hope this helps cure your problem. Post to let us know how this works out. If any more questions just post as I will watch in case you need more answers. Chuick

The Steering box adjustments are all described in detail in the manual, and include 2 types of end play (sector gear and worm gear)and pitman arm backlash. Realtively easy adjustments, but depending on condition of box (and the source of the shimmy), they may not cure the problem.

Thanks again. The mechanic I took it to only works on old cars, but does not specialize in Chevrolet. I am going to see him tomorrow so I will go to the web site you noted and see if he is familiar with the adjustments. If it works it will probably be easier than finding a sector shaft or a steering box in good shape. I will let you know the results. Thanks again.

I am just an old truck mechanic with little experience with autos. Especially older vehicles. If you do not find it in the steering box I would look at the caster. Zero or negative caster can cause a shimmy.

Picked up the car today and still have the shimmy problem. Tires,kingpins,tie rods, tire pressure, and toe-in checked and adjusted. The mechanic was already familiar with the adjustments noted in Bob Barkers site and had already checked them. He said the adjustment for the sector was already maxed out. I drove the car home but had two shimmy episodes during the 12 mile trip at low speed. He said I need a new steering box because he believes the sector shaft is worn and causing the problem. He can overhaul my steering box if I could get a good sector shaft. I believe the odds of getting a new shaft are about zero. So I need a new steering box and hope I can find one that does not have a worn sector shaft.I guess the 31 and 32 steering boxes are inter-changeable are there any other years I could use? Hope someone has one they will sell.

I have seen many new old stock sector shafts for sale over the years so you might want to try to find one instead of purchasing a used steering box. Many of the used steering boxes that you find will have as much wear as your steering box....or they might be even worse.

If you buy a replacement steering box make sure it is either dry or filled with oil not grease. We have found those with grease have the outside bushing and shaft worn as grease can not get the the bushing to lube it.

Thanks to everyone. I have an ad under parts wanted. I hope someone has a NOS steering sector shaft. If I have to get a steering box I will check to make sure it was not packed with lube.

I have a '31 coach as well, after trying everything that the good people here are suggesting you try make sure you try what CRS1929 has said and check the caster before you spend money on parts, that's what fixed my car, I had to put wedges under the front axle to get it right now it's perfect.

I agree with Brian. Increasing caster has helped me solve shimmy problems on beam axle vehicles. In addition, I found it easier to go straight without constant corrections. The sacrifice is more low speed (while parking for example) steering effort. Spring shops have wedges of various thickness and widths. Easy experiment to try that versus expensive- tough to install steering boxes.
Dan

I like this idea. My 32 shimmies once in a while but a touch of the brakes stops it.
Negative caster by rotating the axle with small wedges in the spring perch!!! Nifty and the steering effort would be a bit harder but no too much. Excellent and brilliant...Thanks guys...

Mac

Sounds like an easy solution if it works. Do you think a positive caster of 1 degree would be enough? I'll check this week-end.

1 degree would be a good start. Positive caster will help the steering return to straight ahead but will increase the steering input from you. I am sure you know this but with positive caster as you turn you actually pick up the front of the vehicle when you turn. This makes the steering want to return to a neutral position. The more caster the higher you have to pick up the front end when you turn.

I must check mine. Do you place the wedges in the front half of the spring "perch"?

The spring sets on top of the axle. The shim goes between the axle and spring. Now I know this may sound hokey. But go down to to the hardware store and buy a magnetic angle finder. They will run somewhere around $10.00. The vehicle needs to be parked on a level slab. Sit this angle finder on top of the spring. There is a flat place just outside of where the U bolts go through. Clean it up the pad so the angle finder sets on this level spot. (It must be setting level on this machined level spot.) I have checked my 1929 and it might me tight to get the angle finder on top of the axle. If so take a piece of bar stock or hollow square tube about a foot long. Put this on top of the axle and hang the finder from the bar stock. You will be able to read your angle of Caster. Positive caster is when the bottom of the Kingpin is setting forward of the top of the kingpin. In the past 35 years I have checked hundreds of trucks using this method and it does work. You don't have to have a $100,00.00 alignment rack to set alignment on vehicles with straight front axles.
I spent 40 years working in a national truck leasing company. The last 16 before I retired I traveled for the company teaching alignment along with 8 other shop procedures. If I can help you in any way please send me a message and I will give you my phone number. I would be happy to help.

Now that is some great information!!!

Information and a 1/2.......!

Great information on how to check caster. I will find a magnetic angle finder this weekend and check the caster angle. It would be nice if I could get rid of the shimmy with a simple adjustment. It also would be great if I could reduce the frequency of the shimmy until I could find a new steering box or steering sector shaft. I do believe it is worn and should be replaced, but it would be nice to wait awhile to replace it.

Bought mine today from Ace Hardware....12.99....Will try it out tomorrow. I found 5 metal wedges in my Dad's tool box today as well....Thanks for this information along with the coaching as well as how to do it.

Mac

One thing I did not mention is, and this is what I seem to forget when I am working on any project. Before you make any adjustments get before readings, review the readings and only make necessary adjustments.
If I would just do this I would save much time and money.