• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

TR4/4A TR4 front suspension shimmy and shake

Share this page

S

spbvmb

Member
Offline
It's spring in N.H. and the roads are rough and either my memory is bad or my Tr4 front end continues to shake around way more for quite a while after a sharp bump. It feels in the steering wheel like it vibrates horizontally not up and down. Here's what I have done so far with little effect.

Rebuild the rack and pinion and interior ball joints. It is shimmed so there there is no slack but moves freely. I reinstalled the whole rack assembly by the book, even made a spreader to push the rubber bushings tight to to rack flanges. I adjusted the toe in by the book after installing the rack.

There does not seem to be any slop in the out board ball joints when the weight is on the wheels and the steering wheel is moved back and forth.

The front suspension has about 4,000 miles on a rebuild and it just seems bad recently. I lubricate about every 1,000 miles

I just installed new Koni adjustable shocks with only slight improvement. Tires are inflated to spec and well balanced with no shake at all on smooth road up to 80mph.

The shaking is there whether on the straight or in a tight corner in either direction. Usually under 80mph. Actully it seems that the faster I go the less it vibrates after a sharp bump. Probably the gyro effect.

I sure would appreciate any suggestions.

Thanks, Phil
 
Can you feel any play if you grab the top of the front wheels and try to move them towards/away from the car? Try this both with and without the wheels on the ground.

In my case, it turned out to be a stub axle that was no longer round. The bearing seemed to fit snugly onto the axle, but the outer end was oval by .010" or so and would allow the bearing race to move up and down. Replacing the axle & bearing solved the problem.
 
I concur as I had the same problem and found my outer bearing was the culprit
fixed and fine
 
You say your wheels are balanced. If they are steel wheels, they may be balanced but are probably not round. I drive my 1958 TR3A on the best 4 steel wheels I have in my collection of about 11 or 12 wheels. If they are wire wheels, you could have them checked by an expert.
 

Attachments

  • 21006.jpg
    21006.jpg
    50.2 KB · Views: 284
Search every where you want, you will likely find this to be a tire problem.Steel radials age, and when they get to 10 years they should be recycled.Long story short dont bet your life that the old MD is wrong on this one.!!!
MD(mad dog)
 
The outer bearing race is indeed loose on the stub axle. In fact someone tried to fit it by using a punch to squish out the metal. New axles and bearings on order. Will let you all know the results.

Thanks for the suggestions.

Phil Brooks
 
OK helpers on this one. The new stub axles and bearings are installed and we still shake the same.

The tire are two years old on wire wheels which are not out of round if I spin them while off the floor. They do not vibrate at any speed on a smooth road and no matter how I switch them around on the car there is no difference.

The cross tube between the spring brackets is tight. This is a rust free frame.

How can I check for loose front end parts. Forcing the top of the tires in and out with weight on or off, every thing is tight. There is absolutely no slack in the steering, weight on or off. Even the most minute movement in the tires moves the steering wheel. I made a jig to compress the springs and all the suspension parts seem tight as do the ball joints when off the floor.

I would love to drive this car without hanging on to a flailing steering wheel every time I hit a sharp bump. This is my 4th year with this car on the road and it just started this behavior.

Again, thanks for any ideas.

Phil
 
This sounds crazy, but it worked for me. Some years ago, I had a big motorhome that had a similar problem. It would be fine most of the time, but every once in awhile the front end would start shimmying and usually wouldn't stop until I either slowed below 40 mph, or jerked the wheel really hard.

I asked a friend of mine who was running a tire shop at the time, and he said to have the wheels rebalanced, using a static 'bubble' balancer! So, I took it to him, and that's what he did, and it solved the problem! Never happened again.

He also used about half as much weight to balance them.
 
Back
Top