Wedge TR8 Shimmy

[PATR8]

Related to the wheel bearing topic earlier.... it was not the wheel bearings. I replaced the wheel bearings and the shimmy is not as bad but is still definately there. I even swapped out a my TR8 rotors for a brand new set of TR7 rotors to see if maybe the rotors were bad. Thta did not fix it. Wooody suggested the inner control arm, and sub frame. all tight. I am guessing that when my powere steering rack decided to start to ooze PS fluid from every corner on my way back from DC that it may have crooked. Even though I kept PS fluid in it (a quart every 200 miles) I think that is the guilty party. I have a quick ration manual rack I am planning to swap in this week end. Any one else have any idea what else it could be?

I also attached a meeting of old european cars at out local supermarket. The Saab owner was cool and we sat around chatting about our cars but I was amazed how small the Saab was.

 

[tdskip]

Hi Pat,

I like those vintage Saabs too - very cool.

Shimmy = vibration around 40-45 mph that then goes away?

 

[tr8todd]

Those shimmys are almost always caused at the lower control arm and or sway bar. They come together to form a sort of lower A arm. Any play at the subframe mounting holes, bushings, tie rods, ball joints, or sway bar end bushings will cause that. You really have to tear it apart to find it. Every component is so stressed in there, that there has to be serious wear for you to find it without pulling it all apart. You are almost better off replacing all of it. Any play at one component will cause the others to wear rapidly. Whenever I renewed a suspension with shocks and springs, I always intall new bushings, tie rod ends, and ball joints as well. I also take out the power steering and go back to a quick TR7 manual rack.

 

[DNK]

Dave- i have an extra set of sway bar bushings if you need them.

 

[tdskip]

As an FYI my shimmy went away when I put in all poly bushings

 

[DNK]

Again I reiterate . New polys for the asking

 

[tdskip]

Somebody should grab these and send Don a really nice Pinot...

 

[DNK]

Make it a nice Sangiovese

 

[philman]

I have an extra set of poly sway bar bushings also. I also have an extra sway bar off a TR8.

If the locking collars are missing on the sway bar could that cause a shimmy? The previous owner of my fhc had left the locking collars off and I replaced them with an extra set I had stashed aside. I didn't notice a shimmy but that would seem possible.

 

[DNK]

took the collars off mine when I added the anti dive blocks.

 

[PATR8]

I am in the process of taking out the power steering rack and cleaning up the manual rack to install. i noticed the shimmy first when driving to the Roadster Factory show in Indiana Pa and when I was driving the winding road the bends to the left teh shimmy started. By the time I got home and did some local driving the shimmy was all the time. I changed out the wheel bearings and the shimmy when braking is gone but the shimmy in left turns still exsist but not as bad.

I checked the lower control arm and subframe mountings and they were all tight. I really hope going to the manual rack will solve it, and it will eliminate what has been a problem since I had the car, a power steering leak (actually several leaks in several different spot at several different times )

My sway bay bushings are worn and I will be ordering new tie rod ends and ball joints to finish the job. How hard is it to change out sway bar bushings?

I do love the little Saab in the pic, sporty looking and sounding

 

[DNK]

Major- How tough is the power steering removal??
Interested in getting the whole kit and kabodle redone!

 

[PATR8]

Well the Triumph manual says it is easy, I on the other hand am on day two of trying to do it. First you secure the engine using a hoist then drop the subframe ( I beleive the quote was to drop it to the bottom of the subframe bolts) then crank the rack to the right and slide it out of the right side of the subframe until the left side tie rod clears. Then pull it out toward the front of the car. I had a tie rod end that needed encouraging to come out then I can not get the rack to the right far enough to pull it out. I am still probably 4 inches from being able to do it with out resorting to cutting something.

I think tomorrow with a new days worth of patience I should have it done. I need new boots for my manual rack so this will be a prolonged project but not exceptionally hard. I had not thought of doing a photo log to post of the project.

 

[PATR8]

Just an additional wondering, I wonder how much more difficult parking will be with the manual rack, when in DC there is a lot of street parking. At least I will eliminate one spot in my garage.

I will drive it for a while before I decide if I want to invest the money to have it rebuilt

And I am one Post from 700

 

[DNK]

Go for 700 Major

 

[tdskip]

I simply cut the belt on mine when the power unit turned into a sieve. I have the roller bearings from Ted and it is heavy at a dead stop but livable and nicely weighted underway.

 

[tr8todd]

Your best bet is to remove the entire subframe. Once it is out, strip it down and take it to the car wash and power wash it. Inspect the sway bar and control arm mounting holes. If they are not perfect, you will have to do something about them. I like to weld grade 8 washers over the holes and then redrill. I also go to larger diameter grade 8 bolts, but I'm the only one who goes to that trouble. You have to drill out or replace the steel sleeves for the bushings if you go bigger. Paint the subframe and control arms with a nice chassis paint or some Hammerite. Reassemble with the TR7 rack, new poly subframe and control arm bushings, new steering gaiters, and new ball joints. Make sure your control arms are straight. I've seen some bent ones from improper jacking and jack stand placement. Remove everything associated with the pump and backets. If I remember correctly, the front pulley has to come off to remove one of the pump bracket bolts. Now is a good time to drop the oil pan and take a look inside. Clean the sludge from the pan and install a new pan gasket. The only tough part is reinstalling the sway bar. A come along is very helpful here. The lower piece of the steering column is different for a TR7 and a TR8. The 8 has a shoter one because of the power steering control box on top of the rack. You need to make sure to install the TR7 lower piece with the manual rack. There are two different ratio TR7 racks. I think one is 3.9 and the other is 4.5 turns lock to lock. The 4.5 is better for the street and the 3.9 is better for the track. That being said, I have them the other way on my cars. I'll address that obvious mistake some day. If you get stuck, give me a yell. I have 3 spare subframes and about 10 manual racks. One other note. I noticed that Energy Suspensions sells heavy duty poly boots for ball joints. I haven't used them yet, but I plan on it. The last set of ball joint I installed on my street car had the boots crack in less than a year, and that car was just sitting in the garage.

 

[PATR8]

Well when all was said and done, I had to drop the entire rack. I will degrease and paint it (was painted about a year ago). I got to get new boots for the manual rack, I have a set of new tie rod ends to put on it. The Ball joints are less than 3 years old and look good and I have polys on the subframe already. All the monting points look good, no oblonging.

I had cut the belt off my power rack because it was gushing from all over and that included my headers so I kept it full and it just drained thru the rack. Woody warned me about letting the rack go dry but as fast as it was running thru I doubt it had a chance.

I guess have a 3.9 (I thought it seemed less than that but I was just swagging). I could probably benefit from new set of sway bar bushings but I want to get it back on the road. I beleive I may have found a hole in my lower radiator hose while I was down wrestling with the rack so we will add that to the parts list and I may go ahead and through one of Woody's new fans on it. I saw several 8's with them on at the roadster factory and really liked the clean look and the idea of using less than 1/2 the amps.

I am glad I have the replacement rack cause the rest of this is costing more and more

 

[DNK]

Major- If you want them 'll throw them in the mail on Monday!
They are poly's

 

[Mickey Richaud]

I beleive I may have found a hole in my lower radiator hose while I was down wrestling with the rack so we will add that to the parts list and I may go ahead and through one of Woody's new fans on it. I saw several 8's with them on at the roadster factory and really liked the clean look and the idea of using less than 1/2 the amps.

I'm in the middle of some modifications to my cooling system while I'm tracking down some other stuff. Learned that Porsche Boxster fans are a direct replacement (no, really!) for the two TR8 fans. They fit perfectly in the fan shroud - no mods necessary at all - even the three mounting holes are lined up perfectly. Draw less current and move more air while still maintaining the "look" of two fans. The blades are black, and there's a reinforcing ring around them, but look very good.

Got mine off eBay...