Help - Rear Suspension Adjustment

[rms427]

I need to adjust the toe in/out on the rear suspension. The car has the original 427 suspension except for Konis. Is there a way to do this without taking the suspension apart? There are two nuts on either side of the a arm (where it attaches to the frame) that allow adjustment. Unfortunately it looks like I need to take everything apart to get to the nuts. What's the least amount I need to take apart to adjust it?

The reason I need to do this is I screwed up when I redid the rear suspension and changed the setting on one side and now have high wear on that tire. I assume if I go back to where it was I will be OK.

Thanks, Ray

[CSX 4027]

The toe/trailing links on an original car should be pretty easy to get to. You loosen the jam nut on the front anb back of each and turn the shaft to the desired setting. Then snug the jam nuts. If you are using an alignment lift with the car in the air, you shouldn't have any problem. I have done it on the ground but, it is not as reachable unless you are really skinny.

[rms427]

I think I need to adjust where the a arm attaches to the frame. The a arm attachment to the frame fits on a threaded shaft with a nut on each side that allows it to be moved forward or back. I need to move the a arm attachment forward. The shock and spring are in the way to get a wrench on the adusting nuts. I know if I take everything apart it is easy to adjust but it's a lot of work getting to that point. Maybe I need a special thin wrench to adjust the nuts or maybe I can just take off the spring and shock assembly. I just don't want to take apart anything more than I have to.

If I can adjust the toe by the trailing link then I agree that would be easy. But I assume that the attachment point for tha a arm has more effect than the trailing link and that's what I changed when I put the suspension back together.

Thanks, Ray

[CSX 4027]

If you are talking rear lower a-arm inboard rose joint, that would be for rear castor setting. Why do you think you need to move it? That's not how to set rear toe. The wrenches for the rose joint are special thin and large. I forget the size but, you do have to remove other stuff to get to it.
Post pics and maybe I can help more.

[rms427]

It is the rose joint. This is how it came off the car. As you can see there were no threads showing on one side. I centered it with equal threads showing on each side of the nuts when I put it back together. I was carefull to keep all the other adjustments the same as they were. The tire on this side wore out faster than the one on the other side. It was more or less even over the tire so I assumed the toe in/out was changed. The rear tires always wore out at the same speed in the past. Never wore out a set of front tires.

Thanks, Ray

[mickmate]

If you are talking about the threaded sleeve on the lower a-arm inner mount, by centreing it you have moved the arm mount back toeing that wheel in. I'm guessing it is wearing on the outside of that tire? If you use a couple of long straight edges (better against the wheel but the tire will do) you can check the parallel and toe of the wheels to each other. That picture you took will do a lot for getting you back to where you were. Good pic BTW.
Cheers Nick

[CSX 4027]

Regardless of what you did with the rose joint position, you didn't really have to change it. It was probably OK even with all the threads on one side. If someone had set it up that way, there might have been a reason with the castor. It appears you might have another issue that could have been wearing the tire funny. The control arm bushings are probably worn and have movement yielding it next to impossible to control toe under acceleration and deceleration. This is a common problem easily cured with bronze bushings with zirk fittings. The Kirkhams can help you with that.
My original 4027 rear suspension was exactly like yours. The rose joint was also set up the same way with the threads. I also had the delron or urethane bushings that were junk. Everytime I was on the track the car was unpredictable until I changed to bronze. Then it became a predictable car that I could steer out of a corner on the gas and not have to check my underwear.
Put the rose joint back the way it was unless you know for sure it was even at one point and moved which I doubt and get bronze bushings. Also see what type of bushing is in the housing under the seat where the toe link connects. It should be steel.
The idea is you want the whole system solid or the toe adjustment will never help. When the car accelerates the rear wheels want to toe out. When braking, they want to toe in. Only way to stop it is make it solid./

[CSX 4027]

Another gremlin like problem with orginal rear suspension is the rear hub carrier. The preload on the rear wheel bearing need to be checked and possibly shimmed to get tollerances correct. You need to check with a dial indicator and have a max of .005 play. Any more than that will also do everything I previously stated above. It all need to be harmoniously tight.

[rms427]

The tires wore fine until I replaced every wearable part in the rear suspension including the bearings and seals in the hubs. I had close to 70,000 miles on the car at the time and the rear end was leaking so I decided to change out everything when I rebuilt the differential. I was careful to keep all the attachment points the same except I centered the one rose joint. I assume if I put it back, like it was, it should correct the problem. I was just hoping I wouldn't have to take everything apart to do it. Oh well, it was stupid to make the change (it was there for a reason) and now I'll just have to take the time to correct it.

Thanks again, Ray

[mickmate]

Ray, you may want to try bending a wrench to get it around the shock mount. If you heat it with a torch you can customise it to your application. The other tool that may work there is a crows foot with a short socket extension. Worst case if you let the inner mounting bolt go it should all roll out at the bottom enough for you to access the pesky little thing. Steve makes a good point about the bushing material. I was told the delrin bushings are hard and make a street car ride rough and that the original metalistic bushings are better (softer) for a street car. What did you use and what do you think of it?

[rms427]

CSX4027 & mickmate,

Thanks for the help. I will try to make a tool to adjust it. I had already decided to try and take out the bolt and try to roll out the rose joint from the frame before I took everything else apart.

I replaced the all the original metalastic bushings with new ones. I was surprised that the old ones still looked good after 70,000 miles. I decided to stick with the metalastic bushings based on the fact that they worked well on my car and lasted a long time.

Thanks again, Ray

[Anthony]

Originally posted by rms427


As you can see there were no threads showing on one side. I centered it with equal threads showing on each side of the nuts when I put it back together. I was carefull to keep all the other adjustments the same as they were.
Thanks, Ray

I guess you mean the trailing arm, and not the A arm. The lower trailing arm will adjust the toe-in-out. The upper A-arm will adjust camber, and I think will affect the toe-in as well, as does the ride height. You want to first adjust your ride height. Then, you want to adjust the camber, if needed, and then adjust the toe in with the trailing arm. If you centered the trailing arm adjustment, I would think you should now have the same number of threads showing, combining both ends, as you initially had showing on just the one end. Most people say you want about 1/4" toe in, although I set mine neutral, or maybe 1/8" toe in.

I used a pipe wrench on the threaded tube, as the square end was outboard, near the jam nut. If you re-assemble it, I would orient the tube such that the square end (place to put wrench) is inboard, as I think it would be easier to adjust in the future.

[Anthony]

Originally posted by CSX 4027

. When the car accelerates the rear wheels want to toe out. When braking, they want to toe in../

I thought when you accelerate, the tires want to move forward, and therefore toe-in. With braking, they pull back, and therefore toe-out.

[Specialk]

Anthony,

The inboard side of the lower control arm is where the toe is adjusted, not the trailing arm/drag link.

[rms427]

The inboard side of the lower control arm is what I need to move back to where it was. From what I can see I need to remove the inboard attachment of the lower control arm to adjust it. May have to remove everything else as well to do it. Since I had just installed new master cylinders and need to bleed the brakes I might as well tackle this before I bleed them since I may need to remove the caliper. Rather than trying to find a shortcut it probably will be quicker to just take everything apart. Boy, I hate to redo stuff. Especially when I should have known I was making a mistake.

Have fun, Ray

[mickmate]

He knows what he needs to adjust. If the trailing arm is adjusted it will only make minor changes to toe with more of an effect on caster and wheelbase. Notice it has a heim on one end only not like the new generation that use the swaged tube with a heim on both ends. Thanks for your thoughts on the bushings I've been trying to decide what to use for a street car.
Cheers Nick

[Anthony]

I learn something new every day.

[Guinness]

Ray,
Give me a call if you need any help holding wrenches or drinking beer. I need a break from working on the LWW house.

Jeff

[rms427]

I GIVE UP! I went to take out the bolt that holds the lower a arm on the frame and it won't come out without taking out the gas tank. There has to be an easier way to adjust the suspension.

Anyone know of a good alignment shop in the Grass Valley to Sacramento area. I think I'll let a professional see if they can adjust the rear suspension without removing the lower control arm. The trailing link should alow some adjustment but will probably require other adustments as well.

Have fun, Ray

[mickmate]

That stinks Ray, can you see the nuts you want to adjust. I would definetely look at a custom made wrench if you can see the nuts. I thought those mounts were angled to allow that bolt to come out but I guess not huh. You'll get it one way or the other.