cgarcer

I have my trailing arm completely disassembled. My car had been in an accident. I want to check the trailing arm and make sure it is still straight before I send it off to be rebuilt. Are there any measurements or methods without a jig to verify it is straight?

DUB

If you posted photos before you took them part...I could look at one area and tell right away that it was shot...but being disassembled...it is about impossible for a visual confirmation.

If in doubt...buy new ones.....OR...whoever you are sending them to...hopefully they have a jig and can check them.

DUB

doorgunner

Members gave me a dimension to check on my trailing arms when I had to straighten them because of the previous owner's modifications.

This will give you a quick check: On a bare trailing arm.....laying a straightedge on the flat surface where the spindle housing would fit.......there should be about 1 7/8" between the straightedge and the arm near the pivot bushing.....








I used a string to check mine with the spindle housing still in place on the trailing arm.

As for twisting......use a level to place the spindle hub vertically on a workbench.......then put a tight-fitting rod in the pivot bushing hole and check the rod for level (if it is not level, the arm is twisted)

cgarcer

Here is a pic of the one I'm working with. I suspect someone might have worked on it already. These appear to be hammer marks along the bend. I assume these marks weren't factory.

doorgunner

Even though "it's not pretty".....it still could be O.K. Use the straightedge to check the "offset" of the area that you show in the photo....it should be about 1 7/8" gap between the straightedge and the flat part of the arm near the bushing.

Laying the large end of the trailing arm on a table, and put a tight=fitting dowel into the bushing, you can see if the arm is "twisted" by holding a level against the dowel. (You may have to let the smaller end extend past the edge of the table).

My t. arms were bent so badly that I was unable to adjust for "toe", as the side of each arm was jammed against the frame "pocket"---now they are straight witin 1/16"....but they are dinged from being straightened. (The previous owner gets credit for NOT dinging them up/the bends were un-noticeable to me at first, being a rookie---He must have used a large heating torch and a large vice to bend the to fit wide racing tires)

LIKE DUB SAID...IF IN DOUBT, LET THE REPAIR SHOP CHECK THEM.

cgarcer

I'm afraid my suspicion is confirmed. I get 2 1/8" on one side of the bushing and closer to 2 1/4" on the other.

doorgunner

You'd better let Dub advise you on that measurement....I'm a rookie

(If you have moderate mechanical skill......you could tweak the factory bend at the offset to be correct again)

DUB

cgarcer,

Using this method that was shown to get a measurement seems to be a valid method. I would be using rigid piece of steel myself.

BUT my major concern is another dynamic. What I run into quite often when I am doing trailing arms ( bearings and bushings) is that when I get them in...I can look at the inner bearing flange where the half-shaft bolts to and look at the flange and see how well centered it is in the big hole of the trailing arm itself.

I have seem MANY that when they come in...the car has 'curbed' something...and one of the outer areas of the inner bearing flange is slightly rubbing or darn near touching the inside diameter of the trailing arm hole. What this is telling me is that the machine flat surface that the bearing support housing and other parts are bolted to are 'tweaked'. BUT YES...the rest of the arm looks fine. BUT knowing that it is tweaked...if I use it ...(because I have and found out the HARD WAY)....is that when the car went if for an alignment....it was impossible to set the toe....due to the arm being tweaked.

So...you can have a bend where you see something that looks kinda funky...and you can actually have the machined surface be tweaked.

****UNSOLICITED PROFESSIONAL ADVICE******

For those who plan on doing their own trialing arm bushings and using a urethane bushing that you can do yourself without needing the specific staking fixture like what is needed for rubber bushings....BE AWARE OF THIS!!!!

These aftermarket style bushings are wider....and I would measure them before you do anything. Both the factory one still in the arm and the aftermarket one and decide from there. 'Why do I write this?" you ask....because...due to this type of aftermarket bushing being wider than the stock design....and depending on how your trailing arm shims were packed for an alignment initially.....this WIDER bushing can actually make it so you can not set eh toe....due to its width is restricting the trailing arm movement. It does not happen all the time....but it has bit me in the backside more times than I can count....and now will not use that specific design trailing arm bushing.

Also...just because the factory shims seem like they are fine....and have been in there since the car was built...and you have a good amount of shims on both sides of the trailing arm bushing...you have to ask yourself.... when you go in for an alignment...if there is/are other issues in the trailing arms, etc...that would drastically change the set-up of these shims packs. because it can happen....because it happens to me. Not always...but it does happen.

DUB