LegendsRacer - Legends & Bandolero Racing Forum

LEGENDS => Drivetrain & Gearing => Topic started by: DARK AGE 53 on June 23, 2007, 05:23:41 pm

Title: How To.....squaring axle housing.
Post by: DARK AGE 53 on June 23, 2007, 05:23:41 pm
Here's what I use.

1. Aluminum vertical drapery track.
2. Braided Nylon String, 14" or so long.
3. 4 multipurpose magnets from Harbor Freight ( 6 1/4" magnets for $2 each ).
4. Ruler.
5. A couple of nuts for the string.
6. Masking tape.

From the pics you can see how I mount the aluminum track to the frame, I use this to measure back to the string.
I like to place to the string as far out as possible, using masking tape to hold it to the top of the  axle tubes.
I measure from the track ( or what ever you're using ) to the string, if not square adjust one or both of the trailing arms......this can change your wheel base though.

Here's some pics.

Al

Title: Re: How To.....squaring axle housing.
Post by: DARK AGE 53 on June 23, 2007, 05:27:01 pm
three more pics..

Title: Re: How To.....squaring axle housing.
Post by: DARK AGE 53 on June 23, 2007, 05:31:36 pm
I think this is it..

Title: Re: How To.....squaring axle housing.
Post by: DARK AGE 53 on June 24, 2007, 07:36:59 am
last pic, BTW, the reason the aluminum track is longer ( 60" long ) then needed is because that's what I had and it was free. ;D

Title: Re: How To.....squaring axle housing.
Post by: gramps05 on June 25, 2007, 07:05:12 pm
For what its worth, to get the most accurate readings your string should be on the bearing carriers not on the tubes, they are usually not centered but the bearing carriers should be if the unit was built properly. One of the pictures shows  the string on the weld, if you moved it about 1/2 inch to the left it would be on the carrier. Some of the rear ends are way out of alignment, see the CMG motorsports web site for a how to check the alignment. Why so much lead?          http:cmgmotorsports.com/housings.htm
Title: Re: How To.....squaring axle housing.
Post by: Tom Cole on June 25, 2007, 07:58:20 pm
I have my frame sandwiched with lead where Al 's rear piece is bolted.  We added it to get our numbers right and to keep it from transferring so hard over to the RS.

I wish I had a lift like that in my garage.
Title: Re: How To.....squaring axle housing.
Post by: DARK AGE 53 on June 26, 2007, 04:28:49 am
Why so much lead? 

Needed the lead to get the car/driver to the legal weight.


Title: Re: How To.....squaring axle housing.
Post by: surfx on April 25, 2008, 08:26:22 pm
how do you make sure you have the drapery track square?
thanks
mike
Title: Re: How To.....squaring axle housing.
Post by: justfreaky on April 26, 2008, 03:34:05 am
To the best of my knowledge, Pick a common point (such as a cross member);
Then measure from there.

Steve
Title: Re: How To.....squaring axle housing.
Post by: IraceLegends77 on April 26, 2008, 12:56:58 pm
Call Roger Austin at Austin Legends. He has a real simple and quick tool.  www.austinlegends.com but it is best to call him.

Hope this helps

Scott
Title: Re: How To.....squaring axle housing.
Post by: knoxracing on April 29, 2010, 10:01:27 am
I would be careful using this method, its not real accurate, I DO NOT mean to be disrespectful, just HELPFUL . You are squaring the housing to the rear cross bar located 10-12 inches apart. if you are off a 1/16th or the bar is off a 1/16th the error is greatly amplified by the time you reach the front area of the car. being out a 1/16 will effect the car, amplifying that number will make a much bigger difference.  I plumb bobbed cars for a long time as you are, it is ok, but I found out later its not that accurate and you are not squaring the rear to the front area of the car.  I have spent alot of money on expensive lasers and can tell you squaring to the rear cross member will  probably be close, but the difference between 5th and 1st on ASPHALT is being better than close.  Stand back and look at the car,  the housing is to close to the cross member, if there is an error it will be huge when stretched the length of the chassis, and after racing a car multiple times they all move and twist differently. If you plumb bob the car to the cross member, double check yourself by the following method. Remove the front clip(fenders, hood, grill).  Find the point where the shock towers rise from the frame rails. Measure forward on top of the frame rail to within an inch of the bumper and mark it, do the same to the other side.  Clamp your 60 inch bar across the front of the car on top of the frame rails on your marks. measure back to the rear wheels. (you can use the wheel base gauge to help you do this).  You will say how do i know if the clip is straight? You may not, but if the clip isnt straight, then squaring to the rear cross member is that much worse.  This is easy, takes simple tools and will give you alot of info. This car needs to be AS square as it can be,  you need the rear square with the front area of the chassis.
Dennis Knox
Buckyey Legends
330-310-9212
Title: Re: How To.....squaring axle housing.
Post by: JGRacing on April 29, 2010, 12:18:14 pm
Thanks for the information Dennis.  It sounds like a really easy way to do it.  Now I just need to make sure that my front clip is reasonably straight.    :)
Title: Re: How To.....squaring axle housing.
Post by: JGRacing on August 19, 2010, 06:23:54 pm
Just wanted to bump this post up again.  I used Dennis's method and it was much easier and more accurate than when I crawled around on the floor last year to measure the rear end housing to to the cross member. 
Title: Re: How To.....squaring axle housing.
Post by: slack11 on June 22, 2011, 09:53:41 am
I am trying to do this but running myself in circles.  Here is what I have...

I have set the wheelbase to the same on either side, both 72 7/8"  If I drop a plumb bob off the bottom ball joint from the grease fitting on either side.  If I then drop a line from the rear on either side,  and measure distances from the rear to the front lower ball joint marks, and then measure diagonally, if it all is the same I am square.

I was using the  method Dennis described above last night, and had a late model/modified guy helping me who is very experienced.  He was wondering if the shock towers on these cars are true and square to the car, if they are a good point to be measuring from to square the  rear.  He was saying that by using the lower ball joints, you are squaring all 4 contact patches with one another.
 
Would dropping lines from the lower ball joint be better, or just complicating things with all the measuring of diagonals....
Title: Re: How To.....squaring axle housing.
Post by: VMS Motorsports on June 22, 2011, 11:34:09 am
Just my dirt driver 2 cents here...may not be accurate enough for the asphalt guys, but it takes me 5 minutes and can be done by myself anywhere.

Dirt Boy Hillbilly Rear End Squaring (patent not pending)

Duct tape
Nylon string
Two 3/4 Jam nuts
Tape measure

-As somewhat described above, except I duct tape (I can't afford magnets  :D  ) 2 pieces of the nylon strings with nuts tied to the end (hillbilly plumb bob) to the rear housing bearing carriers.

-measure from the string to the front of the cage/firewall/crossmember/whatever you call it in your local area (underneath) because most clips I've seen aren't straight, 'specialy on dirt, or from USLCi (my own personal opinion, not that of management of VMS Motorsports, their subsidiaries, Gimpster, or LegendsRacer.com). I agree with Dennis that the rear crossmember is too close to be a pure number.

This works great for me, can do it alone, and can do it with whats in the truck anyway. Also eliminates any "irregularities" in the front clip/shock towers
Title: Re: How To.....squaring axle housing.
Post by: knoxracing on June 22, 2011, 04:43:16 pm
You can square the rear by plumb  bobbing from the lower ball joints to the rear bearing carriers. BUT if you are trying to measure diagonal be careful because the rear off set is only about a 1/4". The front ball joints are not the same. In other words the ball joints are not inline with the bearing carriers and this will throw your diagonal measure off. To answer the question about the towers being straight, you are taking the measurement from the base of the shock towers, they usually  stay pretty close to straight.  You can always call me and I will be happy to offer free info.
Dennis Knox
Buckeye Legends
330-310-9212
Title: Re: How To.....squaring axle housing.
Post by: slack11 on June 22, 2011, 05:46:07 pm
thanks for the info and the offer... I'm gonna give it another go tonight and see how I fare.  Good to know about the balljoints/ diagonals, that could have been the next thing I would have chased for a few hours before realizing.....
This is the first time I have had to do this, and when trying to drop lines/ measure from the front lower ball joints it started to seem as if that would be a moving target...  The bar across the front and the measurements from the rear to that have got to be very, very close....

I measured it that way (with the bar on the front) last night and ended up getting numbers that told me my rear was 1/2" out of square.... Pointing towards the outside wall....  my car has been horrible this year, I have been chasing this since I started, but a 1/2' from what I have read would just about kill any setup I  put in it.


Thanks again, and I'll call if I get stuck.

Nate
Title: Re: How To.....squaring axle housing.
Post by: cmg motorsports on February 01, 2013, 04:30:02 pm
The other guy was correct to a point measuring off the tubes. However, when we build ours , the cap is machined so that it fits in the tube tight with a seam left for me to weld. No room for mis alignment.
However, I always stress to my customers to measure off the end cap if at all possible. When our housings are built, they are within .004 of being straight through the center  and off the caps so that what makes measuring off the cap better. If the housing is not straight through the middle or off the caps, it doesnt matter how you measure. In other words, when squaring you rear housing, be sure to start with a new or housing that has been checked for straightness.
I also say to square your rear off your front clip and not the bar behind the seat. Most chassis I have found the bar not square with the front. That will not allow you to square the car up correctly.
I also suggest running a little rear steer in the car. This will also help the car on corner entry.
Just my opinion.

Mike
CMG Motorsports.com
Title: Re: How To.....squaring axle housing.
Post by: justfreaky on February 01, 2013, 09:04:27 pm
Mike,

You do realize this thread was first posted in '07? Technology may have changed some of the thinking since then.
I am still of the thinking to keep the rear end square.
JMHO,

Steve
Title: Re: How To.....squaring axle housing.
Post by: DMAMotorsports on June 03, 2014, 04:18:42 pm
excuse my lack of knowledge on the subject but these measurements are all taken with the car sitting on all fours? how do you guys with out a drive on lift get an accurate reading? any pictures of the redneck version Jim?
Title: Re: How To.....squaring axle housing.
Post by: Matt08 on June 19, 2019, 05:29:12 pm
When measureing from the front shock towers back to the rear end with the tool clamped to the frame wouldn?t the rf wheel be sticking out further then the rr making a stright measurement not possibull ?
Title: Re: How To.....squaring axle housing.
Post by: justfreaky on June 19, 2019, 08:13:29 pm
Measure across the center of the wheel. Camber can certainly make the tire stick out farther (top or bottom). Here is a n easy explanation on caster, camber and toe. http://yospeed.com/wheel-alignment-explained-camber-caster-toe/
Hope that helps you.

Steve