Four Link Adjustments

[Mr. Fixit]

Rick,

The framework is for the beginning of my new metal body that I am calling a T Boy. It will be a combination of a modified t-bucket, and a a 32 high boy. I like both designs and want a trunk to keep my beer cold on the way home. LOL

I really don't have any drawings, but I am happy ot make them for others as I get further along. I recently built a great heavy duty ring roller and pneumatic/hydraulic pipe bender that I am using for the project. If anyone has an interest in these items, I can provide reference material for those that are machinery saavy.

Thanks,

Steve

 

[Mr. Fixit]

Believe it or not, that's exactly what I did when I thought I was posting them. I will try it again with progress photos of the body when I get a bit further along.

Thanks.

 

[fluidfloyd]

Mr. Fixit

I recently built a great heavy duty ring roller and pneumatic/hydraulic pipe bender that I am using for the project. If anyone has an interest in these items, I can provide reference material for those that are machinery saavy.

Thanks,

Steve

Steve,

Welcome to the forum.

Perhaps you could put that information in the technical section. I know a lot of people would be interested in both the bender and the ring roller. I have a Hossfeld Hydraulic tube bender and I have all of it in auto cad so I guess I need to post it. I have thought about a ring/tube roller but really haven't had the need for one but you never can tell. Thanks for the offer.

George

 

[Mr. Fixit]

George,

Thanks for the suggestion to post the bender photos in the technical section. I will be doing that soon.

Mr. Fixit

 

[fluidfloyd]

Mr. Fixit,

I'll be looking for them. I don't know if you have a cad drawing program or not but if not and you want some help then please let me know. Right now my days are pretty crowded but I'm usually drawing late most nights. Just let me know.

George
prodesigns1@yahoo.com

 

[old round fart]

Rick, I tried your method and this is what I got. Where did I go wrong? I'm running VISTA is that the probiem?
http://i296.photobucket.com/albums/mm193/oldroundfart/Scan_1.jpg

 

[Rick]

I'm not sure i dont know anything about Vista.Sorry

 

[Mr. Fixit]

I wish that I was versed in CAD, but I'm not. I have very little experience drawing that way and usually wind up with a pencil, scale rulers, squares, triangles, etc to get it accomplished. I would be thrilled to get the ring roller on CAD for others to build from though. Any help would be welcome.

Thanks,

Mr. Fixit

 

[fluidfloyd]

Thanks,

Mr. Fixit

Mr. Fixit,

Just let me know when you want to do it. I'm in!

George
prodesigns1@yahoo.com

 

[Mr. Fixit]

Jim,

I have review the link, set up everything as prescribed with tape, strings (front and rear) and the results were as follows. The front revealed a dimensional toe out of 1/8". When measuring between the front and rear strings, I get the same dimension at both the front of the tire, and the 2' mark in front of the tire on both sides. However, the dimensions vary from one side to the other by over 2", meaning that the rear is offset by about one inch. Do you or anyone know if this is an issue?

The rear axle, or the inside sidewall of the rear tires measures the same distance from the chassis on both the left and right sides. This being the same resolves my body alignment concerns as I build the new body, but I am not clear if the dimensional difference as compared to the front (offset) is any thing to fret over. Thoughts???

The

This may be of some help to you.

NTBA

Jim

 

[Ted Brown]

If the rear end is out of square as far as the front goes, maybe it is the front end that is off?? use that info that George sent you to check that out, that should tell you what is off... You don't want it walking like John Wayne... hehe

 

[Mr. Fixit]

Thanks for the idea, but that doesn's seem possible since the leaf spring (which is centered) determines the center of the entire front end, correct? The spring would need to move about 1" in order to correct this. I just checked the rear end and took some measurements and believe that I see the cause. The rear end housing/shaft on the passenger side appears to be about 1 1/5" longer than the other side. Rear ends (at least the ones on cars) are uncharted terratory for me, so I am not sure what is normal/standard as far as equality of each shaft end length.

Any help would be much appreciated.

Here are a few photos of the alignment set up with dimensions.

Thanks,

Mr. Fixit

 

[fluidfloyd]

Mr. Fixit'

Just looking at the rearend pictures it appears that you have an OEM widthe (uncut or narrowed) 9' Ford. if the inside tire to frame rail dimenions are the same left to right then the rearend should be correct. Check the frame and make sure it is square. Check the angles of the upper control links in relation to the frame rails. If you have some known reference mid to front on the frame and it measures back to the axle housing the same on both sides then your rearend should be good.

If that checks out good then measure forward from the rear housing to the front axle and make sure they are parallel. Then start the process over with the fronend assembly. I think you said you had toe out and I feel it needs to be toe in.

One other thing, anyone that is planning to build the body that you have in mind will be able to get this alignment problem worked out. Hope this helps you.

George

 

[Mr. Fixit]

George,

Thanks for the suggestions. I have checked some of these things, but will proceed with some of the other measurements as you have suggested as well. As for the building the body comment, thanks for the vote of confidence. I will post some progress photos of that work on the body forum under "t-boy" later today.

Mr. Fixit

 

[Mr. Fixit]

George,

One other thing. On the stock OEM rear end, do you know if the axle length is the same on bot sides? As I had mentioned, the housing/axle appears to be about 1 1/2" longer on the passenger side of the rear.

Thanks,

Mr. Fixit

 

[fluidfloyd]

Mr. Fixit

One other thing. On the stock OEM rear end, do you know if the axle length is the same on bot sides? As I had mentioned, the housing/axle appears to be about 1 1/2" longer on the passenger side of the rear.

If the housing has never been narrowed then most of the time one side will be longer as measured from the pinion centerline. That number varied on 9" Fords depending on what it came out of. I hve seen some vans and 4 wheel drive trucks that had a lot of pinion offset. I have an 8" Ford out of a '66 Cougar here in the shop and it has a centered pinion. The GM 10 & 12 olts from the earlier years all had a 1.0" offset that allowed both axles to be the same length. The 9" Fords didn't really seem to have any reasoning as to what they came in or offset. On very short driveshaft cars you need to have about a 1.0" to zero offset. Just enought to let the u-joints work all the bearings equally. Drag race guys want zero offset or pinion center as they want minimum frictional loss through the driveline. Just from looking at your pictures I would think you're looking good. Hope this helps you out.

George

 

[Mr. Fixit]

George,

This does help a lot, I appreciate it.

I decided to start from scratch with the alignment set up, etc. As per the details that others had sent the other day, I loosened the upper right link completely, used the bottom links to set the track and alignment with the strings pulled up front, and now have the rear set dimensionally equal and parallel to the front.

Now that this was done, I tried to set the pinion angle using a digital protractor and turning the upper left link with the right link loosened/removed as instructed. It seems that all I am accomplishing by doing this is to shift the chassis/body further to one side and off center.

This is giving me dane brammage :lol:. LOL

Thanks again,

Mr. Fixit

 

[Ted Brown]

Take some pics from the top to show all the rear suspension at once, can't really say much till it is seen, as to why it is doing what you say it is.... :lol:

 

[fluidfloyd]

Mr. Fixit; George,

This does help a lot, I appreciate it.

I decided to start from scratch with the alignment set up, etc. As per the details that others had sent the other day, I loosened the upper right link completely, used the bottom links to set the track and alignment with the strings pulled up front, and now have the rear set dimensionally equal and parallel to the front.

Now that this was done, I tried to set the pinion angle using a digital protractor and turning the upper left link with the right link loosened/removed as instructed. It seems that all I am accomplishing by doing this is to shift the chassis/body further to one side and off center.

This is giving me dane brammage :lol:. LOL

Thanks again,

Mr. Fixit

You are on the right track but I think you got one piece of misinformation. Go ahead with setting the lower links. Then remove the one upper and set your pinion angle. If the rearend is still correct left to right then adjust your removed upper link untill the bolts float in. Do Not put any preload in either upper link. This is really a drag race trick to counter starting line torque. Those 4 links are not angled or triangulated. They are concerned only with leaving straight. Most of their torque roll is controlled with a very still anti-roll bar system and then they fine tune it with some preload adustments. These adjustments are usually very small as in 1/2 to 1 turn. In a triangulated 4 link you force the rearend to move one way or the other as you shorten or lengthen that upper link. Just remember that when you adjust it you are either shortening or lengthening one side of a triangle. It has to move the rear housing. The triangled upper links are what center the rear housing to the frame. If you want to lead foot it from time to time then consider installing an anti-roll bar.

Ron at RPM told you right as to adjusting it but he races a 4 link truck so those adjustments are correct in that application. Hope this helps clear it up for you. Now my brain hurts but that's usually the case everyday.

George

 

[Mr. Fixit]

Mr. Fixit;

George,

This does help a lot, I appreciate it.

I decided to start from scratch with the alignment set up, etc. As per the details that others had sent the other day, I loosened the upper right link completely, used the bottom links to set the track and alignment with the strings pulled up front, and now have the rear set dimensionally equal and parallel to the front.

Now that this was done, I tried to set the pinion angle using a digital protractor and turning the upper left link with the right link loosened/removed as instructed. It seems that all I am accomplishing by doing this is to shift the chassis/body further to one side and off center.

This is giving me dane brammage :lol:. LOL

Thanks again,

Mr. Fixit

You are on the right track but I think you got one piece of misinformation. Go ahead with setting the lower links. Then remove the one upper and set your pinion angle. If the rearend is still correct left to right then adjust your removed upper link untill the bolts float in. Do Not put any preload in either upper link. This is really a drag race trick to counter starting line torque. Those 4 links are not angled or triangulated. They are concerned only with leaving straight. Most of their torque roll is controlled with a very still anti-roll bar system and then they fine tune it with some preload adustments. These adjustments are usually very small as in 1/2 to 1 turn. In a triangulated 4 link you force the rearend to move one way or the other as you shorten or lengthen that upper link. Just remember that when you adjust it you are either shortening or lengthening one side of a triangle. It has to move the rear housing. The triangled upper links are what center the rear housing to the frame. If you want to lead foot it from time to time then consider installing an anti-roll bar.

Ron at RPM told you right as to adjusting it but he races a 4 link truck so those adjustments are correct in that application. Hope this helps clear it up for you. Now my brain hurts but that's usually the case everyday.

George

George,

I hate to say that I am a bit confused with one thing that you mentioned.
You state to "remove the one upper and set your pinion angle". You also said "DO NOT preload either of the uppers". Ok, my confusion is how then do you set the pinion angle without and load on either of the uppers?

When I try to set the pinion angle with the left upper, I am putting quite a bit of load on it and only seem to shift the chassis off center.

Please let me know when you are tired of me.

Thanks,

Mr. Fixit