Welding on rear LCA brackets

[fordsbyjay]

When I install my Griggs T/A LCA brackets do I install them perpendicular to the housing face and then adjust my Pinion angle by adjusting the length of the LCA?? According to Bruce (@Griggs) I want to have a 0° pinion angle. I have never used a T/A before so I am having a hard time seeing this action in my head. Now that I think about it the T/A to the housing is what would make up your pinion angle. Now I am really confused...:confused:

[fordsbyjay]

In case anyone is not familiar with their setup I figured I would post a couple FILE pictures I have. This is not my car but pictures I have found while researching Griggs setup.

https://static1.pt-content.com/images/pt/2010/01/RearSuspensionviewfrombackofcar-1.jpg

https://static1.pt-content.com/images/pt/2010/03/griggs9wattslink-1.jpg

https://static1.pt-content.com/images/pt/2010/03/RearCoilOver-1.jpg

[BMR Tech]

When I install my Griggs T/A LCA brackets do I install them perpendicular to the housing face and then adjust my Pinion angle by adjusting the length of the LCA?? According to Bruce (@Griggs) I want to have a 0° pinion angle. I have never used a T/A before so I am having a hard time seeing this action in my head. Now that I think about it the T/A to the housing is what would make up your pinion angle. Now I am really confused...:confused:

We have a lot of experience in torque arm design and setup but I don't see any features in their design that would permit pinion angle adjustment after the installation. Typically you would adjust pinion angle via the torque arm with an adjuster or shims. It's hard to tell with these pictures, is their any form of adjustment at the front mount of the torque arm?

[DRJDVM's '69]

If you adjust the length of the LCA, wont that change the pinion?
Interesting set-up.....

[MrQuick]

If you adjust the length of the LCA, wont that change the pinion?
Interesting set-up.....
Hey Ned,

Not on that set up, that would only change toe/axle alignment if adjusted unevenly. The torque arm is mounted to the diff and there is a bushing up front. You will see very little if no climb.


vince

[fordsbyjay]

We have a lot of experience in torque arm design and setup but I don't see any features in their design that would permit pinion angle adjustment after the installation. Typically you would adjust pinion angle via the torque arm with an adjuster or shims. It's hard to tell with these pictures, is their any form of adjustment at the front mount of the torque arm?

Sorry I should have posted a picture of the front mount. The use a rubber bushing to allow for axle rotation.


https://static1.pt-content.com/images/pt/2010/03/TACrossmember-1.jpg

The way I understood it you set the pinion angle upon installation and do not change it after.

[fordsbyjay]

So are far as I can tell the LCA bracket location is really not that important. The placement would be more a factor of LCA length and mounting position.

What started this thread was I was trying to figure out the installation steps necessary.

1. I will need to mock it all up, see where the LCA is and make sure it is parallel to the ground.

2. Set the pinion angle to zero degrees.

3. Set the T/A in place to figure out where the housing tabs and x-member need to be located.

[funcars]

Not exactly an answer to your question but I would use some stock car bolt-on coilover/LC mounts that you bolt onto your axle tubes and tack weld in a couple of spots. It results in less distortion of the axle tubes because you don't have to put so much heat into them. Port city racing has some nicely made ones for reasonable cost and Coleman has them too. Doesn't help with the piniion angle question though.

Give Griggs a call and ask them what they typically do when they install to get the angle right. Seems to me that you need to place the cross support bar at the right height to get the right pinion angle. You might be able to fabricate an adjustable front mount to give you some adjustment - multiple height locations?

Good luck

[silver69camaro]

Sorry I should have posted a picture of the front mount. The use a rubber bushing to allow for axle rotation.


https://static1.pt-content.com/images/pt/2010/03/TACrossmember-1.jpg

The way I understood it you set the pinion angle upon installation and do not change it after.

The lower cap on that torque arm looks like a series of spot welds...are they all like that?

[fordsbyjay]

Not exactly an answer to your question but I would use some stock car bolt-on coilover/LC mounts that you bolt onto your axle tubes and tack weld in a couple of spots. It results in less distortion of the axle tubes because you don't have to put so much heat into them. Port city racing has some nicely made ones for reasonable cost and Coleman has them too. Doesn't help with the piniion angle question though.

Give Griggs a call and ask them what they typically do when they install to get the angle right. Seems to me that you need to place the cross support bar at the right height to get the right pinion angle. You might be able to fabricate an adjustable front mount to give you some adjustment - multiple height locations?

Good luck

I'll check into those mounts. I believe the basic premise for Griggs kit are to be relatively a bolt on deal with little welding so they make their LCA brackets that way to weld on the bottom of the bracket that would normally sit on the leaf spring.