11 replies to this topic

[William Keeling]

Does anyone sell rack shims yet?

If not, does anyone have NA subframe that they could measure for me. I need the dimensions of rack mounting surface and bolt hole location (relative to the shim dimensions and bolt center to center).

[Qik Nip]

Does anyone sell rack shims yet?

If not, does anyone have NA subframe that they could measure for me. I need the dimensions of rack mounting surface and bolt hole location (relative to the shim dimensions and bolt center to center).

Wilie:
I have a NA sub frame I can measure, but I'm unsure exactly what to measure. Are you asking for the hole spacing, the distance center to center of them or what? Also, can you enlighten me as to what the shimming modification is and what it accomplishes? Thanks.
Rick

[William Keeling]

Wilie:
I have a NA sub frame I can measure, but I'm unsure exactly what to measure. Are you asking for the hole spacing, the distance center to center of them or what? Also, can you enlighten me as to what the shimming modification is and what it accomplishes? Thanks.
Rick

all -- the hole spacing (center to center), how big I should make the shim (the size of the flat of the subframe) and the location of the holes in the shim (the size of the flat of the subframe)

[Qik Nip]

all -- the hole spacing (center to center), how big I should make the shim (the size of the flat of the subframe) and the location of the holes in the shim (the size of the flat of the subframe)

Willie:
I'll try to measure it tonight.

Anyone out there who can explain the rack shimming idea and what it accomplishes? I am assumimg that if the rack is elevated (relative to it's current relationship to the sub frame) that toe out under hard braking is lessened? Is that the goal?
Rick

[Colin MacLean]

Willie:
I'll try to measure it tonight.

Anyone out there who can explain the rack shimming idea and what it accomplishes? I am assumimg that if the rack is elevated (relative to it's current relationship to the sub frame) that toe out under hard braking is lessened? Is that the goal?
Rick

It fixes the bump-steer issue. At rest you want your tie-rods parallel to the ground not at a sharp angle like they are in 'most' SM's. The r package tie rod ends help but this is the better solution.

[dmathias]

There has been some debate on that "Classified" website whether shimming improves or exacerbates the problem.

[Qik Nip]

It fixes the bump-steer issue. At rest you want your tie-rods parallel to the ground not at a sharp angle like they are in 'most' SM's. The r package tie rod ends help but this is the better solution.

Colin:
Does anyone sell a ready to use shim kit?
Rick

[Bench Racer]

Willie, put my boots on, shoveled my way behind the garage, sweep the snow off the 1990 front subframe & measured the power steering threaded mounting hole locations.

If you were to make a pad 1 inch wide by 4 1/8 inch long with one hole 1/2 inch from one end & the hole centers 3 1/8 inch you would be in fat city. Make the holes 7/16 inch diameter to cover any error I made in measuring the hole centers.

For my 2 cents worth Longacre has a great article on bump steer including an illustration.

[Qik Nip]

Willie, put my boots on, shoveled my way behind the garage, sweep the snow off the 1990 front subframe & measured the power steering threaded mounting hole locations.

If you were to make a pad 1 inch wide by 4 1/8 inch long with one hole 1/2 inch from one end & the hole centers 3 1/8 inch you would be in fat city. Make the holes 7/16 inch diameter to cover any error I made in measuring the hole centers.

For my 2 cents worth Longacre has a great article on bump steer including an illustration.

Anybody got a feel for the thickness to use for the pad?
Rick

[Qik Nip]

For my 2 cents worth Longacre has a great article on bump steer including an illustration.

David:
Thanks for the Longacre tip. It explains everthing!
Rick

[Astro]

Is anyone selling a shim kit yet?

[Qik Nip]

Is anyone selling a shim kit yet?

Don't waste your money. Remove one of the collars that secure the rack to the sub-frame and use it to space the holes you need to drill in the 1/4" thick by 1" wide strap steel. Use two layers (and get four longer bolts).
Rick