55 Tranny Crossmember Interchangeability

[BuickCrazy]

I know the 55 Roadmaster and Super are larger on the outside than the Special and Century, but do all models share the same frame. More specifically, would a tranny cross member from a Century be the same as a tranny cross member from a Roadmaster?

Randy

[MrEarl]

all 1954-55 Buick Dynaflow transmission supports are the same

Edited March 1, 2011 by MrEarl
add Dynaflow (see edit history)

[BuickCrazy]

Mr. Earl

Thank you for yuor reply and assistance.

Randy

[Gene Brink]

Randy,

May be slightly different. My '55 shop manual shows the following:

40-60 series - measurement from centerline of holes in the side rail to center of transmission mount = 21 1/4"

50-70 series - measurement from centerline of holes in the side rail to center of transmission mount = 22"

Overall side rail to side rail (center of each) is 42 1/2 to 44" - 50-70 being larger. No measurement for the actual trans mount member but the drawing looks as though the mounts welded to the frame are identical on both frames which would mean the trans mount member would be slighter longer on the large series car. If you are looking to buy I'd suggest measuring to be certain what you buy matches the measurement on your frame.

[Bhigdog]

Parts book says one part # for all 54/55 dynaflow cars................Bob

[stealthbob]

Here are the frame dimensions.....

Large Body:

Small Body

The frame is different but the main cross member mount remains the same part.

My Roadmaster cross member is 17 3/4" FWIW

Edited March 3, 2011 by stealthbob (see edit history)