TR4/4A TR4 steering rack

[BRSLimited]

Anyone know what the difference is between the TR4 and 4A steering rack? They both mount the same way starting after CT20064 but the catalog still shows a different part number. However quick ratio racks available show for 4 and 4A. Are they interchangeable?

 

[TR4nut]

I believe its a slight difference in the geometry. The 4A front suspension is the same as the TR6, with camber adjustment on the lower arms. I've not compared them directly, but on the steering racks the inner tie rods are different lengths (can't recall which ones are longer). Looking at Revington's site and comparing numbers both cars used the same rack portion so the inner tie rods are likely the only difference.


ps. addition: the above comparison is for late TR4s compared to TR4As only - the early TR4 had a different rack, I think it was actually a quicker ratio than what the later TR4 had.

 

[HerronScott]

Comparing the SPC's I think Randy hit the main difference which is the inner tie rod ("ball joint" assembly. On the rack itself, the only part difference is the spring under the cap. On the inner tie rods, the only part differences are the rod itself ("ball pin") and a lock nut.

Scott