Ask the tech if this trans has a ratcheting sprang, was one of ford better ideas on the 01 4r100's, Best to change the related hard parts to the less feeble hard parts used before and after the period of use. MFG dates were mid to late 2000 to early 2001. about an 8 month period. Make sure the builder uses all the trans go updates. Makes for a long lived HEALTHY trans under most normal conditions. I know this first hand. Went through mine and had these mods done and several others before I murdered mine at84 k. 1500.00 in up grades. Hope these guys know what s going on. 3500.00 For a Brian's trans. be tuff to beat. My buddy has one in his 02, and he can break an anvil with a feather duster!!!