hey all. I noticed when I put my trans into 'D' instead of 'O/D', it seems to shift alot tighter & take off harder. I know I lose the overdrive, but I usually just shift into O/D when i hit the freeway or longer runs when there's no red lites/stops/traffic for awhile. Does 'D' bypass the tcc also? Whats the difference between just leaving it in 'D' & wiring up a lockup switch? Thanx

 

The lock-up doesn't care if it's in D or OD--it will usually lock in either one, in some cases even 2nd. So, a lock-up switch is completely different than keeping it in D. I 'think' D offers a little more line pressure than OD, giving you a little better shift.