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To start I have A 78 f100, 320 horse 302. I have had my trans rebuilt twice by a friend. Each time when I got it back it would really slip bad when going from second to third. It also slips bad in reverse. I have a 2600 rpm converter in it so that could possibly be the slipping in reverse, I dont know. It has a b&m transpack kit with the street/strip option. I also have a c6 off of a 390 for parts. The first to second shift is not hard when it shifts unless I take my foot off of the pedal. I really want hard shifts even when I have my foot all the way too the floorboard! Do I need to get a 2-3 super servo? I recently bought a Fairbanks trans action kit but have not put it in. I do almost all of the work on my truck but I know nothing 'bout transmissions so I am going to have a pro do it this time!
By the way, if it helps, it doesnt slip after it gets into third it only slips when it shifts.
Also I had to modify my kickdown rod. My carb sits about 2" higher than stock so I cut the kickdown rod and lengthened it 2".
One last thing, I manually shift it because If I stick it in drive it shifts realy fast. Thanks for any help
Matt
I am guessing that the problem is with the Reverse-High clutch. Either the seals on the piston are leaking or the clutch plates are worn out and slipping. If you find out that there are only 3 friction disks in the pack, you can have your drum machined for a second snap-ring groove to allow for 5. This will give you more torque capacity, longer life, and harder 2-3 shift.
The servo only affects the holding power of the intermediate band which gives 2nd gear. Therefore, goung to a high performance servo piston will only make the 1-2 up shift and 3-2 down shift harder. It will have little affect on 2-3 upshift.
If the torque converter was failing, it would have an affect on all gears.
I think one problem you may have is the kickdown rod adjustment and maybe even it's geometry. If it isn't functioning you would get early shifts, at least the 2/3 one.
1977 Ford F-100
400m/c6/4:11/Gear Vender O.D.
Crane hydralic roller, forged, ported polished,Deamon,Edlebrock, yada, yada, yada
280,000 miles
Stock on the outside
modified/rebuilt everything