The .500 TV boost valve is an excellent suggestion. They are only like $12.50.
Grinding the land on the pressure regulator valve is good also. Early GM trannie's didn't circulate fluid out of the converter during lockup(from a tech doc by Sonnax), grinding off the land turns it into a fulltime lube system(later 93 3LHM trannies already had the modified valve in them).
Get the stiffer orange spring for the 1-2 accumulator($5)
Flip the the 3-4 accumulator piston. Basically put the spring in first and flip the piston over and put it back in.(Don't need to block it unless the pin in the center was leaking).
You HAVE to replace the forward sprag. Any unit with over 50K miles on it should have the forward sprag replaced no matter what condition it is in.
USE A BORG WARNER UNIT. It has a solid liner top and bottom and the extra "bones" to hold. It will have a gold or copper color to it.
I think Wes meant the overrun clutch piston. I'm sorry, Wes, if I mistated what you meant. The overrun clutch piston tends to blow the seal off on downshift when shift selector is in 3rd. Pressures are increased coupled with engine braking and a steep gear ratio make a hard 2-1 shift when coming to a stop or manually downshifting. Forward clutch piston seal does fail but just not NEARLY as often as the overrun clutch piston seal. Especially if you tow.
Dacco of Detroit sells the steel apply piston with a molded lip instead of a push on seal. It won't come off. The part number is #77762A. If you buy this piston you MUST also get part number 77736A. 77736A is a special spring and retainer setup just for this piston. When you get it apart you'll see why you need it. Get 77763A and 77764A. These are also steel pistons with the seals actually molded right to them. The seals will NEVER tear or blow off. 1997 and up 700s use them but they retro all the way to 82. Their number is 1-800-44-DACCO. See if you can find a local distributer. That way you can walk in and get what you need. They are very inexpensive insurance.
They are a Sonnax distributer also.
If you want a very firm TC clutch apply, you can take a flat head screwdriver, grind a notch in the side close to the tip and use it to reach into input shaft and pull the check ball and retainer out. The ATSG recommends this for HD application ONLY but the SYTY is a HD application. Cost $0
TC clutch apply will be VERY firm.
Get some JB weld(slow set stuff good to 600 degrees F) and seal up the air bleed hole in the input drum. Helps prevent 3-4 clutch burnups. Recommended by several local builders and Transonline(they are a pay site now).
Modify the oil drainback in the pump housing by drilling it out to 9/32". This is in the ATSG and EVERY local builder does it. Prevents blowing out the front seal by reducing back pressure.
Get the Beast sun gear reaction shell. The only difference I have seen between this and the stock 1997 sun gear shell is the rectangular "windows" aren't in line with the little tabs that stick up.
Get a shim or HD purple pump spring from Sonnax(or whoever you decide to buy from)for the pump slide. This holds the pump in the high flow position to increase lube flow. May have some additional "whine" in 1st gear when taking off but small price to pay for higher lube flow. At idle, my pump puts out just over a quart of tranny fluid ever 10 seconds. That's a lot. You want at least on quart every 20 secs at idle.
Let's see...put in the TekPak 700r4 reverse piston capsule. The part number is #77761C. Reduces the size of the orifice and eliminates reverse clutch burnout. You check them out at
www.teckpack-fitzall.com This is an ATSG recommendation.
Get rid of the TV check ball from the valvebody. If this checkball fails and sticks, you will burn up your tranny. This check ball stands out because it is larger than the rest. They are all 1/4" checkballs except for this one. If you lay the valve body out, there will be a "finger" kinda sticking out. There is a circular dish machined out to accept the large checkball. Don't put it back in there.
Delete the 5 takeup springs(sometimes called "load release" springs) from the input drum AND drill out the #44 hole in the valve body to .093" You must drill the #44 hole to provide more lube to pass on the 3rd and 4th gear changes. The 3rd and 4th release MUST happen quickly to prevent burnup. You'll notice a much firmer 2-3 if you do this. Don't worry. You're not gonna hurt the tranny. It just keeps from burning up the 3-4 clutches.
Much of this stuff is on
http://www.syty.huryde.com/html/Tech/mofotranny.htm
There is a big update coming on the tranny stuff for the site. Instead of making a bunch of little updates, I'm trying to make one big update. Especially since Transonline went to pay per view.
That's about all I can think of right now that is realatively inexpensive for what you are getting in return.
There is a LOT more you can do but this is the cheapest route and helps the tranny significantly. You MUST make sure your clearances are PERFECT on your clutch stacks or you'll burn up the tranny. You have to follow the directions on the ATSG perfectly of you will burn up your tranny. They are sensitive. If your rear driveshaft has mega miles on it like mine, you may want to replace it as well. When you tranny shifts firm up, a failing u-joint will reel its ugly head. Buzzing on acceleration. Very irritating.
