RPOL98

the ATSG 700R4 book recommends installing an orifice cup plug into the Reverse Input Piston. p. 85, figure 151.

Teckpak 77761C.

so i ordered a couple of these (about $8), since i'm already paying for shipping. the vendor didn't post a photo, but had the right description. it didn't mention that it comes in a 10-pack. so now i have oodles of them. lifetime supply. oh well.

it is a tiny little thing. the hole passes a #54 drill bit (0.550"), but not a #53 (0.595").

i think you could probably replicate the effect with a tap, a threaded set screw, red loctite, and a #54 drill. but at 80 cents a pop, hey.

the hard part was finding somebody who sells them, and getting it shipped to your door.











i'm going off of the 2004 edition of the ATSG THM 700R4 TechTran manual, 1987-1993 4L60.

Pro Built Automatics

I never use or offer the restrictors as they are not necessary. When the idea of the "feed/bleed" system came about, many thought that this was going to be a problematic clutch failure condition, it wasn't. If you are going to install the restrictor, then drill it out to .065". Past experience has shown that in transmissions going over apx. 5,000 rpm, (with the restrictor installed) the residual oil cannot leave the area behind the piston fast enough and this condition called centrifuge, causes the reverse/input clutches to lightly apply and this will cause the clutches to glaze, and over time reverse will become a problem. I replace the "belville" steel with a waved steel from the 1982 - 1986 transmission, and use the early reverse/input clutches (.080" thick) from 1982 - 1986 to get the correct clutch clearance. You can run thicker steels and/or change the pressure plate to get the desired clutch clearance if you do not want to change the original (.070" thick) clutches. Getting rid of the belville steel will stop it from tearing up the drum, as the waved steel does not do this. I never have reverse problems. I hope this helps.

RPOL98

thanks for the insights. as i had already installed the restrictor, i drilled it out to .067" (#51 next larger drill size). when i used the recommended 3/32" punch to install, i guess is swedged some material into the orifice, so i had to drill it out anyways to clean it up. of course, after that, i had to use half a can of Brakleen to flush out any drill shavings.

that wavy plate seems to be elusive. maybe you could offer that with the aforementioned 0.080" early clutches, etc as a package. seems you like already have an excellent "product description".


thank you for all the technical insights, very helpful, informative, and explanatory. much appreciated.