First off, I have no history on this C4 trans, got it from a donor car, never seen it perform.....I am putting a TCI Pro Super rebuild kit in it ( '67 C4 trans). Included is a shift kit for the valve body. Part of that mod is to drill a 1/16 in hole in the seperator plate, at a designated area. Well, I split the valve body as part of the shift mod and am looking for the location where they want me to drill the 1/16in hole. Low and behold, someone has previously beat me to it! BUT, the hole is 3/16 in, instead of the 1/16 that I am suppose to drill. Question is what will be be the result of a hole that big being in there, compared to the hole called out by Summit and TCI? Anyone familiar with all this, This is only my second automatic trans job in all my life, and I am reluctant to just call it done with a hole 3 times the called out size.
Good question......according to my calculations (area of a circle is pi r squared) while the diameter of the existing hole is 3 times that specifed, the area is 9 times greater. If flow rate is important, you certainly will have increased that. Ray
What ever the increased flow is supposed to do it will be a hell of a lot more. If it is to improve the shift it should really slam it in there.
I recently did my '68 C4 with a Transgo stage II kit. Sorry I have no answer for you, but I do know that '67-'69 valve bodies (and separator plates) are pretty hard to come by (read expen$ive), so if I were you I'd run it and see how it performs. I don't think you can hurt anything, but your shifts may be a bit harsh.
Is it a drilled hole or a factory hole? And is the kit meant for a '67 C4, because pre '70 and '70 and up C4 valve body's are different.
My kit is from Summit and is for a 67-69, so I gotts assume it is correct. The hole that is in it is def a drilled hole. It is in the correct spot, just way big!
I am going to agree with Mike51Merc, as to the hard to find part and I have decided that since I can change it without a trans pull, at a later time, to just go with it and see what happens. It will just add to the excitement of the initial startup and drive !
Is it possible to have the hole spot welded and redrilled or a flat rivet installed and drilled? I realize the seperator plate has to be very flat and smooth surface to seal properly, but I don't know how much 'free area' you have surrounding the hole location. Just a thought and probably worth what it cost.......zippo! Ray
I thought that for a while, but it is just too thin to fill it and try to redrill and flatten it. This particular valve body does not use any type of paper gasket, metal to metal!
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