The newbie and his TH400

Everything from the motor to the wheels

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krazyhorse1
Posts: 54
Joined: Thu Oct 23, 2008 9:13 pm

Re: The newbie and his TH400

#16 Post by krazyhorse1 » Wed Apr 08, 2009 8:35 pm

here are the check ball locations.
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th400checkballs.jpg

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wikd69
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Location: Rocklin, CA
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Re: The newbie and his TH400

#17 Post by wikd69 » Thu Apr 09, 2009 12:36 am

krazyhorse1 wrote:well wicked you are in for a surprise there is really nothing to building one. i do suggest you use the coan piece. there should only be five check balls when you pull it apart. oem there are six but you take the one out for third so you get more flow to hold it from slipping. i will find you you a diagram for the placement of the check balls. i would recomend you completely take apart your valve body to clean and check for galling of the slide valves and for excess wear. if it is wore out you could either replace or repair with bushings I.E. machine work. if you need anything new i would go with hughes stuff. for what it is worth i would go ahead and replace the clutches while your in there so you dont have to go back to soon. also take your pump apart and inspect it also mostly for trash and galling of the gears. oh yeah in case you want to know you are breaking case lugs because you have to much line pressure. you need to limit it to about 150 to 175. tci is notorious for to much line pressure. not that you want to but tci has a great rebuild book that is a copy of the gm original. tons of pics.
Thanks for the info :)

I've been considering whether or not to do the rebuild myself, but I've never been inside one of these automatics before. I'll do some more research on it before I decide.

And on pressure: The dyno tag I got with my last TCI trans showed 255 psi constant line pressure, a bit over the top. To be fair to TCI, this trans is supposed to be an all out competition unit and isn't intended for street use. We ended up toning it down a bit, dropping pressure down to around 190 or 200 - it still hits hard but doesn't hurt your neck or break the back tires loose when I bang second gear in traffic anymore :mrgreen:
1969 ProStreet Camaro RS Best 9.75@139 1.46 60'
Blown 427 BBC, TH400 w/Brake, Back-Half Ladderbar
Narrowed 12-Bolt, 4.10 Gears, Spool, Moser 33 Spline

http://www.marsh-racing.com/harrys_camaro-1.htm

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krazyhorse1
Posts: 54
Joined: Thu Oct 23, 2008 9:13 pm

Re: The newbie and his TH400

#18 Post by krazyhorse1 » Thu Apr 09, 2009 7:21 pm

that is a better pressure but i would still back it down on a 400. ive never had trouble with 150-175 even in the highest horse power all out comp cars and trucks.

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