What to do next with tranny??

87gnblackdemon

Don't Be Redikulas!!
Joined
May 24, 2001
Decided to investigate trans shifting problem. So we drained fluid figuring we'd have some evidence of the problem, well this trans is as cleans as you can get, no signs of anything. I have a postons street/strip shift kit that I've been wanting to put in, I've been hesitant becuase I had the instruction faxed to me and the illustrations aren't all that great, replacing the springs doesn't sound too hard, but when it gets to removing some parts, the pictures don't help much. My dad feels with the condition the trans looks to be in, that we just replace filter, and gasket and put back together, then adjust throttle cable and see how that affects the shifts. Should I leave it alone? Will I benifit from using the shift kit in the long run? Also, in the shift kit instructions it says to not install check ball #1 and #5 if using a 9" converter, what is the stock converter??
 
I sent postons an email asking to have the instructions mailed to me. I do have a video that shows a few mods to do to a gn to run 12's, nice detialed video, pretty old though. And they take you through the steps of installing an art carr shift kit, very close to the kit I have. In postons instructions in section B, they have four steps:

1.Locate TV Valve, bushing #45, and plunger #44. Remove the roll pin #42 from the rough casting side of vlave body. Remove throttle valve plunger bushing #45 and throttle valve plunger #44. Discard throttle spring #43 and replace with new larger green spring. Reinstall

2. Line Bias Valve Assembly
Remove retaining pin #2, aluminum plug #18, line bias valve #32 and line bias valve #31. Discard sping and replace with red spring. Reassemble

3. Upshift Valve Assembly
Remove retaing pin#2, plug #18, MTV upshift valve #36 and spring #35 Discard spring, reinstall without spring.

4. Buick Grand National And T-Type Only
Locate 2-3 shift valve train. Remove retaining pin #2, 2-3 throttle valve bushing #3, spring #4 and 2-3 throttle valve #5. Discard spring and replace with small green spring. Reinstall

Does all of this sound right? Do I do all four steps or just number 4? Also, what size is the stock converter?
 
DO NOT DO STEPS 1 Or 4. If you do, you will be sorry.
Other than that... Fine... and TC is a 12" converter..
 
There really is nothing inherently wrong with the calibration of the BRF valve body. Modifications that merely serve to alter the calibration usually do more harm than good. That is what's wrong with steps 1 & 4.

As for 2 & 3 well, you'll find the Hydramatic already took care of #3 (BRF didn't have that spring) so that leaves you with #2. A stiffer line bias spring is a good idea. You can do that if you'd like. :p
 
Seems like a waste of time then to just do step 2. Now how about the rest of the instructions: In the 1-2 accumulator housing you will find a hole in the casting, take 1/4" drill and enlarge hole inhousing.Tap 5/16-18 and install cup plug making sure cup plug is recessed at least 1/16 below surface of housing.Reinstall.Then it says to drill three 1/8 holes in the new plate. It says not to install check ball number 1 and 5, 1 is the 4th accumulator cast check ball and 5 is the tv exhasut cast check ball. Should I bother doing any of this?? Should I just buy a different shift kit??
 
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