Hi All, After a 7 year build process I finally drove my project today. It is a ratrod with a 425 nailhead and st400 transmission. While I was super excited that it moved under its own power I have some issues I need help with: -First, what is the tube coming out the passenger side of the transmission and where should it go? It was blowing air/tranny fluid steam when the engine was running (see pic). -Second, I have no idea what is what on this transmission. I bought a shifter from a '65 Riviera to match the engine/tranny but it didn't seem to match. I've labeled the notches in the pic below 1-4. It seems #1 should be park, 2-3 forward drive of some sort and the #4 area reverse? When in #1 the car seemed to want to go backwards. In either 2 or 3 it went forward but not well (lurchy). The #4 area didn't seem to do anything. My thoughts are...the tube in my first question needs hooked up to something so that is making the transmission act odd, or the fluid is low ( I couldn't check because the engine RPM's started racing so I have to figure that out), or I have the shifting hooked up totally backwards to where my #1 is actually reverse and #4 area is park. Thoughts? I appreciate any help or direction. I built the car but am no expert in transmissions.
Nice ride. First.... is just a vent second...... Im no help. the ST400 is basically the same as a th400. PRND21. What makes it a ST is a 2 speed TC. With is operated by the Carburator linkage that has 2 switches.... That uses the 2nd prong on the kick down switch plug on the left side of the trans... th400 has 1 prong ST400 has 2 prongs.
Dig those headers! If it's a 1964 transmission, it differs from the 65-6. The 64 only has shifter detents for PRND and low. For 65-6, you can select PRND21. If the length of your shifter rod is properly adjusted: Location 1= Park 2 = Reverse 3 = (forward)=Neutral, (back) = Drive 4= 2 and 1 (65-6) or =low (1964)
Thank you both. -Good to know that is just a vent...it was really blowing, I'll put a hose on it and lead it out of the cab somewhere. -This tranny is a ST400 (one prong) vs the SP400 (two prongs). I have a "switch pitch" SP400 that I can put in if this ST400 is bad for some reason. -Good to know PRNDd or PRND21. My linkage is adjusted correctly...each detent for the tranny lever lines up with each notch in the shifter. -How do I tell if it is a 64 vs a 65-66 year? In the below pic the shifter is in position #1 which should be P and the lever on the tranny is straight up and down...is that the correct position for that lever for Park or is that the position for drive? That is the farthest forward position, the lever moves back from there.
Single prong would be on the 1964 model (No switch pitch converter). Check the tag on the trans, it should have an ID code and maybe a date stamp. This '64 trans only has shifter detents for Drive and Low, not Drive, 2 and 1. Both are 3 speed transmissions tho. The lever on the trans should point UP. With yours pointing DOWN, it reverses the shift pattern, assuming the rest of the shifter linkage is correct. Proper operation would put the trans in Park when the shifter shaft on the trans is rotated fully clockwise, in LOW when it's rotated fully counter clockwise. I think yours may be reversed?
Thank you wkillgs! Hopefully that is my problem. I got this engine/trans from a guy who was doing an LS swap into his riviera and I haven't touched the trans (besides mounting it) so that is the was the lever was.
Thanks! I wanted "medusa-y" looking headers and had to build my own cause nobody makes anything like it. I still have a lot to do on the car (blend the paint & rust, chop the doors and windshield, get glass, a few electrical issues, etc). But I'm thrilled the engine fired and to have it out of the garage for the first time ever!
On the passenger side of the transmission is a riveted tag, with letters and numbers. Post them. If fluid is coming out of the vent, the transmission is overfilled. The single electrical connection is the kick down. It should be used with a gas pedal activated switch to activate the kick down (passing gear). 12 volts causes a down shift. Constant 12 volts will cause a no shift condition.
To add to potential vent tube "burpage" causes, a leak or mis-fit at the filter o-rings may do it too, possibly allowing air into the inlet side of the pump and frothing it up. And regarding the filter, if you're not familiar with it, it's an odd duck for 1964-1967, you can see it here: https://store7079484.ecwid.com/1964-1967-TH400-Transmission-Oil-Filter-p69115832 It's possible to convert to the newer style pancake filter but it involves tapping an existing hole in the valve body for the new filter bolt, a TH400 filter pickup tube w/oring and maybe a newer TH400 pan (I'm trying to remember if the dimples in the newer TH400 pans play a role w/new filter). Devon
If you are unable to read the numbers in the tag it is: 330 BN 64 1044 so this must be a 64 for sure. My other 2 prong transmission has 66 so it must be a 66.
"The lever on the trans should point UP. With yours pointing DOWN, it reverses the shift pattern, assuming the rest of the shifter linkage is correct. Proper operation would put the trans in Park when the shifter shaft on the trans is rotated fully clockwise, in LOW when it's rotated fully counter clockwise. I think yours may be reversed?" After thinking about this, while my lever goes down my shifter pulls the lever which has the same pattern as if the lever went up and it was being pushed by the shifter so I *think* my pattern is correct. Also, when in park (or any position for that matter) I can push the car easily so "P" is not working.
The 1964 ST400 is a weird one. Found an older post I wrote explaining gear selector function and what the trans does. From 1965-'67, you get variable pitch plus PRND21 like we're used to these days. https://www.v8buick.com/index.php?threads/1964-wildcat-video-on-youtube.375963/#post-3285477 Devon
So the transmission is a 1964 BN. It came behind the 425 single 4 bbl and was used with a console shifter. The 66 transmission is likely a switch pitch. You can confirm that by looking at the input shaft and converter. https://www.v8buick.com/index.php?threads/vp-converter-trans-visual-id-guide.143723/
It does depend on the linkage on your shifter. If it's missing a lever it could reverse the pattern. There is a slot on the end of the shift shaft, that may be a better indicator of which gear it's in. Here's are some pics from the 66 chassis manual. I'd guess the 64 shifter is similar:
Good job on fabbing those. You can still get Sanderson "Twisters", but they are proud of them. https://www.centuryperformance.com/sanderson-twister-header-set-buick-nailhead.html
