my 66 riviera has the st400 transmission and i was wondering if the pump out of a th400 would work in the st400. if not were can iget a pump for this trans. thanks for youre help.mike
Is it a switch pitch transmission? I believe the ST400 is just Buick's name for the THM400, so yes. But Buick had a switch pitch ST400 from 65-67, and the pump and input shaft is different than the fixed pitch 400's. Here is a thread with pictures showing the differences between the fixed pitch and switch pitch input shafts. http://www.v8buick.com/showthread.php?143723-VP-converter-Trans-visual-ID-guide
The 65-67 Olds & Cad pumps & torque converters will directly interchange. Anything else is fixed pitch. It is possible to swap a complete set from a 68 on (or earlier Chev/Pont) and convert your trans to fixed pitch, but you will give up some real & potential performance. Rebuild shops have been known to do this, watch out. What is wrong with your present pump? Bruce Roe
Sorry about the hijack. So the pump itself between switch pitch and a switch pitch tranny are different? What other parts besides the convertor and input shaft are not the same? Im getting ready to have my SP400 rebuilt and want to make sure the rebuild guy knows what he is doing. Brandon
Unique items for the variable pitch transmissions: Torque converter Input shaft Front pump (with stator solenoid and wiring attached) Dual prong case electrical connector Trans case restricting orifice plug at the 7 o'clock position behind the front pump Devon
I ju st got this car and I dont know much about it.the transmision started makeing a whining sound and its not wanting to go in to gear. I thought the pump was going out but was wrong.I was told it could be cavitating if it was rebuilt wrong. now im just trying to find out as much information about this car as I can.
Make sure the filter isn't plugged, and fluid level is up. The switch pitch use a different filter & pan (heel print), but can be converted to the common later setup. If the trans has never been rebuilt, its waaaay overdue for new soft (rubber seal) parts, though the rest might be fine. A bad clutch pack seal could lose pressure and fail to engage properly; maybe even burn up & ruin the trans. Bruce Roe
Great transmission, worth every penny you might spend on it! Get the level where it needs to be and re-check. Dont let anybody talk you into replacing it with a regular TH400! I had problems when I put my ST300 back together because i didnt use a gasket between the case and valve body plate (long story) and it would lose line pressure there. Something to check if it comes out.
There's only a few things you can do. Make sure that the vacuum modulator is good, it has a a leak free source of manifold vacuum. Take the pan down, and make sure the filter is connected properly, and the pick up tube is inserted into the valve body. I certainly wouldn't jump to the conclusion that it was rebuilt wrong.
where can i get a pic of how the filter and pickup tube are supposed to look? ---------- Post added at 12:32 PM ---------- Previous post was at 12:08 PM ---------- i would like to find some detailed pics of this car so ican make it right.
Serious about keeping and working on your car? If you are, the very first thing you should buy is the factory service manual. THAT IS THE BIBLE FOR YOUR CAR. Pictures, and how to do ALL SERVICE on your car. It is a must have. Here it is on CD ROM, http://www.gearheadcafe.com/servlet/the-508/1966-Buick-shop-manual,repair/Detail Here is a reprint manual on E Bay, http://www.ebay.com/itm/1966-Buick-...anuals_Literature&hash=item53edaf3f3a&vxp=mtr The stock switch pitch transmission filter is different than the 68 and up filter. The pick up tube pushes in to the valve body and has an O ring seal. If you drop the pan, it will be very obvious whether it is in the valve body, or just hanging out. Be careful when you drop the pan. You could get a Dexron shampoo. http://www.buickperformanceclub.com/switchpitch.htm
