OK so here is the deal, I have a 66 Riviera with the TH400 in it, from waht I understand is that these trannys had a specian feature where it is the SP and it has two pitches. one for performance and one for crusing. On the linkage I have done electrical testing and it works the same as another one I have so the electrics should be fine and it is plugged into the tranny. It doesn't make a difference if the converter switch on the linkage is even on the car, under any circumstance. My dad said that it did used to work but he has no idea what happened. I have another TH400 sitting in my garage. so is it the actual tourqe converter or the tranny or what? any ideas?
The switch pitch is controlled by a solenoid in the tranny, activated by the switch on the throttle linkage you mentioned. Try applying 12 volts to the wire for the s/p and listen for it to click. I've heard the wire inside the trans can go bad. There is a solenoid for the downshift function too. Good luck... Frank
OK well it clicks on one of the wires that goes down and it doesn't on the other so what do you think?
You should hear a click when you apply power to either terminal on the side of the trans. One is for the detent/downshift and the other is the SP. Those are tough to set up correctly if you don't have a service manual......in your above post did you say the linkage with the switches is missing? If so, you need that, if not, they may be out of adjustment. I have attached the page from my book that describes how to do it, although it's hard to read. I don't know how to make it show up clearer. If one is not clicking as you stated, it may just be sludged up. I'll bet if one is dirty it is not the SP but the other one, b/c the SP solenoid is up high where the sediment can't settle. You'd have to take it apart to clean it out or replace it. And good luck finding a tranny shop that even knows what a SP in a Buick even is. ou: The wires inside the tranny usually dry out and get brittle, but in order to break off someone would have to have gone in there and done it physically. There are other threads on this site under "the juicebox" about this adjustment proceedure perhaps you should try doing a search......you may come across more info. Larry70GS has posted a lot in the past on this subject. I think the blade on the plug on the side of the tranny that runs vertically is for the SP. I hope my info helps you. :bglasses:
well what I ment is that I have the linkage and the switch on there works good, what I was saying is I know the SP isn't working becuase you can take the linkage switch off and it doesn't make a difference. When I am driving the downshift DOES work tho, so I am guessing that is the one that clicks? So do you know what it is? and is there anyway to get a better picture of that?
The connector on the side of the trans has two blades forming a T. The horizontal blade is the SP, the vertical blade, the kickdown. Apply 12 volts to the SP connection, you should get high stall, take the 12 volts away, low stall. Simple as that. You can run a 12 volt wire with a toggle switch to the SP connection. Idle the car in gear. Throw the switch, and the RPM's should increase as the converter goes to high stall. THe SP 400 has a different front pump, and input shaft, and of course the converter. The SP solenoid is located on the front pump, and the trans needs to be disassembled to replace it. If you aren't hearing a click from the SP solenoid, it could be a wiring problem, or it could be the solenoid. Drop the pan, and check the wiring. If you can't get the solenoid to click, you'll have to replace it.
Hi, I was just wondering if when you replaced the tranny that you also put the correct s/p torque converter on , not to be a smart a-- but.... some times mistakes can happen... or is it just me.. Good luck Ben
One easy way to find out if the solenoid is getting power is to lightly press on the accelerator pedal and release it (with the ignition switch in "lock" position) and listen at the noise made by the smaller switch mounted on the accelerator linkage (will make a click if working and correctly adjusted). This switch makes the torque converter switch to high stall when you aren't pressing on the accelerator pedal (mainly for a smoother idle in drive) and as soon as you touch the gas pedal, before the carb linkage even moves, the transmission sould switch to low stall. Then, turn the key to the accessory position and listen again, if the solenoid is geting power and working, you should hear the additional noise of the SP solenoid clicking at the same moment. Having the car parked in a quiet place near a concrete wall will help to hear the solenoid. If you hear the solenoid, start the car, brake with the left foot and shift to "Drive", gently press on the accelerator while braking, just enough to make the switch click (you probably won't hear it with the engine running but you'll know when it happens) and RPM should decrease as the stator gets in low stall. It should go faster when you release it (this is more noticeable as it happens less gradually) The larger switch mounted on the intake has two functions: It switches to high stall and then activates downshift near W.O.T. for added performance. I guess you should hear both solenoids clicking somewhere near the end of the pedal travel (I haven't tried this). Unlike the smaller switch, this one doesn't make clearly audible sounds by itself but the solenoids will do. If the solenoid fails to work but the rest seems OK, use a test light to see if current is going to both sides of the connector on the transmission.
You meant the "on" position.....turn key to the right. There's no power to the tranny in "acc". :bglasses:
I haven't tried it on the Riv but there is power to the transmission on "ACC" in my 65 Wildcat. Joe is certainly right, Rivs are wired differently so you might need to use the ON position to hear them... Today, I listened to the solenoid with the ignition switch in accessory position and I heard it clearly just with with the driver's door open.
Here is the prongs... This is from a 65 switch pitch I may be posting on ebay shortly... the prong going up and down is the kickdown, and the top one that looks like the top of the letter "T" is for the switch pitch.
OK so this weekend I tryed putting power directly on the tranny and it clicks and the wire does too, so the silonoid is clicking but the SP is not, I have another SP TH400 sitting there in teh garage, do you think I should just rebuild that one and put it in?
Sounds to me like some jacka$$ put the wrong converter in it.......I don't know how to tell one from the other, but if it's painted it's been replaced. Drop the converter pan and look at the converter to see. Many guys don't know what a SP is, and just don't know any better thinking all TH400's are the same. :bglasses:
OK, so the solenoid is clicking. Did you try putting the car in gear, and applying 12 volts to the trans directly. A stock fixed pitch converter will not fit on the switch pitch input shaft.
Ill try that larry, the transmission that is in there is the original and never rebuilt, my dad said it worked about 15 years ago but then suddenly just stopped working, like I said I also have another SP TH 400 off another 66 riv so that is an option as well
The only way to be sure is to go to an empty parking lot. Then get 2 long wires, connect one to the batt + and the other to the SP pin on the tranny. Then connect a tach to the motor, then press the brake pedal as hard as you can and floor it, taking note of the stall RPM. Then connect the wires together and do it again......the stall speed should be at least 400 rpm higher. This way you will know for sure........just be careful, it's hard to hold back all that torque without the tires cracking loose. :Brow:
I'd really be surprised if it wasn't working but I suppose anything is possible. If you're tranny isn't slipping and otherwise works well, I'd make sure first before taking a chance on another tranny that may not be any good. And you still have the option of fixing the one you have, it may be a bad converter but I haven't fixed enough of those to be able to guess the cause of the problem with any accuracy. In my own experience with my own car when mine wasn't working right it was always an electrical problem, those switches are very tempermental and tricky to get right. If you are going to fix it right you'll have to just figure out how it works and do it yourself. I posted a copy of the page in the book that explains how to do this last month in another thread in this "juicebox" forum.....if you search you can find it. It's clicking when you energize it so that's a good sign. Good luck finding a shop that knows how or even cares about a SP. If you are persistant you'll fix it. :bglasses:
