65 buick riviera kickdown switch

[bluesy66]

Working on a 64 rivi with 401 and a 65 th400 tranny

The tranny has a kickdown switch attached to a carter afb 4 bbl

seems that another piece has to hookup to the kickdown sw but don't know what that is

looking to keep this original if possible

also missing a dashpot for carb

what do I need to complete this system. also plug on tranny has the vertical and horizontal spade

this is a ground up resto

thanks

[joe_padavano]

The ST400 (TH400) in your car has a switch pitch torque converter. The angle of the stator vanes in the torque converter are varied to change stall speed and thus torque multiplication. As with the kickdown, the converter is controlled by an electrically operated solenoid valve.  The connector on the side of the trans should have two terminals in a "T" orientation.  The top of the "T" controls the converter solenoid valve; the other leg controls the kickdown solenoid valve.

 

The kickdown solenoid is only energized at wide open throttle. The converter solenoid is actually energized at WOT and at small throttle openings. This off-idle actuation of the converter allows for additional torque multiplication off the line. As a result, there is a second switch that is closed when the throttle is at idle and just off idle. Usually this is a dashpot with a switch built into it - that switch plugs into the two terminals on your kickdown switch.

 

[misterc9]

You should have the 400 Hydramatic with the variable pitch stator. Two of the wires on the switch go to the electrically controlled downshift. The other two are for the electrically controlled variable pitch stator in the torque converter. These transmissions were sometimes replaced with a non variable model when they went bad. I'm looking at a 66 Electra 401 and the switch has four connections on it. There is just a regular dashpot.

Edited November 20, 2017 by misterc9 (see edit history)

[joe_padavano]

17 minutes ago, misterc9 said:

You should have the 400 Hydramatic with the variable pitch stator. Two of the wires on the switch go to the electrically controlled downshift. The other two are for the electrically controlled variable pitch stator in the torque converter. These transmissions were sometimes replaced with a non variable model when they went bad.There should be two more connections on the transmission in addition to the two that come from that switch. The Buick service manual explains how it works and how to adjust and troubleshoot it.

 

Sorry, this is not correct. The switch pitch trans only has two wires going to it, one +12V switched for the kickdown and one +12V switched for the converter.  Converter control is the top terminal in this photo.

 

 

The correct kickdown switch has one output wire for each of these functions and a single 12V hot wire coming in. As I noted above, the additional two terminals on the kickdown switch are the "piggyback" terminals for the low speed switch on the dashpot. The dashpot simply plugs into the kickdown switch. The dashpot mounts in front of the carb so the throttle arm actuates the switch at idle.

 

[bluesy66]

thanks for the info

know where I can get one?

[bluesy66]

how important is this dashpot for tranny operation?

[joe_padavano]

30 minutes ago, bluesy66 said:

thanks for the info

know where I can get one?

 

There is one on ebay right now.

Without it, you won't get high stall off the line, so acceleration will suffer.

[bluesy66]

just bought it new for $25

thanks to all

[bluesy66]

Hi again,

Can someone post some pics of the carb and linkage on this car. It seems that this carb is off a 64 caddy. Am in the process of getting the correct carb and want to make sure it comes with the correct linkage hookups.

Thanks

[PONTIAC1953]

On 11/20/2017 at 10:25 AM, misterc9 said:

You should have the 400 Hydramatic with the variable pitch stator. Two of the wires on the switch go to the electrically controlled downshift. The other two are for the electrically controlled variable pitch stator in the torque converter. These transmissions were sometimes replaced with a non variable model when they went bad. I'm looking at a 66 Electra 401 and the switch has four connections on it. There is just a regular dashpot.

i never heard of a switch pitch turbo hydramatic 400 going bad, quite the other way around, GM wasn't pleased with so few repairs or rebuilding jobs from this transmission, so unhappy that they discontinue the switch pitch at the end of the 1967 model year, and gave cadillac, buick, and oldsmobile the non switch pitch TH400 trans startimg with the 1968 model year.

[joe_padavano]

11 hours ago, pontiac1953 said:

i never heard of a switch pitch turbo hydramatic 400 going bad, quite the other way around, GM wasn't pleased with so few repairs or rebuilding jobs from this transmission, so unhappy that they discontinue the switch pitch at the end of the 1967 model year, and gave cadillac, buick, and oldsmobile the non switch pitch TH400 trans startimg with the 1968 model year.

 

Sorry, but your statement makes no sense.  The only differences between the switch pitch and non-switch pitch TH400s are the input shaft (which has an extra oil hole for the stator oil feed), the front pump (which has the extra solenoid to actuate the stator), an added orifice plug to feed the stator oil, and the converter.  I've built a number of TH400s, and the rest of the internals are exactly the same (ignoring the minor differences in things like number of internal clutch plates or governor springs for different applications having nothing to do with the switch pitch configuration).  I've also personally converted two standard TH400s to switch pitch and the only changes were the parts I mentioned. I fail to see how deleting the switch pitch functionality makes the trans less reliable, which is what you seem to be implying. The TH400 in all forms has to be the most bulletproof automatic that GM ever created.

[PONTIAC1953]

4 hours ago, joe_padavano said:

 

Sorry, but your statement makes no sense.  The only differences between the switch pitch and non-switch pitch TH400s are the input shaft (which has an extra oil hole for the stator oil feed), the front pump (which has the extra solenoid to actuate the stator), an added orifice plug to feed the stator oil, and the converter.  I've built a number of TH400s, and the rest of the internals are exactly the same (ignoring the minor differences in things like number of internal clutch plates or governor springs for different applications having nothing to do with the switch pitch configuration).  I've also personally converted two standard TH400s to switch pitch and the only changes were the parts I mentioned. I fail to see how deleting the switch pitch functionality makes the trans less reliable, which is what you seem to be implying. The TH400 in all forms has to be the most bulletproof automatic that GM ever created.

i never said that regular TH400 were less reliable than the switch pitch TH400 trans, i said that General Motors was not happy with how few repair and rebuild jobs they got from the switch pitch TH400, it cost less money to produce the regular TH400, you missed the point of my post completely joe. i too have built both the SP TH400 and TH400 trans.

[joe_padavano]

10 minutes ago, pontiac1953 said:

i never said that regular TH400 were less reliable than the switch pitch TH400 trans, i said that General Motors was not happy with how few repair and rebuild jobs they got from the switch pitch TH400, it cost less money to produce the regular TH400, you missed the point of my post completely joe. i too have built both the SP TH400 and TH400 trans.

 

That didn't come out in your prior post at all. I don't really know how else to interpret this statement:

 

16 hours ago, pontiac1953 said:

GM wasn't pleased with so few repairs or rebuilding jobs from this transmission, so unhappy that they discontinue the switch pitch at the end of the 1967 model year,

 

Lower cost of production was absolutely the reason for dropping the switch pitch system. Of course, when the trans is bolted to a 455 making 500 ft-lbs of torque, you really don't need the higher stall speed, either.  I don't understand how the lack of repair jobs for the switch pitch trans has anything to do with this.  GM corporate bean counters certainly would prefer not to have any warranty costs.  Repairs outside of warranty were a dealer service issue, not a GM corporate profitability issue. GM corporate only cared about maximizing profits from the sale of new cars - thus the decision to discontinue using the switch pitch.

[PONTIAC1953]

well you're the one who misunderstood my original post, as for the lack of repair work, those done beyond the end of warranty was certainly profits for both the dealership and GM, both in parts and labor. can't make it any plainer than that.