Identifying Switch-Pitch tranny's

Are all switch pitch pans the same?,I know that it should have the three dimples and the shoe heel impression.
I'm searching old Buicks,Pontiacs,Caddy's
I found this in a wagon but probably NOT what I'm looking for
TAG
Super Turbine 400
B 496 W
BW-68-1077

 

That is not an SP trans. From the numbers, it is the original trans to a 68 Sportwagon 400. Only 65-67 Buick and Olds (some Cadillac) were SP units.
Late 67 trans's did not have the heel in the pan. Best units are the 66/67 ones as the pumps and some internals were improved over the 65's

Mark

 

This is going to be a hard item to find,but as long as there's old cars around I'll keep crawling over and under to get one.Thanks for narrowing down my search Mark,very much appreciated.
Harry

 

Harry,
Most pre 74 TH400's can be converted to SP easily with a kit available from either Tri-Shield or PAE. Even a long tail from that Sportwagon can be made into a short shaft for a GS by changing just the output shaft and housing.
Should make your search easier.

Mark

 

You should get that TH400 to just have as a spare. They have disappeared here in FL along with the BOP 455 engines.

 

Don't they also have 2 plugs on the side instead of one (where reverse light plugs in)?
Thanx.

 

On the 65-67 trannys are 2 electrical connections on the driver side of the trans. The vertical one is for kick down (passing gear) and the horizontal one is for the SP.
Backup lights are powered off a switch on either the steering column or center console.
The early 70's TH400's once again had 2 electrical connections on the drivers side. However, they are NOT SP trannys. The horizontal one was now used for something called TCS (transmission controlled spark). A solenoid was mounted to the carburetor that controlled vacuum to the distributor. A switch in the trans activated the solenoid to allow vacuum advance only when the trans had shifted into 3rd gear.

Mark

 

There is an excellent SP article regarding identification online at http://buickperformance.com/switchpitch.htm

 

e mail RACEBUICKS on this board. i believe he has all of the guts you need to turn normall th 400 into a switch pitch. he also has a convertor if i remember right. if he doesn't have a converter, i do.

 

Thanks :beer I'll pm Racebuicks

 

What size converter do you have?I recently aquired a SP out of a 67 Riviera and am looking for the smaller converter. o No:

 

This article makes me a bit confused.
Were there some 1966 Nailheads with a BOP bellhousing??? That's what understood when I read it, but it's late maybe I didn't read well!

Also, were there 1964 Buicks with Nailheads and a switch pitch ST400 transmission or was the S.P. ST400 introduced in 1964 on 1965 models?

If there were Switch Pitch ST400 transmissions installed on 1964 Buicks, did these cars have PRNDL selectors like the early 64 Buicks with fixed stator 400 transmissions or did they have PNDL2L1 selectors like the 1965 and later 400 transmissions?

I know that my 65 Wildcat that was built in November 1964 has a s.p. ST400 and as far as I know, all 1965-67 Buicks with automatic transmissions do have a switch pitch torque converter. I think that all the 1964-67 Super Turbine 300 transmissions were also s.p., am I wrong?

The LeSabre 400 and Sportwagon 400 models with 300 and 340 c.i. engines that were built before the 1968 model year also had switch pitch ST400 transmissions and they all had a BOP bellhousing. Did they have the same output shafts and/or clutches as the 400 transmissions for the larger engines?

Also, what are the internal differences between a 1965 ST400 transmission with a Nailhead bellhousing, a 1966 ST400 transmission with a Nailhead bellhousing and a 1967 ST400 with a BOP bellhousing?

Thanks

 

In 1964, the only SP was on the ST300 2 speed. The 64 LeSabre was available with BOP (Wildcat/Estate Wagon/Electra/Riviera had the nailhead pattern) bolt pattern ST400 3 speed. Due to a unique 1 year only valve body, it only had D & L. You could shift 1-2 and then put in back in L and then shift 2-3.
Below approx. 35 mph putting it in L got you 1st, above 35 got you 2nd until you slowed down to less than 35 mph and it went into 1st. Confused. ou:
From 65-67 all 2 speed and ST400's were switch pitch. LeSabre 65-67 and 67 Sportwagon 400's were BOP bolt pattern.
65-66 Wildcat/Electra/Riviera were Nailhead only bolt patterns. Beginning in 67 all ST400's were BOP bolt patterns.
As far as internals, ST400's were bascially the same. All had 5 clutch pack forward and direct clutchs and 3 clutch pack intermediate. The SP pumps were slightly different beginning in 66. Some minor changes in intermediate piston/spring combinations and a roller clutch was used instead of a sprag on the reaction carrier.
Valve body calibration varied by model and year as well. See my post on understanding SP valve bodys. Output shafts and housings were mainly the same from 64-66. In 67 the GS400 used a larger yoke along with the Sportwagon 400 which had the longer lengh tailshaft and housing.
Should cover most of it,
Mark