1967 442 90% original. 400E block, OG code TH400. Trans shifts good. WOT 1-2 @ 45mph, 2-3 @ 75 mph. Cruise at 70 mph=2650 rpm (3.08's). New throttle switch reads 12V @ idle on switch pitch spade. Loses it just off idle then regains it at approx. 60% throttle and the 12V stays all the way to WOT. Kick down spade gets 12V just before WOT. New Harness twix throttle switch and two prong trans connector. Next I had The old front pump, input shaft, both solenoids, and two prong connector removed. A new front pump, solenoids, input shaft, and two prong connector installed. Checked the restrictor plug with the very small hole in the second from the left hole on the bottom of the transmission case while the pump was out. Got two new convertors (13" & 12") from Dacco-Detroit. Neither the original or the two new ones changed to a higher stall. Wired a direct wire through a toggle switch to the switch pitch spade connector on the transmission. Flipping switch to 12V I can hear the solenoid clicking. No change in pitch. Trans shifts and down shifts as a norm TH400 would. Builder noticed a transgo shift kit installed and wondered if the switch pitch valve body and separation plate are different from a non switch pitch TH400? Could the shift kit/separation plate cause the switch pitch to not work? Anyone know. Thanks.

 

Does the solenoid work with the new harness?

I don't think the valve body needs to be specific to the switch pitch, but the front pump may be per something I was reading.

 

"The switch is easy enough to check. Disconnect the wires and then put a jumper across their terminals. If there is no difference in the converter, either with or without the jumper, your problem isn't in the switch. First, check to make sure that one of the wires has power when the ignition switch is on. Next, check the wiring and connector going to the transmission. If none of this makes a difference, the problem is inside the transmission." <this is copied from raycow at team buick dot com board>

"The switch that controls the converter pitch at idle is at the other (firewall) end of the throttle rod. Turn the key to the on position with the engine off and step on and off the the throttle pedal just a little bit. You should hear the solenoid click in the transmission. If not the switch may be broken or improperly adjusted. If that does not do it check the wiring to the switch and transmission next. Then it gets harder!"
<this quotes from drfrankenbuick on the same site>

I know this is Buick but its the same with exception of switch mounting locations. So Id say if your hearing the solenoid you have a converter or some other internal problem. The shift kit may very well be the issue if its plates are different (likely) covering up an important worm passage to allow fluid to the SP circuit. A quick and dirty check may be for you to install a correctly identified ST400 stock separator (program) plate assembly and see if it restores the Switch feature. At minimum you can compare the hole patterns.

 

My observation on your description and trouble shooting voltage readings is the system electrically and mechanically is functioning the way it should if the solenoids are working when you energize them. So it has to be internal to the trans somewhere. I have never run a shift kit on my variable vane Trans's, so I don't know.

 

Thanks for the replies and suggestions. My big question: is the valve body and separation plate unique on a Switch pitch TH400? If the valve body is from a regular TH400 will it interfere with switch pitch operation? I'm presently trying to locate a stock valve body and separation plate to compare and/or try. Thanks again.

 

Here's some links that may be of some help:

The info here applies to Olds also.
http://www.buickperformanceclub.com/SPTrans.htm


http://www.hotrodhomepage.com/hrhp/2...the-overdrive/

 

Talked with Jim Weise today and he was very helpful. Valve body and separation plate not switch pitch unique. Suspects blocked passage internal. Like Oldscutlass said, we're going through the whole transmission (rebuild). Will post findings hopefully next week. Thanks everybody for your help.

 

shop pulled transmission. Changed out Dacco Detroit convertor. It had lost half its balance weight that was welded on the outer shell. Dacco Detroit gave me another 12" convertor. One of the three welded on lugs was metric but trans shop had one so it wasn't the end of the world. After thorough inspection and solenoid checks it was re-installed. Took it out and it worked like a charm. One problem down. Thanks so much to everyone who helped me with this problem. Now to try and solve the lifter noise. Cutting some rusty valve covers so I can run motor without making a mess. Will use a stethoscope to locate which rocker arm/lifter is noisy. Will check to see if any are bleeding down too fast. These are new Johnson topline .921 lifters. Wish me luck. Motor runs great just sounds like an old sewing machine. Thanks again everybody.

 

Cool, glad you got it! Check the wear on the rockers and pivots if they have not been replaced.

 

Harlan Sharp rockers (S50026A two rockers per shaft style). Watched with cut out valve covers. Plenty of oil flowing. Re-adjusted while everything was still warm/hot. Rockers much quieter but still a little sewing machine noise. Thanks to cutlasEFI for an excellent conversation with straight-forward information and the idea to set the rockers while hot. Plus he said the JM 20-22 cam (by Engle) has a faster ramp and will probably be a little noisy. Went back to Valvoline VR1 10W-30 oil. Motor seems quieter? Will run it for awhile. Really likes the switch pitch. Timing still @ 14 initial, 14 mechanical, 12 vacuum. No detonation. Will live with this. No 35 degrees timing for this motor. I really do appreciate every ones help and suggestions.


Some men are Baptist, Some men are Catholics. . . . My father was an oldsmobile man! George in Alabama.

 

For what it's worth my Harland Sharp's are a little noisy also.

 

Some say aluminum roller rockers are noisy some say they are quiet. Fast ramp cam? Different oil pressures? Stronger valve springs? Combo of all, probably. Thanks oldscutlass for the suggestions. Try to use search feature here on CO, but it almost always says it didn't find things like "JM 20-22 cam". I'm sure I'm not the only one to have his camshaft. Tried JM-20-22, and 20-22. Its probably me not know how to use the search forum. Once again thanks for your help.