Yet another transmission mystery. TH400

[Stitz Love]

(Hotrod, -got your pm about kickdown, thanks for the info.)

It seems the trans. has sensor (and internal solenoid) and the wire. But it is either disconnected or connected to the wrong thing up in the engine compartment. I will check that Saturday!

ALSO, NEW INFORMATION on the trans.; It had sat on garage floor for almost ELEVEN years... so a new filter and fluid is likely due, however, If the lucas doesn't work and the seal(s) {clutch pack(s)?} don't make a comeback, It'll have to be opened up for a rebuild... (or I'll have to buy a rebuild (or used) I'd hate to put new filter and all that new fluid in, only to have to have it opened up again... so if it comes to rebuild, it gets new filter and fluid then.

I have talked seperately to two different race car aquaintances here, each said, based on the symptom of shifting fine with WOT but not really getting 3rd. correctly when driven like my Dad, the TC is suspect.
z07 mentioned that also. (cred!)
They went on to say a bad or failing TC may make a grinding, clanging.. or whizzing / whistling sound. I DO hear a whilstling-type sound at 55mph and up, and also with foot off the gas as I slow from those higher speeds, but I really can't tell if it's just wind blowing through the seat-belt shoulder strap or around the window vent shade or around the little drivers door mirror... or if it's coming from under the truck.. or from the tail-pipe.

Looks like I have a lot to research over this weekend. Dang, why couldn't it have just been the governor.

Still looking for anymore thoughts on this... I will be consulting the forum regularly this weekend.
Thanks all!

[hotrodpc]

10-4, Yes I agree, when a TC goes bad, it is usually quite evident with other noises, usually in the severe cases grinding and chunking noises. The whistling is usually a warning that tells you its short lived but that is rare to hear. Usually when they go, they go, and do not pee around gradually. I just think yours is an issue from sitting for a very long time, and another suggestion. New Fluid and Filter is NOT going to change a thing or make a thing better in your case. So I would try the lucas seal conditioner, up to 2 pints, and I think that is what is the directions call for and if it works, GREAT, if not, then its past reviving and rebuild it. And do NOT do as some do, thinking 3 or 4 pints will be better than 1 or 2, because there comes a point, you get to much and it just eats the seals instead of softens and swells them. It has been know with a few guys in my raceing days, that a half pint of brake fluid will do that job. And yes, I agree it works to swell the seals, but it also damages the seals, so I only recommend that to someone who is trying to get one last trip out of the trans, or just make it home or to the rebuild shop. Now I do know 1 person that did it, and they got another 6 months out of the trans before they could have afford to have it rebuilt, and it was still running when he had it rebuilt, so it worked good for him and that was in a 700R4 on its last leg, and the brake fluid brought to life.

[Stitz Love]

Today is the day for the Lucas treatment. But yesterday on a lark, I replaced the vacuum module.
Not only did it not help, I think it is not as good as the old one.
See photo, the old one is blue and much larger than the new one.
I know they are both adjustable but I was surprised by how much more easily third dropped (unwanted) into second with the new one on.

I read somewhere in my research that the 'valve?' (button seen in shot called "under the vacuum modulator") was/is suppose to move freely. I pushed on it with my finger and it didn't budge, but if it were stuck, I don't think I would be getting any shifting at all, much less all three gears with just third being touchy... so perhaps I misunderstood that bit about that piece.

I keep checking this forum and searching the web for more ideas and answers... Hotrod, you are a constant source of very good advice and assistance, thanks for checking back to this thread so often.

This trans. issue will be solved eventually.

[hotrodpc]

Yes, if its shifting at all, the valve and modulator are good. All the modulator does is help decide shift points with the governor. If you are on the throttle, and engine vacuum is low, its telling the trans to wind it up a bit before shifting is all. Usually those small vac modulators can be adjusted too. The new shiney one you have looks like it has the little screw inside it. You can back out or turn in the screw to delay your shift or make it shift sooner. Persoanlly, the non adjustables usually work just right and don't need the adjustment anyway.

[Stitz Love]

Thank you to Hotrodpc and 75k30 for directing me to the immediate issue.
Special thanks to Hotrod for patiently letting me drift off the path on my illogical hopes, tho- based on articles and other forum answers to the same symptoms, still errant. I have learned a lesson; "Try everything you can do for 'Free' before you go spending money."
Shame on me for not getting there quicker.
75k hit it on the 2nd [his first suggestion] and reiterated in 6th. post.
"Disconnect the kick down switch..."

Well, I did that last night and "Ta-DAH!" all gears operated normally. I felt so good I drove around for about an hour!

So, Readers, learn from my foolishness... I spent $28.00 on a new governor (with gasket & $hpping), and $11.00 on a new vacuum module... Before I simply disconnected that kickdown wire. And it's not just the $40.00 I spent needlessly, it's also the number of hours I spent searching and reading about bad governors and vacuum issues... although I did gain a fair bit of knowledge doing so... the truck had been parked (barring about 80 miles in test drives) for about three weeks while I stressed and obbsessed about it. I even looked up rebuilt TH400's and new Torque convertors.

But the resolution is, the kickdown has been disconnected, and I may drive the truck anywhere I like... and attend to other issues like; new tires, new seat belts, oil change, radiator flush & fill, new serp. belt... etc.

And the new questions... "The kick down solenoid..." such as, is the solenoid bad? where is it getting 12v from? Is it connected up there wrong? Is there a bad fuse? fusable link? ... And more which I'm sure have not occurred to me yet.. But THAT my friends, is another thread.

[hotrodpc]

Wow, glad its fixed. I thought the kickdown was never connected in the first place, and that is why you had asked where the switch was. I would lean toward the solenoid is OK. Again, first, lets keep it simple, do not pull your pan and buy a new solenoid. Simply put a test light on the wire. Check for power, first with key off. If its HOT, not good. If off NOT HOT, good. Then turn the key on check for power. If HOT, not good. If NOT HOT, then good. SO assuming it all good there is NO power to the wire, put a brick on the gas pedal to the floor, (WITH MOTOR OFF OF COURSE) and key ON. NOW, you should have power. I am willing to bet, that someone hooked a hot wire to the switch, and it HOT when the key is ON, and its not supposed to be HOT until you put the gas pedal to the floor. IT only gets HOT at WOT (Wide Open Throttle). I am sure your truck orinally was not wired for this, so you need to either set it up yourself at the gas pedal linkage inside the cab, or at the throttle linkage on the carb, tbi or whatever you have. I know its not factory. I know who did thing with a push button. He liked it because he could use it towing and not have to go full throttle for kickdown. He'd be climbing a hill pulling a heavy boat at half throttle, motor start bogging and slowing down, he'd hit the button and hold it till he got the RPMs back up. Not sure I like the idea, it has it advantages and disadvantages.