Th400 shift modulator ?

[Jeep Craze]

How would I know if the shift modulator on my Th400 isn't fuctioning properly. It seems like the only time it kicks down when slowly accelerating is when the motor really starts lugging down. If I tromp it to the floor, it kicks down so I know the electric switch is working on the pedal. Any thoughts would be greatly appreciated. Craig

[LRRH]

if you've got a TH400 just replace the thing...they are around $14 and can make a world of difference. Make sure the vacuum is plugged into it properly.

However, you sig says you have a TF727......so I'm a little confused about your question.

[Jeep Craze]

oh sorry...I have another jeep just recently added to my collection(i just forgot to add it in my sig ) I suppose for the cost of the vacuum modulator I should just replace it. Thank you Craig

Oh yeah is there any special trick to getting the old one off and the new on?

[gsmikie]

could also be the govoner

[Bo]

When the tranny modulator goes isn't there usually a large trail of smoke coming out the exhaust?

[gsmikie]

Originally posted by Bo:
When the tranny modulator goes isn't there usually a large trail of smoke coming out the exhaust?only if the diaphram leaks

[Jeep Craze]

Hey GSmikie, what do u mean by the govoner and where is it located?

[Tad]

If I remember correctly you pull the vacum line off the modulator and inside that nipple is an allen head set screw to adjust shift points.

[Kaiserjeeps]

If anybody finds a part number for the modulator for the th400 please post. I can't seem to find one here in Portland. I have the 350, Th400 and dana 20. It's a 1969...Thanks...Kaiserjeeps..

[gsmikie]

Originally posted by Jeep Craze:
Hey GSmikie, what do u mean by the govoner and where is it located?its on the pass side at the rear of the trans it has 4 bolts holding the square cover on if you pull the gov out and hold it upside down (gear up) and squeeze the fly weights on the other end there is a rod that runs through the middle of it that should slide up and down when you squeeze if it doesnt it should be soaked in lacqur thinner to clean the varnish out of it

[Tad]

UH, OK, so I was way off, guess that's why i'm heading to gsmikie's house Saturday morning ;)

[PhilSine]

NAPA has them. Part Number:ATP17499 cost is $10.99.

[gsmikie]

Originally posted by tadsal:
If I remember correctly you pull the vacum line off the modulator and inside that nipple is an allen head set screw to adjust shift points.its a slot screw turn in for wider shifts and counter clockwise for shorter shifts

[mandoneer]

Hello all
I had that problem and so I put a THM350 adjustable modulator on it and it fixed it right up(I think I adjusted the screw in about 1/4 turn)
as far as I know most 400 modulators arn't adjustable but one for a 350 is and fits right in . smile.gif
hope this helps.

[Kaiserjeeps]

Thanks Philsine! You da man!!!...Kaiserjeeps.

[Jeep Craze]

Thank you everyone, I picked up an adjustable one today and plan on putting it in the next nice day. I think I will start off a stock and keep turning it for longer shift points until it runs good. Thanx again to everyone

Oh yeah and mikie I think that gov. is alittle to complicated for me right now. MAybe once I get myself a manual I will check it out.

[gsmikie]

Oh yeah and mikie I think that gov. is alittle to complicated for me right now. MAybe once I get myself a manual I will check it out.

cool i will be here