TH 400 governor issue

[MAC71]

I have a 69 C20 that after buying it and getting it running and on the road the TH 400 transmission failed after a few days of driving. Pulled it and rebuilt it and everything works well with the exception of the governor. It will hang up and it will not up shift out of first gear. I pull the governor out clean it with brake parts cleaner and compressed air and re install it and it works fine and I will get 400-600 miles on it and it hangs up again. It has done this so far 4 times, easy fix but it always seems to happen on the way to work.
The valve in the governor moves smoothly and no abnormal ware, and it fits well in the boar in the case.

What am I missing here?

[Wildcard]

Hello, Is the body where the counter weight seem loose on the shaft that the valve goes in? they can get sloppy here and constantly play with valve clearance, Best thing to do is just replace the governor valve.

weird part is most the time when a governor valve sticks the trans wont down shift to 1st at a stop, and no upshift would be in the modulator like not vacume to it. anyway.

If you have something wearing or got debree in the system like the cooler, (Did You Blow the cooler system before you reinstalled the trans?) cause if you didn`t the crap in the cooler goes straight into the governor.

Good thing to do to kinda wash or cleanout the governor system is to take the governor valve out and reinstall the cover and start the engine and shift the selector thru the gears without moving the vehicle and this will clean the system with out the governor being in there works good, then reinstall a new governor, also if you ad a bottle or Lubeguard Red bottle that will help all the valves in the valvebody stay clear and not sticky.

Good Luck, Wildcard
I have been a Trans Tech for 30+ years

[MAC71]

Originally Posted by Wildcard

Hello, Is the body where the counter weight seem loose on the shaft that the valve goes in? they can get sloppy here and constantly play with valve clearance, Best thing to do is just replace the governor valve.

weird part is most the time when a governor valve sticks the trans wont down shift to 1st at a stop, and no upshift would be in the modulator like not vacume to it. anyway.

If you have something wearing or got debree in the system like the cooler, (Did You Blow the cooler system before you reinstalled the trans?) cause if you didn`t the crap in the cooler goes straight into the governor.

Good thing to do to kinda wash or cleanout the governor system is to take the governor valve out and reinstall the cover and start the engine and shift the selector thru the gears without moving the vehicle and this will clean the system with out the governor being in there works good, then reinstall a new governor, also if you ad a bottle or Lubeguard Red bottle that will help all the valves in the valvebody stay clear and not sticky.

Good Luck, Wildcard
I have been a Trans Tech for 30+ years

Thank you for the information. I did blow out the cooler system when I reinstalled the transmission. The governor valve seems tight. I was thinking about what you were saying about not downshifting to first and when I come to a stop some times right after I stop there is a slight jerk and I think its delaying in down shifting also.
I am going to do as you stated with clear out the system and I have a new governor on order. The only place I found on locally for a decent price is the local Transtar for $54.00, seams like a lot. It should be there on Monday.

[Wildcard]

Your Welcome and Hope it works out for ya, I get parts from Transtar at my Work I always talk to John or Pat, and our price on the Govenor valve is considerably lower than that course our amount spent thru them quarterly is considerably higher than you would be I`m sure, Ya know. course the price you got was retail.

If you would of went to a NAPA store if you have one localy they get there parts from transtar and would jack the price even higher than what you got, at least the Napa`s around here go thru transtar.

There is another outfit in Boise, ID. ITW (Idaho Transmission Warehouse) and they are a lot more reasonable on parts, Jobs I do on the side from some of my customers before I closed my shop down, I got all my parts from ITW.
Talk to Mark, great guy

When you get the governor also when you put it in the bore twisted in all the way wiggle it up and down and see if you have any case bore wear there will always be a little but you`ll know if its excessive, probably nothing to worry about.

clean the new governor good with like brake cleaner or solvent they are most the times slightly coated with a rust inhibitor called cosmoline, and spray it down good with WD40 its great for keepin valves free. Every trans I build new or old I coat the valvebodies or and governor valves etc.. with it have always had good luck with it.

Oh and after you get it cleaned and lubes hold the counter weight hold the governor out in front of ya with the gear up and squeeze the weight in at the same time and you will see the valves in around the top slots in the stem you should see the valve drop a bit and when you let go of the weight it will go back up.

Did you install a shift kit in this trans, cause if you did that's fine , just don`t replace the springs in the governor of put the spring behind the modulator inner valve they are junk and trans you honestly will not like it, I haven`t messed with those in years work best with stock spring, course most 400 shift kits is only a couple springs and the separator plate change that's pretty much it and it shift great. have on in 400 in my 67 chevy and it hit nice. and quick shifts too

Even with out a shift kit, If you would like a little firmer or touch later shift install a Red Stripe Vacume Modulator.

Good Luck, Wildcard
Darren Card