Modulator Valves

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DoubleDingo

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I haven't done a whole bunch of research on this, but I thought I'd at least bring it up. My truck still shifts weird sometimes, so I figured a new modulator valve may be in order. Sometimes the shifts are noticeable, sometimes they're soft and sounds like it only shifted once. Since I have an account with a mom and pop auto parts store, and that store is based on advance auto, I looked it up advance auto. I'll admit I didn't look real closely at the listings, just that the top one seemed to be one they stocked or could get. So I went in yesterday to get one. He checked every number that came up, ATP, BWD, etc. Nothing. He could order one for TH350 but could guarantee it would work. So I told him I'd check around to see if I could get one. Pep Boys, same thing, and the one they could order was $74 or $125, whichever they chose to charge you. I stopped at Auto Zone, they had a red stripe for $15 out the door with no warrantee.

For those of you that have rebuilt your tranny's, have you had difficulty finding a modulator?
 

78C10BigTen

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I bought an adjustable one for my th350 at autozone.
 

Matt69olds

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The red strip modulator from AutoZone is adjustable. It works on both the 400 and 350. Don’t turn the adjustment screw more than 2-3 turns max either direction. About the best you can hope for is a 3-5 mph change in shift points. Any more than that will require governor modification
 

DoubleDingo

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Thanks. I'll make sure not to over adjust the new one. I may have done that with the other one.

I was more asking if people were finding it difficult to get a modulator valve since there were none available from the store I have an account with. None. None at the warehouse, none from the manufacturers, only the one for a TH350 that he had to order and wasn't sure if it would work because it didn't show TH400 in the description. And then Pep Boys didn't have one, and the one they could order was priced way too high. I told the guy there are still lots of 350's and 400's out there so it's not like they're obsolete.
 

Frankenchevy

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I bought one from Napa. They’re listed for th350/400. I guess they must be the same...hopefully
 

Frankenchevy

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I counted turns on the screw in the old one till it lightly bottomed.

Set the new one up the same. Haven’t driven it yet.

The diameter of the new valve’s body is smaller, but everything else fits.
 

DoubleDingo

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I didn't think of that when I replaced the factory one about 6 years ago. But that one may not have been adjustable. Which way did you turn it to bottom it out and how many turns back to get it similar to the one you're replacing?
 

Frankenchevy

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I didn't think of that when I replaced the factory one about 6 years ago. But that one may not have been adjustable. Which way did you turn it to bottom it out and how many turns back to get it similar to the one you're replacing?
I can’t remember. I believe the adjuster is just about even with the hose barb. I’ll look when I get home.
 

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