Lost 3rd and reverse after changing vacuum modulator

[243]

A tranny manual listed low fluid pressure as a cause of slow upshifts and the modulator as one of the causes of low fluid pressure.

I stopped by the parts house on the way home and they had two for the TH400, one with a red stripe and one with a black and red stripe so I bought both.

When I pulled the modulator from my tranny, there was a small curved piece of sheet metal about 1.25" long that hooked on to the end of the modulator.

The metal part would not hook on to either of the new modules...

What is it?

Is it required with the new modulator?

How do I know which modulator is correct for my tranny?

I tried both modulators without the additional part, the 1-2 upshift was great, the 2-3 almost non-existent. Reverse is slipping quite a bit as well.

Any help would be appreciated!


------------------
243

Ol'e Blue 79 Wagoneer 401/T400/QT (Daily Driver)
Red 75 Wagoneer (The Project)
Mean Green 76 Wagoneer (Parts Jeep)

http://www.0hassleisp.com/dwilk/243'sFSJ.html

[JeepFreak]

That piece was an extension to get the stock modulator up out of the way due to its size. You need to remove it and get a new rod from a chevy tranny. It's really not hard to do. Once you have the rod just install it without the elbow. I made my own rod so if you have an idea on the lenght go for it.

------------------
JeepFreak

[JeepFreak]

Also there is a small screw in the middle of the vacuum inlet on the modulator. If you have that screwed in to much it will not want to upshift. If it's out to far it will shift to fast. So you may need to adjust that as well depending on how hard you like it to shift. I like a good firm shift so mine is srewed in quite a bit.

------------------
JeepFreak

[Dexter Shark]

I was wondering the same thing about the little piece that hangs down from the modulator. I installed it without it and it seems to run fine. I did it about 3 weeks ago and no problems have cropped up. Do I need to take it apart and find a little metal piece that fits it?