I stuffed up my modulator...

[TJ 450]

I pulled the old modulator off the 450's transmission today, only to find that the new one I got (white) had a different sized pin. I also noticed that the one on the car appears to be a lightish green (doh!) plastic body. So, this is where it gets worse... I put the old one back in, drove around the block and now it shifts really harshly into second, even when the modulator is adjusted right out. Perhaps I didn't press the pin all the way back in? I ruined the adjustment when I took it out.

What should I do now 

Tim

[Big_Richard]

stupid question - but did you remember to reconnect the vacuum line ?

[TJ 450]

Cheers for that PB, I'll go and check it, hopefully that's the case 

[TJ 450]

The vac line is connected. BTW, when it's adjusted all the way out (anti-clockwise), is there some kind of stop, or will it just keep on turning forever?

[Big_Richard]

The vac line is connected. BTW, when it's adjusted all the way out (anti-clockwise), is there some kind of stop, or will it just keep on turning forever?

"please explain"

Are you talking about the modulator housing, if so, no, it screws anticlockwise untill it comes out.

IS there some other adjustment internal on these modulators ? I dont know, I put a new one on mine, with a new pin, after replacing every single seal inside the transmission and it worked the first time and still does.

[TJ 450]

There's an adjustment "Tee" inside the unit for adjusting the hydraulic pressure. It's under the cap that the vacuum line attaches to. I have it backed all the way out at the moment, meaning that the pressure should be low, although it's shifting as if it's the opposite. Out of interest, does yours have a white plastic housing, or some other colour?

Tim

[Big_Richard]

There's an adjustment "Tee" inside the unit for adjusting the hydraulic pressure. It's under the cap that the vacuum line attaches to. I have it backed all the way out at the moment, meaning that the pressure should be low, although it's shifting as if it's the opposite. Out of interest, does yours have a white plastic housing, or some other colour?

Tim

Mine is the new white plastic one.

How very interesting - I guess i struck it lucky because ive never adjusted it out of the box, and it works superbly.

What was the reason for messing around with it if it worked before ?

[WGB]

I thought there were white and red ones with different levels of modulation - not sure about that though.

Never heard of green ones though.

Bill

[TJ 450]

That's interesting, PB. The reason for mucking around with it is that the old one has a leaky diaphragm and there was slipping going into third.
Having removed the old modulator for replacement (I have a new white one right here), I realised that the pins are a different diameter, thus I couldn't change them over. Things went bad when I had to put the old modulator back in... I screwed the tee all the way in when I removed the pin, putting it way out of adjustment.
I then put the pin back in the old unit, backed out the adjuster to approx. where it was when I removed it and reinstalled it. I drove the car around the block and it went into 2nd very harshly. I then adjusted the modulator counterclockwise to reduce the pressure. So far I haven't had any luck.

I'm thinking what I might do is just order the correct pin for the new modulator and hope for the best.

WGB, I think the colour of my old one is due to age, BTW I'm colour blind so it might be off-white.

Thanks for the replies 

[Big_Richard]

with all the messing around with the vacuum box ajustments, is it possible that the modulator pin has fallen from the vacuum box connection and jammed itself against the hydraulic modulator in the extension housing of the transmission. It may be a case of removing the vacuum box once again, and double checking that its been reinserted correctly.

If your tallented enough, you can take a look in the hole that the vacuum box screws into. the pin actually actuates a sliding piston valve which modulates hydraulic pressure. There is also a clock spring mounted on the hydraulic valve that ensures the piston returns to the high vacuum position. This may also be malfunctionals.

If you decide to play around in the extension housing - i own the special 32 tooth thin walled socket required to undo and redo the new style flange nuts on the tranny and diff. The old slot nuts are no longer available and can happily be drilled out. no point buying a socket for these.

[Big_Richard]

PS, a stuffed modulator results in hard shifting and sucking in transmission fluid into the engines intake manifold.

Not the symptoms you described. These are those of other problems.

[TJ 450]

That's pretty much as I thought. The main reason for the replacement was due to the ATF entering the intake - there's a fair amount of fluid coming through the vac line. Oddly there was no harsh shifting, in fact the opposite has been occurring... until now. I'm sure the trans will need to rebuilt soon, anyway.

Tim

[nathan]

i know someone who has a spare trans if you need a part, just dont ask me what the parts are called (i leave that to PB)

[TJ 450]

Cool, thanks Nathan, I'll keep that in mind.
I'll be ringing around tomorrow to try and find this updated pin. If all else fails, I'll give you a call  .
About the "show and shine"... I believe it was canceled and the club members went to the North Fremantle Oyster Bar, in their A140's 


Thanks for that info PB, hopefully the pin hasn't fallen in the housing yet   
The part# of the new modulator I have is 123 270 00 79, manufactured by EFFBE. According to all the info I've seen/read it's the correct unit.

Tim

[Big_Richard]

i know someone who has a spare trans if you need a part, just dont ask me what the parts are called (i leave that to PB)

Havent you got 2 of them yourself from those 450s you had ?