Modulater valve

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Nov 13, 2012 | 09:53 AM

dybeepvw

Thread Starter

Mountain Pass

Joined: Sep 2004

Posts: 249

Likes: 2

From: AZ

Modulater valve

Can anyone tell me where the modulater valve is on my A4LD tranny. I have a 93' ranger XLT extra cab 2wd with 4.0 engine. I have looked all over the tranny and thought it would be somewhere I could see it. I know I had one on my old full size Ford truck with C6. Thanks

Nov 13, 2012 | 10:37 AM

KhanTyranitar

Postmaster

Joined: Oct 2009

Posts: 3,432

Likes: 7

on the side of the tranny.

Nov 13, 2012 | 12:56 PM

dybeepvw

Thread Starter

Mountain Pass

Joined: Sep 2004

Posts: 249

Likes: 2

From: AZ

I have searched bothsides but can't seem to find it, unless it is on right side crammed next to cayalytic converter. I will look again. Does it have a vacuum hose going to it?. Thanks again

Nov 13, 2012 | 01:31 PM

dybeepvw

Thread Starter

Mountain Pass

Joined: Sep 2004

Posts: 249

Likes: 2

From: AZ

I found it, was hoping to be able to get to the adjustment screw but it is a very tight area with a heat shield there also.

Nov 15, 2012 | 07:18 PM

wtroger

Cargo Master

Joined: May 2001

Posts: 3,208

Likes: 13

if there is any fluid in the hose the valve is bad and will need to replaced.

Nov 15, 2012 | 08:50 PM

dybeepvw

Thread Starter

Mountain Pass

Joined: Sep 2004

Posts: 249

Likes: 2

From: AZ

I am going to replace it; it is shifting hard and going up in speed before it shifts to the next gear. Think I will remove the passenger seat first to see if I can change it out thru the floorboard rather than pull the exhuast pipe down.

Nov 16, 2012 | 03:22 AM

critterf1

Posting Guru

Joined: Feb 2010

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From: Newport, N.C.

Through the floor-board?

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Nov 16, 2012 | 07:53 AM

tomw

Logistics Pro

Joined: Jan 2002

Posts: 4,907

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From: suburban atlanta

Rust? Cutting torch? Zip gun?
The symptoms of a bad modulator are 1)won't upshift or late upshift more likely. 2)smoke out the exhaust followed by low fluid level.
Engine intake manifold vacuum is applied to one side of the modulator diaphragm. At idle, vacuum is high, and at cruise, vacuum rises a little. When you step on the gas, vacuum falls, allowing the modulator spring to push against valve body stuff. When you let off the gas, or the engine approaches 'easy work' at higher rpm, the vacuum rises a bit, so the diaphragm gets retracted, letting the valve body move towards 'upshift'. Additionally, the governor is cranking along, increasing its 'force' proportional to the increase in speed, so the modulator has additional forces 'pulling' for the transmission to "upshift as soon as you can, bud". This happens in each gear position, except R, I think.
Generally, once set properly, you never have to mess with a modulator. They work or they don't. If you aren't getting upshifts, check the vacuum connections at the manifold & modulator.
tom