727 modulator valve location

[RT DAVE]

Can anybody tell me where this is located?  Just noticed there isn't a hose connected to my manifold vac port on my carb which explains why the car doesn't like shifting into third.  Also, anybody know what size hose I would need and how much roughly?  Thanks everyone.

[Runner]

they dont use a modulater valve

[Ghoste]

The vacuum modulator is more commonly found in Ford and GM transmissions from the pre-fwd days.  The same function is performed in a Torqueflite by what we usually and somewhat incorrectly call a kickdown linkage.
The port on your intake is for other needs such as power brake boosters and 68 and 69 headlight doors.
Now as for the car not wanting to shift into third, it could be a number of things.  To start, check the adjustment on the kickdown (properly called a throttle pressure linkage) linkage.

[RT DAVE]

Thanks.  I actually have a LOKAR kickdown assembly on the car and have had some trouble with the car getting into third way too late on the highway.  Also, the thing doesn't seem like it downshifts on the highway once it gets in third.   I shortened the cable yesterday and now it really won't go into third until way too late, so I guess I'll just put some more slack in the line.  The instructions I had when I bought the kit weren't very good.  I wish I could find them.

[Ghoste]

The Lokar ones are bad.  The ones as sent with the Mancini repackaged Lokar are a little better.
I'm pretty sure I've posted them here before.

[Ghoste]

Try this.

[RT DAVE]

Thanks everyone.  I just loosened her up a bit at the carb and she seems better.   It's in the storage facility now, so you won't get any more stupid tech questions from me for about five-six months.   

[is_it_EVER_done?]

I have never been a fan of cable operated kickdown linkages due to the flex, and subsequent tightening/loosening due to the torque of the engine. However if you keep in mind the fundamental requirement of a kickdown, and adjust it accordingly, they work fine.

The important thing to remember when adjusting one is that the carburetor and kickdown need to reach maximum opening at the same time. The problem can arise in that even if adjusted perfectly while the car is sitting on jack stands, engine torque and body flex will effect a cable in ways that a rigid linkage will not experience.

The best ways I have ever found to minimize this is to jack the car up at the front of the drivers side wheel prior to setting the adjustment (in order to simulate torque and body flex), and expect to loosen the adjustment if it isn't working just right in real world use.

On my own cars I won't use them, but if you don't want to change to a rigid system (my preference), I think you will find that this helps, or at least gets you close enough to be able to find the ideal adjustment with just a fraction of an inch adjustment either way.

[Ghoste]

I have one on mine and I'll never go back to a rigid system unless I'm doing a concours restoration.  When I had the rigid types, it seemed like all I did was fuss around with it and it was never right.  I  have had the Lokar on there for a few years now and other than a periodic check, it's given me zero problems.
Each car is different I suppose.  I don't understand how the torque or body flex can affect the cable though.  It's attached to the intake and the trans and nothing else.  If the engine moves, the cable moves with it.  If the body moves, the cable stays with the drivetrain.

[is_it_EVER_done?]

I have one on mine and I'll never go back to a rigid system unless I'm doing a concours restoration.  When I had the rigid types, it seemed like all I did was fuss around with it and it was never right.  I  have had the Lokar on there for a few years now and other than a periodic check, it's given me zero problems.
Each car is different I suppose.  I don't understand how the torque or body flex can affect the cable though.  It's attached to the intake and the trans and nothing else.  If the engine moves, the cable moves with it.  If the body moves, the cable stays with the drivetrain.

Just because you cant understand this doesn't make it any less real. I was pointing out problems and causes with cable kickdowns, and how to minimize them. What I said was actual experience, If you can't understand how a ridged system "follows" the other ridged parts better than a cable system, particularly when you have extraneous forces (throttle pressur and it's resultant flex), than I suggest that you refrain from posting on the subject.

I don't intend to be ultra critical, but lately your posts in response to mine or those of others, requires that a "hard line" be taken as you are not offering up an alternative opinion with a basis, but instead are questioning pure physics, logic, and experience.

If your experiences are different, please share them as that's how we all learn (and you have had many great points over the many months this board has been in effect). But to make defacto statements while admitting you don't understand something is a dis-service to everyone.

[Ghoste]

If you read carefully, you will find that my experiences are different and that is why I post them.  I would have to say that your evidence in the posts you are speaking of is no different than mine.  Personal experience.  We have each offered anecdotal evidence and nothing more.
You still have not explained how a cable is more susceptible to body flex than a rigid mechanism.  Both are firmly attached at each end to the portion of the drivetrain which is moving independantly of the body.  The part between those two attached points does not care whether it is a free floating cable or a steel rod.  It is doing nothing but going along for the ride.
I will continue to post on this thank you as my experiences are actual as well.

[Runner]

I have one on mine and I'll never go back to a rigid system unless I'm doing a concours restoration.  When I had the rigid types, it seemed like all I did was fuss around with it and it was never right.  I  have had the Lokar on there for a few years now and other than a periodic check, it's given me zero problems.
Each car is different I suppose.  I don't understand how the torque or body flex can affect the cable though.  It's attached to the intake and the trans and nothing else.  If the engine moves, the cable moves with it.  If the body moves, the cable stays with the drivetrain.

Just because you cant understand this doesn't make it any less real. I was pointing out problems and causes with cable kickdowns, and how to minimize them. What I said was actual experience, If you can't understand how a ridged system "follows" the other ridged parts better than a cable system, particularly when you have extraneous forces (throttle pressur and it's resultant flex), than I suggest that you refrain from posting on the subject.

I don't intend to be ultra critical, but lately your posts in response to mine or those of others, requires that a "hard line" be taken as you are not offering up an alternative opinion with a basis, but instead are questioning pure physics, logic, and experience.

If your experiences are different, please share them as that's how we all learn (and you have had many great points over the many months this board has been in effect). But to make defacto statements while admitting you don't understand something is a dis-service to everyone.

      i also would love to have the laws of physics explained to me.   how is a cable going to be more prone to body flex when it NEVER touchs the body. i dont buy it.   i have 3 arengineering throttle brackets and lokar kickdown cables on 3 different cars.   i personally love them, they are cleaner and way easier to deal with when using an aftermarket intake/ carb.

   

[John_Kunkel]

I have never been a fan of cable operated kickdown linkages due to the flex, and subsequent tightening/loosening due to the torque of the engine. However if you keep in mind the fundamental requirement of a kickdown, and adjust it accordingly, they work fine.

I, too, fail to see how engine torque can tighten/loosen a cable. Engine torque is lateral and the cable runs longitudinal.

The important thing to remember when adjusting one is that the carburetor and kickdown need to reach maximum opening at the same time.

An often claimed but incorrect assertion. If you take note of the factory linkage operation you will find that, when correctly adjusted, the linkage has additional movement when the carb is at WOT. In fact, adjusting the linkage so that the carb and trans lever reach full travel together you will most often experience late part throttle upshifts and, occasionally, no WOT upshifts.

The problem can arise in that even if adjusted perfectly while the car is sitting on jack stands, engine torque and body flex will effect a cable in ways that a rigid linkage will not experience. The best ways I have ever found to minimize this is to jack the car up at the front of the drivers side wheel prior to setting the adjustment (in order to simulate torque and body flex), and expect to loosen the adjustment if it isn't working just right in real world use.

Total nonsense.

On my own cars I won't use them,

On that we agree but for different reasons.


My objection to the cable setup (especially the Lokar) is the one-size-fits-all approach to their design. In order for the cable setup to work correctly the travel of the carb attach point and the trans lever attach point must closely match; given the variety of transmission levers and carb throttle levers, the travels seldom match.

With mismatched carb/trans lever travel the trans will tend to operate correctly at one end of the range of travel but not both. The OP's situation is common of the Lokar on a Mopar. The Bouchillon cable setup is engineered for a Mopar and will suffer less from mismatch than will the Lokar.