[Tommy Davis]

I recently bought a 84 suburban with a 350 and 700R4('85 year). All of the emissions have been pulled off. It has a edelbrock 1406 carb and 2101 intake on it. My problem is there is no vacuum to run the lockup on it and we use this vehicle for towing. I was told to use this article and hook it to my unused port on my carb. <a href="http://www.73-87.com/garage/lockup.htm" target="_blank">http://www.73-87.com/garage/lockup.htm</a> But, I was told the vacuum needs to decrease as my throttle is pushed. Can anyone please suggest to me on what to do. BTW, I am not very mechanically inclined. Only know the basics and learning by reading repair books.

[ March 28, 2003: Message edited by: Tommy Davis ]</p>

[willys36@aol.com]

The vacuum doesn't lock up the tranny per se. It is used to unlock the lock-up feature when you are accelerating so use any port on your intake manifold or base of the carb to feed the switch.

Get the straight story by calling these guys.

<a href="http://www.bowtieoverdrives.com/" target="_blank">http://www.bowtieoverdrives.com/</a>

[ March 27, 2003: Message edited by: willys36@aol.com ]</p>

[airworld2]

early production gm trucks had 2 vaccume sensor's
one one the fire wall that did require a vaccume signal from carb to close and complete the circuit!the other one was used to unlock torq converter under heavy throttle. but to answer your question paper clip in the sensor will make to connection complete but over rides the sensor!
to test circuit remove plug on trans case driver side , with key on use test light ground to trans pan and probe wires e mail me for more infor for free(not a web site that sells products)

[Tommy Davis]

airworld2 I emailed you about my findings. Please email me back and let me know Thanks Tommy

[bonuts]

Wow thanks for the link "Willy's" I've been looking for the set-up to put the 700r4 in my
S-10.

bonuts

[Crosley]

I've been trying answering tommy's question on another bbs...

He does not seem to understand the 700 does not need a vacuum conection to the tranny.

The site he is quoting shows the lock up setup on a 200R4 tranny. Although tthey function the same, the placement of parts is differnet.

========== I will also add; the creator of the page does admit he is unsure about lock up in 3rd gear on early 700's since he is not a mechanic. Early 700's locked up the converter in 2nd gear too. this was eliminated in later units.

[ March 29, 2003: Message edited by: Crosley ]</p>

[Tommy Davis]

Crosley, I am very sorry I am bothering everyone on this subject. I have been talking to a few trans shops here and they Have told me I do need to get the vacuum working before they will rebuild my trans. If they do the vacuum, they will charge me over $2000. If I do the vacuum, It will only cost me $950. I am just trying to save some $. That is why I am trying my best to understand what you all are telling me.

[airworld2]

There are many ways to set lock up torq converter
to activate, and many ways to change what gear and mph that it will apply.A vist to your local radio shack and gm dealer you can get wire and pin that will allow you to connect lock up to fuse box with out vaccum switch provides lock up in 4th gear only when it really necessary.just a after thought 200 r4 can be made to have lock in 4th without removal of trans pan with pressure switch outside.

[ March 30, 2003: Message edited by: airworld2 ]</p>

[Jason]

I know what you mean about the vacuum source to lock up the converter, I used to own an '84 camaro bought used with a rebuilt 700, the converter would never lock up and I happened to notice a small black box under the hood with a vacuum hose and wire connector going to it,..The wire connector was disconnected, I plugged it back in and it locked up as normal.
Now if all the computer and wiring were gone yours won't lock up either.

I would do as suggested and set it up to lock up in fourth gear, this seems pretty common and several companies make kits for this, you really don't even need a kit. So if your trans shop doesn't know of this you need to go somewhere else.

[Crosley]

I would find a new shop if there is that much difference from the tranny only to the vacuum system hook up included at $2k.


As mentioned , lock up in 4th gear only would probably be the way to set the tranny up for the best service and some ease on your wallet.

There is the possiblity your tranny shop will not know how to perform the simple mods needed for lock up only in OD.