700r4 lock-up converter help

[factory2wdblazer's]

dose the lock up have to be hook up on a 1990 700r4 transmission???.... i have drove the truck and it get's all four gear's. but while driveing threw town doing 30-40 when in over drive it seem's like it's sliping while in over drive...is it because iam in town doing 30-40 and in over drive is that to high of a gear for driveing in town??? is it like driveing a stick shift in 5th gear threw town you know how it would be sliping........pretty much i'am confused on the lock up converter deal

[N2TRUX]

Use it or loose it. If the transmission is equipped with a lock up convertor it must be hooked up, or it will burn the transmission up.

Look here for tons of details....www.bowtieoverdrives.com

[Jonboy]

It will also cause the vehicle to run hot.

[rcbildr]

I have an 83 shortbed I just replaced the 700R4 in and it's not locking up. I talked to a local shop and I was told that it is supposed to lock up in 2nd and overdrive. IIRC when it locks up it feels like a manual tranny when you let off the gas the engine will aid in slowing the vehicle down...like compression braking. The shop also told me it's not a big deal if the converter doesn't lock up in second, but not locking up in overdrive is the problem. The tranny will generate too much heat/slippage and cook itself. I'm pretty sure my situation is just an adjustment of a switch. The 83 is diesel and there is a switch on the injector pump I had to swap out when I replaced the engine (bought the truck with a bad engine and the replacement engine came from a rig that had a TH-400). I was told to put the tranny in drive (so it won't go in to overdrive) and that would be ok until I can get it to lock up properly...but that's on that back-burner until I can get the rear end replaced or fixed, the pinion bearing is shot.

I saw something online somewhere that I want to talk to the shop about. There is a place that sells a device that plugs in to the electrical connection on the 700r4 that locks up the converter based on the line pressure on the tranny. IIRC you have to drop the pan and make a couple connections in there and then on the outside you have to hook up a 12v power wire to it. When the time comes, I want to look in to that and then take the truck to the shop and have them make sure everything is set up right.

Hope this helps.

[factory2wdblazer's]

well i took the truck to the tranny shop today to get the lock up on the converter hooked up and he said. that the lock up dose not have to be hooked up. he said that if the t.v cable is not set right it will burn up the transmission. he has the same tran's in his 79 box van for the past 10 year's and has no problem's, this tranmission shop has been in business for 20 year's..........this was the frist tranny shop i visted... on the way home i stop at another local tranny shop and they could not stop stressing the fact that the tork converter had to be locked.........iam confused

[James McClure]

Factory. I am a 33 year Chevy mechanic. The TTC has to be working for the trans to last & heres why. On TCC transmissions there is a restrictor in the valve body to reduce fluid flow to the cooler because in TCC lock the fluid gets to cool. If the TCC is left off the trans will overheat. Most of the heat generated by an auto trans is in the converter. When TCC is locked, in effect you don't have a converter. Bottom line is TCC has to work or the trans will end up toast.

[factory2wdblazer's]

thank's james mclure.....ok so what would be the right way to hook it up?.

[James McClure]

How the trans is hooked up is a function of the application. There are a bunch of different hookups depending on the number of connections in or at the trans. Your best bet is go to the trans shop that told you it had to be connected or go to your local dealer and have them do it. Jim

[tvblazer78]

B&M has a cool kit that come with all the parts that you need and you can change what speeds you want it to lock up in. I think it is only $65.00 or so.

[Jonboy]

I would avoid the firs shop at all costs. It is true the TV cable has to be hooked up, but so does the TCC. It is supposed to lock up in 3rd & OD.

[BIG BEARDED BASTARD]

this is a great thread as i too just recently put a new 700r4 in my 89 jimmy....the trans i bought has a tcc bypass built into it...but i have the same problem driving through town....the trans guy told me i need to install a toggle switch in the power wire to the tranny to be able to lock and unlock the tcc for intown driving...does this make sense?? and if it does, which wire is the power wire?

[tvblazer78]

This is the best way to go.. I had one on my last one..

Provides control of converter lockup through vehicle speed on GM transmissions with a lockup converter. Eliminates converter lock and unlock cycling and premature unwanted converter lockup avoiding engine lugging and spark knock. Provides lockup at highway speeds for fuel economy. Can be used for converter lockup operation when converting a non-lockup equipped vehicle to a lock up style transmission and converter. Provides dash mounted control to govern converter lockup at any speed between 30 and 90 mph. LED tells whether converter is locked or unlocked.
Fits GM TH200, TH350, TH700R4, 4L60, & 200R4.

[factory2wdblazer's]

well guy's again today i visted a couple more transmission shop's in my local area.. i had stoped by a transmission shop that i know of has been in busniess for 10 year's. a older gentelmen say's the same exact thing the frist transmission guy told me yesterday. transmission shop told me.. that there is no need for the lock up to be hooked up on the converter.. he say's it will not hurt the transmission at all.. he has these transmission's in his vechical's for year's with no look up hooked up....he say's he's been playing with these transmission for year's and the lock up is not needed at all...........these transmission shop's that are telling me this information about the lock up on the converter no haveing to be locked up have been in busniess for year's.. one shop has been open 20 year's and the other shop a little over 10 year's.. they are currently running 700r4 transmission's in a few of there car's with the lock up not hooked up.. one guy has a 79 box van 700r4 transmission converter lock up not hooked up and has no problem's has been driving like that for ten year's.. and tow's his race car's., he said he build's these transmission all the time.. and that he can hook it up if i want he to.. but he said there's no need to. you would be paying me do do some thing to your transmission that is not even need to be done said he would not feel right taking my money for nouthing.......i visted a few more shop's and they said it must be hooked up.. but all the transmission shop's that say that the lock up has to be hooked up, can't explain how it work's.. or will say i have to do some reserach on it and give you a call back, cant or won't explain how it work's just quick to say yes i can fix it for about $300.00 to $350.00.........bring it in......................................................................the transmission shop's that say i don't need the lock up hooked up have these transmission's in there own car's.. for year's with no lock up hook up... one guy has his 79 box van with a 90 700r4 tansmission has had it in there for over 10 year's with no lock up hooked up and pull's his race car's all over with it...............

[factory2wdblazer's]

if you go goggle performance automotive and transmission center... and you click on it, and go click on 700r4 swap information. it stats that on the 82, 83, and 84 transmission's must have the lock up hooked up or will fry the tran's..but stats that 85 and newer to 92 dose not have to be locked up.. i beleave because of a change they made........good information on this site..............

[N2TRUX]

Please look at the site I posted above. Here it is again-www.bowtieoverdrives.com.

I have no idea why the shops keep telling you that you don't need a transmission with a lockup converter hooked up. Please take their advice if you wish. When your transmission burns up take it to them and have them rebuild it for you too.....

[tvblazer78]

Well this is new to me, I think I had 2-3 of them and all the guys I talk to say it has to lock up in 4th and your kick down has to be set just right or you will burn it up. I guess my thinking is it;s not hard to make it lock up plus you can run down the road with lower RPM's when it's locked up. It's easy to do and you will not have that in the back of your mind saying I think it is ok, you will know it's ok..

Trav

[blazer2007]

I,ve had the same response about a 200 tranny,don,t need to be locked up and if you want he told me to use a toggle switch,the only thing I would hurt not using the lockup was some bad gas milage but not much,I just don,t know

[tvblazer78]

Here is more info on locking it up.

http://67-72chevytrucks.com/vboard/s....php?p=2698885


And more about why you need to lock it up..
http://67-72chevytrucks.com/vboard/s....php?p=2934803

Last one.
http://67-72chevytrucks.com/vboard/s....php?p=3093628

[factory2wdblazer's]

what's up guy's... i had a gentelmen at a wrecking yard today tell me if i want the converter locked in overdrive. i'll i have to do is run power to the "A" wire on the transmission harness when in overdrive and it will lock. and to un lock it disconect the power... and that the wire is purple dose any-body know if this is true?? can you hook it up like this. ...........

[factory2wdblazer's]

ok i've been reading some information off the site's that are posted by member's and it say's "A" conect to a hot and "D" to a ground. can any-body confrim this? has any body done this?

[tvblazer78]

Check out the links I posted I think all the info that you will need will be in them..

Let us know how it goes...

[factory2wdblazer's]

do i have to take the pan down to find out what wire is "A" and what wire is "D"... i can buy that open/closed vacume switch at a part store or do i have to go to the dealer

[factory2wdblazer's]

well guy's about a half hour ago i ran a power wire to the "A" pin on the transmission plug and i grounded the "D" pin... i used a (on and off )switch.. when the transmission shifted in to over drive a would wait a sec or two and flip the switch and the converter would lock....
.
.
.......i just tryed this and WOW i can't beleave the big diffrence it make's when the converter is locked i don't have a tach right know but i know the rpm's drop by a least 300, 400, rmp's. and has no slip in over drive like it use ............................