new motor now hard shifts

[MNorby]

well, it still isn't locking up, or at least dropping the RPM like it used to before the new motor. I think I got the shifts softened out but I';m afraid to use OD if it isn't locking up. How would you tell with a cicut tester if it is getting power to the wires to lockup?

 

[Thunder]

Beings you proababally dont have any of the computer controlls on your new motor. The lock up isn't going to work.
You will need to get a lock up switch kit. Or if you are handy with electrics just wire in a switch your self and turn it on when in OD. Just dont use it at speeds under 45 mph.
Here's a site with a bunch of info you might need<a target="_blank" href=http://www.700r4.com/Tech/TCC/>Torque convertoe lockup info</a>

 

[MNorby]

thanks for the link. I see your point but the only thing on the old motor and the new one that was different in regards to electrical was the carb and I swapped it so teh 400 has the old 305 carb. I may have a bad wire or something but I don't see how. I wil look into that switch idea. Thanks for the help guys, you're all awesome!

 

[dyeager535]

I believe the TCC gets 12V when the vehicle is on, and the circuit is grounded to lockup. So with the key in the run position, if I remember correctly, you should see voltage on one of the connector pins.

Pins A and F on the ALDL connector, when jumpered, *probably* will force the converter to lockup. Whatever position on the ALDL connector is ground and TCC is what you need to jumper to force lockup, IF the trucks are set up this way. Cars are, but lockup on them is controlled entirely by the ECM.

 

[MNorby]

I found this on that web page you gave me. If I basically wire it in like this then I can just put a toggle switch in and turn it one when I hit OD right? Is it safe to drive it now even though it is not locking up like it is supposed to? Should I just run in 3rd gear instead? Thanks again for the help
<a target="_blank" href=http://www.700r4.com/Tech/TCC/GM_Switch.htm>http://www.700r4.com/Tech/TCC/GM_Switch.htm</a>

 

[dyeager535]

You could wire it up that way, but to me, if I'm going to have an automatic transmission, I want it to be automatic. Besides, leaving the converter locked (by forgetting to flip the switch) probably doesn't help things anymore than not running it at all.

If it were I, I'd run it as is, but I'd fix the problem ASAP. Seriously. I believe you said you have a tranny cooler, so the only difference will be the extra heat generated by it not locking up..thats no different than driving in 1st or second though. I just don't think I'd let myself be fooled into thinking that "it works ok without being hooked up, so I won't fix it" as happens sometimes.

 

[MNorby]

ya, since I have an aux cooler I should be safe for the week till I can get to fixing it the weekend or sooner. I have been drining in 3rd for the last week because I don't wanna burn it up. I live 12 miles from town and w/o using OD I am getting very crappy mileage. Just about gotta fil up every day if not every other day. Anyhow, with it the way it is it's probly hurting it just as bad running in 3rd than I would be running in OD? I really don't wanna make it a manual lockup because that defeats the idea of an auto tranny.

 

[dyeager535]

I'm just going on the assumption that if you aren't locking the converter up, you are heating the fluid up no matter what gear you are in. Although OD is only two clutches in the 700 (I think, it is in the 200) I'm not aware that there is any other difference if you are in OD, except if it is locked up or not. You likely have the same "line pressure" holding the cltuches together, and as long as you can keep them cool, then you shouldn't have any problems.

I mean, think about it. It doesn't matter what gear you are in, if the tranny gets hot, there is no one gear that has the ability to cool itself more than the others...the fluid has to be cool, and thats it.

 

[MNorby]

that makes alot of sense. I think I just read somewhere about not using OD if not locking up. Eventually I wanna put of of those aux tranny filters w/ temp gause in but that is down the road. Tonight after work and shooting I'll see what I can find. I don't know what is missing that is causing it not to lockup but I have the same carb on it that the old 305 had. I may call the co that rebuilt this tranny 2 years ago and ask if they know where that extra wire goes. I looked up quadrajet on the net and found some had a throttle possiotion sensor that mines doesn't but that extra plug I have looks like the shape of what the port on teh carb is supposed to look like. You don't suppose the wring from the tranny is made so it can work either or with a TPS or the vacuum actuated switch? Is there any other test to see if it is locking up besides touching the brakes and see if it drops RMP? I am wondering maybe it is locking but the brakes aren't unlocking it, is that possible?

 

[dyeager535]

I'm sure anything can be rigged up, like you say, brake switch not working right, etc. Obviously someons been in there messing stuff up, so who knows? The system is exceedingly simple on the earlier trucks ('82 up to who knows when, at latest '87) and doesn't require much at all in the way of wiring and components. I'd verify that first there is voltage getting to the plug at the tranny.

I'm not going to go back through all of the other posts, but you need Vacuum, VSS, and probbaly temp input to lock the transmission up (as well as the brake not being depressed) when the system is working correctly. Cruise is tied into the VSS, so there exists the possibility the VSS has been hacked up, or that the cruise/VSS box (I'm thinking thats what your truck uses to lockup too) has been tampered with. But if you aren't getting voltage when you should be, theres your first problem to solve.