Hey guys, I made a thread about this a couple months ago but after getting the correct connector it still has the problem. Whenever the trans shifts into 2nd it'll drop rpms like normal and then drop them again and chug. If I leave the speed sensor unplugged it shifts perfectly. the transmission is a rebuilt one with an estimated 3000-4000 miles on it. detent cable is also correctly set.

Skip to :30 seconds to see and hear it clearly. It may seem like I took my foot off the gas but I kept my foot on the gas at the same position the whole time this happened.

 

seam like early trq converter lock up-

 

That's what I was thinking, maybe the wrong driven gear is sending the wrong speed to the ecm?

I have a 17/37 drive/driven gear ratio for my 2.77 rear and 26 diameter wheels

 

So I unplugged the white 4 prong connector for the torque converter on the side of the trans and my problems went away. I'm wondering if it's safe for the trans to drive around like this for a little while until I can wire in an internal torque converter lockup kit?

I haven't had lockup for over 1.5 years so I'm not worried about that, I'm just wondering if that plug controls anything else besides lockup?

 

You can wire a -manual- lock up switch with ease, by using the ADL port.

 

That plug is only for TCC lockup purposes.

RBob.

 

The 1982 -1986 700R4's have 2nd, 3rd & 4th lockup. To get rid of 2nd lockup (which all 1987 & up 700R4's did), you will have to go through the wiring on the valve body and disable the 2nd gear lockup. Once this is done it will perform much better. GM was playing the CAFE games and trying to get maximum mileage "on paper" but in reality it made things much worse. When GM looked at the "real world", then they got rid of the "annoying" 2nd gear lockup.

 

I've been reading into adding the switch but would prefer not to have to deal with a switch. It's a possibility for sure though

 

Wow thanks for the clarification. I was pretty sure when I got the rebuilt trans it was a later model 700r4 so I'm assuming by pairing it up with my 86 trans am it's causing this weird issue that I didn't have with the first transmission. Along with disabling the 2nd gear lockup should I disable the 3rd gear lockup as well and just have it lock up in 4th?

 

Thank you for clarifying that. Been driving around with it disconnected and love finally having a working speedo without a check engine light. First time I haven't had one since I got the car lol

 

You are going to disable the 2nd gear lockup, leaving 3rd & 4th only. The switches are on the valve body. The 3-4 switch on the valve body is next to the 2nd accumulator that bolts to the separator plate in the corner. Do not use a manual lockup switch that will not unlock automatically when you go to WOT or when you let off the throttle. This setup tends to tear up the torque converter clutch. If you have the transmission out update the input shaft capsule to the 1995 & up GM "dual feed" capsule. This will improve the lockup and improve the torque converter clutch life without making lockup annoying as when you remove the capsule altogether.

 

Thanks again for the information and clarification. the trans is still in the car if that's what you were referring to. I'd update the input shaft capsule if it was right there next to the switches, otherwise I'd rather not tear more into the trans than I already have to. Transmission work intimidates me lol.