Early shift, no down shift

#1
And before you say it, I searched already. That's how I got to this point. So I have an 85 t type, and the speedometer wasn't working. It threw a code 24 at me, I read that there would be an issue if the speedometer wasn't working. I bought the 100" speedo cable instead of the two piece like it originally had. I replaced the cable today and have the following issue:

I didn't realize that the car has the 140 mph dash. Speedometer cable replaced and code 24 went away, but at 25 mph its reading 50 at 50, reads 75 etc. I don't care about that, the issue is the car now shifts from first to second before rpms climb, then quickly from second to third and then locks into overdrive. It doesn't downshift when slowing down so it lags, or does out at a light. Any suggestions? I've attached a picture of the piece I removed. Thank guys!!
 

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Steve V

Steve V's Automotive 757 560 2782
#2
TCC lock-up is controlled by VSS. If the input is off(appears yours is badly) that "may" be your issue. Unscrew the cable at trans or unplug TCC on the side. Go for a short ride. See if it's fixed or not.
 
#3
Sorry to sound incompetent sir, but a little bit of help. So you're saying that if I unscrew the speedometer cable at the trans and it shifts normally. If it shifts normaly, what would I do next, if it doesn't, then I'm assuming that its the TCC or VSS. I'm sorry for so many questions, I just love this car and want to make this thing work. Also, can you tell me what that thing in the pictures is? It was between the two speedomater cables, maybe I need to reinstall it, maybe it converted the two?
 

Steve V

Steve V's Automotive 757 560 2782
#4
Sorry to sound incompetent sir, but a little bit of help. So you're saying that if I unscrew the speedometer cable at the trans and it shifts normally. If it shifts normaly, what would I do next, if it doesn't, then I'm assuming that its the TCC or VSS. I'm sorry for so many questions, I just love this car and want to make this thing work. Also, can you tell me what that thing in the pictures is? It was between the two speedomater cables, maybe I need to reinstall it, maybe it converted the two?
No problem. If it's corrected the issue is the speedo is reading wrong and giving the ECM bad info. Perhaps there was a reducer in the old 2 piece cable?
 
#5
Thank you so much. I'm going to be trying it tomorrow afternoon. Maybe I'll order a shorter upper cable, insert that reducer and see how it works out as well! so happy that this may not be another 200 dollar fix!
 

Steve V

Steve V's Automotive 757 560 2782
#6
Thank you so much. I'm going to be trying it tomorrow afternoon. Maybe I'll order a shorter upper cable, insert that reducer and see how it works out as well! so happy that this may not be another 200 dollar fix!
You need that reducer or another speedo that reads 85 mph
 

mikestertwo

Well-Known Member
#7
Sounds like you have a bad TCC solenoid. You didn't notice it before because the converter was never locking because the speedo was disconnected. Now that the speedo is connected the converter locked and now won't unlock because the solenoid is bad. Putting the reducer in to correct the speedometer will cause the computer to see a slower speed than actual. I would just remove the overlay on the speedometer if that's what it has or get an 85 mph speedometer.