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Discussion Starter #1
Brand new (about 150 miles) Darrin built trans. Shifted fine prior to getting dyno tuned last week. And was fine for about another twenty miles after tune. Trans functions were not altered from stock as Tim said Darrin takes care of all that through the valve body when he builds them. What is happening is the car is not shifting out of second gear sometimes while driving in town (around thirty). When normally if the OD is left on it will shift to third and into OD. Checked MLPS alignment tonight and is a little better I think but still not as it should be. The car shifts fine once you accelerate out of town. Anyone have any ideas? I've looked through a crap ton of posts with no luck on this. Thanks in advance for your help.
 

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1997 Thunderbird 4.6, 1998 Mark VIII LSC
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Have you done any data logging to see if the PCM is commanding any gears other than 2nd when the symptoms are present?
 

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Discussion Starter #3
No, I'll have to borrow a lap top and do some data logging when I get a chance. Anything specific in the trans to watch or should I log everything available for the trans?
 

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1997 Thunderbird 4.6, 1998 Mark VIII LSC
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Commanded_gear and desired_gear are the PIDs to watch. If commanded_gear is always 2nd, then I'd venture to say it's most likely an MLPS problem. If commanded_gear is different than the actual gear you're in, then there may be problems with the [wiring to the] shift solenoids (neither being on will give you 2nd).
 

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Discussion Starter #5
Commanded_gear and desired_gear are the PIDs to watch. If commanded_gear is always 2nd, then I'd venture to say it's most likely an MLPS problem. If commanded_gear is different than the actual gear you're in, then there may be problems with the [wiring to the] shift solenoids (neither being on will give you 2nd).
Data logged tonight and the x cal read third on commanded and desired gears but was definitely in second. Also accelerated with OD on and I am 99% sure the trans is going from second right to fourth and also skipping third when it downshifts. I am noticing it shifts properly while the trans is below normal operating temp. Three times now I've driven the car and it shifted fine until I had driven it about two or so miles (in town). No CEL and the OD off light is NOT flashing.
 

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Discussion Starter #6
How likely is it that my problem could be in the transmission main wiring harness? It got soaked with trans fluid last year from a leak in the old trans. Sprayed it with contact cleaner at the time it was giving me issues but wasn't perfect by any means and I also noticed the wire insulation looked like it had shrunk back on some of the wires maybe a half inch or so. It fixed the problem I had at that time but wonder if it is the culprit here.......
 

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PostWhore, The AFDB is on a lil tight.
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My wire harness had all the insulation coming off the wires at the main bulkhead trans harness. I personally cleaned mine best I could with power washer. I had to rewrap all the wires on both sides of the harness for about an inch on either side. The insulation wasnt even there it was just dirt. Was a mess that was. So dont be surprised if your wire insulation just crumbles away at the harness when you begin to mess with it.
 

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Discussion Starter #8
Am I correct in thinking that if either shift solenoid were bad I would have issues with shifts other than just the 2-3 shift? If I remember correctly the 2-3 shift utilizes both solenoids so therefore whichever one wasn't working would affect the shift that utilizes that particular solenoid. Or am I way off base here?
 

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1997 Thunderbird 4.6, 1998 Mark VIII LSC
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1st gear uses SS1, 2nd uses neither, 3rd uses SS2, and 4th uses SS1 and SS2.
 

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Discussion Starter #10
1st gear uses SS1, 2nd uses neither, 3rd uses SS2, and 4th uses SS1 and SS2.
So if solenoid 2 was not working the shift on 3 and 4 would be malfunctioning right?
 

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Discussion Starter #13
I am pretty confident I will have the solution to this later today........
 

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Discussion Starter #14
Finally got this fixed, not exactly sure which thing fixed it but upon the suggestion of Alan AKA Dirty Dog (whom I would like to give a thanks to and highly recommend for any transmission work anyone may need done. He was glad to lend his knowledge when the guy who built the trans was nowhere to be found after several calls AND emails which he always claims is the best way to reach him- unless of course he hasn't received your money yet then a phone call will reach him immediately!!!!!!!.......) So thank you Alan your customer service is outstanding and others could learn from you. Anyway back to what was done to fix my issue, Embalmer and I dropped the trans pan and out fell the 2-3 retainer (initially thought it was left out but later found it in the fluid pan). We replaced both the shift solenoids and tcc solenoid, reinstalled the retainer and siliconed some bare wires on the main transmission harness. Everything works again so issue resolved
 
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