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Discussion Starter #1
Hello,
I found something interesting today. I had a 95 Z28 convertible come in the shop today. The customer said that he couldn't shift into manual first. Upon further inspection, i found that there was a plastic stop in the shifter mechanism that was preventing this shifter from selecting manual first. The stop was defiantly factory.

I got to looking on the internet and found that there are two different shifter part numbers for the car 12558644 (For 2.73 rear end gear) and 12558643 (for 3.23 gears). So it seems that the difference is in the final drive ratio. For some reason GM didn't want the user to manual shift to first depending on the final drive ratio but why? And which ratio had the restriction?

Has anyone else had this issue where you cant shift into manual first? I popped the cable off the shifter and pulled out to select manual first and it works fine... Very strange
 

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Has it always been like this?
Or did something break and now won't shift into first gear?
 

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Discussion Starter #3
No, this car had defiantly never been able to shift to first from the factory. I looked closely, and the stop had been formed with the rest of the plastic detent piece that fits on the shifter.
 

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I found the manual 1st gear explanation in GM Service Information. No where does it state that this is different between gear ratio's. All V8 auto trans cars had a 4L60E.
However I can confirm that based on gear ratio, GM did offer two different shift controls. Why however is a question for the engineers. I can't find it. - this reply from my GM Parts Mgr

The part numbers given are for a controller according to GMPARTSDIRECT.com
 

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Discussion Starter #6
Thanks Everett! That is what i was looking for. I really think that this was a defective shifter that wasn't caught by the factory, dealership, or the first owner. I took a dremel tool and cut the stop down to where the shifter would go down into first(about 1/2" of plastic) and all is well. It's just very strange. I couldn't find anything in the owners manual either- i figure that they would have put a note in there if this is what the engineers intended. I also think that as many camaro's were produced with these shifters, I wouldn't be the first one to be bringing this up on the internet.
 

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You're welcome, glad to help.
Good you have manual first gear by manual means.
 

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Maybe 1 of 1 prototype that got out the door by mistake like the carbs that would get 100 mpg that we heard about in the 60's or 70's? Stranger things have happened...:wink2:
 
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