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Tranny shifts weird after adding 3.54 gears

  • Thread starter Thread starter MagikDraggin
  • Start date Start date
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MagikDraggin

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After replacing the 2.59's with 3.54 gears and having the ECM flashed to reflect the change, the tranny shifts really strange now. On a normal take-off, it will go from 1st to 4th gear by the time the speed is 15 mph. Around 35-40, the overdrive will engage.

So in effect, I am always driving around in 4th gear unless I come to a complete stop and then right after the car starts to move, it shifts into 2nd, then 3rd and then 4th, zap, zap, zap, just like that. Sometimes, it feels like it just goes right from 1st into 4th at one time.

Is this normal after different rear end gears are put in?
 
That dosen't sound right. My 94 which has 3.73 gears and a shift kit tranny shifts great. The shift to second occurs at about 15 mph where it should but then shifts nice and smooth up to 45 mph where it goes into overdrive. If your going into overdrive slower than 45 or so something is not right. Also the 2-3 shifts should be spaced out.

Sorry I don't know how to fix it but sounds like a program change is needed.
 
It may be in the computer program itself, 96 is a 4L60E-computer controlled.
 
You probably need them to reflash your ecm. Sounds like you received a bad reflash. It is also hard on the transmission to drive that way.
 
In a conversation with the one that did the reprogramming, I am told this is perfectly normal. It isn't that the transmission is actually shifting faster than it was, it is simply doing it at a much lower speed (same rpms though) due to the big jump in going from 2.59 to 3.54 gears.

I hope he is willing to stand by his decision if this A4 decides to give up the ghost in a few weeks.

I took the car out on a quiet country backroad for some serious testing this afternoon and found that when I romp on it with no preloading of the stall converter, I got some wheelspin, but not excessive. The tranny shifts out of 1st into 2nd gear at 38 mph 6000 rpm with a very pronounced screech...not the typical "chirp" I had expected. It was still in second gear pulling very hard at 70 mph when I backed off the throttle.

I can't wait to get this sucker to the drag strip and see what it will do in the quarter. I can smell 12's already.....
 
i got 3.75's coming to me soon. so you guys are telling me that if i dont get on it i'll be in overdrive earlier than i was with the 3.07's?
 
regalniz said:
i got 3.75's coming to me soon. so you guys are telling me that if i dont get on it i'll be in overdrive earlier than i was with the 3.07's?

the wheels are spinning slower but the motor is spinning faster so the answer is Yes :)

it will only engage OD a few mph slower but the shifts from 1st to 4th will come quicker unless you romp on it. if not you could be in Drive at 30mph.
 
regalniz said:
i got 3.75's coming to me soon. so you guys are telling me that if i dont get on it i'll be in overdrive earlier than i was with the 3.07's?


Yup, that's about what it amounts to. With normal acceleration from a stop, my OD comes in at 39 mph. I can slow down to make a turn on a residential street and the tranny is still in OD but pulls strong right up to speed with no problems, like hesitation or bucking. I think the 2400 stall convertor is helping here a lot, though.

The "experts" tell me this is normal.....it's just going to take some getting used to, that's all.
 
after the gears are in ill most likely get a stall converter. i already have a hayden tranny cooler installed. what brand and stall speed do you have?
 
regalniz said:
after the gears are in ill most likely get a stall converter. i already have a hayden tranny cooler installed. what brand and stall speed do you have?

Mine was provided by TPIS, and they said it was manufactured by Borg Warner. I went with their knowledge and reputation on it. Since I am not intending on racing this vette, I got one with lockup capabilities because I do a lot of highway driving.

So far I am very satisfied with the results.
 

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