Weird sporadic shift hesitation in '97 LS4???
#1
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Weird sporadic shift hesitation in '97 LS4???
A few weeks back, I did a partial drain of the tranny fluid. About 2 quarts came out so that is exactly what I filled it back up to.
Well, next day I'm driving (engine still cold) and from a stop, I press the gas (first gear) and the car doesn't move, I back off the gas and press it slowly and it shifted into gear. This happened three times so I came back home and pulled the tranny dipstick. The fluid was halfway on the <cold> mark. The tranny drain plug is fine so I poured in about 6-7 oz. more fluid and this brought the fluid to normal levels if just a touch high.
Drove it for the next week and it was fine until yesterday when trying to go from a stop (shifter in <D> and it hesitated again.
Car has 105K miles and the tranny fluid has been changed with the incermental drain schedule every 10K. Fluid is a bright red so it's not burnt or such. Might the low condition allowed some air to cycle throughthe system?
Thoughts?
Well, next day I'm driving (engine still cold) and from a stop, I press the gas (first gear) and the car doesn't move, I back off the gas and press it slowly and it shifted into gear. This happened three times so I came back home and pulled the tranny dipstick. The fluid was halfway on the <cold> mark. The tranny drain plug is fine so I poured in about 6-7 oz. more fluid and this brought the fluid to normal levels if just a touch high.
Drove it for the next week and it was fine until yesterday when trying to go from a stop (shifter in <D> and it hesitated again.
Car has 105K miles and the tranny fluid has been changed with the incermental drain schedule every 10K. Fluid is a bright red so it's not burnt or such. Might the low condition allowed some air to cycle throughthe system?
Thoughts?
#2
When draining from the pan, most of the fluid will stay in the torque converter anyway. After adding fluid, with your foot on the brake pedal, slowly cycle through all the gears. P>R>N>D>2>L and back up again, letting the tranny catch each gear for a quick second. Then check the fluid level.
Only use the recommended ATF, and check to see if there's any leakage around the housing, especially if the tranny has been opened up/rebuilt before. I doubt it's air cycling through the tranny causing the hesitation, but something is letting the inner clutches slip. A tranny that is dying from old age will start to slip like that, but usually through other gears too (not just from a standstill). Plus it will often times have burnt fluid.
While you're at it, check your rear end too.
Only use the recommended ATF, and check to see if there's any leakage around the housing, especially if the tranny has been opened up/rebuilt before. I doubt it's air cycling through the tranny causing the hesitation, but something is letting the inner clutches slip. A tranny that is dying from old age will start to slip like that, but usually through other gears too (not just from a standstill). Plus it will often times have burnt fluid.
While you're at it, check your rear end too.
#3
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Tranny has been good till the low fill. I was planning on draining it again so I can closely monitor the fill level this time around.
Rear end diff fluid was changed about 20k miles ago with Mobil 1 gear oil.
Thanks.
Rear end diff fluid was changed about 20k miles ago with Mobil 1 gear oil.
Thanks.
#4
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Did it again but today in reverse. I checked to see if the clutches are slipping and they don't feel like it to me. Seems more like it is coming out of gear then going back in so that may be the hesitation as it sync's. I may check to see how the engine and tranny mounts are holding up. I wonder if if these are worn that the slight play may be causing the tranny selector to think it is not in the right position.
#5
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A local mechanic told me the tranny was sensitive to fluid levels. Drain it and refill to the exact level. As it turned out, I'd overfilled it by about 7 oz. (I simply put back what drained from the pan thinking it was correct.) At the right level now...no problems. Whew.
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