The tranny I built for a buddy of mine is starting to act weirdly. It slips but only when the transmission downshifts into 1 and maybe 2 gear. Pretty sure only in 1st. When you hammer it from a stop it doesn't do it. Nor does it do it from highway speeds. To get it to do it you have to floor it just after the transmission shifts into 2nd gear, it downshifts to 1st pull for a split second and slips all the way to redline and stays right there. Any ideas. I know it is not the clutches because they are brand new. Does anyone know how to check the pressures and can you do it with a tech II.
Slipping when downshifting
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Are those bands grabing and holding? If you just did some tranny work, you may need an adjustment.
You've got my attention, elaborate please.tan said:Are those bands grabing and holding? If you just did some tranny work, you may need an adjustment.
You don't say what type of trans. I had a similar problem on my GTP 4t65e-hd. Replaced torque converter and clutch packs. (I didn't, I had it done). After driving a few days began to slip when down shfting into 2nd and 1st. Got worse quickly. Soon began to slip when up shifting into 2nd. I took it back and the guy said the band was slipping he showed me what was happening. He worked on it a short while and I was off, trouble fixed. I'm not exactly sure what all he did, all I cared about is that it was fixed.
Does anyone know how to adjust the bands on a 98 GTP. Thanks.
Howdy,
Bands can be adjusted in this trans, but it is not likely your problem. Apply pin length on each bands servo determines adjustment of band. This is set at the factory, and almost never needs changed. It sounds to me like a low pressure, or low pressure rise situation. If you air tested all clutch pistons, then I would look at sealing rings on the input drum and on the rear of the driven sprocket support. If those are o.k., I would look for loose channel plate bolts or loose valve body bol ts. if these are o.k., then a valve body or p.c. solenoid are likely the cause.
BIG JEFF
Bands can be adjusted in this trans, but it is not likely your problem. Apply pin length on each bands servo determines adjustment of band. This is set at the factory, and almost never needs changed. It sounds to me like a low pressure, or low pressure rise situation. If you air tested all clutch pistons, then I would look at sealing rings on the input drum and on the rear of the driven sprocket support. If those are o.k., I would look for loose channel plate bolts or loose valve body bol ts. if these are o.k., then a valve body or p.c. solenoid are likely the cause.
BIG JEFF
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