I just installed a transmission in my 1999 pontiac bonneville. It seems to hesitate when pulling out from a stop. It is almost as if it does not want to go in to first gear but it goes directly into 2nd then 3rd and so on. Once it goes it has no problem you can't even feel it shift. I have someone tell me the new/used transmission may need calibrated to my vehicle. ????.... Not sure. Any ideas?

Nothing needs to be calibrated. As long as it'* a compatible transmission it should be fine. Is this a new, rebuilt, or salvage yard transmission? Have you checked the fluid level to make sure it'* full? Did you put a new filter in when you installed it.

No new filter when I installed it. It is a salvaged used, already pulled and has 90 day guarantee. Fluid level is full.

I was just wondering myself if it could be something electrical.

Kind of sounds like the input band isn't engaging right away. Perhaps have the oil pressure tested. Post up what you have. Also, have the car scanned. Many transmission codes will not trip a SES light. But will store a code. Post them up here.

Okay thanks will do that tomorrow.

Dan... what'* an input band?

The foward band is definately engaged or there would be a problem with all foward gears. The input piston would typically cause a bang start if it was leaking badly and the pressure had to ramp quickly to overcome the seal issue.

Did you buy the same gear ratio? When you were asking about calibration, that was the first thing that came to mind. The way to check if your gear ratio is correct with the ratio programmed into your pcm is to have it scanned with a capable tool that can see the gear ratio when driving. Third gear should be 1:1 if the programming is correct.

Down partway on the right is the soleniod chart. It wouldn't appear that you are having a soleniod issue. Because 1st gear has both on. And another gear shares each on soleniod. When you have a bad soleniod, you lose two gears.

I guys I am not following you with the olenoid issue are you sayin if first gears solenoid is out then there would be another gear out, if so what other gear or are you saying first gear has it'* own solenoid. And another thing too is that if I drop it down into first manually out seems to work and has more power then driving it with it on auto shift. Another question too can I scan the car for codes with an OBDS scanner or does a trans shop have to do it?

Here'* my thought Bill. Look at the chart on page 4 of the ATSG manual. You will see that the input clutch is on for 1st gear. It'* also on for 2nd gear but is not effective. Every other gear does not use the input clutch, it'* only 1st gear. From what I under stand the OP is saying it'* not starting out in first, or it seems that way. So, either the clutches are bad, or the band is bad.


As for the solenoids. There are 2 solenoids. 1-2 and 2-3

1st gear, on on
2nd gear, off on
3rd gear, off off
4th gear, on off

So you can see if the 1-2 solenoid is stuck off, you would lose 1st and 4th gear, if stuck on, you loose 2nd and 3rd. Does this help?

One other question, do you have reverse. If you do that rules out the input clutch because reverse also uses the input clutch.