Hi so I've had so many problems with this suv. Right now my drive shaft rear snapped at the front part of it so we've taken it out. Now my tranny is messing up so I know I need to fix the drive shaft but I feel my problems with this started long ago and I'm wondering if they don't stem from the ecm cuz all the symptoms that everyone has described I either had or still have from hard shifting to battery and alternator replacement to have no shift and having to pull over turn off then restart and then it'll shift overheating transmission.

Hi so I've had so many problems with this suv. Right now my drive shaft rear snapped at the front part of it so we've taken it out. Now my tranny is messing up so I know I need to fix the drive shaft but I feel my problems with this started long ago and I'm wondering if they don't stem from the ecm cuz all the symptoms that everyone has described I either had or still have from hard shifting to battery and alternator replacement to have no shift and having to pull over turn off then restart and then it'll shift overheating transmission.

Merged a duplicate thread for the same issue with this thread.

Okay, need to unpack this:

How many miles on this vehicle?

How many miles have you owned it?

I am assuming this is a complete list below.

I've never heard of this happening on one of these. Has it been damaged somehow? . . . like in an accident or driven over a boulder or lifted by a poor forklift driver at Copart or . . . ?

It should be able to run without the rear drive shaft without changing the transmission'* behavior.

The ECM did not cause the drive shaft to snap. It could be related to the rest of it because it has a play in it, but I don't see any real diagnostics performed here as of yet. Blaming the ECM without diagnosis is an expensive way of condemning a part for being there while symptoms happened.

Could be related, or not. What is the fluid level?

How many miles since it was last serviced?

What gear is it shifting from and to when it shifts hard?

Has it had the 35R wave plate issue repaired?

Could be related, or not. Often, a battery and alternator will fail on older cars at nearly the same time. We need to know more about the symptoms that led to these being replaced.

This could be a number of things, but if the light for [overheating transmission] is illuminated, then likely it will need an overhaul.

It has 164,000 miles and I have done diagnostics and it comes up like with 10 different codes and I'm not sure what they are but I will look them up again and repost them later

What'* a 35r plate. And thank you you answered my Q on if it can be driven with the rear drive shaft out

Still looking for answers on these:

How many miles have you owned it?

I am assuming this is a complete list below.

I've never heard of this happening on one of these. Has it been damaged somehow? . . . like in an accident or driven over a boulder or lifted by a poor forklift driver at Copart or . . . ?

What is the fluid level?

How many miles since it was last serviced?

What gear is it shifting from and to when it shifts hard?

Has it had the 35R wave plate issue repaired?

Thanks for the odometer reading!

It would be good to know the codes.

Many 2007 and 2008 and possibly some 2009 Acadias and Outlooks were produced with an issue where, after some amount of driving, the 3-5-R wave plate would fracture and tear up the inside of the transmission case. This would cause the transmission to fail and need replacement. If caught very very early, it was repairable. Mine didn't have the issue until 141,000, and I caught it very quickly, and was able to take it to a transmission shop that was willing to do the specific repair. GM was forced to offer an extended warranty on all of these vehicles, but the warranty was for 120,000 miles after the odometer reading as of the vehicle'* original purchase odometer reading. The wave plate itself is a wavy (instead of flat) spring steel plate that softens clutch engagements in 3rd, 5th, and reverse gears. When it fails, it leaves extra space in that clutch pack, which allows the engine to rev up during gear changes into and out of 3rd, 5th, and reverse, then slam into the next gear like dropping the clutch on a manual transmission.