I know there’s quite a few of these “will this transmission work” threads but I have not found a definitive answer for mine and am ready to throw in the towel.



I have a 2006 HHR 2.4 with an automatic (which I presume is the 4T45E which took a dump last night

I found a wrecked 2007 Cobalt locally, his has the 2.2 engine but from what I have studied up on the transmission should be the same one, but the guy is pretty sure the wiring inside is different and it will not work.

if this is so, maybe the wiring can be changed from one to the other? Yes I can find a “right” one at a salvage yard for 3X the price (plus core), tax, and I have to drive a good way to get it but this one is the next town over. It sure would be handy.

It is not beyond me to rebuild his too. Hesitant to rebuild mine as there is something defiantly broken inside making horrible grinding noises when I try to put in gear so I’m sure hard parts will be needed

 

The automatic transmission in all years HHR was the 4T45E , might be slightly different final drive ratio but still works in all years.

 

Sure but what about being from a cobalt? This is the million dollar question

 

Well I guess what I’m hearing on a FB group it won’t work. I suppose it’s time to suck it up and just buy what’s known to work. I could have sworn I read somewhere that they were all interchangeable perhaps they were wrong or I read it wrong

 

Why does Facebook say it won’t fit ?
The 06 HHR and the 07 Cobalt are both built on the GM Delta platform. In other words they share the same drivetrain. So should be the same transmission. Maybe different gear ratio.

 

Something about the wiring being different and having to get a different ecm etc. that’s why I didn’t understand. I was sure I read somewhere that they were all the same with the exception of small gear ratios

 

Ok, listen to FB folks, spend your money. The ECM controls the engine , the TCM controls the transmission. You don’t change them , just the transmission. The TCM harness plugs into the TCM .

 

https://www.fs1inc.com/24243901-2006...-24234503.html


Same part number TCM

https://www.fs1inc.com/24243901-2007...-24234503.html

 

Same part numbers but the SKU #’s are different. I’ll assume that’s because of the application descriptions being different.

 

All a moot point anyway, I still do not have the car home yet I had no choice to leave it where it broke down about 20 miles from here, the restaurant I pulled it to is being kind enough to let me leave it there until my day off Monday but they did ask if I could move it around back so I gladly obliged. (Busy duck hunting season here in Southern Illinois, everything is filled up). I was able to climb under it a bit last night and to my surprise I see the axle on the passenger side just hanging there. I just assumed with the loss of drive and loud banging that something in my transmission had let go but it looks like the axle just came out.

It’s a bit much to fix in a gravel parking lot so I still need to go get the car onto my trailer and bring her home but my suspicion is that when I did the lower control arms I either did not get the axle pushed in far enough, or perhaps the clip that holds it in is a bit too worn. Seems like I remember the axle wanting to come back out a bit too easily. It probably would not hurt to replace the c clip.

As long as nothing is damaged, fingers crossed, this will be a fairly straightforward repair