2003 trailblazer transmission questions

[Kyknight40065]

Hey guys,

I am currently in the process of replacing the transmission in my 2003 4.2 LT 4wd with one from a salvage yard. My question is what model years transmissions are compatible with the 2003? Everything I am seeing is that only 2003's are compatible. Is that correct? It seems that other model years should be compatible. Also, is it absolutely necessary to remove the catalytic converter assembly? It looks like there is room to remove the transmission without dropping the exhaust assembly. I have the transfer case unbolted and am now ready to remove the transmission. Any helpful hints?

[Kyknight40065]

I might also mention that it is a state of emergency here so I have the next couple of days here to slowly remove the transmission while we are snowed in.

[Jrgunn5150]

Man, info is all over the map on that. Internally, parts are largely swapable a crossed the year's. The went to the PWM Trans in 1997, after that thing's get cloudy.

For simplicity's sake, I think I would stick to an 03 donor. Or have your current unit rebuilt, prices on that range from 600 to 2500.

[Aries]

My question is what model years transmissions are compatible with the 2003? Everything I am seeing is that only 2003's are compatible. Any helpful hints? Any helpful hints?

2002-2005 model years, your also gonna need to get a re-flash after the install.

There's one bolt in the cross member that will need to be cut once it lose in order to be removed so when you get your replacement grab the cross member bolts. When your getting the replacement grab a few of the trans line retainer clips, easy to remove with a 90* pick but can be a bastard to install blind folded You will also need 3 ft of extension to get to the top two bell housing bolts and a set of mechanical fingers helps pull those bolts out. Napa sells the Auto Trak II and the Kooler Kleen trans line flush the cheapest, buy online with discount code then pick up in store.

[Norcrosski]

Why would you need a reflash?

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[Aries]

The 4L60E is a electronically controlled transmission, as it wears and starts to act up the ECM adjust the other engine functions accordingly for best performance (this all depends on the model year and the type of program installed). When a different transmission is swapped if it's a re-man or one from a salvage yard the ECM will perform in a manner it's familiar with, the old trans. This explains why the vehicle will shift to soon or to late during acceleration after a RRR. Doing a re-flash will clear any codes and let the ECM start new, some say pulling a fuse or disconnecting the positive battery cable will work as well. Ask five mechanics get five different answers.

[Kyknight40065]

Well. I have ran into an issue. How do you remove the crossmember bolt on the driver's side. The nut is off and it slides, but it won't slide out enough to release the cross member. It is hitting a large black plastic box. Evap canister? Whatever it is, I can not get the bolt out. I have tried to pry on the box to move it a little towards the rear of the vehicle, but no luck. How do you remove this box? I don't see any bolts. If I can't get the box to budge, I will never be able to drop the cross member. I've been at it for a while now, but cannot get that last crossmember bolt out.

[Aries]

Cut it, I've read where the vapor box can be released with a flat blade screw driver but I've never been able to do it and didn't want to waste time figuring it out.

[Kyknight40065]

Aries,

Thank you for the advice. I started to cut the bolt, but then I thought well how would I cut it at the salvage yard when I pull the salvage transmission so I took one more look. It took all of 30 seconds to move the box after I figured it out. On the side towards the front of the vehicle you will see two clips. If you take a flat head screwdriver and insert it in the slit in the middle of the clip, the clips will pop right off. Just give it a good push towards the front of the vehicle and they come loose. It will probably be a bear getting them back together, but the bolt is out and the crossmember is off.

[Aries]

It took all of 30 seconds

That's to funny. I've done 4 transmissions and have never been able to get those clips to pop. Glad you got it.

[v7guy]

It may be of interest, while I was admittedly pretty foggy headed after being up 30 something hours, when we were giving Regulator a hand putting his trans back in I don't recall us having to put the exhaust back in. Maybe Dave will pop in here to confirm it in the morning.

[Kyknight40065]

Okay guys. Next question. How many bolts do I have to remove to get the transmission off? I dropped the cross member but the trans did not lower in the back and I am having a hard time getting to the upper bolts. How many total are there? Also, do I need to unbolt the starter? I currently have 9 bolts removed.

[Norcrosski]

The trans will come out with the starter in place but to remove torque converter it needs to be removed

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[Jrgunn5150]

Okay guys. Next question. How many bolts do I have to remove to get the transmission off? I dropped the cross member but the trans did not lower in the back and I am having a hard time getting to the upper bolts. How many total are there? Also, do I need to unbolt the starter? I currently have 9 bolts removed.

Possibly tipping the trans upwards, towards the floor may help you get the upper bolt's out.

[Kyknight40065]

Okay. I now have 11 bell housing bolts out. Are there any more?

[Aries]

I believe 11 is it. Did you remove = the 3 bolts holding the torque converter to the flex plat. The alignment dowels can have a little corrosion but with some force it will break free. That bracket at the top can be a pain also, on the reinstall it will need to be tied up as high as you can get it.

[v7guy]

I would assume it's the torque converter bolts holding it up as well. You have to pull the trans back a lil and then reach a wrench in to get to the torque converter bolts.

[Jrgunn5150]

I'm a little lost as to how you're coming up with the bolt count in the first place? Are there not 7 bolt's from the bellhousing to the engine on a I6? Then four from the converter to the flexplate, which I guess total's eleven... Then you should be able to pry it back from the block, with it supported of course, and ASSuming you took care of the lines, linkage, harnesses, etc.

[Kyknight40065]

Actually, there are 11 bolts on the bell housing alone. I haven't unbolted the torque converter bolts yet. That should be 3 more.

[Jrgunn5150]

Actually, there are 11 bolts on the bell housing alone. I haven't unbolted the torque converter bolts yet. That should be 3 more.

The this reaffirms that my next GMT360 be a V8 also lol.