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Discussion Starter #1
First let me ask the question, Is there any other reason for no reverse other than a broken sunshell gear?
History: 04 envoy 170k miles rebuilt motor unknown miles since rebuild. Tranny went out this fall (drive band) bought a used lower mileage trans at a reasonable price. put it in and in true "learning a lesson" fashion broke the pump. pulled trans back out, replaced the pump and put the trans back in. After everything was back in & fluid filled and all hooked back up I have no reverse, 1st & 2nd gear feel like they are binding bad. I have 3rd & drive but it also turns the wheels in neutral- like its in drive.
I pulled the linkage & there appears to be nothing wrong with the shift mechanism. Tried manually shifting the trans (while up on blocks) from on the side of the trans but it doesn't make any difference. all fuses are good no lights out.
I am this close <-----> to sending it off to the salvage yard. #notgonnapullitagain. any ideas?
 

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2008 gmc envoy_sle
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631 Posts
hi and welcome to the site.

odd that the motor would need a rebuild but as for your trans issue. if your sure the linkage is correct and pump was installed properly. the lower mileage trans is likely the issue.
 

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Discussion Starter #3
I suspect the motor may had a valve job not a complete rebuild, common issue is burned valves (low compression on 1 or 2 cylinders). Great cars up to about 230k-250k miles then expect bigger issues. I have had 3 of them I bought off auctions and they usually don't have any maintenance records.
back to the issue, Is there a solenoid or valve that controls just reverse?.
 

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2003 chevy trailblazer_ls
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I suspect the motor may had a valve job not a complete rebuild, common issue is burned valves (low compression on 1 or 2 cylinders). Great cars up to about 230k-250k miles then expect bigger issues. I have had 3 of them I bought off auctions and they usually don't have any maintenance records.
back to the issue, Is there a solenoid or valve that controls just reverse?.
There are no electronics involved with reverse. It's hard to say what's wrong with it. I would have to drive it, but I'd say something in the trans messed up. As far as will any other thing besides a broken sun shell cause no reverse, yes there is. The low reverse clutch could have failed and the reverse input clutch could have failed.

The quick thing that comes to mind to fix it is if the linkage rod inside the pan is not connected. That can make not go into all the gears.
 

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Discussion Starter #5
update

So the latest is, I went back over the whole manifold, checked all the solenoids & valves, pulled anything removable from the bottom of the transmission & checked for proper ohms. replaced the TCC solenoid (was just a little off on ohms) already replaced everything else... put it all back together and... still had no reverse. So, I decided to drive it off a cliff... or not. My wife said I didn't have life insurance =P. I drove around the block checking the shifting as I drove. it seemed to shift better as I went, then for some reason it actually went into reverse! got all gears back too. I suspect some foreign object just got into something & just finally broke free. I did notice a small part of the TCC valve tip was chipped, so maybe? I don't care any more it runs & went up for sale yesterday =) Thank you for your input!:thumbsup:
 

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2003 chevy trailblazer_ls
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So the latest is, I went back over the whole manifold, checked all the solenoids & valves, pulled anything removable from the bottom of the transmission & checked for proper ohms. replaced the TCC solenoid (was just a little off on ohms) already replaced everything else... put it all back together and... still had no reverse. So, I decided to drive it off a cliff... or not. My wife said I didn't have life insurance =P. I drove around the block checking the shifting as I drove. it seemed to shift better as I went, then for some reason it actually went into reverse! got all gears back too. I suspect some foreign object just got into something & just finally broke free. I did notice a small part of the TCC valve tip was chipped, so maybe? I don't care any more it runs & went up for sale yesterday =) Thank you for your input!:thumbsup:
Sounds like magic.
 
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