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2007 saab 9_7x
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11 Posts
Discussion Starter · #1 · (Edited)
I've had my 2007 Saab 9-7x mothballed for about a year due to annoyance issues that made it too irritating to drive (crap like the key not releasing from the ignition after shutting down, windows getting stuck, locks on certain doors not working, DOA engine kill after driving 10 feet from anti-theft if it decides it doesn't like the key today (didn't they get sued for people dying when this happened at highway speed), "memory" mirrors that always looking up at the clouds).

Anyway, I usually charge the battery every couple months and take it down the road just to keep the brakes from seizing up, tires from dry-rotting, etc. The last go round it probably sat for 6 months. Today I hook up the battery and as usual it starts on the first try, but there is no reverse! Transmission fluid is leaking from the front right area when it's running (I think it's A/T fluid cause it's redish) but it will NOT engage reverse... it just revs like it's in neutral. It will go forward, but unfortunately there is a wall in front of the car. The level of AT fluid on the dipstick still looks to be OK.

I know the loss of reverse is a common thing for Trailblazer / clones due to failure of a sun gear(?) -- so I'm wondering if that's the kind of thing that just goes bad sitting around. Or, alternatively, could a leak be causing an issue with the hydraulics in a peculiar way so that only reverse is affected? Maybe there is a particular part involved in engaging reverse with the tranny that is known to "freeze up" if left sitting too long? Maybe there are tactics for "unfreezing" it?

Thoughts?
 

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2003 chevy trailblazer_ls
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627 Posts
There are no electrical concerns that will effect reverse, so if it has no reverse then it is definitely a problem inside the trans.

First check to see that it is full of fluid. If so, drive it and see that it goes through the forward gears correctly. if it stays in first a long time then shifts and stays there and never shifts to OD then the sun gear shell is bad. Normally that is all that ever causes reverse to go out on a 4l60.

It is possible the linkage may have become disconnected, which is why it's important see if all the shifter postilions work. Like if when it's in park the trans really is in park and the vehicle will not roll. Then shift to drive. Once in drive move to neutral and if it still tries to drive. If so then either the linkage is loose or you have some serious intentional malfunction.
 

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Registered
2007 saab 9_7x
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11 Posts
Discussion Starter · #3 ·
There are no electrical concerns that will effect reverse, so if it has no reverse then it is definitely a problem inside the trans.

First check to see that it is full of fluid. If so, drive it and see that it goes through the forward gears correctly. if it stays in first a long time then shifts and stays there and never shifts to OD then the sun gear shell is bad. Normally that is all that ever causes reverse to go out on a 4l60.

It is possible the linkage may have become disconnected, which is why it's important see if all the shifter postilions work. Like if when it's in park the trans really is in park and the vehicle will not roll. Then shift to drive. Once in drive move to neutral and if it still tries to drive. If so then either the linkage is loose or you have some serious intentional malfunction.
Thanks for the insight! As soon as I can get it pulled out of the garage and up the driveway, I'll run through the gears like you suggest.
 
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