We have a 08 Saturn astra,the transmission grinds &wont shift o go into gear,only grinds. If I turn engine off I can put it into gear,if I then push clutch to floor with the trani in first gear and start the car it will idle and not try to move until I begin to let the clutch out the car moves forward but when I push the clutch to the floor I cannot get it out of gear. There is no hydraulic fluid leaking out

Anybody have any input as to what might be going on?

 

Sounds like clutch slave cylinder is bad, an issue with the release bearing not moving far enough (possibly as a result or for another reason), or the pressure plate is weak and cannot fully disengage the clutch.

Check clutch master cyl to ensure it is not dry or low).

My bet is on the slave cyl. Especially since you are getting irreproducible behavior when clutch pedal is on the floor.

Do the same as described above (shifter in 1st, key off, clutch pedal to the floor).
Start the car and hold the clutch in for several minutes straight.

My prediction is that the car will start creeping forward eventually because there is not enough hydraulic pressure in the failed clutch slave cylinder for it to keep the vehicle from going into 1st gear. The release bearing's position is controlled by the slave cylinder, and as the hydraulic pressure creeps downward, 1st gear engages.

Putting the clutch pedal to the floor at this time no longer corresponds to the same movement distance of the clutch release bearing....it's a shorter distance so the tranny is unable to be shifted out of first gear.

Try starting the car in neutral and pump the clutch pedal 15 times full travel, then hold in and try to shift into 1st --- STOP if it grinds. This is a cheesy way to try to build pressure in the slave cyl faster than it can dissipate.

As for parts,


GMPartsnow has a clutch slave cyl for $18.

Somehow I sense that there is more to it since there is
at Partsgeek

Dorman Clutch Slave Cylinder

$102.33

Out of Stock
Part Number: 29131-05511465
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There is some funky UNIVERSAL slave cyl release bearing combo at partstrain:

Centerforce Clutch Release Bearing and Slave Cylinder Assembly
Universal - Fits all vehicles (SCARY)
PART#: C78601878 MFR#: 601878

Not sure what universal means in this context.
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Not sure what this means in terms of repairing it; may be simple if the slave cyl is external to the transmission; if it is internal, then the questions become
1) is it accessible
2) how much work to get to it
3) how you bleed the master-slave combo
4) do I want to take this on.

Note that the parts for the Astras were never made in quantities sufficient to support whatever was purchased for very long.

The fact that RockAuto is completely out of stock of these slave cyls makes me think this is a common issue with the Astra.

In all honesty, I'd recommend you join an Astra-specific forum to figure out how to definitively diagnose and repair the issue. There are no Astra users currently active on this forum. I'm just doing a general diagnosis based on the symptoms and giving you ways to test if I am on target or in left field.

You are of course welcome to stay on our forum too.

I just want you to get advice from other Astra folks who have been through what you are going through so that you get the right answers, the right fix, and back on the road....

 

The Astra has an internal slave like my L series. If that is the problem the tranny has to come out.