2001 Saturn SC2 Reverse Slam and Bang

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MALORY
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we have a saturn sc2, 2001, with roughly 100,000 mileson it. when going into reverse the car seems to rev up slightly and slam into gear ( also a slight delay in shifting into gear) there is also some timeS when accel. it will bang into the next gear. we are now getting a whirring/squealing noise untill its into overdrive. TRANSMISSION PUMP???
Mar 26, 2007 at 12:41 AM
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MERLIN2021
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only way to know for sure is to pressure test it, pull the pan off and see if there is any clutch material or metal in the fluid...
Mar 26, 2007 at 3:06 AM
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PEPPERMRJ
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Saturn trannies are kinda weird. They are sort of a hybrid using solenoids to shift gears.

That said they are prone to a condition called "revese slam". This is caused by either gummed up or worn reverse passage in the valve body. Now if the condition has not been ignored for too long there is a possible (not 100% but not bad) inexpensive cure.

In the beginning you get the reverse slam. The cure reguires a tranny fluid change, with the additive of your choice, and letting it idle in reverse for a certain period of time. If you are interested it trying this let me know and I will post the exact procedure.

If this does not work after 2 attempts it is time for a valve body rebuild and replacement. As things deteriorate the nut on the input shaft will normally back off. You know have to rev the engine just to get it in reverse. Time for a pro unless you are up to the task of removing the end cover and re-torque the nut.

Lastly if let go too long you have no reverse and forward is acting up. Especially 2nd gear as it shares it's clutch with reverse. Time for a toal rebuild.


Saturn's automatic transmisions should have their fluid changed at prescribed intervals using Saturn OEM filters and synthetic trans fluid. this will insure long life.

Good luck and let us know. :)
Mar 30, 2007 at 2:39 PM
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MALORY
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Thanks for the information on this, it most likley was the valve body, but the pinion pin came loose and wore a hole on the casing which in return lost all the fluid and my daughter continued to drive, resulting in a rebuild, I love my daughter!!!!
Thanks to all !!!

these are not fun trannys to swap out
Apr 17, 2007 at 4:30 AM

Suggested Repair

Pressure-test the transmission and inspect the pan fluid for clutch material or metal. Reverse slam on these units is often a gummed or worn reverse passage in the valve body; a fluid change with additive and idling in reverse may help if caught early, otherwise rebuild or replace the valve body. If the input-shaft nut backs off or a pinion pin loosens and holes the case, fluid loss requires a professional rebuild. Use Saturn OEM filters and synthetic fluid at the prescribed intervals.

Conversation Summary

A 2001 Saturn SC2 with about 100,000 miles revved and slammed into reverse with a delay, sometimes banged into the next gear, and whirred or squealed until overdrive. Experts recommended a pressure test and pan inspection for debris, and explained that reverse slam is common from a worn or gummed valve-body passage, with fluid service as a possible early fix and a valve-body or full rebuild if it progresses. The owner later reported a loose pinion pin wore a hole in the case, fluid was lost, and continued driving led to a transmission rebuild.

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