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I have a 94 saturn sc2 that has a clunk and slam sound as i ...
Sent to Car Experts April 12 10:13 AM

I have a 94 saturn sc2 that has a clunk and slam sound as i put the car into reverce and it slams into gear on second and third. This is an intermitant problem sometimes it wont do it at all. I have taken it to two different mechanics and had the motor mounts and trans mount replaced and the second time a fuse was missing and replaced along with upper valve body to the tranny car drove fine for 1 day and the problem is back. It seems to me as if the car is going in gear hard when put into reverce it makes a clunk noise and car shifts into revervce rather hard and when driving as gears change with speed it cluks and slams into the next gear hard enough to cherp the tires. But the problem will go away at any time cold or hot. what els may be my problem seems to me as if somthing is trying to catch up with the engine speed.

Edited by Customer (name blocked for privacy) on April 12 2006 at 10:22 AM

 

Optional Information:
1994 Saturn sc2 4cyl 16 val

Already Tried:
replaced motor and transmission mounts. Had a fuse put in that controls pressure in the tranny and have the upper valve body replaced alot of money but not fixed.

Customer (name blocked for privacy)
Status:  Closed   Value: $20
Answer
April 12 10:36 AM (22 minutes and 33 seconds later)
         
REPLIEDCheck Mark

Greetings!

The symptoms you describe seem to be a common problem with this transmission. In general, the harsh shifting is usually the result of excessively high line pressure. The usual cause is a pressure regulator valve in teh valve body sticking in the bore; Saturn has a redesigned valve body to correct this concern. I realize you have already had the upper valve body replaced; was it with the new design, or was the replacement a copy of the original faulty design, a reman unit that may not have been manufactured correctly, or a used one with the design flaws? If it was not a new one from Saturn, of the latest part # revision, the new one may have the same fault as the one that was removed. It is interesting that it worked well for one day after the replacement; that would seem to indicate that they were on the right track...

Another cause could be a piece of dirt or debris that lodged in the pressure regulator solenoid, or in the valve body, resulting in high line pressure.

You don't mention any codes or other diagnostic information. Fault codes and/ or transmission data would be most helpful in trying to isolate the location of the problem. I see you also had to replace a blown fuse; did the shop that did the transmission work ever determine teh cause of the blown fuse? Fuses blow when there is high current draw in a circuit. If the circuit containing the pressure regulator solenoid is experiencing a current draw high enough to cause a fuse to pop, then there is a very good chance that the solenoid may be failing;shorted solenoid windings or a solenoid that is mechanically sticking will cause current draw to spike.

Is teh shop that is doing the diagnostic work equipped with the factory scanner for this vehicle? The factory scan tool (Vetronix Tech-2) allows the technician to actuate the various solenoids in the transmission to measure current draw, and check for proper operation. If not, you may want to consider taking the vehicle in to a GM (preferably Saturn) dealer for diagnosis. having teh proper equipment and diagnostic procedures available makes the whole process go so much quicker, and is therefore much cheaper than trying things to see if they help...

I hope this is helpful to you; if so, an accept would be most aprpeciated! thanks!

Steve7654 -- Auto Service Technician99% Positive Feedback on 1735 Car Accepts
27 yrs ASE L1 Master Technician, Service manager
Reply
April 12 10:52 AM (16 minutes and 23 seconds later)
         
Reply to Steve7654's Post: The valve body was replaces by witha aftermarket assemble i was told that the one saturn uses as the original part had steel parts with alumminun sleeve and would eventully ware out again that the part he used was a better part to replace it with as for the fuse it was missing not blown.I just perchaced this car so i didi not remove it to be missing as for the tech he had my car for five days ran every test he could no codes other than high pressure so valve was replased but like said when i put the car into reverce it slams into gear is if somethig is not conneted to the tranny to tell it to go into reverce soon enogh or as if the drive shaft is catching up and the car jurks to go in reverse.
Customer (name blocked for privacy)
Answer
April 13 7:58 AM (21 hours and 5 minutes and 49 seconds later)
         
ACCEPTEDCheck Mark

Here is a copy of a Saturn TSB regarding harsh shifting:

____________________________

BULLETIN NO.: 01-T-09

SUBJECT:
Harsh Shifts No Shifts, and/or No TCC Operation with Transaxle Related DTCs Set (Replace Transaxle Connector and Harness

MODELS AFFECTED:
1994 - 2001 Saturn S-Series vehicles with automatic transaxles (RPO MP6 or MP7

CONDITION:
Some customers may comment about harsh transaxle shifting and/or erratic transaxle shifting. One or more transaxle-related diagnostic trouble codes (DTCs) may have set. The Malfunction Indicator Lamp (MIL) may or may not be illuminated depending on what DTC is set.

Images available only to Customers.

One or more of the DTCs shown may be set and indicate what circuits are affected

CAUSE:
Due to normal powertrain vibration, the transaxle wiring may flex and cause a circuit to open inside wire insulation near transaxle connector. In some cases, insulation will look distorted at point of open circuit

CORRECTION:
Perform procedure in this bulletin to replace transaxle connector (P/N 21024415).

_____________________________

As noted in the TSB above, Saturn has had some problems with the electrical harness inside the transmission causing harsh shifting such as you describe.

The other likely cause is still a valve body problem; I would return the vehicle to the shop that performed the valve body replacement and let them continue diagnosis of the problem. if they are stumped, the Saturn dealer service department would be the next place to go; they likely see this problem often and also have factory technical assistance available for tough diagnostic problems.

I hope this is helpful to you!

Steve7654 -- Auto Service Technician99% Positive Feedback on 1735 Car Accepts
27 yrs ASE L1 Master Technician, Service manager
Reply
April 13 9:53 AM (1 hour and 54 minutes and 42 seconds later)
         
Reply to Steve7654's Post: Thank you for the ansure to my qwestion I called my mech the day it started to act up again and he told me the car needed to rememorize the pressure settings to operate properly not sure what kind of crap that is when i fix a car its fixed i dont have to wait to fix itself but anyway the car has not had the prblen for a few drives now so the next time it happens i will bring this info with me to the mech and have him fix it for free since i have already spent 800.00 to get this problem solved in the first place.
Customer (name blocked for privacy)
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