Hard Shifting

[McClane]

I have a 95 sl1 that's shifting hard. Here's the story.

A while back we took the car in because it was leaking trans fluid. Turns out our filter had a hold in it. So the shop changes it. We leave and get a little down the road when the car shifts hard and the check engine light came on. So we go back and the guy tells us that its just air bubbles in the lines and it'll stop in a few miles. 10 miles later, no luck so we went back. He looks at the car and says that they had put the wrong filter on it, so he rechanges it. The car ran fine, but the check engine light was still on. He then says that they had bumped the trans temp sensor and it came off, so they plugged it back in. The light goes off. A few days later on comes the light and the car shifts hard. The light doesn't stay on long, mostly only after the hard shift. We take a look at the sensor again and notice the wires are stressed. After we un-then re plugged the sensor, the car ran fine for a day or two. Now here we are with the engine light on and the hard shifting.

It seems to happen mostly from 1st to 2nd gear. The other gears seem to shift fine, although occasionally the car takes a long time to shift into 3rd, but when it does it's pretty smooth. The check engine light usually comes on right after a hard shift, stays on a while, then goes off. The car will shift fine sometimes, and will start shifting hard for no apparent reason.

What do you think could be the problem? Could the repair shop have damaged the transmission when they put the wrong filter on? Could the stressed trans temp sensor cause the hard shifts?

Thank you for any help.

[fdryer]

Although this may seem totally unrelated, replace the engine coolant temperature sensor (ECTS) before contemplating a transmission valve body repair. The original ects is failure prone and the replacement is brass - use the Forum Jump below to find the How-to library's video, pictures and procedures about it and its two-wire conector. The coolant sensor runs the engine rich as well as alters transmission shifts so replacing it may kill two birds with one stone otherwise it will at least fix one problem. Then look up a resident transmission guru, Special Forces and tap into his knowledge base. He's had a few good repairs and advises here - look up his threads.

[madpogue]

Also, when you get to the How-To Library, do a search on "paper clip". You'll find a thread describing how you can obtain the code(s) yourself when the SES light comes on.

[1995sl1sohc]

Did they change the fluid when they did the filter?
Check the transmission fluid level on a flat surface in park with the car running after about 15-20 minutes of driving. It should be in the crosshatched area if it is high or low it can cause hard shifting.

[McClane]

Thanks for your replies. When we had the filter changed, they said that they also changed the fluid. Since, they put the wrong filter on, I wouldn't be surprised if they put the wrong fluid in. If the fluid is the wrong type would that cause the problem? Also, you mentioned the engine temp sensor might cause this. Could the trans temp sensor also cause it? Since the car ran fine before we took it in, it's hard not to think that the shop somehow caused it. Thanks again.

[fdryer]

Do as suggested already, look up Wolfman's gallery on parts location for the transmission temperature sensor if you're in doubt as its the same coolant sensor as on the engine. Anything is possible when transmission fluids are replaced. Theoretically this isn't supposed to occur but it may just be coincidental that hard shifting occurred right after the fluids were changed.

Its more important to pull the codes with the SES light on as this can clue you in instead of guessing and speculating.

[McClane]

So we followed the directions for getting our codes using a paperclip. First the ses light flashed a code 11, than the red thermometer and bottle light (not sure what those are, exactly) flashed a code 35 and 36. Any thoughts? Thanks again

[fdryer]

From the How-to library on page 6, titled OBD I Codes (1991-1995 Saturns);

11 Transaxle Codes present

35 No turbine speed sensor signal
36 Turbine speed sensor signal noise

I think this means the vehicle speed sensor (VSS) is faulty or loosely connected? For more information on the individual codes; http://www.differentracing.com/tech_articles/index.html, click on the transaxle trouble code chart under OBD I Transaxle codes.

[McClane]

Where would I find this sensor?

[McClane]

Hey, I looked through the how-to's and I found a picture of the turbine speed sensor. It's right next to the trans filter, so I'm guessing it was damaged when they were changing the filter. We're gonna take a look at it, and see if it helps our problem.
On a side note: This forum and the people here are just Awesome! I can't thank you enough for all the help so far.

[McClane]

Just an update. We fixed the turbine speed sensor and now the car runs like new! Thanks to everyone for your help!