My '06 Cobalt LS has a fairly noisy transmission while driving at lower speeds. This is a nice chatter noise from the gearing. Anyone else have this issue, and is it possible to quite it down some by changing the fluid?

Any recommendations on specific fluid?

Thanks.

 

its probably just from the cold, ur manual right? sounds kinda like when ur in revese?

nm on the cold ur in AZ haha

 

redline mt90

 

It's been fairly chilly lately in the mornings. But yeah, manual trans and it's mainly in the lower RPM's.

 

and that will make shifting very hard, almost impossible to get into gear, and burn the syncros up. he has an ls, that will have the f23, not the f35. the 2 transmissions take different oil

the correct fluid for the f23 is automatic transmission fluid, specifically dex 3. if you want to find an aftermarket synthetic fluid, feel free, just make sure its a replacement for manual transmissions that use atf.

 

So Dex 3 for manuals.

Got it.

 

dex 3 for the f23 transmission, thats in the 2.2/2.4l cars. the f35 in the 2.0l cars is specific gm fluid.

 

You won't quiet up that gear rattle. Its just not going to happen. There has to be some clearence in the transmission for it to work properly without melting.

Also Dexron 3 is no longer available. Dexron 6 will work just fine though.

 

i just used stock ac delco **** my brother got for basically free.

 

gm no longer licensed the name dexron 3. there was no point once dexron 6 came out, thats all gm sells for automatic trans fluid. however dex 6 isnt a complete replacement for dex 3. for most applications it works, however it doesnt work in some manual transmissions and gm came out with a manual transmission fluid that was nothing more than dex 3 with a different label. the reason for this is dexron 6 is quite a bit thinner and will cause lube problems in some manuals. there are still many "aftermarket" transmission fluids that are dexron 3/mercon rated, its still the most commonly used atf out there. you will be able to find it at any parts store.

 

This is the first car I have owned that has a transmission that makes this much racket. It's also the first domestic car I have ever owned, so maybe that has something to do with it. All my Nissans & Mazdas never chattered this much. I just figured maybe a better fluid than what it comes with from the factory might help. That's usually the case with any other car I've ever driven.

I'll just try a fluid flush with the stock stuff and if it doesn't quiet down, then I'll just chock it up as normal. (yet annoying)

 

did you buy the car used? how long have you had it? has it done this all along?

you may want to take your car in and have it looked at. if its under warrenty take it to the dealer, if not, find a local transmission shop and take it in and have them look at it. its very hard to diagnose things like this over the internet, it could be something normal, it may be something worn out or broken.

 

NO!

Dex 6 has additives in it that will eat the syncros. GM does still offer dex 3 but it is in bottles and its not called dextron 3. Its manual transmission/transfer case fluid, any GM dealer should in stock it.

 

I bought it from a small used car dealer, definitely not under factory warranty but it does have a warranty from where I bought it. I'm not worried about it failing, they should replace it. If not...well then they can have their car back.