I'm no expert on transmission fluid, but I replaced my OEM fluid with the GM Synchromesh stuff right after I got bought my car (06 TL with 6MT). Now I have 40K miles and the dealer is telling me that the fluid "looks dark and need to be replaced".

Just wondering how long I should expect for the life of the GM Synchromesh fluid versus the stock fluid? Is it reasonable to replace it after about 40K miles?

Thanks!

 

I think most people are changing it every 30k. That's the interval I'm going by atleast.

 

thank you gentelman, that was exactly what I was looking for!

 

Make sure you are using GMSFM not GMSF.

 

...

 

Is this an easy DIY or would it be better to bring it into the dealership. My DIY skills are pretty bad!

 

I'm at ~45K miles and will change it soon. Still shifts perfectly though.

 

+1.

 

Easy. SAME level of difficulty as a regular engine oil change.

 

Well......not so fast. I do agree it's easy and I do it myself but this is a bit more involved than an oil change.

You need to get the bottom engine cover off which usually requires getting the car up high enough safely. Plus, getting the gearbox fill cap off requires a bit more work than opening up the dip stick for sure. Then you need to understand how to use the 10mm level/overflow plug correctly. I guess you could skip the fill cap and fill it through the overflow but that's not for me.

Oh, and to the OP I'm going to do it in the 25Kmi range. That's about an even 2 years for me. Plus I thing the GM is darker than the OE stuff right from the bottle.

 

Just see it this way...The more you change it the better... More and Better Lube for bearing, gears and syncs. I usually change it as 30-45k...

 

Thanks for the info. This is something I may have the dealership do.

Do I just go into any GM dealership and buy this?

 

^ i believe so

 

I can look this up tonight in the manual but does anyone already know how many quarts I'll need? Thanks in advance!

 

Between 2 and 3 qts so buy 3. I think the actual number is 2.4 but I fill until the overflow starts to drip. That's the small 10mm bolt you remove above the MTF drain.

 

^^^Great. Thanks for the info!

 

I did the fluid change two weeks ago on my car (base) and my friends type S. It was really easy to do and mildly harder than changing the engine oil.

The transmission, after draining, should hold 2.3 quarts. I had read some where that if its overfilled the fluid would vent out of another hole and destroy your clutch. IDK if this is true or not but I am not willing to take the chance of putting in 2.3 quarts and calling it a day on hopes and dreams.

I did NOT have to remove the intake, battery, or any other pieces from either car except one of the plastic panels in the engine compartment and of course the lower protection pan diffuser thingy under the tranny.

I connected a piece of rubber fuel hose to a funnel to fill the tranny back up after draining...stuck the hose in the fill hole and poured the fluid in with the drain open to hopefully move out the old tranny fluid. Then tightened the drain plug to appropriate torque specs and filled the tranny until the fluid drained out of the check hole.

You will need a long ~18" extension to access the fill plug and a small torpedo level to make sure the car is level as well as assorted other basic tools.

If you have questions let me know, I'll try to help you out as best I can.

 

Great write up.

We need a video DIY.

 

If you mean my little blurb, then we're gonna have to wait another ~30000 miles. I'll gladly do someone else's car though and do a DIY vid.

I completely forgot to mention. The third gear issue has disappeared. The tranny shifts silky smooth. I can honestly say this may be the best thing I've ever done to my car.

 

Thanks for the help!!!!! I found a Chevy dealer that has it in stock (Northridge, CA) and sells it for $15.55/each. I'm gonna pick up 3 bottles next week.

Great info...I appreciate it!