LS3 manual trans fluid change - less noise, etc?

[TommyTSquared]

I've read the manual, I know it's a sealed transmission, I've done a search. Don't post a reply if you're not going to answer the question please.


Ok, I remember reading a thread (which I cannot find now) about a few people changed their transmission fluid and now have a smoother shift with less noise. I've also read that the fluid bought from GM is just Dex 3 ATF re-packaged. So here are my questions to those that have changed their transmission fluid:

Which fluid (brand, was it dex 3, or is there a weight) did you use?

Did you also change the filter for whatever reason?

Have you noticed a change (better/worse/none) in shifting after changing your fluid?


Thanks in advance.

[mtcwby]

The Tremec manual transmission is not sealed. There is a drain plug and a fill plug on the passenger side of tranny. There is no filter. It takes 4.2 qts.
You can use Royal Purple Synchromax with good luck. Shifting also seems to be smoother. The Chevrolet dealer that I go to is who recommended the RP Synchromax to me.
The GM Manual Trans. Fluid recommended for this is not just Dex III. It is dexIII plus alot of other additives to help with engaging the synchronizers. Regular DexIII will not work very good and you will notice difficulty shifting.

[TommyTSquared]

Originally Posted by mtcwby

The Tremec manual transmission is not sealed. There is a drain plug and a fill plug on the passenger side of tranny. There is no filter. It takes 4.2 qts.
You can use Royal Purple Synchromax with good luck. Shifting also seems to be smoother. The Chevrolet dealer that I go to is who recommended the RP Synchromax to me.
The GM Manual Trans. Fluid recommended for this is not just Dex III. It is dexIII plus alot of other additives to help with engaging the synchronizers. Regular DexIII will not work very good and you will notice difficulty shifting.

Sweet, thanks for clearing that up. I reread the manual and I don't know where I got sealed from (maybe another thread?). Do any of the transmissions come with filters? The manual doesn't specify to which transmission it is referring to when it says "Pan Removal and Filter Replacement" .

I will look into the RP fluid. Thanks for clearing everything up! One post is all it takes with the right information !

[mtcwby]

Originally Posted by TommyTSquared

Sweet, thanks for clearing that up. I reread the manual and I don't know where I got sealed from (maybe another thread?). Do any of the transmissions come with filters? The manual doesn't specify to which transmission it is referring to when it says "Pan Removal and Filter Replacement" .

I will look into the RP fluid. Thanks for clearing everything up! One post is all it takes with the right information !

No problem, You were probably reading about the Automatic trans. It is sealed and has a filter in the pan.

Have you changed your Diff fluid yet? I put RP GearMax in mine and it works great. Takes just a hair over 1 qt. and you don't need the limited slip additive with the RP. It already has additives in it.

[TommyTSquared]

Originally Posted by mtcwby

No problem, You were probably reading about the Automatic trans. It is sealed and has a filter in the pan.

Have you changed your Diff fluid yet? I put RP GearMax in mine and it works great. Takes just a hair over 1 qt. and you don't need the limited slip additive with the RP. It already has additives in it.

You know what they say about great minds... went and picked up some RP 75w90 the other night with the hopes of doing it this weekend. Then we went from 66 down to the teens with some snow/ice .

Once I get the trans fluid I can just make a day (or rather an hr or so) out of this!

[Russell James]

Yup, go with Royal Purple Synchromax in the Trans. I found some at a Napa store near me. Pricey though - about $18 per qt.

You'll need some way to pump it up into the fill hole. It is tight up next to the trans. I bought an el cheapo hand pump at an auto parts store. They usually have them near the gear lubes. A good time to disable the skip shift while it's up in the air.

I've found the RP Synchromax to be a little smoother shifting than the OEM fluid. Which is what I wanted and to switch to a synthetic.

[SSOOCH]

At what mileage would you suggest changing the fluid? Thanks.

[Russell James]

I changed mine at 25 miles. I wanted synthetic in there, and I like the results of the RP Synchromax. If your shifting perfectly smooth, you really don't need to. I'm in really cold temps and wanted a synthetic in there that is a hair better when cold.

I've changed out the trans fluid to synthetic in all the 6 speed manual cars I've bought over the years.

[mtcwby]

Originally Posted by Russell James

Yup, go with Royal Purple Synchromax in the Trans. I found some at a Napa store near me. Pricey though - about $18 per qt.

You'll need some way to pump it up into the fill hole. It is tight up next to the trans. I bought an el cheapo hand pump at an auto parts store. They usually have them near the gear lubes. A good time to disable the skip shift while it's up in the air.

I've found the RP Synchromax to be a little smoother shifting than the OEM fluid. Which is what I wanted and to switch to a synthetic.

My Chevy dealer has the Synchromax for only $12 per quart.

Originally Posted by SSOOCH

At what mileage would you suggest changing the fluid? Thanks.

As soon as you can, you won't regret it and you'll wonder why you didn't do it sooner.

[SSOOCH]

Thanks!

[TommyTSquared]

Skip shift eliminator is on my list of what to buy with the next paycheck (and left over from car payment) and I will be sure to install when I get to changing the fluids. Thanks for the tip with the pump, I will be picking one up whenever I find the Synchromax.

[Ject]

I know this isn't exactly on topic but Just as a reference, I believe us Automatic users use the RP Max ATF, correct?

[jimpfromwv]

I changed mine at 3000 miles and used RP synchromax. Shifts are smoother but man that stuff stinks!

[Russell James]

Originally Posted by Ject

I know this isn't exactly on topic but Just as a reference, I believe us Automatic users use the RP Max ATF, correct?

No I don't think so. The auto needs a Dex VI, and I don't see that spec on the RP ATF.

Amsoil has a Dex VI called Fuel Efficient Low Viscosity.

What ever you pick, make sure it says Dex VI for the automatic. That really shouldn't need a change though for quite a while.