Pontiac GTO Forum banner
1 - 14 of 14 Posts

·
Premium Member
Joined
·
111 Posts
Discussion Starter · #1 ·
What oil would you use in a new TKX 5 speed? I saw a couple different versions of GM Synchromesh. Had read that was the best, but not sure which one to use. some say "friction modified", others are different part number. what do you guys use?
 

·
Premium Member
Joined
·
111 Posts
Discussion Starter · #4 ·
Thanks army. ive seen places where they mention synchromesh for tkx too,so was not sure. Dexron certainly a better price, so thats good. But feel like I’ve heard folks talk about how synchromesh really smoothies out shifting?
 

·
Premium Member
Cameo Ivory 1967
Joined
·
3,377 Posts
Thanks army. ive seen places where they mention synchromesh for tkx too,so was not sure. Dexron certainly a better price, so thats good. But feel like I’ve heard folks talk about how synchromesh really smoothies out shifting?
For some reason, a lot of internet folks seem to insist on getting creative with oil... which was a small issue before the internet, but now it's so widespread.

We'd all be hard pressed to spend the time and money on research and development that the oil companies and manufacturers do.

That being said, when I was getting ready to do my TKX transplant, synchromesh was mentioned to me as well, and Im a boutique-oil freak, so I was just looking for any excuse to use something other than dex. But, I had enough trouble getting the trans in, so I wasnt looking for any added aggravation.

Now I have 5000 HARD miles on my tkx, with dex in it. I drive the car several hundred miles a week and do horrendous, speed-shift-burnouts through every gear.
 

·
Premium Member
Cameo Ivory 1967
Joined
·
3,377 Posts
Isn't the TKX a modified TKO? Its a smaller case for a no cut fit from what I saw.... Why would one use a different oil? (I have 10k miles on my TKO - using Penzoil Synco..oil, same as it came with
)
If a TKX is a modified TKO, I wasnt aware of it.

Regardless, even if so, one of the key selling points of the TKX is its ability to handle higher horsepower and higher shift points. I would think those features could easily warrant a different fluid. That being said, I have no data to support that claim.

Ive seen the pros recommend Dex III, and Ive seen them recommend Synchromesh. I have no idea who's right.
 

·
Premium Member
Cameo Ivory 1967
Joined
·
3,377 Posts
I didnt take any chances...... especially for warranty purposes....
When I purchased my TKX kit from American Powertrain I had them send me the break in oil and the oil to put in it after the 500 miles....

They sent this

TREMEC HP-MTF Transmission Fluid - American Powertrain
Nothing wrong with using the Tremec stuff... IF you can get it. Biggest issue there is having to overlook the principal issue... knowing that they just rebranded $15 worth oil so that they could sell it for $100, but Harley Davidson, Ford, GM, Yamaha, Honda, Kawasaki,and Chrysler have all been doing it for decades.

Tremec told me to use Dex 3, so I did.
 

·
Registered
Joined
·
78 Posts
I used the break-in fluid (Dex III) from Silver Sport in my TKX for the first few break-in drives then changed it with Supertech Dex III. Once I get another 500 on the trans I've got some Pennzoil Synchromesh for the next change.
 

·
Premium Member
Cameo Ivory 1967
Joined
·
3,377 Posts
I spent many hours researching this again yesterday, and came up with the same results. There are at least five oils listed as suitable for the TKX. Dex 3, Tremec, Mobil 1, Amsoil, and Synchromesh.

If there is a better oil to use, Im all for it. One thing is for sure, when the transmission is new, during break-in, there's probably more heat and debris than there will ever be again, so if Tremec thinks that Dex 3 can handle that, then I don't know why it couldnt handle daily driving.

Either way, as I said, more info is needed... And, of course now that Tremec is selling thier own oil, I expect this information to be more vague/ hidden than ever before.

Harley Davidson oil is the ONLY oil suitable for use in their engine, transmission, and clutch (yes, Harleys require three separate oils). Well the engine is an easy one, but when you ask, what kind of oil does Harley use in the trans and clutch, the answer is, Harley Oil.

So I guess the answer to this question is Tremec oil?
 
1 - 14 of 14 Posts
Top