I'm trying to get some Syntorq lt Tanny fluid to go into my rebuild, but calling the dealers they don't know what I'm talking about. Is the fluid they sell as OEM the same as the Syntorq?

 

I wouldn't buy from the Dealer. It would cost more. Here is a recent thread on this subject. Even has a couple of good places to buy it too.

https://www.dieseltruckresource.com/...ight=syntorque

 

Have you thought about using AMSOIL?

 

I've had the Royal Purple in it, and liked the change it made in shifting, but talking to people about this rebuild, everybody that I consider to have in depth knowledge of these tranny's says to only use the Syntorq. I was just trying to find some place local to get it so I didn't have to wait on the mail.

 

I wouldn't use anything but Syntorq, even though some people say they've had luck with other fluids unless they've gone over a 100k on it I wouldn't trust the other brands. Additives in other brands aren't always compatible with the syncos and will eat them like acid.
Make sure they don't try to sell you Castrol Syntex, it's different than Syntorq.

Castrol has a deal worked out where only dealers can buy Syntorq in small containers, you have to buy it from them or from someone who rebottles it like these guys, bottom of page http://www.standardtransmission.com/dodge.html
or
http://www.quad4x4.com/NV4500%20Parts.htm

Also from Dodge (p/n 4874459) and GM dealers (p/n 12346190)

 

I run redline mtl in my 6spd.Big shifting improvement over whatever was in it.

 

I called the local dealers, none of them knew what I was talking about when I asked for syntorq. They only sell there respective oem brand. I just don't know if there oem is Syntorq in there generic bottle.

 

The stuff the dealer sells IS Syntorque, get out your wallet!!!!

Tom

 

Different type of synchros in the 5 and 6 speed. 5 speed has fiber syncros, 6 speed has brass.

Syntorque is the only fluid that has the proper heat range for the syncros in the 5 speed.

99 Cummins, look on the side of the tranny case, there should be a GM and a Dodge part # stamped into the side for the Syntorque fluid. It would most likely be packaged in a AC delco or Mopar bottle.

 

Ya they both have it in the delco and mopar bottles and the prices here aren't bad. Dodge had it for $12.00 a qt. That was the same as the internet shops but without the shipping. Blew my mind that they had no idea what I was talking about when I asked for Syntorq. They had never heard of it. Still hate givin Dodge any money though.

 

Been using the big A and got near 160000 miles and well over 400 HP. Installed the Transcoolers to boost the capacity. Say what you want but I won't play the "dealer only" supply thing. When I bought mine, it had six miles on it and the oil was going for something around $30 a quart or something at the dealer. They too told me that my trans would never hold up with anything else but that (Syntorq) oil. I pull up to 26000 pounds with mine. Shifts fine, no noise, and all. Guess we'll see.
Not telling you what to do, just telling you my experience here.

 

Like I said, I had the Royal Purple in it, and loved the change it made in how it drives. My kid is rebuilding the tranny as I type, and is complaining that he can't get the oil residue off the parts. That tells me that the lube capacity was there anyway.

 

My first question then would be why are you rebuilding it at this point and my second question would be why not go back with the royal stuff if you feel it is that good?

You have to use what makes you feel good since it is your truck.
How did the synchros and the gear teeth look when you tore it down? That will tell you a lot about the lube part.

Joel

 

The rebuild is because I lost 5th gear and am putting the full spline shaft in it. It didn't add that much more money to it to change the small parts. I do alot of miles over the road pulling trailers, so I can't afford breakdown's, to take the chance on the factory mainshaft. I can't afford to just change out useable parts for Hi Performance, so each time something goes bad I've been replacing it with better parts. Luv my Cummins, Hate my Dodge. I only had about 25,000 on the Royal Purple so still to early to tell how it was treating the Syncros.

 

Isn't the Syntorq the same as the Pennzoil Synchromesh?

http://www.pennzoil.com/products/gea...cro_fluid.html

oops, never mind...noticed your talking about the Castrol SyntorQ....