What kind of oil or additive can you add to the ZF to help it shift easier??

some say Lucus works wel but I have not tried it (probably will). doubt that anything is gonna make a zf6 shift very easy, however . . . .

Elbow grease:D

Elbow grease:D

:funnypost

personally i think they shift very easy. a hell of alot better than the old sm465's. but i dont know of any additive that would help with shifting:confuzeld other than the one dog mentioned...:HiHi:

I run the lucas atf for noise deadening, as for the shifts it still shifts like a clunky truck transmission!!!

I run the lucas atf for noise deadening, as for the shifts it still shifts like a clunky truck transmission!!!

It might be because it is a truck transmission!

I'm having all kinds of trouble locating Castrol Transynd at any of the local parts houses. O'Rielly's can't even order it, Autozone sent me to O'Riellys. I guess I'm going to have to go to an allison shop to get it.

Where did y'all buy the fluid?

MaxRock

MaxRock

I would have ordered it from a vendor here, but I needed it right away. The cold weather was setting in and my truck was slightly grinding in most of the gears (11,000mi over due on trans fluid). I found out that I had to haul a tractor a day after that, so I could not wait for shipping.

Yes, it's very hard to find. I went to, or called, 8 different places looking for it. All of them never heard of it. I went to the big name auto parts shops, small parts shops, and truck repair shops. Nothing. Then I gave up and called the GMC dealer I bought my truck from, they did not have it, or even heard of it. They search for the GM part number (#12378515) and found the Chevy dealer down the road had 36 quarts of it. So I went to them and asked for Transynd transmission fluid. And guess what, they never heard of it either. I told them they had it in stock. Gave them the part number, he looked it up, and went to the back and came back with 7 VERY dusty quart bottles. Even thow he had them in his hands, he still never heard if it.
The total bill was $92.30 w/tax.

The thing I found strange is, I thought that Transynd was recomended for the Allison also, but
the bottle says "TranSyndä Manual Transmission Fluid."

And yes, the gear grind went away!!! It also shifts a lot smooooother.

jc

At 109,000 miles when I had the DMF replaced I refilled the tranny with Mobil1 Synthetic ATF. It runs like a champ and no grinding. It cost me $5 a quart.

whats wrong with running the syncromesh fluid from gm? other than it cost a arm and a leg...

is there some kind of benefit from other brands?

jc64- i believe thats the same stuff my 01 5 speed 1/2 ton required.

you don't run GM antifreeze. No true benefits and cost A LOT MORE!

Kinda like putting amsol or other synthetics in the rearend -vs- grape juice in the rearend.

I run Amsoil Torque-Drive; it has the same chemical make-up as Castroltransyd and is allot cheaper. If your trans breaks and there is anything but transyd in there GM won’t warranty it. According to Amsoil, Castrol/Allison have kind of a monopoly on the transyd oil, so Amsoil came up with a duplicate fluid that Amsoil will warranty if your trans breaks because of the oil.

does your oil get dark and smell burn't. i have been installing a south bend clutch as i get time this last week and some oil came out when i seperated the transfer case from the trans. and the oil was burnt smelling and kinda dark. i do have oil coming for it and now that the drain plug is out ,going to change the oil. does your oil in your 6 speed stick dark and smell ????????? 25k on rig.

I use what ever it is that GM put in it when they serviced the tranns. it is a little stiff in the morn, but after its been driven a few it warms up and shifts nice. when its cold the clutch is almost a requirement but after it warms up i dont use the clutch.