Transmission Fluid

[walleye]

What type (Dextron 111) or brand do you recommend?

 

Thanks T

[walleye]

98 s/n 1500 hours on transmission - red fluid.

[oldjeep]

Not a big fan of high mileage trans fluid, it contains additives that can cause otherwise good seals to swell. Better off sticking with plain old dextron of whatever number your manual says. Typically it says right on the dipstick what the fluid requirement is. No idea if pcm does that.

[oldjeep]

Manual just says dextron (55th page of PDF), so Dextron VI is going to be the easiest thing to find that will work

1998 Manual

[walleye]

@oldjeep Thanks why I ask the manual says dextron. You go to the store there is High mileage, dextron/merc, dextron 111, synthetic etc. etc. Did not see dextron v1

[oldjeep]

Dextron 3 no longer really exists since gm does not licence that name any more. Dextrin vi is the current version and ok for anything that calls for dextron

[oldjeep]

Dex/merc is also theoretically ok but I had a bad experience with the Oreilly dex/merc in a dex 2 jeep transmission so I only use the dex vi now

[jetpilotg4]

While we are on the subject of trannys how do you drain it to replace ? 04 SN 196?

[dvskier]

@jetpilotg4 I have the same boat and I use a drill pump from Overtons. I think harbor freight has them as well. Only takes 2-3 minutes to remove the 2 quarts of fluid. Make sure not to overfill when replenishing. Have used the same pump for 20 years now, no problems.

[jetpilotg4]

Thanks @dvskier

[oldjeep]

I use a syringe type fluid extractor so that I can measure what I take out and put back the same amount. Mine is a different brand, but similar to this:

Fluid extractor at wally world

[Orlando76]

DO NOT use synthetic fluid. I use a sophisticated system for draining the fluid..... I unscrew the squirted pump from a Windex bottle, stick the hose in the transmission and pump away.

[oldjeep]

@Orlando76 that is going to be tough. Dextron vi is all synthetic or synthetic blend. Where does you recommendation come from and what brand are you buying?

[Orlando76]

Castrol Transmax Dex/Merc. Eric Lavine, former owner of Fantastic Finish Marine and probably the leading rebuilder of marine transmissions says to never ever run synthetic in a Velvet Drive or the PCM 40a which has been agreed upon by others as well as Second hand from PCM. Evidently Synthetic or anything labeled high mileage is too slippery for the clutches. Keep in mind the the PCM 40a originally was built for 20w oil to be used which has pretty much disappeared.

[DW]

FWIW: my vessel has a 71C velvet drive & I prefer to run the hydraulic (tractor) oil as it reduces the "clatter" level of the trans at low speeds/idle. Seen a few similar comments to that effect & I have been happy with the Mobil offering.

[Jody_Seal]

Hi, yes stay away from any synthetic and never use any of the trans additives. PCM Series 40 transmission's use Dextron ATF , nothing special in fact we use the O'riley house brand here.

I have a SS 1/4" tube rigged to a oil transfer pump and pump out the fluid. The series 40 takes right at 2 qt's. Do not over fill.

 

@DW yes the Borg 71/72 can use motor oil usually 30W. however for higher rpm usage the preference is ATF.

 

The Hurth v-drive transmissions also use 30W oil.

[DW]

@Jody_Seal : thanks, and what is the rationale behind ATF preference at higher speeds?

[The_MS]

Do you need the transmission hot when you check the level?