Borg Warner 72c

[micky]

What type of oil does a Borg Warner 72c transmission uses?

Thanks

[Boatsb]

I believe it's now velvet drive.


GM Dexron III, Ford Mercon, Daimler-Benz 236.6 or any SAE 10 hydraulic oil that meets Allison Type C3, Caterpillar TO-2 or equivalent specifications.

[micky]

Thanks.

[DCMY #92]

Depends on which engine it's behind. The BW manual (I think anticipating a gas engine's high RPM with external gear oil cooler) recommends the products listed in the previous reply. The DDC manual for the 6V53 NA recommends the same straight 40 weigh motor oil the engine uses (1963 vintage I have).

The DDV packaged unit has the gear oil cooler mounted in the engine's water jacket, hence its lowest operating temperature is 180F. The BW manual says don't let the gear operate over 150F. I don't know how this was supposed to work, and it didn't in my case.

After a couple of rebuilds I installed external gear oil coolers and ran transmission fluid in the BWs. This did not work either, I think because the low viscosity and relative low rotating speed of the diesel when compared to a gas motor results in minimal oil flow to the cooler. The only BW oil that flows to the cooler is what discharges from the pressure relief valve, so if oil pressure is relatively low, so is cooer oil flow.

I changed from transmission fluid to 30 weight engine lube oil in the gears (same I use in my gen-set). This has worked successfully now for many years.

The durability of the BW is strongly influenced by which reduction gear its using. Mine both have the 2:1 reduction (the weaker model). The 2:1 has a double set of planetary gears so that input and output rotation direction is the same. The 1:97 reduction has a single set of planetary gears that results in input rotation being opposite from output rotation. The single gear set create less heat than the double set.

My 6V53s are opposite hand rotation. I think DDC used the 2:1 gear to keep rotation the same throughout the train. I wish they had used the 1:97 BW and swapped sides with the engines.

If you have gear coolers internal to the engine water jacket and decide to change to external coolers, be sure to put the new cooler between the sea strainer and the raw waster pump. If downstream of the engine heat exchanger gear cooling will be compromised.

[micky]

Engines are Detoit 453t, 175hp each and it has oil coolers. Trannies are 1.52:1

[DCMY #92]

Are the gear coolers in the engine water jacket? If so, the engine manual should give guidance on the recommended oil.

Do the prop shafts turn the same direction as the engine's crankshaft? If so, the reduction gears will have double planetary gears.

[DCMY #92]

Depends on which engine it's behind. The BW manual (I think anticipating a gas engine's high RPM with external gear oil cooler) recommends the products listed in the previous reply. The DDC manual for the 6V53 NA recommends the same straight 40 weigh motor oil the engine uses (1963 vintage I have).

The DDV packaged unit has the gear oil cooler mounted in the engine's water jacket, hence its lowest operating temperature is 180F. The BW manual says don't let the gear operate over 150F. I don't know how this was supposed to work, and it didn't in my case.

After a couple of rebuilds I installed external gear oil coolers and ran transmission fluid in the BWs. This did not work either, I think because the low viscosity and relative low rotating speed of the diesel when compared to a gas motor results in minimal oil flow to the cooler. The only BW oil that flows to the cooler is what discharges from the pressure relief valve, so if oil pressure is relatively low, so is cooer oil flow.

I changed from transmission fluid to 30 weight engine lube oil in the gears (same I use in my gen-set). This has worked successfully now for many years.

The durability of the BW is strongly influenced by which reduction gear its using. Mine both have the 2:1 reduction (the weaker model). The 2:1 has a double set of planetary gears so that input and output rotation direction is the same. The 1:97 reduction has a single set of planetary gears that results in input rotation being opposite from output rotation. The single gear set create less heat than the double set.

My 6V53s are opposite hand rotation. I think DDC used the 2:1 gear to keep rotation the same throughout the train. I wish they had used the 1:97 BW and swapped sides with the engines.

If you have gear coolers internal to the engine water jacket and decide to change to external coolers, be sure to put the new cooler between the sea strainer and the raw waster pump. If downstream of the engine heat exchanger gear cooling will be compromised.

Error Correction: My gears are not 2:1. They are 2.10:1 Model AS13-72CR.