Borg Warner 72 series V drive oil venting.

Durango318

Seaman
Joined
Jun 12, 2010
Messages
68
I had a problem with oil coming out of the vent on top (72V 1005-000-002 1.99 to1 gear type) It was not due to water in the oil, over/under filling, old oil, shift lever position, poor cooling or bad vent. I've been told that some just have a flaw in the casting. Lucky Me. The manual also says to try other oils for oil venting. This is a new trany with only 65 hrs on it and yes it is on warranty, but what a PITHA to R&R (they don't pay for that). This only became apparent because now the engines are broken in so I've been on them harder. Any extended time over 4000 rpm (over a minute) would result in oil running down the side from the vent. After a lot of research I've found out that these are very tough tranies and people run everything from 10W motor oil (low rpm use), Dextron III (most recommended) to Type F. The killers are dirty oil, water contamination and most synthetics as far as oils go. After a lot digging and agonizing I decided to try Amsoil Super shift oil. Yes this is a synthetic but it has no friction modifiers that could cause the clutches to slip. This oil also has a very powerful anti foaming trait. The result? No oil leakage and a temperature drop! Running a thoroughly warmed up engine and trany at 5100 RPM for over a minute it's bone dry and temperature went from 182* to 160*. As a side note, there is all sorts of data regarding oil capacity. What the heck! I've seen 3 quarts to 5 quarts! Here's the deal. On a 71/72 BW V drive with an oil cooler lower than the top of the oil in the trany, it holds 3 & 3/4 quarts WHEN CHANGED, not new filled. This is IF you have a 9" cooler mounted aside the engine and the cooler is slightly inclined as it should be (oil inlet low) and if you pull the oil for change from the disconnected top hose of the trany with an extractor (West Marine). Make an adapter. Drawing from this top hose is easier than pulling the rear bottom hose, faster than a small tube in the dipstick hole and back draws oil thru the cooler. About half the oil coolers volume is still trapped unless you upright it, no big deal Amsoil is compatible. There are no filters at the lower fitting on these V drives. Do Not Check the oil if the prop shaft is turning even if its just windmilling from momentum or wind moving the boat. The dipstick can get caught in the gears! Just ask me! This is especially true on the chain drive type with the dipstick tube is mounted in the V dive section (late models). I hope this info helps someone else.
 
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