Does a Guv-lock need the posi additive?

[Dayzedandkonfuzed]

While we're on the subject... just about all the gear oil manufacturers toss the LSD additive in the mix now anyway. Grab any bottle you've bought within the last 5ish years, somewhere it will say "no LSD additive neccessary," or something to similar effect. Everything from 80w90 to 75w140

 

[Supercharged111]

They do have clutches.
https://rover.ebay.com/rover/1/711-...0001&campid=5335822911&icep_item=264668269058

I promise they do.

 

[Doug213xrj]

I would use the additive, Better have it and not need it then need it and not have it. PS, I use the complete bottle of additive.

Doug

 

[Bonnewagon]

Well on another take- the reason they used Whale oil as the additive was that it had the peculiar property of clinging to hot metal rather than being repelled. They finally found an artificial substitute and stopped using the Whale oil. It also became the hot tip to use it in manual transmissions for that reason. So I use it in those as well as the rears. As noted, better to have it, etc.

 

[pontiac guy]

Well on another take- the reason they used Whale oil as the additive was that it had the peculiar property of clinging to hot metal rather than being repelled. They finally found an artificial substitute and stopped using the Whale oil. It also became the hot tip to use it in manual transmissions for that reason. So I use it in those as well as the rears. As noted, better to have it, etc.

Dude another person old enough to remember that stuff used to be whale oil. I thought I was the old dog. Woof woof. Welcome to my wolf pack. I won't ruffie you tho.

 

[81cutlass]

I always thought the additive was a friction modifier that just made stuff 'slippy-er' and made the clutches grab a bit less hard in a Eaton 'Posi' style diff (one that uses spring preload to load the clutches and prevent relative motion between the side gears) so it didn't chatter when you turn corners.

Since a gov-lock is a locker (on or off) it can't chatter. I think it does use clutches but I don't think the clutches see near the slip like a posi style pure clutch diff. Although it very well could.

I blew my stock 8.5 gov lock up long ago and never ran posi additive and never noticed chatter. Same goes with my gov lock on my Rainier. Never additive, no problem.

 

[Bonnewagon]

All that I read long ago was that it caused the oil to stay put on the clutches and gears. Thus- they slip instead of chatter. I will run this past my Enginerd Cousin.

 

[Bonnewagon]

And... he replied. Yes, the "Whale Oil" stuff we want is from toothed whales and is called Spermaceti oil found in the foreheads of sonar using Whales and even Bats. It is a long/tight chain organic hydrocarbon molecule. This not the stuff that was rendered from whale fat and burnt cleanly in lamps. Our stuff is a friction modifier and even a few molecules per square millimeter will keep the clutches slipping smoothly. And by "clutch" we mean all except a Detroit Locker. The others employ spring-loaded friction discs or twin-conical friction cups of dissimilar sintered metals, even the unpopular Gov-Lock. A “clutch” if you will. Similar to the bronze synchro hubs in a trans, the oil keeps them slipping nicely without grabbing. He said there is still 3-5% Whale Oil in the new additive. They get it from Japan that still kills Whales. (nice) He also said he often used 90wt oil with an ounce of ATF in the diffs without problems. Why buy $8 additive when an ounce of left-over ATF will work? So- are there clutches in a Guv-Lock? Yes. Does additive help? Yes.