When is thicker not better?

[rondg]

shown here is the transfer case of a suzuki jimny/samurai. simple TC w/ old-school mechanical shift lever. all the power goes through the chain (green) even the rear wheels so yes you're on the chain while you're towing a heavy trailer on 2-HI

factory fill is a super thin 75w GL-4, though the previous generations of the jimny had 75w-90

if fuel efficiency doesn't matter, and minimizing wear on the transfer chain is the priority, would thicker oil be better? thicker than 75w-90? or maybe even a dual-rated GL4/GL5?

 

[oldhp]

In my opinion, yes. Might even step up to Redline 75W110.

 

[shortyb]

In this application, you could probably use the "dual rated" GL-4/5 due to lack of synchros and hypoid gears, and benefit from the additional EP adds of a GL-5, without harming anything. Unless its packed with brass/bronze/copper components, then I would use a heavier GL-4. Give HPL a call if you want to go the GL-4/5 route.

 

[nwjones18]

I've got Supertech synthetic 75w-90 in my Samurai and it seems to be doing just fine

 

[wings&wheels]

In this application, you could probably use the "dual rated" GL-4/5 due to lack of synchros and hypoid gears, and benefit from the additional EP adds of a GL-5, without harming anything. Unless its packed with brass/bronze/copper components, then I would use a heavier GL-4. Give HPL a call if you want to go the GL-4/5 route.

Redline's GL5 are also yellow metal safe, or at least Dave there stated that a while back and they still claim it on their website. We have their various gear oils in the drivetrains of the old British stuff.

 

[Rand]

"When is thicker not better"

*crickets noise*

When using common sense.. never.

no need to pull out the 25w70 for a prius located in MN.

"as thin as possible, as thick as needed" Err on the side of thickness.. because that does no harm.

 

[AZjeff]

When would you be towing a heavy trailer with a Samurai? Granted you have new model Jimnys that may have higher ratings, I remember the max tow of my '86 being 1000 lbs and I thought you'd be crazy towing that much.