Dif lube?

[61frogeye]

I am in the process of servicing oil/grease/lube my (new to me) BE. What do you use in the differential and what grease do you use for the grease fittings?

Thanks,
Dave

 

[Gerard]

Hi Dave,

For the differential, 90 wt gear lube. Adjust weight for your climate. Synthetic is OK too. The gearbox is specified for 30 weight non-detergent motor oil, but you can use whatever you in the engine. Do not use gear oil in the transmission. As far as grease, I think I'd use the synthetic type that is available today.

 

[Westfield_XI]

Gerard, I am filling a diff in the next couple of days and was planning to use 90wt. Your comment about making an adjustment for climate got me to thinking. I live and drive in southern Cal. and wondered if I should go to 100wt since it is over 100 degrees for 6 months a year and it never gets below 40. I use Royal Purple lubricants in the diff and trans. What do you think?

 

[Gerard]

Gerard, I am filling a diff in the next couple of days and was planning to use 90wt. Your comment about making an adjustment for climate got me to thinking. I live and drive in southern Cal. and wondered if I should go to 100wt since it is over 100 degrees for 6 months a year and it never gets below 40. I use Royal Purple lubricants in the diff and trans. What do you think?

Westfield XI,

Below are specs for the Datsun 5 speed gearbox. I would use it as a "rule of thumb" for other applications regarding temperatures.

I've used Redline MTL, a very good choice. I've not used Royal Purple, but heard good things from others.

Datsun Spec is 2.5 pints of API GL4 (or superseding) classification -

Viscosity @ Outside temperature range
+50F to -20= 75W,
+86F to -20= 80W
+104 to -20= 75W-90/80W-90,
Between +14 and +86 = 85W,
+32 to +104= 90,
+50 to +104= 140

Recommended service is "Inspect @ 15,000 miles"

 

[61frogeye]

Hi Dave,

For the differential, 90 wt gear lube. Adjust weight for your climate. Synthetic is OK too. The gearbox is specified for 30 weight non-detergent motor oil, but you can use whatever you in the engine. Do not use gear oil in the transmission. As far as grease, I think I'd use the synthetic type that is available today.

Hey Gerard,
I was at the local O'Reilly's and Advanced today, they did not have a straight 90wt gear lube. They had Castrol and other brands but they were spec'd as 75/90 or 80/90. If those are not a good idea (my climate extremes are generally 0f to 95f) got any brand names that still make a straight 90 that I should look for?
Thanks
D

 

[Westfield_XI]

Gerard, I am filling a diff in the next couple of days and was planning to use 90wt. Your comment about making an adjustment for climate got me to thinking. I live and drive in southern Cal. and wondered if I should go to 100wt since it is over 100 degrees for 6 months a year and it never gets below 40. I use Royal Purple lubricants in the diff and trans. What do you think?

Westfield XI,

Below are specs for the Datsun 5 speed gearbox. I would use it as a "rule of thumb" for other applications regarding temperatures.

I've used Redline MTL, a very good choice. I've not used Royal Purple, but heard good things from others.

Datsun Spec is 2.5 pints of API GL4 (or superseding) classification -

Viscosity @ Outside temperature range
+50F to -20= 75W,
+86F to -20= 80W
+104 to -20= 75W-90/80W-90,
Between +14 and +86 = 85W,
+32 to +104= 90,
+50 to +104= 140

Recommended service is "Inspect @ 15,000 miles"

Thanks, but what about that diff that I will be filling soon? There is no issue with my g/b.

 

[Gerard]

I posted this for the viscosity@ outside temperature range data, not specific to transmission, but to specify source data.

Here's a link with the same data.


https://www.engineeringtoolbox.com/engine-gear-oil-viscosity-temperature-limits-d_1545.html

 

[Gerard]

Dave,

I'm not an expert on oils, but I think I'd go with a 75w-90 synthetic. That seems ideal for the temperature range.

 

[61frogeye]

OK, thanks Gerard