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Differential Lubricant

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03-29-2010, 02:08 PM
Jim and Tere
Differential Lubricant
I am going to change the gear oil in the differential. 85 Regal, P32, 454. My owners manual says GL5 80 or GL5 80/90. I plan to go to synthetic.
Which is best, Amsoil, Royal Purple, Mobile 1, or Red Line. They are all synthetics.
Thanks
Jim


Jim and TereJim and Tere

1985 Regal
29' Chevy 454 P32
8411 3172 29FP3B
Gear Vendor 6 Speed Tranny
03-29-2010, 09:21 PM
Rusty
Mobil 1 or Kendall synthetic.


Rusty

MilSpec AMG 6.5L TD 230HP; built-to-order by Peninsular Engines: Hi-pop injectors, gear-driven camshaft, non-waste-gated, high-output turbo, 18:1 pistons. Fuel economy increased by 15-20%, power, WOW!"StaRV II"

'94 28' Breakaway: MilSpec AMG 6.5L TD 230HP

Nelson and Chester, not-spoiled Golden Retrievers

Sometimes I think we're alone in the universe, and sometimes I think we're not.
In either case the idea is quite staggering. - Arthur C. Clarke

It was a woman who drove me to drink, and I've been searching thirty years to find her and thank her - W. C. Fields
03-29-2010, 10:54 PM
bill h
Several years ago, on Rusty's rec, I switched from standard gear lube (forgot the brand) to Kendall synthetic. I forgot the figures, but at the top of the same hill on about the same OAT, the diff read cooler on a temp gun.


.

84 30T PeeThirty-Something, 502 powered
03-30-2010, 12:06 AM
Rusty
When I worked for Shell, we were candid about competitors' products. Sun had the best metalworking oils, Kendall had the best gear lubes, and Shell had the best diesel engine oils.


Rusty

MilSpec AMG 6.5L TD 230HP; built-to-order by Peninsular Engines: Hi-pop injectors, gear-driven camshaft, non-waste-gated, high-output turbo, 18:1 pistons. Fuel economy increased by 15-20%, power, WOW!"StaRV II"

'94 28' Breakaway: MilSpec AMG 6.5L TD 230HP

Nelson and Chester, not-spoiled Golden Retrievers

Sometimes I think we're alone in the universe, and sometimes I think we're not.
In either case the idea is quite staggering. - Arthur C. Clarke

It was a woman who drove me to drink, and I've been searching thirty years to find her and thank her - W. C. Fields
03-31-2010, 07:01 PM
Jim and Tere
Rusty, presume you mean Mobile Delvac. What do you think about Royal Purple? That stuff is really 'Royal'. They want $20 a quart for it at Autozone.
Jim


Jim and TereJim and Tere

1985 Regal
29' Chevy 454 P32
8411 3172 29FP3B
Gear Vendor 6 Speed Tranny
03-31-2010, 09:13 PM
Rusty
Delvac is Mobil's diesel engine oil. I'm unfamiliar with Royal Purple - they're about as candid with tech speca as Amsoil.


Rusty

MilSpec AMG 6.5L TD 230HP; built-to-order by Peninsular Engines: Hi-pop injectors, gear-driven camshaft, non-waste-gated, high-output turbo, 18:1 pistons. Fuel economy increased by 15-20%, power, WOW!"StaRV II"

'94 28' Breakaway: MilSpec AMG 6.5L TD 230HP

Nelson and Chester, not-spoiled Golden Retrievers

Sometimes I think we're alone in the universe, and sometimes I think we're not.
In either case the idea is quite staggering. - Arthur C. Clarke

It was a woman who drove me to drink, and I've been searching thirty years to find her and thank her - W. C. Fields