I've decided I'm going to put Amsoil in the rear end and 4 speed manual trans in my '79 Chevy 1 ton truck. Both call for 80w90 GL5. What's the difference between Amsoil's "Severe Gear" oil and the "Long Life Synthetic Gear Lube" both in 75w90? And, would one or the other be better in the trans vs the rear end?
Amsoil Severe Gear vs Long Life 75w90?
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Originally Posted By: SecondMonkey
I've decided I'm going to put Amsoil in the rear end and 4 speed manual trans in my '79 Chevy 1 ton truck. Both call for 80w90 GL5. What's the difference between Amsoil's "Severe Gear" oil and the "Long Life Synthetic Gear Lube" both in 75w90? And, would one or the other be better in the trans vs the rear end?
Severe Gear is much more additized, a much better base oil combo. Just a better product. The Long Life gear oil is closer to M1, for example. That said, you don't want Amsoil 75W-90 in that truck, you want 75W-110. (Amsoil uses the new SAE J306)
Amsoil SVT 75W-110
http://www.lubrizol.com/J306.aspx?id=33216&terms=J306
I've decided I'm going to put Amsoil in the rear end and 4 speed manual trans in my '79 Chevy 1 ton truck. Both call for 80w90 GL5. What's the difference between Amsoil's "Severe Gear" oil and the "Long Life Synthetic Gear Lube" both in 75w90? And, would one or the other be better in the trans vs the rear end?
Severe Gear is much more additized, a much better base oil combo. Just a better product. The Long Life gear oil is closer to M1, for example. That said, you don't want Amsoil 75W-90 in that truck, you want 75W-110. (Amsoil uses the new SAE J306)
Amsoil SVT 75W-110
http://www.lubrizol.com/J306.aspx?id=33216&terms=J306
Originally Posted By: Pablo
That said, you don't want Amsoil 75W-90 in that truck, you want 75W-110. (Amsoil uses the new SAE J306)
Hmmm...can you elaborate on that? You mean to say the numbers are different than they were before? I know that generally a heavy duty truck should have thicker oil, but I'm mostly hoping for efficiency here. Wouldn't 75w90 be slightly better for that? 75w90 has got to be better than whatever they were using in 1979, right?
That said, you don't want Amsoil 75W-90 in that truck, you want 75W-110. (Amsoil uses the new SAE J306)
Hmmm...can you elaborate on that? You mean to say the numbers are different than they were before? I know that generally a heavy duty truck should have thicker oil, but I'm mostly hoping for efficiency here. Wouldn't 75w90 be slightly better for that? 75w90 has got to be better than whatever they were using in 1979, right?
The 90 grade was wider in 1979. Back, in 2001 or 2002, I think, SAE split 90 grade and 140 grade each down the middle. The bottom half of 90 stayed 90 but the top half was named '110' Same thing happened with 140, bottom half kept the name, top half got 190. They figured the grades, were too wide...
So really, when you think about it, 110 is within the OE specification back in 1979.
So really, when you think about it, 110 is within the OE specification back in 1979.
Ah, I guess I'll use the 110 in the rear then. What about the transmission? (SM465) Can I/should I use the 90 in there in hopes of easier shifting and better mileage? This truck was designed to tow 12k, but the most it will probably ever see is my little speed boat.
Not sure on the 79 tranny - what does it call for?
Originally Posted By: Pablo
Not sure on the 79 tranny - what does it call for?
Same 80w90 as the rear end.
Not sure on the 79 tranny - what does it call for?
Same 80w90 as the rear end.
You could give the 75W-90 a try, but might be on the light side.
In my fleet of 3500 Savanas with the big Dana Rear End, the 75w-90 is too thin.
use the severe gear 75w-140 for less noise and a wider range of protection.
use the severe gear 75w-140 for less noise and a wider range of protection.
Originally Posted By: SteveSRT8
In my fleet of 3500 Savanas with the big Dana Rear End, the 75w-90 is too thin.
use the severe gear 75w-140 for less noise and a wider range of protection.
Hmmm...have you tried the 110? My gears are pretty noisy at 4.56:1. This is a 'heavy duty' truck, but I won't really be using it for much besides moving my butt around.
In my fleet of 3500 Savanas with the big Dana Rear End, the 75w-90 is too thin.
use the severe gear 75w-140 for less noise and a wider range of protection.
Hmmm...have you tried the 110? My gears are pretty noisy at 4.56:1. This is a 'heavy duty' truck, but I won't really be using it for much besides moving my butt around.
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