2nd Gen Non-Engine/Transmission rear oil change

[dodge cummins]

i am getting conflicting data. which weight of oil is best for the rear in my truck. is it 75w90 or 75w140. which weight of oil offers the best all around protection.

 

[MACHINEST]

I would run the75W90 if your in a cool climateand warm summers,The 75W140 is ok for The hot states,If you want it to run cool put the Syenthic in it... Hope this Helps

 

[EBottema]

140 is for towing and heavy use, 90 is for regular duty

 

[WBusa]

Been real happy with 80W90 here in PA, which has weather not unlike yours in NJ, with moderate towing. Just keep it clean, and maybe do yourself a favor and get a Mag-Hytec or other cover with a dipstick... there is NO substitute for being able to SEE your oil now and again without crackin' the punkin.

 

[JPope]

"... 140 is for towing and heavy use, 90 is for regular duty... "



Agree, My Dodge manual (2000) says the 140, SYNTHETIC, was recommended for towing.

 

[dodge cummins]

thanks for the clarity

 

[mechanic]

I have run 80/140 synthetic for several years for heavy duty axles or axles doing heavy duty work. If you mix a synthetic and mineral at about a 50/50 mix, you get the lubricating ability of synthetic with the coating ability of mineral oil. Synthetic tends not to "climb" the gears as well as mineral oil, but synthetic has better temp stablilty, and does not brake down under intense heat like mineral. When I change mine, I will use a mix of 80/140 synthetic/mineral. In your temp range I would use a mineral 75/90 mixed 50/50 with a synthetic 85/140. This should give you the best protection under all operating conditions. Just thought I would add my thought to the mix for what it is worth. It does have some research behind it though.

 

[WBusa]

Let the pros do what you pay 'em to do

If you mix a synthetic and mineral at about a 50/50 mix, you get the lubricating ability of synthetic with the coating ability of mineral oil.

Just my $0. 02 worth: I feel that mixing products to make your own 'superior' custom blend made some sense back in the old days, when oil was just oil, but today's lubricants are very complex chemical formulations that have been optimized by people with decades of expertise and millions of dollars of research behind them. If it was this simple to improve their products, they'd be doing it. When you mix and match like this you're diluting each product's additive packages, maybe to the point of making them ineffective - you just don't know. So you're still paying for all those additives, but you're maybe not getting the benefit from them. When I buy a lubricant I'm not just paying for the product... I'm also paying for the expertise that went into making the product as good as it can be.

 

[Jschafer]

What should be run in the transfer case

 

[PLaFrombois]

I'd suggest the 75W/90. Don't mix different weights, or synthetic/petroleum.



Jschafer; ATF is used in the transfer case. It will take almost 3qts.



Paul

 

[mechanic]

I'd suggest the 75W/90. Don't mix different weights, or synthetic/petroleum.



Jschafer; ATF is used in the transfer case. It will take almost 3qts.



Paul

Ok, I surrender. Given a choice of one or the other, I vote synthetic 80/140. It is good for all load and weather conditions, and may give a very small increase in fuel milage. The new MERCON V ATF is really great in the transfercase. It is a parasynthetic fluid and has considerabley better heat stability then DEXRON III, yet is a drop-in replacement for DEXRON III. Hope this helps.

 

[Walleye mike]

how many quarts does it take to do a change? what about the front?

 

[dodge cummins]

my 4. 10 rear took 3 and a quarter quarts of mobil 1 75w140 along with 7oz of limited slip additive. the front i am not sure but genos garage has a prompt of where you can find that out.