Firebird
Senior Member
- Joined
- Jul 19, 2015
- Posts
- 1,488
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- Ram Year
- 2019 Ram 2500
- Engine
- Hemi
My trans will stay at 168 degrees for hours on end, pulling 9000 pounds.
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Yes, for some reason the HD RAM's with the ZF 8 speed seem to run quite a bit cooler than the 1500's. Possibly because of different temperature parameters used in whatever thermal management system exists on the HD? On another thread an owner posted a photo of the Transmission oil cooler by pass block, so we know that is in use on the HD.. It could be set at a lower Temp. than the 1500 to allow fluid to flow to the cooler in front of the radiator. A part number comparison probably could confirm or defeat that theory. Until someone looks I for one cannot say whether or not it has the Fluid to fluid heater on the transmission like the 1500's. If I had to guess I would suspect not as they are not under the gun for efficiency like in the 1500.My trans will stay at 168 degrees for hours on end, pulling 9000 pounds.
ditto thread in 4 gen
So when you look at stat sheets it reveals the characteristics of the base oils. And the stat sheets reveal that zf8 fluid is not what we thought, as in pao base oils. It seams to be in line with maxlife multi use instead of true performance like redline or amsoil. The issue is sense the transmissions run hot, they really do need pao base oils for longevity, and according to the stat sheet, the zf8 fluid seams to similar to mineral oils in performance to be real pao fluid. So for guys with zf8, I say do some research when making a choice on transmission service. The only thing in common zf fluid has with the real pao based oils is the price tag, you guys are being hosed.
ZF Fluid
Viscosity at 100°C 5.6
Pour point -42°C
Maxlife multi-
Viscosity at 100°C 5.9
Pour Point -42c
Add a impressive VI at 163
Very decent fluid.
Redline d6-
Vis @ 100°C, CSt 6.3
Pour Point, °C -60
VI 163
Amsoil Multi
Vis @ 100, 6.3
Pour point, -65c
VI, 159
You see below second line, pao based oils do perform well in hot and cold, perfect for zf transmission. When you look at continual use, that is the nature of the base oil, the other parts of the graph are achieved with additives such as vii's that are very temporary in service. So when they say lifetime fluid, a real pao is possibly that, but as you can plainly see, mineral oil is not when you consider the temp the zf transmission operates at. Do what you will with this info, but at a minimum lower the interval if you use zf fluid because it is not what we have thought it was in the past. These stat sheets have been illusive, can't find one for mopar fluid either, but I bet it is the same. Funny fact because of the temp a zf operates at, and the fluid specs, it makes more sense to change it more often then an rfe.
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Some guys have reported issues with Amsoil and Redline in the 8 speed,but so far i haven't heard of anybody having issues with Valvolene's Maxlife. If you have issues,i'd try swapping out the Amsoil for Maxlife,or if you're feeling rich the ZF 8/9 speed fluid.Numbers don’t lie. But I’m wondering. I just did an oil and pan/filter change. Used the Amsoil. Trans shifting shady AF now. Bit concerned. Maybe should have used the rip off ZF fluid
Awesome. Thank you. I will check that out today. Have you ever had to do the Quick learn on the transmission using alphaobd to get it adjust to the fluid? Just a stab in the dark thereSome guys have reported issues with Amsoil and Redline in the 8 speed,but so far i haven't heard of anybody having issues with Valvolene's Maxlife. If you have issues,i'd try swapping out the Amsoil for Maxlife,or if you're feeling rich the ZF 8/9 speed fluid.
But before you do that,maybe re-check the fluid level first,as the 8 speed is very picky about fluid levels.
These are the factory instructions that come with a brand new 8 speed from the dealer,and the very first paragraph is important,you have to jack the rear tires a fair ways in the air to get the transmissions pan rail level.
I've probably changed the fluid about a 1/2 dozen times on the truck,and once on the wifes Challenger,and have never had to use AlphaOBD afterwards.Should be no reason to,all you're doing is a fluid and filter swap,you're not putting a new transmission in the truck,lol. I'd start by jacking the truck up so the rear tires are probably 8 or 9" off the ground and rechecking the fluid level,and go from there.The 8 speeds do not like even being a 1/2 quart down on fluid,and i'm more inclined to think your fluid level is low,more then the amsoil fluid causing your issuesAwesome. Thank you. I will check that out today. Have you ever had to do the Quick learn on the transmission using alphaobd to get it adjust to the fluid? Just a stab in the dark there
I sure hope so. Thank you for the guidance. Greatly appreciatedI've probably changed the fluid about a 1/2 dozen times on the truck,and once on the wifes Challenger,and have never had to use AlphaOBD afterwards.Should be no reason to,all you're doing is a fluid and filter swap,you're not putting a new transmission in the truck,lol. I'd start by jacking the truck up so the rear tires are probably 8 or 9" off the ground and rechecking the fluid level,and go from there.The 8 speeds do not like even being a 1/2 quart down on fluid,and i'm more inclined to think your fluid level is low,more then the amsoil fluid causing your issues