Fluid types? Syn brands? oil, fluid, lube

[Baja71]

Search is not my friend today. Too varied.


I'd like to use synthetics where I can. Recommendations for Mobil 1, Lucas, Amsoil, Royal Purple, others?

Dana20: Calls for 50w, but some use 80/90w gear oil. Problems with that? Too thick?

Manual 3spd: Just calls for man. trans oil. Use 80/90w here? 50w, same as transfer case?

Dana44: I plan on using 80/90w gear lube for the diffs. Why would you use 80/140? Towing?

Ford9: Same as D44 with friction modifier for the rear.

Any suggestions appreciated.

 

[needabronco]

I generally use Mobil 1, Lucus, or Castrol, Syntec. For my D20 I did use the 50W, and then later switched to regular 75/90w and it doesn't leak anymore.

 

[Baja71]

I generally use Mobil 1, Lucus, or Castrol, Syntec. For my D20 I did use the 50W, and then later switched to regular 75/90w and it doesn't leak anymore.

It slowed your leaks? Did you notice any other difference?

 

[BroncoMatt13]

i prefer amsoil synthetic, the best around.... severe gear 75w 90 in both diffs and dana 20, works great!

 

[Baja71]

I didn't realize that gear oil and motor oil were measured differently until I started poking around for my lube. I came across this chart comparing the two.

SAE crankcase oil / Kinematic(approx)

SAE Gear Oil
----------------------------------------------
M 10W 22-32
G 75W 20-45
-----------------------------------------------
M 20W 32-70
G 80W 45-80
--------------------------------------------
M 30W 70-110
G 85W 80-125
--------------------------------------------
M 40W 110-150
G 90W 145-340
----------------------------------------------
M50W 150-250
G 140W 340-800

 

[needabronco]

One of my yoke seals still seeps a little after I rebuilt it. With 50W it was noticable, with 75w 90 instead of a drip every couple of day's the outside of the case is wet, but there's no drips...

 

[Baja71]

One of my yoke seals still seeps a little after I rebuilt it. With 50W it was noticable, with 75w 90 instead of a drip every couple of day's the outside of the case is wet, but there's no drips...

The 50w you were using was gear oil then?

 

[Baja71]

i prefer amsoil synthetic, the best around.... severe gear 75w 90 in both diffs and dana 20, works great!

I wonder what the 3spd would shift like with that in it.

 

[73stallion]

I wonder what the 3spd would shift like with that in it.

when i changed from chrysler synchromesh to the AMSoil 10w30 synchromesh, my NV3550 shifted easier almost immediately.

 

[73Russell]

I wonder what the 3spd would shift like with that in it.

Mine seems to shift just fine with it in there but I have only gotten it out for like 10 miles city driving have other issues to deal with first before I will truly know.

 

[BroncoMatt13]

I wonder what the 3spd would shift like with that in it.

I use there type f for my c4, im sure they have a great synthetic for the 3 speed

 

[Dbteak]

This might help with difference of viscosity of gear oil vs engine oil.

www.bobistheoilguy.com/visc.html

 

[Baja71]

Hmmm. That one's a little different. Basically the same concept.

 

[kancox]

amsoil from one end to the other!!! i have a f350 crew cab 4 wheel drive 7.3 diesel. a couple years ago i had a gauge installed to monitor automatic trans temp. went to pick it up but my mechanic said it would be a bit longer. he had test drove it and tranny temp would only get to 80 and this couldn't be right. it was about 60 degrees out.he tested sending unit tested perfect.normally the temp runs 20 to 28 degrees above outside air temp!i have never seen the temp over 170 on a 102 degree day pulling my 25 foot flatbed loaded approx. 14 to 15 K trailer and load. that's in overdrive!!Amazing stuff!!

 

[blubuckaroo]

Say what you want but you can pour SAE 50 motor oil but SAE 90 gear oil looks like honey. Until I make a bazillion dollars a year as an oil engineer, I'll take their advice and continue putting SAE 50 motor oil into my transfer case. Besides, motor oil costs less. I do know that mine has 280K on it and shifts way better than most.

 

[Baja71]

Say what you want but you can pour SAE 50 motor oil but SAE 90 gear oil looks like honey. Until I make a bazillion dollars a year as an oil engineer, I'll take their advice and continue putting SAE 50 motor oil into my transfer case. Besides, motor oil costs less. I do know that mine has 280K on it and shifts way better than most.

Well, I'm sure you can make it too thick and cause problems. I'm just trying to find out the best for each application. I need it all and want synthetics from day one...except the first few thousand on the motor.

 

[kbronco]

FWIW, I just bought a new NV3550 and the guy at the tranny dealer told me to just use synthetic 5w-30 in it.

Kaleb

 

[TOFIC]

Search is not my friend today. Too varied.


I'd like to use synthetics where I can. Recommendations for Mobil 1, Lucas, Amsoil, Royal Purple, others?

Dana20: Calls for 50w, but some use 80/90w gear oil. Problems with that? Too thick?

Manual 3spd: Just calls for man. trans oil. Use 80/90w here? 50w, same as transfer case?

Dana44: I plan on using 80/90w gear lube for the diffs. Why would you use 80/140? Towing?

Ford9: Same as D44 with friction modifier for the rear.

Any suggestions appreciated.

Heres what I use in my 351 automatic.
Dana 20, non-detergent synthetic oil, Shell, 50W, available at shell distributor
Front End, 44, trac lock, Castrol Syntec 75-140 synthetic
Transmission, C4, ATF synthetic, AMSOIL, got it cheap at farm supply place
Rear end, 9", Trac lock, same as front with modifier added.
Engine, 355 (351 20 over) 5w-50 Synthetic either Castrol or QS
Grease for greasable points, any synthetic grease, got mine from farm place.
TOFIC