2nd Gen Non-Engine/Transmission what is the prefered dana 80 lube weight

[WDixon27]

i noticed a spot on the floor under the pumpkin after being parked a few days so i need to do a gasket and refill, i am going with royal purple but what do they like better 75w90 or 75w140, it is 4. 10 gears with posi and i don't really tow much but i do flog it hard

 

[kenny61]

Manual calls for the 90w. Other than that it's probably a matter of opinion

 

[GAmes]

i noticed a spot on the floor under the pumpkin after being parked a few days so i need to do a gasket and refill, i am going with royal purple but what do they like better 75w90 or 75w140, it is 4. 10 gears with posi and i don't really tow much but i do flog it hard

Don't wear youself out looking for a gasket, there is none. Before I bought my MagHytec I used black RTV. I use 75w140 royal purple, but I tow a lot. However, if the local NAPA doesn't have 7 bottles of the 140 I make up the difference with 75w90. BTW, Royal Purple requires no anti-slip additive.

 

[Bob Cochran]

I used the gray RTV and 75w140 Amsoil with no anti-slip. I tow probably more than you and so far no problems.

 

[CumminsPower98]

I ran Amsoil 75W140 when towing regularly. When not towing I use 75W90 for a little less drag. I could really feel the 140 drag during warmup when running in real cold weather. It really doesn't matter though and is up too you. Main thing is if you are going to tow a lot the heavier stuff is better.

 

[SHobbs]

Royal Purple 75W140 since new. I change it every year which is about 24k, I have 241k on the truck now with no problems. As said above RTV will do just fine to seal it back up.

 

[DMcLeod]

FYI - I picked up some gray Loctite brand RTV a few yrs back, went home, drained the diff, cleaned it up, and proceeded to use the RTV when intalling the cover. The next morning, I went out to fill 'er up (letting the RTV dry overnight) and the gray RTV was still wet goo. I got to clean it up again and this time used black. Loctite dealer told me later that gray was to be used in anaerobic locations (absence of air) only and will not set up when exposed to air. That tube of gray still sits in my toolbox.

 

[fest3er]

i noticed a spot on the floor under the pumpkin after being parked a few days so i need to do a gasket and refill, i am going with royal purple but what do they like better 75w90 or 75w140, it is 4. 10 gears with posi and i don't really tow much but i do flog it hard

Don't use less than 75W110. 75W90 is the same viscosity lube used in rear ends 40 years ago. Engine power and torque have increased dramatically since then, but the recommended lube hasn't changed. 75W110 is a fair compromise for easily-driven diesel P/Us. If you drive it as hard as you say you do, run the 75W140.

 

[BDaugherty]

My '01 owner's manual calls for 80w90 under normal conditions and 75w140 if you tow. It's really your choice. If you make a lot of short trips unloaded, then the lighter oil would be better. If you make a lot of really long trips or stay loaded a lot, then the heavier oil would be beneficial.

 

[Dick Davis]

Preferred Dana 80 Lubr Weight

Amzoil now has a 75W-10 weight lube that attempts to bridge the gap betweer 75W-90 and the 75W-140.



I use the 75W-90 in the front and 75W-110 in the rear of my 01 dually.



Dick in Idaho

 

[wcjp]

Are you sure the diff cover is leaking? Seems odd to start leaking. Verify the pinion seal is ok.


edit: Look for Dana 80

says available 2004? Not sure. I'm running Lube Locker on my Jeep. They work great. I'm RTV free.

 

[DHayden]

I use Royal Purple 75w140. I dont tow alot but when I do its usually heavy. Never a problem, no additives.

 

[DIESELWRKS]

I have went back and forth with redline and royal purple both have anti-slip additive in them. redline I can usually find alot cheaper lately. I dont have any decent amsoil dealers in my area that I know of so I have never used amsoil. have almost 175k on the truck



2002 HO 6-SPD LB 4X4 QC HTT 62/14 SB-DD3600 TST PM3/*REVO-BETA*SMARTY MACH 4'S, RINGED AND STUDS, AFE/2 " FTE 6" STACK D/PRICOL GAUGES, FASS 150, VULCAN 1/2 DRAW-STRAW, 3/8 FUEL LINE, DSS-BOX DT PRO-FAB TRAC BAR, CONV-T STYLE STEERING,DUNKS TRACTION BARS, AIR BAGS,17'' KMC BLACK HOSS, 37" TOYO MT'S 6" RCD LONG ARM LIFT. :-laf... THANKS RIP DiPricol Gauges

 

[SRath]

Not to get off-track, but the issue of RTV and no-gasket-available has been brought up. I have posted before about having once used the wrong RTV, the copper stuff (orange colored) and it cost me an expensive Chevy Dana 60.

I had just serviced the front axle and refilled the diff with Mobil 1 synthetic, then bought my Diesel Dodge shortly afterwards and the Chevy sat for a couple of years.

My wife used it (my K/V30 Chevy) one snowy day when her S10 Blazer gave her trouble. She had to use 4wd to come the 2 miles home from work, and when she got here, told me it was "making terrible noises". I dropped the front cover after discovering terrible slop in the pinion when I grabbed and shook the front driveshaft (also new before parked). The only thing that rolled out into the oil drainpan was rollers from the pinion bearings. Not a single drop of oil.

There was still a perfect bead of RTV from the oil line (fill plug) on up, and not a trace of it to be found from the fill plug on down.

During the years it sat there, the Mobil 1 had dissolved the RTV and slowly leaked out. Those two miles with the hubs locked in and the t-case engaged not only destroyed the bearings, it welded the big pinion inner race to the pinion and spun and gouged the outer race into the housing completely ruining the entire axle housing.

I DO NOT trust RTV anymore, but like you said, cannot buy a Dana 80 gasket. I now use LubeLocker gaskets on my Dana 60's.

Mark once said he had better luck with RTV than gaskets after hearing this story before. So what's the deal?

Well, according to Dana, if your stock diff cover has a perfectly flat flange, you should use RTV. If it has a raised rib in the gasket surface, it was designed to use a gasket. Makes sense.

Whatever you do, don't use the copper RTV. I did simply because I happened to have an unopened tube handy and thought all RTV's were the same more-or-less.

Nowadays, if I MUST use RTV, I use the Ultra Black on a brake-cleanered surface, wait a few minutes for it to skin a bit, assemble and torque, then wait until the next day to add any oil to play it safe and allow time for it to thoroughly set up.

The gooey RTV mentioned earlier by DMcLeod is a sign of either incompatible RTV and oil or improper drying time before filling, or both. Learn from my expensive lesson.

 

[Gary - K7GLD]

In recent decades, I've used a grey sealant in a tube bought from Suzuki - their "#1216 Silicone gasket sealant" - bought back in my motorcycling days, and used on cycles, lawn mower engines, automotive pan, manifold and valve covers, transmissions, and differentials - NEVER EVER had any leakage issues!



The stuff is/was expensive, at about $25 a tube - but worth it in applications that didn't leak! The Parts guy at the Suzuki shop said he had seen demos, where the stuff was applied to surfaces SUBMERGED in oil - and it still worked perfectly! The stuff doesn't harden - and the 20 year old tube I have is still flexible and apples properly, tho stored out in my garage thru summer heat and winter cold!

 

[SRath]

That sounds like the stuff we use to mate motorcycle case halves, which use no gasket and cannot leak at all, Gary. I should probably try it next time. Like you said, it's pricey.

 

[Bob Cochran]

While and aircraft mechanic I can tell you RTV is used a lot. The real problem is using the correct one for the correct application. You have red, blue, gray, black, etc. Some can be used for the same applications others cannot. You have to read each tube and determine which one is correct. Most people make the mistake of applying slapping it on and torquing and filling with oil. Sometimes this will work most times not. Best apply bead let skin over the bolt and torque on. I have also found a lot of times synthetic oils are not compatible with a lot of sealers or make-a-gasket type stuff. I found gray RTV worked good with my diff and 5600 covers.