Dana 80 gear oils

My 2000 Ford F-350 DRW came with a 4.10:1 geared dana 80 dualie axle. IT was factory filled with 75W-90 But ford has since updated to use 75W-145 for in service fluid changes on the rear ends. The other manufactures that use the Dana 80 (mainly mopar) still spec the 75W-90 in their rear ends. I'm thinking I'm going to stick with the factory fill 75W-90 from redline. any reason I shouldn't? This truck runs fast 85+ constantly and pulls heavy loads of up to 30K combined in city traffic and out on the highways @ 65 mph. The truck also has an exhaust brake if that changes anything
 
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MS
If Ford updated the spec to the thicker viscosity, surely they must have had a reason? Ford is definitely pro thin viscosity oil when they can get away with it. I say follow the TSB and go with the recommended 75W-140.
 
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1,067
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Northern, NY
Sounds like your truck does some heavy hauling and could see some high differential temperatures. I would use a 75w140 or 80w140 in that application, cheap insurance IMO.
 
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8,756
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RI
Sad when many automakers re'spec the requirements 'after' the failures come in from the consumer. Makes you wonder how good all that OE testing was??? Definitely use the 75w140!
 
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1,340
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minneapolis mn
I wonder if its an air flow across the rear end issue in the ford rather than a rear end issue? My vote would be for the thicker lube, you work the heck out of your truck.
 
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Waterloo, ON
Given how you are using the truck I would use the 75W140. It's its getting up there in miles then even more so. Axel will run a bit hotter and 1-2% less fuel economy...
 

Dualie

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700
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SF bay area, San leandro, Ca
well the truck is currently getting a new set of spider gears after the bottom one shead 3 teeth off making a lazy right hand turn in a parking lot empty. Thankfully the ring gear and pinion are fine. Having new bearings and races put in the hubs at the same time. I have the 75W 90 in stock so im going to use that. but it still makes me wonder why ford changed the spec's I just looked and my 1994 F-Superduty (F-450) with the dana 80 still specs the same fluid.
 
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8,598
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Florida
My mom's 2005 Jeep Grand Cherokee has a Dana-built rear axle, and it calls for 75w140. Every version calls for that, even with the weak V6 engine. It also calls for 12,000 mile gear oil changes when towing. I'd say go to 75w140.
 
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4,563
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NW Ohio
 Originally Posted By: Dualie
well the truck is currently getting a new set of spider gears after the bottom one shead 3 teeth off making a lazy right hand turn in a parking lot empty. Thankfully the ring gear and pinion are fine. Having new bearings and races put in the hubs at the same time. I have the 75W 90 in stock so im going to use that. but it still makes me wonder why ford changed the spec's I just looked and my 1994 F-Superduty (F-450) with the dana 80 still specs the same fluid.
Most likely, the tooth was ready to go and damaged from another incident or extreme wear, then picked that moment to let go. Lot's of towing or tire spinning (either burnouts or spinning up in mud or snow) will hasten side/spider failure. What does everything look like? Is it all dark, black or burned looking? Was the gear oil evil smelling? If so, that's low lube or heat from towing. I have had a rear axle temp gauge on my towing rig for some time now and it isn't hard to reach 250 degrees. It's a cmbo of high loads and high speed that makes heat. Also, the lower the gear ratio, the hotter the axle will run (more teeth and friction surfaces to generate heat). I have found that at 55 with a given load, the temp is 180. I increase to 70... it goes up to 225. It would probably be worth putting in a temp gauge, at least. Autometer makes a nice one and they also sell a bung you can weld into the steel cover, or you can buy an aftermarket voer that has a built-in port (I use the Mag Hytec) The Dana 80 had a so-so reputation in towing circles... at least in the extreme end of it). It's used as a medium duty axle, but it isn't really one. It has a high torque rating but a relatively low oil capacity and tend to get hot.That's one reason why Ford started putting the finned covers on them. They die like flies in motor homes due to cooked oil. The aforementioned temp gauge and an expanded capacity cover will help a lot. If nothing else go to 15K oil changes. The temp gauge will tell you if you need Grade 90 or 140 (odds are good it will need 140). If it consistently runs over 210 degrees, it should be 140. At 250 degrees the 90 has thinned a bunch.... depending on the oil, it could be to something around7-8 cSt (about a 75W). At 250, the 140 may have thinned to below a Grade 90 viscosity. Remember, at 210 degrees,viscosity will be right at graded viscosity. Above, it gets thinner.
 

Dualie

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700
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SF bay area, San leandro, Ca
I just realized that this gear oil had 80,000 Miles on it. IM definitely paying for my own negligence. The bottom spider is the one that let go and took the right side axle gear with it. the bottom spider had galled the living [censored] out of the cross pin so that's what most likely heated the oil so badly. But I know that this truck has ran at 27,000Lbs @75 MPH in 110 deg heat through Texas so I really cant complain. I'm thinking I might drop the hammer on a mag hytec cover for it. Its seen some shock loading and the Limited slip has been needed and used a time or two. with 170,000 miles on it the Yukon gear ring & pinion looks PERFECT. The carrier has a nick taken out of one of the corners of the view windows But with some cleanup its going to be fine. $430 for a complete spicer limited slip carrier refresh kit with new gears pins frictions and springs. Plus im going to do new races, bearings and seals in the hubs. other good news is that even with the weight and the speed the rear brake rotors are still well within spec with 343,000 miles on them.
 
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4,563
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NW Ohio
If you drop the dime on a Mag-Hytec, why not order the AutoMeter temp gauge? The Mag-Hytec has a magnet built in and I'll bet you will have a lot of metal in the oil, even if the housing was thoroughly cleaned (unless removed and run though a parts washer), plus break in metals from the new parts. If you install some Grade 90 for break-in, you can then run it a short while to determine if you need to go with 140. I've had excellent service from Yukon parts also.
 

Dualie

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SF bay area, San leandro, Ca
because the auto meter gauge wont match my isspro's. surprisingly the magnet on my current diff cover had just a small amount of fuzz on it that was way less than I expected it to be. Even pulling 127,000 lbs the 52K rears in my Kenworth never get over 190 deg but they have an integral pump and cooler in them. I do recall the most weight I have pulled with the ford. I wont post it here for fear of prosecution but it was WAY WAY WAY more than you should ever attempt with a pickup.
 
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4,563
Location
NW Ohio
 Originally Posted By: Dualie
because the auto meter gauge wont match my isspro's. surprisingly the magnet on my current diff cover had just a small amount of fuzz on it that was way less than I expected it to be. Even pulling 127,000 lbs the 52K rears in my Kenworth never get over 190 deg but they have an integral pump and cooler in them. I do recall the most weight I have pulled with the ford. I wont post it here for fear of prosecution but it was WAY WAY WAY more than you should ever attempt with a pickup.
Isspro makes a Diff temp gauge too. I am putting an Isspro Powermax system (8 gauges... My name is Jim and I'm a gauge-o-haulic) in my F-150 as we speak and I'm putting in the diff temp. I pull up to about 36 tons with my pickups... grain trailers (with brakes)... but only for short distances and no more than 25 mph. The '86 F-250 has seen nearly 19K GCVW a coupla times in it's early days. Besides the grain wagons, the F-150HD has not been tested with a big/big trailer over long distances. It's hard to tell what the "chicken" was from your interesting pics, but if I had to guess, extensive wear... perhaps due to lubricant breakdown. I think the failure started on the pinion shaft. Could be that it just wore out or, as I said, the oil started to go. The pinion shaft is a high stress area. One thing to keep in mind for high stress towing is the importance of matched diameter rear tires. Any difference between them will ad a lot of stress to the diff. Kinda like perpetually spinning the tires. An interesting thin gI learned about magnets lately is that they lose effectiveness with heat. Those big magnets will be loaded with good when you pull the cover but if you could see it from the inside of a hot diff, they release some of it back into the oil. Until they cool off and then the slowly draw it all back
 
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1,067
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Northern, NY
Good call on the break-in oil, I'd imagine that housing has some nasty stuff in it. It seems that most of the guys running Mag-Hytec covers stick with a 75w90 or 80w90. I would like to know how much the additional capacity lowers the oil temperature, but I don't know anyone that has installed the cover and a guage that knew what the oil temperatures ran prior to the install.
 
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18,449
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East of IGO
Run 85w/140 of your choice there was a failure,look at the wear ,I bet the wear caused the breaking . The diesel loads the parts pretty good IMO the heavier oil would be better .I would guess Schaeffers or L.E.oils are better than Redline .In fact Chevron Delo ESIis probably better than Redline.
 
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18,449
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East of IGO
 Originally Posted By: Dualie
because the auto meter gauge wont match my isspro's. surprisingly the magnet on my current diff cover had just a small amount of fuzz on it that was way less than I expected it to be. Even pulling 127,000 lbs the 52K rears in my Kenworth never get over 190 deg but they have an integral pump and cooler in them. I do recall the most weight I have pulled with the ford. I wont post it here for fear of prosecution but it was WAY WAY WAY more than you should ever attempt with a pickup.
I would bet the rear ends in the big truck is way over built in proportion to the Dana 80 for the work that it does.
 

Dualie

Thread starter
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700
Location
SF bay area, San leandro, Ca
 Originally Posted By: Steve S
 Originally Posted By: Dualie
because the auto meter gauge wont match my isspro's. surprisingly the magnet on my current diff cover had just a small amount of fuzz on it that was way less than I expected it to be. Even pulling 127,000 lbs the 52K rears in my Kenworth never get over 190 deg but they have an integral pump and cooler in them. I do recall the most weight I have pulled with the ford. I wont post it here for fear of prosecution but it was WAY WAY WAY more than you should ever attempt with a pickup.
I would bet the rear ends in the big truck is way over built in proportion to the Dana 80 for the work that it does.
well the d52-190's in the KW have a 18.5" ring gear diameter vs the 11.25" of the Dana 80. I think the advantage of the 52K rears is the On-demand high efficiency lube pump keeping everything cool and circulating. The also came factory filled with the new high zoot delo gear oil in them from the factory. They say lube life is over 100,000 miles. I ended up dropping it at 75,000 miles along with the 50W in the trans.
 
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1,335
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Arizona
"In fact Chevron Delo ESIis probably better than Redline". Based on what? Chevron, really!?? I hope this isnt based on UOA's. Cause in that case Amsoil is the best.
 
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