Differential Covers--> I outsmarted myself 20 years ago.

[Matt42]

Well, I got it done, on August 6 or so. I bought the gear oil about a year ago and kept it in the garage. Health issues prevented getting the work done. I needed 3 more quarts because my original plan was to reuse the OEM differential covers. The Mag-Hytec covers were just about the easiest installation of anything on this truck. And that includes needing to pop off the left tie rod end for access. They torqued easily to 15 ft/lbs and are not leaking a drop.

For some reason, I thought I had valvoline gear oil on hand. It was Royal Purple!

The oil that came out of the rear axle was dark, dark brown. The front's oil was still nearly translucent. The transmission oil was dark, and it was replaced with Syntorq.

Thanks, everyone.

 

[AH64ID]

Well, I got it done, on August 6 or so. I bought the gear oil about a year ago and kept it in the garage. Health issues prevented getting the work done. I needed 3 more quarts because my original plan was to reuse the OEM differential covers. The Mag-Hytec covers were just about the easiest installation of anything on this truck. And that includes needing to pop off the left tie rod end for access. They torqued easily to 15 ft/lbs and are not leaking a drop.

For some reason, I thought I had valvoline gear oil on hand. It was Royal Purple!

The oil that came out of the rear axle was dark, dark brown. The front's oil was still nearly translucent. The transmission oil was dark, and it was replaced with Syntorq.

Thanks, everyone.

Why only 15 ft/lbs? Torque specs are 20-25.

 

[Matt42]

Why only 15 ft/lbs? Torque specs are 20-25.

Oh, arrgh. Typographical error. (Or, as things are going today, typogogographicall eror.) I did indeed torque to 25 foot-pounds.

I need to stop posting things today. Thanks for the catch.

 

[Ozymandias]

Check out the clearance of the Tierod to the Cover at full lock steering on both sides.
I had bought a PML cover once that didn't clear the steering linkage, $$$ for the trash bin it was..

 

[AH64ID]

Check out the clearance of the Tierod to the Cover at full lock steering on both sides.
I had bought a PML cover once that didn't clear the steering linkage, $$$ for the trash bin it was..

I had to grind the MH down for tie rod clearance on my 05. It wasn’t much, maybe 1/8” and only on one side.

 

[Matt42]

Check out the clearance of the Tierod to the Cover at full lock steering on both sides.
I had bought a PML cover once that didn't clear the steering linkage, $$$ for the trash bin it was..

I had to grind the MH down for tie rod clearance on my 05. It wasn’t much, maybe 1/8” and only on one side.

Uggh. I will check and report back. May take a while. The rod itself clears nicely, but that's without turning the steering.

 

[Extreme1]

A few of things I've done with my Dana 80:

1) Mag-Hytec drain is great but, it isn't the lowest point. There is a small "sump" in the bottom of the case, that's where all the solids (wear metals) end up along with any other stuff you'd like to get out when changing the fluid (like a little bit old fluid). I drilled and tapped a hole and installed an 1/8" pipe plug (stainless socket head) set flush with the bottom of the housing so it won't catch on anything. The material in the housing there is pretty thin, I'm not worried about any effect on the strength of the case.

2) The Mag-Hytec does a nice job of sealing but the area outside of the O-ring is exposed to the to whatever you drive through. The gasket surface outside of the O-ring on my rearend was rusty. I wire wheeled it clean and applied some copper anti-seize, that stuff holds up the best in the rust belt.

3) When you change the fluid, the lube in the bottom of the outer hubs doesn't drain because it's below the bottom of the tubes. I drilled and tapped the hub outside of the area where the wheels pilot on them for another pipe plug. I was concerned about affecting the strength of the hubs so I called Dana, the engineer I talked to said it was good to get the lube out of the hubs and that there isn't a problem with what I was planning. He also mentioned that Mac Truck got a patent on their (Dana) axle because they drilled a small hole through the bottom of one of the tapped holes where the axle bolts on (it goes into the area where the lube is) and replaced a stud (heavy trucks use studs) with a bolt. When they change the lube, they pull the bolt out and rotate the wheel so that the open hole is at the bottom and drain the hubs.

 

[Turbo Terry]

My front MH on my 99 wore itself in. I was always worried about it leaking Never did . I kept the old one just in case. I threw it away when I sold the truck. I spent about $750 for front and rear and transmission pan. It was nice having the drain plugs I guess. Really on the transmission pan and the diff dip sticking as well but $750 is a lot of money and that was 20 years ago

 

[GAmes]

After having a couple of oil samples analyzed I'm not concerned with the small amount of oil that is trapped in the axle when the fluid is changed. Then again, on a 12 valve there is always a quart of oil that is trapped in the injector pump so oil changes don't replace all the oil either.

 

[AH64ID]

After having a couple of oil samples analyzed I'm not concerned with the small amount of oil that is trapped in the axle when the fluid is changed. Then again, on a 12 valve there is always a quart of oil that is trapped in the injector pump so oil changes don't replace all the oil either.

The engineers are well aware of this and plan the service intervals accordingly.

I’ve wasted a lot of time and effort to try and overthink maintenance and servicing. Change it according to the published procedure and call it good.

That being said I’m still a fan of early oil/fluid changes on new equipment.