Rearend lube?

[gillguy]

I agree 100% with what Jim said! the key to getting your new truck tow ready is take a few trips to warm up the the rearend but not over heat things. change the fluid after 300~1000 miles and do it again around 5000 miles. I have been using mobil1 syn gear lube with zero issues. its easy to change , there is a drain and a fill plug so you can do it basicly anywhere . FYI you need 4Qts to fill it.

We are planning a trip to PA in July. But I should hit the 500 miles before then. We will be towing our travel trailer when we go to PA.
Should I change the rearend lube before we go? Or wait until the return home?

[DmaxMaverick]

After, or both. 500 miles non-towing has just begun the break-in process. It wouldn't hurt to do it before and after, but you'll want to do it after, in any case. The drain plug in the diff makes the change very simple. So simple, you could do it during if you wish. 3.5 - 4 qts is all the lube you'll need for a fill. The level (when parked on a level surface) should be ~3/4" below the fill hole. Use a quality GL-5 synthetic lube. Mobil 1, Redline, Royal Purple, Amsoil, and even Penzoil (full synthetic only) has good stuff. You can use the GM lube, but it's 4x the cost, and we've seen no advantage of it. The factory fill is 75-90, but you can use 75-140 if you intend on heavy, frequent towing, especially in hot climates with lots of grades. I wouldn't suggest 75-140 during break-in, though. Too heavy. Allow for more frequent cooling off periods during this time. If you work harden it properly at the beginning, it will last a lifetime.

[enforcer233]

DmaxMaverick, If I understand what was written above; you are suggesting that if someone changes axle lube from dino to synthetic it should be changed again after +/- 500 miles then again +/- 5000 miles???

It is in my plans to do this to my Suburban with 98000 miles on it in the near future. I changed the engine to Mobil 1 Turbo Diesel Truck 5W40 full synthetic yesterday. And I wanted to make sure I understand what was written.

Thanks

[DmaxMaverick]

DmaxMaverick, If I understand what was written above; you are suggesting that if someone changes axle lube from dino to synthetic it should be changed again after +/- 500 miles then again +/- 5000 miles???

It is in my plans to do this to my Suburban with 98000 miles on it in the near future. I changed the engine to Mobil 1 Turbo Diesel Truck 5W40 full synthetic yesterday. And I wanted to make sure I understand what was written.

Thanks


I wasn't refering to a change from dino to synthetic. The recommendation is for a new axle during breakin, with a factory fill. Break it in right and get the bad stuff out, and it'll last a lifetime.

For a healthy axle with miles on it, switching from dino to synthetic isn't as dramatic. I recommend an initial change (after the synthetic fill) at 50% of the regular change interval you intend. Dino lube will break down, leaving it to contaminate the lube. The synthetic or fresh dino lube will reject the decomposed properties of the old lube, causing sludge and glazing.