[Latitude 28]

Hello Gurus,
What seems to be the choice synthetic lube for the rear differential oil change?  From what I can gather it takes 5 gallons for a complete oil change.....is that correct?

[Richard]

5 gallons did it for me, the cost differential (no puns) between Dino and synthetic was not very much so I went with the synthetic

[BusNit]

Timely manner as I think mine has been in there for a few years. No receipts on anything done back there. Even with a pit, I am not looking forward to that stench if I do it myself.

[Jack Houpe]

Steve, Simon I also have been thinking about changing this its got 168k miles on the coach and who knows if its ever been done.

[Latitude 28]

Thanks for the input....mine has 112k and is probably original hence the desire to get it changed.

[BusNit]

With this topic opened up, I am on the search for a decent synthetic 75-90w oil. Can I safely assume if it's synthetic, they are all the same? (brands) Also, would it be worth going with a 75-140wt oil?

[Latitude 28]

With this topic opened up, I am on the search for a decent synthetic 75-90w oil. Can I safely assume if it's synthetic, they are all the same? (brands) Also, would it be worth going with a 75-140wt oil?

Simon,
I have used Mobil One synthetic oils in my cars for years with no extended intervals and a oil change a 5,000 miles.      About two years ago did some updated research into the current brands of synthetic oils.  Came across some great reviews on Walmart's Super Tech oils.....its cheaper probably due to a low marketing budget.  A friend of mine and I switched our vehicles over to Super Tech (he also used Mobile One with a 5k interval oil change).  I have done four oil changes with an oil sample taken at least twice with no detectable difference compared to Mobile One.  He has taken oil samples as well with the same results.  Having said all that, the Walmart Super Tech Synthetic is made by Warren Oil company and they probably make oil for several synthetic brands out there.  The ST 75-90w synthetic is $10.42 a qt. compared to Mobile One at $14.98 at walmart.  Cant say if the 75-140w oil would be any help to normal operating temps.......might be of some help to someone living in a desert:-)

[Jack Houpe]

Steve I have an 1979 928 Porsche that I've been restoring for awhile and the manual transaxle would grind bad going into first gear when coming to a stop indicating bad synchros so I called called 928srus.com where I buy my parts and he said don't rebuilt the box yet try changing out the oil from 90 weight gear oil to red line synthetic gear oil. I don't have a lot of faith in snake oil treatments but I did and it worked the synchro is still bad but you could shift it into first without stopping. Sort of putting a Band-Aid on a amputated finger but it still worked.

The cheapest way to buy oil is from a oil company in 5 gallon buckets, I would bet you have plenty in your area, I buy from a place 100 miles away but they deliver to a hub in Springdale AR for free which is 25 miles away. Keep us in tune on what you use.

[[email protected]]

I put Lucas Synthetic 75-140 in my Rockwell axle in my WL. Figured I would not have to mess with it again, hopefully. Not as cheap as some but how much is a new diff? 

Speaking of this, what axles are under Newells, I know the newer stuff has ZF, how about the 98 I am looking at? 


https://www.speedwaymotors.com/Lucas-Oil...lREALw_wcB

[BusNit]

I bought a 5 gallon bucket of synthetic 75-90 since that is what the Rockwell paperwork on mine shows. It can also use 75-140 but figured I would not really be driving this in desert heat anyway. Since it was time to do this, I also bought a McNaught pump, nozzle and battery. Might come in handy for other uses and allows me to buy the 5 gallon buckets of coolant, oils and trans fluids at a cheaper price. I'll make a cabinet in the pit to keep those tools in.