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nate
06-24-2005, 08:01 AM
Does is make sense that gear oil is "lifetime"?

I read the owners manual for my truck (98 Dodge 2500) and it more or less says you don't need to chance the diff oil unless you have been in water. :partyman:

Also doesn't tell you what oil to put in but says from the factory the front (D60) has 80w90 and the rear (D70) has SAE 90.

Ok... I'm still changing the oil. 80w90 in teh rear of a tow rig... does that make any sense?

Pearce
06-24-2005, 01:02 PM
That seems odd. Mine has a regular change schedule and they say to use synthetic front and rear. See if the maintenace scheule in the back has something in it about when to change.

nate
06-24-2005, 02:07 PM
What weight of old does it say to use for yours?

Troy
06-24-2005, 11:04 PM
2001 Dodge Ram 1500-3500 FSM:

front axle: have MIL-L-2105C and API GL 6 quality specs, libricant is SAE 75W140 synthetic

rear axle: have MIL-L-2105C and API GL 6 quality specs, libricant is a thermally stable SAE80W90 or for axles intended for heavy duty or trailer tow SAE 75W140 synthetic, add friction modifier if you have a limited slip.

For heavy duty trucks the FSM recommends changing the gear oil every 15,000 miles. For medium duty trucks every 30-36,000 miles. It does not have a schedule for the light duty trucks. Also these are the numbers for the schedule "B" for these trucks (frequent stop and go traffic/towing).

nate
06-25-2005, 05:37 AM
Thanks. That makes more sense.

I'm not sure what teh hell they are talking about it my book, but it's wrong if you ask me. They may as well put that engine oil is "lifetime" as well.

I'm going to look for a FSM for the truck. I got a Haynes, but for alot of the stuff, it says to bring it a qualified shop. WTF?!

Troy
06-25-2005, 08:12 AM
The FSM I have is 2 volumes and covers all 2001 Dodge Ram Series (1500, 2500, 3500, all engines, axles, etc.)

If a local buddy has any of those and the FSM just use his.

Pearce
06-25-2005, 12:17 PM
You can order print and CD versions here:
http://198.104.149.53/CoastalData/showprod.cfm?&DID=30&User_ID=529154&st=2710&st2=79 082567&st3=-56474600&CATID=1&ObjectGroup_ID=150

Cue-Ball
07-31-2005, 02:19 PM
When it's time to change the gear oil, why not try some Amsoil??

egon
12-13-2005, 05:51 PM
From DCX DealerConnect:

"LUBRICANT SPECIFICATIONS A multi-purpose, hypoid gear lubricant which conforms to the following specifications should be used. Mopar® Hypoid Gear Lubricant conforms to all of these specifications.
The lubricant should have MIL - L - 2105C and API GL 5 quality specifications.
Lubricant is a thermally stable SAE 80W - 90 gear lubricant.Trac-lok differential equipped 4X2 vehicles require the addition of 7 oz. of friction modifier to the axle lubricant. Trac-lok differential equipped 4X4 vehicles require the addition of 10 oz. of friction modifier to the axle lubricant. The 286 RBI axle lubricant capacity is 3.22 L (6.81 pts.) for 4X2 vehicles and 4.80 L (10.125 pts.) for 4X4 vehicles total, including the friction modifier if necessary.
CAUTION: If axle is submerged in water, lubricant must be replaced immediately to avoid possible premature axle failure."


That being said, If it was my truck and I was towing with it I'd use 75w140. The Amsoil Severe Gear stuff would be my choice. Even being synthetic, I'd still replace it every 30k. Nothing is fill for life.


--Matt

nate
12-13-2005, 09:55 PM
I think I put Wal-Mart brand synthetic 75w140 in it. I forget now, it's been a while since I did that.

rsl
02-25-2006, 03:14 AM
Anyone know exactly what is in the friction modifier? Or the cheapest place to buy it?

rob92xj
02-25-2006, 08:42 AM
There should be another book with the owners manual it is a maintence log and has you servicing the diffs every 15000 miles.
If the truck has a trac-lock(LSD) then you need to put the friction modifier in or the clutchs will not slip when needed to slip.
Dealerconnect every 12000 miles for a 98 Ram 25/3500 with a Cummins to service front and rear diffs, every 12000 to service trans and 36000 for t-case 48000 to replace the coolant.

ZJZJ
02-25-2006, 10:23 AM
Gear oil is lifetime. Lifetime of the axle that is. It will last right up until the time the axle explodes. I try to replace mine every 30,000. I went with the Amsoil in mine the last time and have been happy. Nothing has blown up and I don't hear any noise. I need to do the fluid change again since I'm up to 67,000 miles now.

nate
02-25-2006, 11:17 AM
Yeah I change it every 3rd oil change (15k). No Limited Slip. I put a Detroit in the D70 :D