Differential & oil

[Slow Six]

First off I do not want to start a bashing session or a b. s. slinging session. I would like to get some informed opinions or knowledge based thoughts. I have been using Redline MTL in the transmission and Redline gear oil in the diffs. A month ago I lost 6th gear in my NV 5600. There were pieces broke off both gears. I was going to use Redline again. The Reman transmission comes with a 3 year 150,000km warranty and you can use any oil as long as it has the Chrysler specs. (MS-9224) on it. The Redline oil does not have this spec so after spending $6500 on a transmission I put in the Mopar oil. It doesn't cost much more than the Redline anyways. Now this week the rear diff started whining a little. I took it in to be looked at and it got quite noisy by the time I got there. They took it apart and told me the pinion bearings were hard to turn and that they would have to be replaced along with crown gear and pinion. I went in this morning to look at the parts. The bearings actually look "good" as in there is no scoring or discoloration that would indicate they had gotten hot. I had a good discussion with the tech and he said to get a perfect job the crown gear and pinion should be changed as well. Everything else looks good other than a leaking wheel seal that he found when he pulled wheels to clean. I am no mechanic or engineer but I am really suspecting the oil of not doing its job and that I was not getting proper lubrication. I do change the oil on a regular basis and up until now the oil has always been clean. The technician even said it was still clean other than some stuff from the last trip. As with the transmission I am not using the Redline oil again. Again I am not bashing or starting another oil war but I would like to try and make a more informed line of thought.

 

[Jim W]

I am not a transmission expert by no means, but I was (retired now) a hydraulic design engineer for a large heavy equipment manufacture for 40 years. I do know something thing about oils and the lubricity of them. There is also an engineering expression called B10 life. B10 life is when 10 percent of the components will fail before a certain time period/mileage before the given life of a component should fail. This is what the design teams will design to.

Now I know from personnel experience that an individual does not need to use the brand name oil from the manufacture of the product. You do need to use an oil that meets the specification set forth by the manufacture. The reason is that the specification set forth will ensures that the oil's will have the lubricity and wear properties in it. This will then ensure adequate life of the bearings and gears.

What you did not mention is the total mileage or hours that are on your truck. This will could be beyond the excepted life of this component or the one component that falls into the B10 life. This could be true for the differential's also.

My recommendation is to use name brand lubricant that meet the manufacture specification for the given component. This will insure that the oil has the proper lubricity and wear properties required.

 

[HBarlow]

I am certainly not an engineer or scientist but I do have adequate reading and comprehension skills. I read the owner's manual of new trucks and use only quality brand name lubricants that meet the manufacturer's specifications. I never purchase MOPAR branded lubes because I know that MOPAR does not own or operate any petroleum refineries or labratories that refine or blend the lubes they sell.

I used Pennzoil Synchromesh Gear Lube meeting OEM specs purchased at AutoZones in my '01 Ram w/NV-5600 transmission. The transmission needed a rebuild at 302,000 miles after lots of towing. Standard Transmission found wear when disassembled but no broken parts.

Likewise, I used high quality brandname synthetic gear lubes meeting OEM specs in the differentials of my previous two high mileage Rams. I put a total of 555,000 miles on those two trucks and never experienced a noisy or failed rear end assembly in either.

IMO, many of the guys who proudly use snake oils with magical properties don't ever put enough miles on their trucks to see the results of the lubricants they use.

This is just my experience and my opinion. YRMV.

Afterthought: Engineers who design and manufacture machinery such as transmissions and differentials know what metals are used, what stresses are placed on their products, and have good solid reasons for selecting the lubricants they specify in owner's manuals. I accept their knowledge, experience, and judgement about thier products as superior to my own so I follow their recommendations.

 

[BDaugherty]

Was your transmission and rear axle failure due to marginal oil or was it due to heat buildup from towing heavy? Maybe some fast coolers and a finned differential cover would help more than high dollar oil.



I use Amsoil syncromesh transmission oil in my NV5600. It meets the Mopar spec and actually costs a little less than the Mopar oil.



I've just been using regular 80w90 in my diffs, but if I pulled heavy I would switch to 75w140.

 

[steved]

I have over 100k on redline in my NV5600... there's almost 200k on the trans.



A gear failure (where the gear actually breaks into pieces) is not typically lubricant related, but more related to shock loading. I would wonder if the gear was faulty from the getgo and took this long to finally let go??

 

[amsoilman]

I have to agree with Steve concerning gear breakage. As he said, gear breakage is usually due to gear loading, and not lubricant. As far as a lube meeting the manufactures specs. , I would always consider the specs of the lube with regards to the manufacurer's specs. The Amsoil NV-5600 lube does meet/exceed the MS-9224 and MS-9417 chrysler specs.



Wayne

 

[rbattelle]

I'm hesitant to blame Redline for these failures, although that is a very convenient explanation.

Do you tow with the vehicle? What viscosity is the Redline fluid?

Ryan