patrick335d

Hi Guys,

I have a offroad truck and its got a Moser Third member unit in my 9" rear end.
The truck is new, its done less than 150Miles, during first startup i followed the Moser guidelines. i pulled it apart a few weeks ago( about 50miles since new), since the flange was leaking a bit on the silicone.
then i made some remarks to the builder regarding the gear pattern.
I said that the back lash was too big, they said it was all right.

so i assembled it back, no i done little of 100 miles more, i started noticing oil deposit around the vent line, and again the damn silicone leaking.
I opened it up, it looked like the whole rear end was full of molykote.

have a look at the pictures, and give me your thoughts please.




doesnt seem like 150 miles

ssvert99

iTrader: (26)

It's worn out. Replace the gears and bearings, make absolute sure to clean the inside of the housing extremely well and do the proper break-in process.

Due to the nature of what you do with that vehicle I may also suggest using a different center section and pinion support. Chances are what you have will not properly oil the pinion.

patrick335d

Hi thanks for your comments, I followed the circular track brake in.
running SAE 140 gear oil, i didn't notice abnormal sounds until last Friday.
The case was noticeably hotter then before.
I kept the casing overfilled always by 1 qrt, during running on the axle stands and the filler cap off, a nice sprayer of oil was there in the casing, even now you don't see heat in the gears. if it was due to low oil lever or lack of lube the gears would be blue and the oil smell burnt but it isn't.


this was the gear at 50 miles.

RockinWs6

Are you sure you put gear oil in there? I've rebuilt -setup 100s of rears and NEVER EVER did anything special to break them in..................Your rear was obviously never setup properly. If that rear only has 50 miles on it I HOPE you drive a TOP FUEL Dragster.

patrick335d

I used SAE 140 gear oil all the time.
thats a negative, just a 525hp LS3.
it was a complete assembled rearend, with the Moser 3th member.
What i think is strange that there is not an uniform wear on the gears.
It has about 5 different angles worn into it.
i got the rear end back together did the first test last friday.
I will do 3 more test sessions and then pull the diff to see how it looks.

1 FMF

iTrader: (1)

how do you know there is no runout on the pinion and on the ring gear and carrier? prior to install and while in operation?
and is the casing, and pinion support aluminum? you mention the flange silicone leaking twice, andthat gives an impression thats where the problem might be.


i have read numerous times in many reputable publications,
for proper lubrication any gearset like this all that is needed is the ring gear to rotate into the oil sump the length of the gear teeth. so i doubt the oil was your problem, unless it was not a GL-5 gear oil for a hypoid gear. what oil did you use?

patrick335d

Im sorry but i cant make much out of your first few lines of comment.

Oil has always been sufficient.
Local oil brand but for Hypoid gears, mineral SAE140.
anyways the low hours on it, the gears aint blue so its enough for me to say that Moser supplied an improper setup rear end.

I put all together with new upand it sounds a lot better then before, it runs smoother aswell.

1 FMF

iTrader: (1)

here is a quick read on gear teeth type and oil requirement: http://www.lubetrak.com/newsletter/jan10html.html


to summarize: the ring & pinion in your axle requires a GL-5 rated gear oil because as the gear teeth mesh, there is a significant sliding action of the teeth. This is what requires the extra additives gear oil making it GL-5 rated, which is also why GL-5 gear oil has that pungent stinky odor.

you only said local oil brand, if your location of Dubai is correct I have no idea what oil you may have used... I've never been over there. In the states for example you can still find "non-detergent" motor oil in some grocery stores and without knowing better one can easily mistake it for acceptable engine oil (it says motor oil on the bottle). But if you were to use it in your car engine it will lead to engine failure. So from looking at your pic and to give an internet opinion my first guess would be a non GL-5 gear oil that resulted in what looks like a wiping type of wear on the gear tooth. It still lubricated but not enough because it lacked those extreme pressure additives. The heat you felt on the axle housing may or may not have been normal, I don't think you would be able to tell by hand you would need to take a temperature measurement.

Just because there was no bluing of the gears... which indicates extreme heat... does not mean there was acceptable lubrication. Nor does no bluing mean everything is ok and there is not excessive wear happening.

by runout, I mean wobble. do the gears rotate true, with no wobble. is the differential carrier machined properly so when the ring gear is bolted to it and that third member assembly is bolted into the axle housing, it rotates with zero wobble. same for the pinion gear. runout will cause noise and wear.

Won-Ton

Looking at the pattern, that rear end was not setup correctly. Also, don't get a local oil who knows what they put in there, I don't think that is the issue but why risk it. What silicone are you using?

patrick335d

Hi,

when I installed the new gears few weeks ago, i measured the runout but nothing out of the ordinairy. I ordered the assembly kit from Moser aswell.
changed all the bearings and races.
I shimmed the pinion, done the backlash and the gear pattern.
it runs perfectly free without binding.

I run the truck just before my holiday.
I will be going this weekend again, I was planning to run it for 4 times and then pull the dif to see how the gears are holding up.

regarding the oil I use the local brand Enoc Zenon Ultra, and it is GL5 rated.
I wish i could find something here like Redline or swepco etc but unfortunately not.