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View Full Version : Post Gear Install/Axle Service Diff Fluid Change


corsair23
12-12-2009, 11:26 PM
Completed my 500 mile post gear install/axle service gear oil change today...Actual miles are probably more like 650 though...

I was surprised by the color of the fluid given the low miles. More concerned about the front fluid because it appears to have some moly grease mixed in with it :confused:. Could just be remnants of moly that got in before the axle service I guess.

Metal shavings wise the front was also worse that the rear...Mostly small pieces but there was one odd piece on the front drain plug magnet...It looked like a thin sliver of a pencil eraser or end of a bolt. Not sure where that would have come from. The rear drain plug magnet had nothing remarkable stuck to it...

Thoughts on what you can see/discern from the pictures?

Noise wise the gears seem quiet...I think I have a slight noise on coast but only when the speed drops below 32mph. Never noticed it before and it might not be the gears but it is consistent in that everytime I slow down I hear it from 32mph to around 25ish or so...

Front plug #1

16119


Front plug #2 with the pencil eraser sliver

16120


Rear plug #1

16121


Rear plug #2

16122


Gear oil - Rear is on the left, front is on the right

16123

Bikeman
12-13-2009, 12:00 PM
That's a fair amount of metal that came out the front. Might ask Robbie or Ben Ashcroft if it's normal. I didn't have any come out on my 500 mile oil change FWIW. I just did another change on the front and came to the conclusion that you can change the front oil and do it again the next day and it will always be yucky looking, even without blown seals. My rear fluid has been super clean after 3000 miles. I also came to the conclusion that I will never run full synthetic in the front, just not worth it, whereas I would never run but Mobil 1 in the 80's T-case.


I have about 3500 miles on my gear change and still have a little gear whine on deceleration or coast below 20 mph, which I think is coming out of the front. I get no other noise at anytime, at any speed. I think it is the quality of the Nitro gears. The better quality gears I was told are not available any longer.I have been told some sets esp. in higher numerically above 5 to 1 that it is normal. Some Dana 60 gear sets have in writing that they will make noise. I still need to talk to ring & Pinion.biz about the whine, though I'm used to what very little was left. I also need to confirm it's the front when I pull my rear DC shaft to check the balance this spring.

Red_Chili
12-13-2009, 01:20 PM
I run TG gears now, both ends. AFAIK they are equivalent to Nitro, same plant from what I have heard. They set up as well and consistently as any quality gearset I have dealt with (in my very limited experience) and make no noise. 4.88 ratios.

Then again the Chili is not a quiet 80... but I have radar ears for mechanical noise. Have Da Boyz give a listen (Robbie and/or Ben)

farnhamstj
12-13-2009, 03:40 PM
Rear looks good to me. Front lookes similar to mine when the outer pinion bearing failed. Maybe change it again soon(100-300mi) and see how it looks.

corsair23
12-14-2009, 12:15 AM
That's a fair amount of metal that came out the front. Might ask Robbie or Ben Ashcroft if it's normal. I didn't have any come out on my 500 mile oil change FWIW. I just did another change on the front and came to the conclusion that you can change the front oil and do it again the next day and it will always be yucky looking, even without blown seals. My rear fluid has been super clean after 3000 miles. I also came to the conclusion that I will never run full synthetic in the front, just not worth it, whereas I would never run but Mobil 1 in the 80's T-case.

Thanks for the info...Not really wanting to drain the $9/qt Mobil 1 I just put in anytime soon but I'm not liking the metal from the front. Maybe Ben/Robbie/Christo will post up some thoughts. I was more concerned with the "yucky" look of the oil as opposed to the metal. The flakes were all pretty small other than that odd looking one. I just wasn't sure what would be considered "normal". If anything I've been REAL easy on these gears...

Rear looks good to me. Front lookes similar to mine when the outer pinion bearing failed. Maybe change it again soon(100-300mi) and see how it looks.

I don't like the sound of that...I'll have to look back at what all was replaced but IIRC pretty much everything inside the diffs front and rear is all new...

Romer
12-14-2009, 12:29 AM
So was your front like that when you pulled the diff? The diff would have ben clean from the rebuild, but the axle tubes wouldn't have been unless you ran some fluid down them.

I would look at the backside of your knuckles to see if you see anything, also might try and check the thickness of the fluid via the inspection hole next to the ABS sensor.

No clue on the shavings though

powderpig
12-14-2009, 06:07 AM
You may need to talk to Ben(Ben did your diff set up, Right) and see what his thoughts are. That would be proper, before I will comment.

Red_Chili
12-14-2009, 08:41 AM
Thanks for the info...Not really wanting to drain the $9/qt Mobil 1 I just put in anytime soon ...
How many miles post rebuild?

I don't run synth anyway before break-in is completely done, but that is just me. For that matter DuraBlend is as close to synth as I get. I tend to change the fluid for one reason or another anyway, before the service interval. If it ain't one thing it's ano... OK, condensation from cold streamwater, leaky axle seals, welding a housing glide on so I don't put 1/64" scraped sheetmetal to granite....

corsair23
12-14-2009, 11:37 AM
So was your front like that when you pulled the diff? The diff would have ben clean from the rebuild, but the axle tubes wouldn't have been unless you ran some fluid down them.

I would look at the backside of your knuckles to see if you see anything, also might try and check the thickness of the fluid via the inspection hole next to the ABS sensor.

Don't know what the front fluid really looked like on the initial drain before gears as it went into one of my enclosed drain pans and I didn't pay much attention. Backside of the knuckles look fine to me...No wet/soupy moly oozing out or anything. Good idea on checking the moly via the inspection hole...

You may need to talk to Ben(Ben did your diff set up, Right) and see what his thoughts are. That would be proper, before I will comment.

Yes, Ben set up the gears and we chatted this morning :thumb:

How many miles post rebuild?

I don't run synth anyway before break-in is completely done, but that is just me. For that matter DuraBlend is as close to synth as I get. I tend to change the fluid for one reason or another anyway, before the service interval. If it ain't one thing it's ano... OK, condensation from cold streamwater, leaky axle seals, welding a housing glide on so I don't put 1/64" scraped sheetmetal to granite....

Miles on the fluid was 650+ and I used the Wally World gear oil FWIW.

After talking to Ben we decided the best course of action is to run the Mobil 1 for awhile (500-1000 miles or more) and recheck it. I'll probably run it till early spring and then drain it and see what I have. I'm more concerned that I fubarred the axle svc and screwed up the inner axle seals than I am about the metal flakes. I tried to be very careful on installing the axles but the DS side was a PITA so who knows...

Red_Chili
12-14-2009, 01:06 PM
Yeah I hate the stock axle seals. Still trying to figure out how to shimmy the Marlin seals in the rear of mine. Now those are a proper SEAL.

nakman
12-14-2009, 02:20 PM
Jeff, the last thing to worry about is your inner axle seal.. all of that will get mixed together to at least some level eventually, futile to worry. It's a full time axle, so it's always spinning, always warm, as long as it's wet & slippery I personally don't think it matters much if it's gear oil, wheel bearing grease, moly fortified, whatever... sure put the right stuff in the right place to begin with, but don't lose sleep over what gets mixed together afterwords.

You've already got birfield grease sneaking past the brass bushing in the spindle, mixing with the wheel bearing grease behind the drive flange. Your hot gear oil is literally laying on top of that inner axle seal on every corner and every side hill.. there is some amount of osmosis going on there, I promise you, even with Marlin seals. Like Red Chilli I too change gear oil way more frequent than what is recommended, as do you. The fact that there is lubrication, and that it's relatively new, far exceeds its specific weight and viscosity, IMO. I hope you don't find much when you drop that oil again next spring.. and you can worry about it or not worry about it, and the same amount of metal is going to drain out either way. :thumb:

powderpig
12-14-2009, 03:22 PM
You can always use the upper fill plug as a swap to save the gear lube while you are looking at the magnet. No real need to drain the whole thing if you just want to look for metal. Just be sure you have enough lube around, if you can not get the swap complete and you drain more than you want.

corsair23
12-14-2009, 03:48 PM
Thanks guys...Marlin's inner axle seals and they are mucho better than the stock ones from what little I know...At least much easier for a dweeb like me to install because they have the flange to you smack 'em in till they stop...No need to wonder if they should or should not go just a little further in :)

Nakman, you as always make a lot of sense :) - I'll probably drain and fill next spring just because I am OCD and the $30 or so it will cost will ease my noggin :D...Maybe I'll drive through some deep water first just to make me feel like it should be changed anyway :)

nakman
12-14-2009, 04:08 PM
Maybe I'll drive through some deep water first just to make me feel like it should be changed anyway :)

Now you're talking... want to go to Moab in March? I know just where this is... :D even "on trail" too you can see the carsonite!

wesintl
12-14-2009, 04:36 PM
you should probably dump that rig before it starts costing too much $ ;)

sorry I can't offer any help :o

corsair23
12-14-2009, 05:15 PM
Now you're talking... want to go to Moab in March? I know just where this is... :D even "on trail" too you can see the carsonite!

:thumb:

you should probably dump that rig before it starts costing too much $ ;)

Too late :hill:

farnhamstj
12-14-2009, 07:29 PM
Cane creek?

nakman
12-15-2009, 10:32 AM
Kane creek, yes.

corsair23
05-08-2010, 02:23 AM
Just a quick follow up....Replaced the front gear oil (and center diff gear oil) just before CM10

Metal shavings are MUCH less...no big flakes etc. this go around and more in line with what I would expect. The front gear oil was still more "green" than I was hoping it would be which leads me to believe I'm still getting some mixing of moly grease into the axle :rolleyes: - I read a couple posts on MUD where others have experienced this until they extended their axle breather tubes. I haven't done that yet but their theory was that the old tubes/vents were partially blocked off and creating a vacuum effect sucking moly into the axle. After they extended their breather no more mixing...Since I need to extend my breathers just because that will be my next step but until then, stuff can go ahead and mix :hill:

.

Bikeman
05-08-2010, 09:06 AM
Jeff, how about any gear noise left?

corsair23
05-08-2010, 02:12 PM
Jeff, how about any gear noise left?

Same to less...Might just be getting more use to the noise :confused:

Certainly nothing obnoxious or anything that anyone but me even notices and only then do I tend to hear it when the radio is off and I'm coasting to a stop.

Bikeman
05-08-2010, 02:17 PM
I'll let you hear mine (same brand of gears) at the next meeting.

rover67
05-09-2010, 09:52 PM
green is clean....

that magnet would make me happy if it came out of my truck.

corsair23
05-10-2010, 03:33 AM
Nothing remarkable other than to report I'm and idiot :hill:

When I posted up the pic in post #19 something didn't look right but I couldn't figure out what it was...It just dawned on me that the plug is the old style and I have the new allen plug in the diffs :rolleyes: - That means that the plug in the pic is actuallt my center diff plug which I hadn't changed over yet :doh:

Not sure what I did with the front diff plug pic, if I even took one, but the metal was similar, probably less. Oh well...center diff now has the allen head plugs as well so next time I won't even notice when I take a pic of the wrong plug :hill: