Thanks for posting that link. I've been planning to change the tranny fluid in my CJ3B which was in there when I bought it. Definately a little nervous as to what might drain out.
Matt

Macgraham - that's exactly what mine looked like. I was kicking myself for not taking a pic to post...but you nailed it. How long have you been using that oil? What's the history of your transmission? Recently rebuilt or unknown?

Macgraham wrote on 03/17/13 at 23:45:52:


So yours is about the same story as mine. At least we caught it when we did. There are undoubtedly countless other transmissions - in jeeps and otherwise - that have been soaking in this corrosive fluid for much longer than 1 year and you don't hear of it being any sort of mass epidemic. Change out the fluid, hope for the best, and keep on rolling.

I had the same experience with some CRC straight GL4 oil.  Back of the bottle said it wouldn't hurt yellow metal but they too lied.  It wasn't in there long because I found a thread that talked about the misleading claims that different manufacturers make.  There was a slight amount of brass color, like Carlsjeep, but any is too much.  I'm back to the mineral oil but if I lived farther north I would have to look a little closer because I'm sure the cold weather would have to be taken into consideration.  It got down into the low 40's (BRrrrr) here and I noticed a difference in the shifting.  I just read a post on the new members forum about a member driving his new jeep at -27 in CANADA - THAT SHOULD BE SOME KIND OF A RECORD.

Ryan,
You may have spotted this one, but here is my most recent experience with metal eating gear oil.

http://cj3apage.com/forum-yabb/YaBB.pl?num=1360175221

Macgraham - I ended up with NAPA Part Number: NHF 65205 which is a 5 gallon pail. The 1 gallon jug is NHF 65201.

Tim - I do remember your posts but I didn't realize they were as recent until I re-read them and checked the dates. Seemed like eons ago, not last month. I think I was trying to subconsciously deny having to face my own impending disaster.

1oldracer wrote on 03/18/13 at 03:01:41:

I've been watching this thread with great interest.  This particular post from 1oldracer caught my interest because, like him, I believed what it said on the back of the bottle.







I called the Technical Service number and spoke with a tech-rep.  He told me that part of their testing and manufacturing process requires the statements on the back of the bottle to be certified.  He assured me that yellow metals are safe in GL-4.
I asked if they make a GL-1 and he said that they do not.  He said that there isn't much call for it because it's only for farm equipment.  I thanked him kindly and didn't come away very "assured".  
I completed my restoration 5 years ago.  I wasn't aware of the yellow metal problem at the time and after the transmission overhaul I put GL-5 in it.  One year later I saw the gear oil looked like matalic gold paint.  I had to go into the tranny for other reasons and by this time, after installing new brass parts, I was aware and in good faith installed GL-4.  Last fall when Carl Darnell was here, we pulled my tranny to install a new pilot bushing.  We didn't drain the oil, but had to pull the top plate and shifter.  At that time we looked for the matalic color in the gear oil but didn't see any.  I'm going to be putting my Jeep back into service soon as the days are getting nice once again.  One of the things I'll do is check the gear oil for metalic contamination.  If there is any at all I will follow so many of you now to the GL-1.
I asked this question last month when Tim got us going on this same issue, "Why are we having to discover this problem by our experience?  Why hasn't someone like Carl Walck been on top of this for some time?

gmcjr,
  Yes, that chart does help.  It helps a lot.  The only thing is, now you've embarrassed me because when Carl sees this I'll be in trouble.  I just hate it when he's right.  (Just kidding.) 
 
  Seriously, though, this chart has caused me to do a Google study of viscosity classifications (in order to properly understand the chart).  I must admit that it's not the first time I assumed something to be a certain way just to find out it wasn't that way at all.  I remember my dad quoting an old German friend, "So soon vee get old. So late vee get smart."

  So, my conclusion will be, as I go though my Jeep preparation for this summer's drives, I will inspect the transmission gear oil for metalic flecks.  If there are any I will drain it and install straight mineral oil, most likely aviation 50 wt. non-detergent, uncompounded engine oil.

  I have saved the chart where it will be available for easy access in the future.  Thanks again, I really do appreciate the "education".

Nate,
  What gear oil were you running and how many miles are on it?

calvinhunt wrote on 03/23/13 at 19:43:17:



Glad I was able to help!!
This is what I use now, after seeing the error of my ways.

http://www.tractorsupply.com/en/store/travellerreg%3B-ford-tractor-all-mineral-9...
its cheap enough!!!!!

I knew about the yellow metal issue from working on tractors, but big dummy me didn't put two and two together on my jeep transmission until a couple months ago after reading about it on the 2a page.  

I used this rig that I bought at NAPA a couple days ago. I still ended up with a fair amount of fluid in places it shouldn't be but it was much neater than the funnel method I tried last time around. It's pretty quick too. I think I'll also be able to use this pump to drain the tranny, which should cut down on the usual mess.

Thanks gmcjr for posting the chart. I knew the 30 wt was on the low side of the 90-85 gear oil but since I have used it in my farm tractor for 11 years now working it very hard and no trouble I knew it would work in the Jeep.

My preference is a 40 or 50 wt engine oil but you could also use 100 or 150 ISO oil. Unless I have issues with shifting or something I will stay with the 30 wt non detergent engine oil. So far it shifts just fine now, we'll see how it goes in the summer.

Okay, I'm gonna poke the hornets nest here. First, I think the best oil for the T-90 is the type recommended in the service manual. In looking at the forums it seems to me that the "problem" transmissions are a minority of units with low mileage and that have been recently overhauled. Are the gold metal flakes caused by the oil or a mechanical problem? I agree that metal eating oil is not good for a transmission, but I think it will take many years before this will have any effect. Nate's example of the drum of gear lube is the perfect example. That's the lube almost every manual transmission and rear axle received from the 60s through the 80s. It was in every gas station and repair shop. Does it eat yellow metal? Probably, but how many transmissions actually failed because of it?

I reckon mines the other side of the spectrum, the transmission in my jeep has not been rebuilt since I've had it.(I'm gonna fathom a guess, by the way it shifts sometimes, that it hasn't been rebuilt as long as I've been on this earth. Btw, thats 30 years. The speedo currently shows 91,000 for what little that's worth.) I put gl5 in it a few years back, ran it probably 5,000 miles. I drained it a month or so ago when a similar thread was posted on the 2a page, the oil had a brassy tint.
I let some drain on my finger and then smeared it on a clean paper towel, there was brassy gleam (edited for better description) to it. It was enough to convince me. Your results may very.

That'll be interesting to see. I can't honestly say the brass I saw was just wear and tear, or result of chemical degrading. One the flip side, gl1 is cheaper. The Scottish in me likes that.

I drained the GL-1 oil today after having replaced the GL-5 stuff a couple weeks ago. There is still a small amount of brass but I am hoping that what I'm seeing now is just residual flakes. I've put about 235 miles on the Jeep since this new oil was added. Never mind those pine needles, they were already in the drain pan and did NOT come from the transmission 

Gun,

The GL-1 has no sulfur.  It's straight mineral oil.  It has no sulfur smell, which can confuse when trying to chase a leak between the tranny and bell housing.

I used Valvoline synthetic GL-5 with the MT-1 rating after reading it was safe for gold metals.  I drained it and found gold metal flakes.  I joined many by moving to the GL-1. 

I've read many posts on this subject.  One in particular was at the 2A page.  I believe it was SamCJ2A that mentioned mineral oil was the recommended oil in the 1945 manual.  I can't confirm this, as I don't have that manual.

Tim

I used the same GL5 on all my drive line, it was all put in at about the same time.  I just drained all the fluids this past week:
Front and rear diffs looked like used worn out oil, no gold, no other stuff.
Transfer case same deal little,bitmof,shiny stuff but mostly just dirty oil, this implies,that there is very little oil transfer between the two because;  wait for it;  I just drained the transmission and viola, I must be rich given all the gold in that oil !!! Whoopppeeeee!  Not so cool.

Has anyone torn down a tranny yet to see what the damage is?

Mac,

I wish I had a good answer.

The recommended oil for the Diffs is a EP (Extreme Pressure) hypoid oil.  They would typically be the GL-4 or 5 oils for hypoid gears.  I guess the hypoid gears are more important to protect than the bushing.  Maybe there are different forces on the bushing vs the synchros.

http://www.cj3apage.com/index/Tech_Tips/operation_and_care_manual/Manual%20Lube%...

Tim

I thought that might be the case but wasn't sure. Thank you, Bob.

I have read all three pages of this with interest, I have worked as a heavy equipment mechanic for a contractor for nearly 29 years, they use GL-5 gearlube in everything!, granted they have no T 90's but many many, winch drive PTO's ect, with large brass wormgears and the like, and I can honestly say I have never seen a failure due to brass being eaten away or dissolving. I have talked this over with our Mobil oil rep. he said to do severe damage the sulfer would need water to react with to excellerate the reaction to the yellow parts. His recommendation was to use Mobil 1 75-90 synthetic gear oil as it containes no sulfer at all. That's all good but if you look at Herms site he stresses NO Synthetic oil with overdrives!...........Another question, after rebuilding your trans, Why are you guys not changing the break in oil after lets say 500 miles???????, no doubt there will be brass in the oil after replacing new brass parts, as they break in they will shed the hi spots on them, at that point any oil used would show brass when drained, certainly not the fault of sulfer, gl-5 or 50W motor oil.

MHO, Lee

I went to the shop and looked in my Willys shop manuals. One just said use transmission oil and the other said to use GL4. There are copies of original shop manuals. I don't know when gear oil began using sulfur in it but I wouldn't take a chance on the brass being damaged by the sulfur additive.

I use 30 wt non detergent in my tranny/transfer cases now and have no issues. Many industrial gear boxes recommend ISO mineral oil generally in the range of 32 to 150 depending on the manufacturer and the applications and operating temps.

I started to use an ISO 100 which is about a 30 wt oil in my tranny but decided it would be easier to find the 30 wt non det. oil so that's what I used.

I agree that you should change the oil after a rebuild at about 500 miles and you can expect to find brass and steel shavings in the oil at that point. If the oil has a golden color to it I believe the oil is breaking down the brass parts and that's not good.