[realityguy]

Okay..Great Astro/Safari Knowledge Guys!!..(Hmm ..where is the at little bowing imoje guy...?)
In the past when I had to work 50-60 hours a week I had to take my van(1990 AWD) to the Greased-Up-Jiffy-Lube-Monkeys..
and it appears one of them boogered up my top fill plug head..can't get it out.The bottom one is usable and free(now).
I'm wondering if I can fill through what appears to be a vent plug?(top white circle,,top hose appears to go up into the van rib and stops there) or whatever the black electrical plug one is(by the white circle again below the other..(Vehicle speed sensor?..I haven't removed it or unscrewed yet to see what is behind it)..either one I promise to only add the 2 quarts or capacity!
I know it hasn't been changed out for over 15 years.
My other option might be to pump through the bottom hole under pressure(and a quick plug screwed back in..maybe adding a few ounces and catching/checking how much spilled at the same time..make sure it isn't over the amount needed.
I know it needs to be changed!
The original fill plug..it doesn't hang out beyond the case so I can't grab it with something.The square indent in the head is way out of square..I tried using pb blaster..and heat about 5-6 times..3/8" short extension and 16" torque wrench,won't catch with enough pressure against it ..I'm reluctant to drill it out and get shavings in the case,etc..etc..
I have a small liquid pump that I can get pretty much the correct amount in through a small tube if one of the two spots marked is an option.

 

[tungtide]

If it were me I would stick a square piece of metal in there and tig it to the plug. Then remove it. Replace it with a new one. I. Have never had a BORG but I’m assuming that the plug is cast iron so therefore weldable. I would use Tig to keep the heat down and not screw up the aluminum housing. Yes you could fill it from the drain with a pump. Look up fluid amount the add an ounce of two for what you would loose getting the plug back in. Hope some one smarter has a better idea. Best of. Luck.

 

[realityguy]

Thanks..what I'll probably do..catch what falls out and pump back in the equal amount..until it's right. I'll probably die before I have to do it again..
In the meantime,I've been browsing through my Chilton book and came across this near the beginning:

Certainly the guy has never owned an Astro..and never laid prone down the middle under a half-jacked up vehicle..looking up,dirt and crap falling in your eyes..lying on a gravel driveway on a plastic tarp (tarp being too short that your hair is stuck in pinecones and pitch) and trying to reef on and get some kind of pressure on a torque wrench at both ends at the same time on a plug head someone else stripped out..and it's 37 degrees outside..AND YER 72! Oh yeah..that's ENJOYABLE!🙃🙄 ..Someone told me this is "retirement"!
I think it's time to switch from coffee to BEER! LOL!

 

[tungtide]

At my age I had to buy a two post lift. I can’t do the lay down dirt in eyes anymore. I do suggest you look up the proper amount to re-fill that initial. What you get out may not be the correct amount.

 

[realityguy]

I had to make a quick run to P-n-P for some speakers but some of the set were of course riveted in and I didn't bring a drill..but I got a replacement BW plug for that and a set of round foglamps someone had set up on a safari as backups..easy mount to the bottom of a bumper.I'm going to take a dremel down under mine..weaken the plug sides some and set it up to come out with a large flat screwdriver or something..I'm not drilling all the way through the plug or dinging the threads in the case..keep the metal shavings out of it.
The plug I did get..looks like a newer one,good shape,has some kind of Chrome plate...and whoever put it in there didn't torque the hell out of it..So..I'll fill the TC the normal way ..
I had planned to look at the specs/capacity;why I was looking in the Chilton book to see how accurate they were in that one.The Chilton seems to be more accurate than the other Haynes on,.but maybe not as much as the GM books of course.No need to know now.. I have plenty Dex3.. Thanks..

 

[SainT]

Remove stuck plug the best option but I don't think U can apply big force by flat skrewdriver . Better weld a bolt into plug -U will have strong hex head to rotate and U will heat plug area (and this is very helpfull cause alu case enlarges more than steel by heat)
But if U in a hurry and just wanna make it quick - pull off the tube from white plastic part(seen onto Ur photo) and use it to fill the transfer by injecting oil (transfer hasn't another holes to release air so better not to try inject all oil into 1 attempt)

 

[realityguy]

I tried getting the plug out with different things,finally cutting a slot across the little bit hanging out.Trying to unscrew the plug bent my Makita grinder blade changer into a pretzel and a harder file shattered.I checkd that top vent spot you mentioned(was going to gravity flow from above in a pan near the driver's seat.)..doesn't seem to be much room for even getting a tube in there through that vent hole.I think it might have taken a long time.

I fiddled with that fill plug for several hours yesterday..using Dremels to keep the plug hole square,adding shims alongside the extension end,cutting a slot across for using a steel flat bar(my Makita grinder wrench and a file) and Crescent wrench for more leverage. and other things..just not worth messing with in the long run.It's really stuck in there! I did drill some tiny holes in the plug by the threads with the dremel to get some PB in there also,besides heating it with the propane torch several times,,still wouldn't budge.

Today..I drained the TC fluid out through the bottom drain plug.I kept track of how much came out and replaced it with an equal amount of fluid from the O'Reilly quart bottles,using just a top cap of a 16 oz Titebond glue bottle(the cap screwed on the O'Reilly bottle also),nozzle cut off to fit my 10" or so of 3/8" ID of rubber house that fits inside the drain hole(wrapped with a little rag to make it snug)..and screwed the plug in quick when changing the O'Reilly bottle after squeezing the fluid in..over a pan to keep track of how much I had lost between changes.

It didn't take long holding the bottle up by the floor upside down and squeezing the heck out of it and I capped the TC drain off with a new plug with fresh pipe dope on it(other than the one I used in and out) after the final fluid that was needed. I lost about 4 oz with the changes..but ended up with pretty close to the same amount I took out.I had planned a bit extra in the second bottle for losing some,figuring if I needed to take out a little,that would be easier.just loosen the TC plug to allow some to drip out. It worked out fine but a little messy.

For now,I set up a slightly larger bolt with the head cut off about 3" long,shaved on the 4 sides to fit snug to weld into the old plug in the case and I keep it in the cup holder above the glove box,along with another correct fill cap.When I run into my neighbor with a full shop and welders,I'll have him weld that into the old cap in the case,remove the bad one, and replace it with the correct plug. In the meantime, it can't leak!

The important thing..it CAN be done that way,pumped from the bottom..It's do-able as long as you keep track of what came out and match that amount.(about 1-3/4 qts). AND the best part is..I'm done under that $^%^%$% van for now!..The last few days I installed my new Gas-Adjust-Shocks also..when Mother Nature let me work on that project.

 

[SainT]

One thing I forgot to say - after I read a lot about transfers and oils I changed oil from dex3 to axle oil 75w90-GL5
The reason is the chain -its so expensive and hard to get that I decided use thicker oil with more drag (and fuel consumption of course) to protect it from wear as much as I could

 

[MechBob]

One thing I forgot to say - after I read a lot about transfers and oils I changed oil from dex3 to axle oil 75w90-GL5
The reason is the chain -its so expensive and hard to get that I decided use thicker oil with more drag (and fuel consumption of course) to protect it from wear as much as I could

Bad mistake. The heavier oil will wear the chain faster, as the chain runs all the time. Seen it many times in quadratrac jeeps and NP203's in chevy/ford dodges.

 

[SainT]

. Seen it many times

Will see - I read that old transfer use same oil that used in manual gearboxes. Don't know reasons to use AT oil that actually designed not for transfer cases

The heavier oil will wear the chain faster

How ?

 

[MechBob]

How? Higher resistance. It can also hurt other parts inside, especially needle bearings..
Not sure where you get info, but here is some facts-
Early/original Jeep Quadratrac, chain runs all the time, has a "center diff." with limited slip clutches, use a tractor oil, light weight, with friction modifiers. Originally was mineral oil, I think. About the weight of 10w motor oil.
NP203, used in may trucks, many years. Full time AWD, but, also can be positive locked. Has center diff., no clutches. Uses 10-30w motor oil.
NP205, as big and heavy as a 203, but is all "gear to gear. Used in the same trucks as 203,optional. Uses 75-90 gear oil.
all NP and BW (new process/new venture, Borg Warner) that have a chain, use atf-- Except-
The NP used in newer gm's, 99 up astros, and some full size, any that have the electric motor that applies the clutch pack when slipping is measured, use Autotrak II fluid. Which is a very lightweight atf with lots of friction modifiers.
Basically, if it is after 1985, and has a aluminum case, it's a 98% chance it uses ATF.
Now, some of the bigger trucks still use a big, heavy gear to gear case, f500's and up, and such and use gear oil.
Subaru and audi, a "center diff. transfer case, with clutches that can be locked--use ATF.
The bottom line, if it has a chain, it does not use gear oil. Now there maybe an exception out there, but I have not seen it. And I've been working on these things most my life. Right now, sitting in yard, early Quadratrac, np203, np231, BW4472(all AWD astros, 90-98), and a NV136, 99-05 astros,AWD.
Woops, forgot camper truck--NP241

 

[Mmusicman]

It does surprise me a bit when people think they can "out-engineer" the manufacturer engineers.
If they say run ATF.. then it's probably best to run ATF (in a standard gear box)

Unless it's just a "test" to see how fast you can blow up a gear-box.

Sometimes we can cut corners in a pinch (roadside fix etc)... but long term is a different story. I wouldn't do it

 

[Bikley]

This was a good reminder for me. I've been meaning to order a couple quarts of Dexron III since my transfer case is on the ground at the moment.

 

[SainT]

with clutches

That is the reason - friction clutch pack that require special oil for proper work
bw4472 doesn't have clutch -viscous coupler sealed and not contacted to any oil into transfer

It can also hurt other parts inside, especially needle bearings..

Transfer cases with 75-90 have them too
Manual tranny have them too
Front axles have them too
Special types of needle bearing ? But they can run even on grease lubricants with no issue if read manufacturers specs
Inside 4472 no parts that can hurt -no oil pump, no brass synchronous

people think

That can spent some fuel onto thicker oil that engineers cant cause of they need to reduce drag for better mileage

, BW4472(all AWD astros, 90-98), and a NV136, 99-05 astros,AWD.

They work different and 136 has clutch that require autotruck2 special oil (and lately GM replace it by dex6 if I remember correct)
Most of ur examples have clutches and its not correct to comparison with current 4472
Morse chain works different than conventional chain such as bicycle chains with rollers
Its not roll but slides onto gears and in such conditions better oil film -less wear

 

[MechBob]

You can tell/convince yourself of whatever it takes to help you sleep. Put gear oil in some t/cases and you won't make it 10k miles before catastrophic failure. I guess in your mind, hundreds of thousands of engineers, and millions of hours of testing and real word use are just wrong. Whatever, it's your money. Better be keeping a eye out for a used awd case. Have a nice day.

 

[Mmusicman]

Don't know reasons to use AT oil that actually designed not for transfer cases

You admit you "don't know reason" why they call for AT fluid, and not gear oil.

I decided use thicker oil with more drag (and fuel consumption of course) to protect it from wear as much as I could

You decided??
You decided thicker oil "would protect it"?
More drag = better protection?
How do you "know" the thicker oil is going where it needs to go?

If that's true, then why don't manufacturers just require 85w-140 (instead of 75w-90) in ALL differentials?
If "thicker oil" = "better protection".. then why not use gear oil in your engine?

Why do you suppose the design engineers call for ATF (over gear oil) in transfer case?
Could there be reasons you don't know?

Personally I can't say that it will be catastrophic or not... but I'd certainly be cautious without "knowing" why they call for ATF.

Not all mods are bad.. and you have decided your reasons.
If you're wrong, you admit you'll wait and see, and live with it.
It's fine to vary from popular consensus.. but sometimes there are reasons.

Sidenote: A few years back.. I got caught up on some 4x4 forum site that was calling for modifying your power-steering pressure valve for more pressure (to presumably turn bigger wheels). What wasn't known is that increasing pressure also increases heat and wear. My fluid was foaming and it caused me a great deal of trouble when my power-steering became jerky and failed. I went back to what the engineers designed, and it now works as it should.

It's fine to make an "educated decision".. and if you feel that your mod is better than what the actual engineers designed.. then go for it.

Cheers

 

[SainT]

without "knowing" why they call for ATF.

Less drag = less fuel consumption
The only reason I see -and its happen not only with transfers -every new engine has 0-20 or less , new tranny 8+ speeds require oil thinner than water to save fuel
And nobody cares longevity if its enough to warranty period
I worked for GM dealer and saw engines and trannys that broke off under 10k and nobody cares
Timing chains that wear off less than 50k at every 3.6 motor and a lot of another common problems
And after I ask GM warranty chief engineer(who controls all dealerships in my country) why it so - He sad me - its cheaper for company to repair than upgrade
In conclusion - I work with cars more than 20 years and have my point of view

. then go for it.

Have done it already actually long time ago

You decided??

Yes why not ?

Could there be reasons you don't know?

Nobody knows everything
Even engineers -they still human

More drag = better protection?

More additives supposed to protect metal from wearing -drag is unpleasant bonus to that oil

What wasn't known is that increasing pressure also increases heat and wear

Its no doubt should be so , more load -more heat. Plain and simple
OEM oil "cooler" for PS not enough for stock pressure -its barely can hold PS system from overheat
And I personally dont see benefits from rising pressure -my steering wheel light enough in comparison to non american cars and it not helps at icy roads

 

[SainT]

u won't make it 10k miles before catastrophic failure.

Man I drove more than 80k on oem worn chain after I changed oil to extend time because I cant buy another
Now my chain from another non american car and its not fit well - because I cant buy even HV-015 -so I make experiment with what I have
I would be very happy if I changed oil to 75-90 right after I bought astro and not have any problems with chain

 

[MechBob]

Man I drove more than 80k on oem worn chain after I changed oil to extend time because I cant buy another
Now my chain from another non american car and its not fit well - because I cant buy even HV-015 -so I make experiment with what I have
I would be very happy if I changed oil to 75-90 right after I bought astro and not have any problems with chain

Try not being disingenuous when you quote. By leaving this out-
"Put gear oil in some t/cases and "
you change the meaning of my statement, and make it seem as if I was directing it at your astro case.
"Put gear oil in some t/cases and you won't make it 10k miles before catastrophic failure."

 

[Bikley]

My take.

My Factory Service Manual says Dexron II.

My transfer case is 29 years old and still works flawlessly. We spilled a bit of fluid taking it out and it was still red. I don't know if it was changed by the PO, but I've never changed it, and we've put 80,000 miles on the van since we got it. It's now going to get a fresh fill with AC Delco Gold type III ATF and I fully expect it to last another 29 years.