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H3 - ATF fluid change procedure

alrock

El Diablo
Staff member
Messages
10,442
Location
Scottsdale
I did a fluid drain and fill today. I chose not to do a full flush in part as I just wanted to try this out and see the contents of the pan and the state of the old fluid myself. A drain and refill replaces about 5 quarts of fluid and I believe the transmission holds as many as 11 quarts. (Total capacity is unverified by me; working from memory).

Tools:
14mm socket for transmission pan bolts
11mm socket for prop shaft bolts
Pry bar to hold prop shaft when loosening/tightening bolts
Scraper to remove old gasket
Narrow neck funnel for refilling transmission fluid through the dipstick

Torque:
12 ft/lbs for transmission pan
18 ft/lbs for prop shaft bolts

You do have to move the prop shaft as several of the pan's bolts are not otherwise accessible
i-CTndNsj-L.jpg


Remove UCP if present
Remove the four 11 mm bolts that hold prop shaft to yoke
i-XWjvQDm-L.jpg


Tie prop shaft to torsion bar
i-9ghdzcL-L.jpg


Remove the transmission pan bolts in an alternating pattern so that you slowly release the pressure on the thin metal pan. (It is steel, not aluminum, but it is thin walled). GM recommends leaving two bolts in the rear and undoing those about four turns each so that you can dump some of the contents of the pan slowly by tilting it before doing the full drop.

Wiggle the pan out of place. It may need some coaxing with the pry bar

Get at least 80% of the fluid in the drain pan. With the remaining 20%, about 15% goes on the floor and 5% should drip on your arms, shirt, shoes and hair.
i-4mxLn2T-L.jpg


Wiggle out the filter. There's a ring gasket that holds the filter but I did not replace it as it was pliable and I couldn't figure out how to get it out.
i-jfvdxfX-L.jpg


Inspect the contents of the pan. Here I had some metal shavings on the magnet and the fluid was reddish brown - it wasn't burnt or black. There are also three small rocks in my transmission pan. I have no idea how those got there. That's exactly how I found them.
i-VzzzKL8-L.jpg


The gasket was extremely hard and brittle and took nearly 30 minutes to fully remove and clean the surface for the gasket. I fully cleaned the pan with brake cleaner, including removing the magnet and cleaning off all residue.

I then popped in the new filter, put the new gasket on the pan and put the pan back onto the transmission. I alternated the tightening of the bolts and went around twice to make sure I got them all but did not over-torque them.

The H3 requires Dexron VI. I won't go into the politics of fluids but this is what I went with
i-TT2bd9n-L.jpg


Another tool to consider is a cut down broomstick. Because, in my instance, the hood struts apparently blew in the last day or two and would not support my hood.
i-c77s2DM-L.jpg


GM recommends checking the fluid when the engine has reached normal operating temperature and to do it while the engine is running. Normal operating temp for the transmission is 180-200 degrees per the owner's manual.

Aside from stubborn UCP and skid plates the job took about an hour.
 

MaxPF

AGNTSA
Messages
1,394
Location
The dark side of the globe
Wait at least a week and do another drain and refill. That will effectively give you a full fluid change. You can do a third one a week after that if you're really anal, but two drain-and-refills are usually sufficient.
 

Reloader

Well-Known Member
I usually weld in a drain plug on the first change with a new filter and gasket. Then every other engine oil change, I drain the trans pan and just refill. Five quarts of new trans fluid every 6K miles keeps the fluid looking good. We never change a filter on Toyotas. Just do a flush/fill with the trans tec machine. I dont think we even keep one in stock.
 

alrock

El Diablo
Staff member
Messages
10,442
Location
Scottsdale
I'd like to go either of those routes but I'm kinda missing a welder and a trans tec machine :). Fluid was changed 50,000 miles ago and I think it held up very well. I don't tow with my H3 but it certainly gets a lot of extreme use here in the desert. Actually, I agree it would be great to have a drain plug on the pan.

One other service tip - the pan has to clear two items to pull it or reinsert it. For removal, you'll need to tilt it about an inch to the passenger side first, meaning be prepared on that side to catch fluid. Once the passenger side clears you can work on clearing the cable on the driver's side.
 

4u33er

Well-Known Member
Messages
136
Location
NYC
So there is no drain hole for the Transmission? I have to drop the pan?

Also I will be using Redline D4 ATF, can this be used for the Transfer case as well???
 

alrock

El Diablo
Staff member
Messages
10,442
Location
Scottsdale
If your transfer case calls for ATF then go for it - check your manual. I apologize for the vague answer but I believe different years had different recommendations for the transfer case. My truck (2007) specified manual transmission fluid for the transfer case.
 

alrock

El Diablo
Staff member
Messages
10,442
Location
Scottsdale
I would add that Dexron VI is also recommended by GM for these transfer cases. The decision is up to you and there's certainly a lot of debate on this subject.
 

4u33er

Well-Known Member
Messages
136
Location
NYC
My manual states to use Dexron III with H application so therefor Dexron VI will work therefor Redline D4 will do as well???
 

MaxPF

AGNTSA
Messages
1,394
Location
The dark side of the globe
My manual states to use Dexron III with H application so therefor Dexron VI will work therefor Redline D4 will do as well???

For the trans, D4 will be fine. Redline D6 is a Dex VI viscosity spec fluid, which will also work. Personally, I think the viscosity of Dex VI is too low - ATF has to lubricate meshing gears that are under a great deal of load. So, given a choice I would run the D4.

D4 will also work fine in your t-case - it carries a GL-4 gear oil rating, and is the proper viscosity. Redline MTL would also work fine in the t-case. I ran the stuff for countless miles in my 241, and when I disassembled it to swap in a 27 spline input gear the oil and the internals looked just as good as the last time I had it apart.
 

4u33er

Well-Known Member
Messages
136
Location
NYC
Oh crap, i just ordered Redline D6 for my auto tranny and D4 for my transfer case!

As per owner's manual that came with the car states Dexron VI for Automatic Trans. and Dexron III for T/C.
 

MaxPF

AGNTSA
Messages
1,394
Location
The dark side of the globe
You'll be fine. Don't sweat it ;)

It seem strange that GM spec'd Dex VI for the trans, but kept Dex III for the t-case. The reason it's strange is that when they went to Dex VI, they eliminated the Dex III spec completely. Sounds like a case of the corporate left hand not knowing what the right hand is doing :giggle:
 
Last edited:

4u33er

Well-Known Member
Messages
136
Location
NYC
So is the doing the fluid changed two times to get most of the old stuff out the best way? I mean without going to a shop.
 

Chook

Well-Known Member
Messages
706
Location
Brisbane (Australia)
I would add that Dexron VI is also recommended by GM for these transfer cases. The decision is up to you and there's certainly a lot of debate on this subject.

Def some confusion here. I changed mine on the weekend, the manual just gave a GM Part # so I used the lube guide in store. It told me fully synthetic Manual Gear Oil 70W-75 but when I drained the TCase it had the tell tale red dye of ATF. I contacted GM and they deciphered the part # to confirm it was DEX VI. I contacted the oil company, they said they get their recommendation direct from the OEM (mentioned that GM only uses DEX VI as it is their spec, cheaper for them to use it, & they make money on the license). The TCase is a Borg-Warner so I sent them an email asking to confirm the oil spec and will post here when they do.
 

alrock

El Diablo
Staff member
Messages
10,442
Location
Scottsdale
There's a lot of confusion on transfer case oils. My personal conclusion is that ATF can be used in all of them but early ones had a manual transmission fluid spec and later ones had a Dex VI spec. What would make this even more confusing is that you wouldn't have one of the earlier builds so I don't know why you'd have a Manual Transmission Fluid recommendation.

The inconsistency and confusion I don't think is based in the owners and users but with GM. My owner's manual specs Manual Transmission Fluid but the latest GM Service Manual specs Dex VI. When it comes to inconsistencies (perceived or real) then it is just up to you to decide which decision is most comfortable.

F5 in 2010
the manuals will state for those applications that required Dexron III to use the GM Manual Trans fluid, which is identical to Dexron III.


F5 in Dec 2011
From the GM electronic service manual:
Transfer Case Fluid
DEXRON®VI
88861003
88861004
Vehicle Speed Sensor O-Ring
DEXRON®VI

Back when Dexron VI was first released, there was some confusion from B/W in regard to the fluid they wanted in the t/case. They originally came with Dexron IV. B/W did testing and finally approved Dexron VI. In addition, owner manuals are notorious for being incorrect, at times.
 

Chook

Well-Known Member
Messages
706
Location
Brisbane (Australia)
Info on Mobil LT

Mobil ATF LT 71141​
Mobil ATF LT 71141 automatic transmission fluid is a semisynthetichigh performance ATF with long drain-performancefor use in automatic transmissions and power-steeringsystems. Frictional characteristics make it suitable for use inelectronically controlled converter clutches.​
• Correct frictional properties for smooth shifting• Longer retention of frictional characteristics under severe​
operating conditions​
• Very good high temperature stability to resist lacquer and​
deposit formation​
Approved against MB-Approval 236.11, VW TL52162, Voith Turbo 55.6336.33 (G 1363) and ZF TE-ML​
4D/11B/14B/16L/17C.
 
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