[amosfella]

When I did that change on the 2004, I found that running the car to warm the diff up, and using a mityvac that had air compressor suction abilities was the best. I used a heat gun to warm the case of the diff further. That seemed to help.

 

[amosfella]

A heat gun? That's a good idea. I never thought of that.

In the 2004, there's a cross member that sits in a perfect position to wedge the heat gun in when you take the pan off to drain the engine oil. I started the mityvac, and the heat gun, and went on with draining the other oils while the thing sucked.

With the transfer case, I found it really easy to do simply by using an impact. Took more time to drain than to take it apart and put back, including torquing the whole way along. Use an impact on the plugs, even if you have to use all kinds of funny extensions and wobbles. The top one was the hard one. Open it first.

With the proper extensions, you might be able to get it open without taking the cross member out. You'd need something for the oil to run down to keep it from collecting in the cross member... I've done that on a quad. I took a windshield wiper bottle, cut a square out of it, folded it into a trough with a bit of heat, and used that to get the oil out of a quad without spilling oil on the frame. Wish I had thought of that before I opened the engine oil drain plug on the 2004, even as a deflector to keep the oil from getting on the frame. Next time.

Oh ya, one of those 37L rubbermaid tubs are great for changing oils where there's a lot of oil. The windshield washer bottles with holes cut in a side are great for rear diffs, transfer case, etc. Done right, one can practically drain the whole car at once...

 

[amosfella]

Thanks, @amosfella for the details. However, I don't find it easy to visualize what you did exactly. Do yo have some pictures that you can share or some instruction pages from the MB manual? I deffinitely don't want to remove the cross member under the TC and I don't want to mess up with the drive shaft flex desk, etc. I will also be working under the car in the garage; so, I don't want to jack up the transmission if the cross member and mount are removed and want to keep it the safest in terms of avoiding things to fall over me. My local MB in Vancouver quoted $250 for the job (including the oil) but I just prefer to avoid paying them any cent. But again, if paying $250+tax will avoid having me killed under my car, then I'll just do it! :-/

Conclusion, if there was a way to get to those transfer case fill/drain plugs without removing the cross member, I would love to hear more details about it. I tried to search the forrum for any thread that talks about this, but did not find any.

Thanks!

That was just a supposition from what I remember from when I did it on the 2004. Mind you, mine could be different underneath than yours. If you have your entire car sitting on jackstands (like I did. Also note these were 12 ton a piece jackstands with large bases), having a rolling floor jack underneath it when you remove the cross member is not that dangerous. You're only lowering it an inch, so no need to worry about the flex disk.

While I think that it could be possible to change the TC oil without removing the cross member, I think the first time will be very difficult. It's almost impossible to see in there without taking it off.

A lot of your danger will be limited by not twisting on things. So, that's why I recommend using an impact to remove the plugs. The top one will likely be a bugger. Also, the plugs are much less likely to strip out the head if one used an impact instead of a breaker bar. A flexible extension will be a great tool (they have these at princess auto). I couple or 3 wobbles and a few extensions of different lengths will help. As I recall, I had 3 feet worth of extensions and wobbles on mine to get the top plug out. It was routed up over top of the exhaust pipe. You can go to home depot and rent a cordless impact for the job, if you don't have an impact available. IIRC, you'll need 14, 15, 16, 17 mm sockets.

I've only done the job once, and it was over 5 months ago, and I've had a lot of creative solutions jobs since, so I might not be remembering everything correctly.

I look at it this way, If I do the job myself, I can put the money saved into tools for the job, and that can bu used for other jobs. Keep an eye on kijiji, etc for tools, or rent the ones you can't afford at this time. The hardest part will be getting the new oil back into the transfer case. Get a good oil syringe. Don't buy a cheap one. The cheap ones won't pull the oil up.

 

[amosfella]

Also of note, buying a allen head socket from snap on may very well be worth the investment. For some reason, those sockets seem less likely to strip out the plug heads.

 

[amosfella]

Wow... That's an encouraging set of details. I will have to get the jackstands with large bases. I have only a pair of 3-ton stands (from princess auto)to hold the car up from one side only. I better get another pair, probably of a heavier grade too.
So you are saying that if I remove the cross member, I won't have to hold teh transmission and TC with a jack? I saw a Youtube video and the guy was supporting the TC with a jackstand @1:04 https://youtu.be/IXfQ8h8TvSM?t=1m4s.

Not quite. I used the jackstands to hold the car off the ground as if it was on a lift. I used a rolling floor jack with a soft wood 2x4 on it to support the transfer case when I took the cross member out. Then I could control how much I lowered the transfer case, and get it back in easily.

IMHO, the 6 ton pro point jackstands should be a good option. Check kijiji. I had 12 ton ones as I was using them for brake jobs on semi trailers and trucks. I had to use the 12 ton ones with the adjustable arms removed as my jack was just a little too short to get the car on top of the stand. If you can find a few sets of 12 ton ones, go for it.

Here's the best pic I have of how I set it up. I jacked up the front end first with the jack under the center jacking point. If you only get one set of really heavy/wide base jack stands, I'd put them under the front. Then I jacked up the rear using the rear diff as a jack point and set the jack stands under it. You could easily use the lighter set of jack stands under the rear. Hope this helps.

2018-04-12_12-38-25 by wolverine00089, on Flickr

 

[amosfella]

So, this means also removing the mount and bracket. So I should fill the fluid from the fill port until it starts to drip? sounds like the TC is underfilled by a substantial amount in your car @amosfella!

On another note, in your opinion, how can the inspection port be so low compared to the fill port, @ps2cho? If someone needs to inspect from there, a lot of fluid can come out!

On the 2004, there was no top port that I could find. I filled the TC till it was to the top of the inspection port, then filled another 200 ml into the syringe, wrapped paper tower around the syringe hose and jammed it all in, and got the plug in very quickly. I lost maybe 20 ml doing it that way. There were just a few drops on the floor.

Thanks for your concern, though. I've always jammed extra fluid into diffs, TCs, and other geared boxes. I like to have the plug partially if not fully covered, as it makes taking the plug out later much easier.