First, I though I saw a thread that used a radiator drain type fitting rather than a ball valve for TC drain and fill. Anyone know th thread I'm trying to remember?

Second, does the airvent on the TC allow fast enough flow to allow filling to 600cc without having to jack up the drivers side of the car?

Thanks again,
Bill

 

Bilrata, the radiator drain valve is the design that I came up with. If you have any questions about the setup, let me know. I can answer most of the questions that you can think of.

As for the filling process, using the radiator drain valve, you are going to be limited by the size of the tygon tubing, not by the vent off the transfer case. The big thing that you have to figure out is how to get the fluid in and keep it there as you seal up the transfer case.

 

Wouldn't you just turn the valve closed, wither while rotating the tube with it, or by pulling the tube and blocking the inlet with a finger while turning? Am I missing something? Seems safer than soldering a ball valve into place and depending on the solder to hold up over time.

Bill

 

Bill, some members have taken the path of coming up with a fill assembly that fits in the drain hole. This causes them to have to pull out the fill assembly, plug the hole with their finger and then quickly pull away their finger as they put the drain plug back in. Messy to say the least.

With the radiator drain plug, yes, you are correct in that you simply have to close the valve, then remove the tube and collect the little bit of fluid that was left in the hose.

 

No, according to my experience, the socalled airvent on the TC is very very tight, man. I don't need a tap device connecting to the hole but I can drain and fill it without jetting up the car. you can go to see my own design.

 

Lots of threads on TCs and their problems, double-plus good!

But can anyone explain how the TC actually works? And what changed from the early versions to the later ones? What is fluid-coupling, etc.?

Thanks
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Jaguar: Grace, Pace, and Space - Sir William Lyons

 

pab, fluid coupling (aka, viscous coupling) is simply having 2 surfaces that are near each other with a fluid between the surfaces. Due to the thick nature of the fluid in a high pressure condition, it allows the 2 surfaces to spin at different speeds, yet, the fluid from one surface is pushed into the surface of another. A prime example of this is if you take 2 fans and face them towards each other. Now, turn on 1 fan on high. What happens to the other fan. It starts to spin. This is the same process that occurs in the viscous coupler, but now you are using much closer distances and a much thicker fluid (yes, the air you breathe is considered a fluid).

As for how the transfer case works, I would need to use a picture to help, but it is pretty much 2 gears at a 90 degree angel and the teeth are angled at 45 degrees. As the one shaft turns, it forces the other shaft to turn, but perpendicular to the first shaft. NOthing really special in our transfer cases since they are a single speed transfer cases. Now, trucks on the other hand with high/low gears, those are a bit more involved.

 

So if its just two gears spinning, why does it fail? Or the teeth gets broken from friction? Throw more light on it pls

 

baffourg, the TC case is made from aluminum. While it is a light material, it also is a flexible material. Under heavy loads, the case will flex. Repeated flexing results in the case developing stress fractures. This leads to cracks in the case and once you get a small crack, this is a weakness in the case that allows the case to flex more. Obviously, the more flexing the case does, the less likely everything is going to remain properly lined up, not to mention the loss of lubrication. As the TC flexes, things get out of alignment and you start hearing the gears grind against each other and in general, bad noises. After a certain amount of time, the gears will start eating up each other and as you can imagine, things are not good and failure will happen. In a lot of cases, it isn't so much the gears eating each other up as it is the bearings eating themselves. Some members have been able to get a new case, replace the bearings and rebuilt the TC themselves. But, most of us end up going to a shop to have them do the work for us.

If you want me to get into more detail, I will see what I can find and dive more into my background in metallurgy.

 

Thanks Thermo, got another question...

What changed in the design between early cars and late cars? It sounds like the basic design of the TC changed and that was for reliability reasons. However, someone also said that the early TCs did a better job of supplying torque to the various axles.

They just didn't last very long... =:-0
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Jaguar: Grace, Pace, and Space - Sir William Lyons

 

pab, the 02-03 transfer cases have a viscous coupler in them. The 04+ TCs do not. This was mostly done to make the transfer case cheaper. There was also some redesign of the housing to make it stronger. While they did seem to make it stronger, it isn't quite strong enough still. so, the 04+ transfer cases seem to handle the power better (the 04+ also have 17 more HP than 02-03 X's).

People that have owned both say the 02-03's transfer power back and forth much better and smoother while the 04+'s seem to have less problems. So, hard call there for me.

 

Thermo, what do u mean by 'under heavy load'? Talking about the weakness in the case, are u talking about the housing or the gears inside. If u are talking about the housing developing cracks, how does that happen if nothing hits it? or its bcos the road surface is not flat? Is it possible to change the bearings inside the tc? I just changed my tc oil after driving 5000miles. On my earlier change. My mechanic told me it doesn't need changing but I can't take chances so I insisted and though its done now and I feel confident in driving, he drained about 500ml of oil.

 

baffourg, when I say heavy load, I am talking about wide open throttle (WOT) or near WOT. Also, it isn't a "if you only use 150 hp you are fine, but you get to 151 or more, then you start having problems" kind of problem. The problem revolves around the actual housing for the TC flexing, not the internals of the TC.

The best way that I can explain it to you is for you to do this experiment. Find yourself a metal coat hanger. Cut off a piece of it about 12 inches (30CM) long. Now, put your hands on either end of the coat hanger with about a 2 inches (5 CM) gap between your hands. Now, twist your hands back and forth so the coat hanger bends. After a few bends of the coat hanger, you will feel the coat hanger get easier to bend and adventually it will break into two pieces. The more you bend the coat hanger (more bending would be the same as "a heavier load") the faster it will fail. Slight bends (lighter load) and you have to bend it much, much more to get it to fail. This is the same thing that is happening to the TC, but on a scale of a few thousandths of an inch. But, this is still enough that over time will lead to failure.

As for replacing the internal bearings, members have found the bearings and if you do a search, you will find a post that someone even posted the bearing part numbers that you need.

 

3 words "buy Bill's kit" Bill Beausoleil has developed and is marketing a kit that makes the TC fluid change about as easy as it's gonna get. I paid $125.00 for it and it's worth every penny. You should be able to search X-type forum to get Bill's info

 

I understand u thermo, just wondering how the crack come about. Is it because of uneven tires or due to stresses from the shock absorbers or anything that causes the propshaft to bend? So eventually getting a stronger housing for the tc solves the problem, I guess. I think one needs to examine the housing proper each times one gets to go beneath the car. Wow!

 

baffourg, essentially what is happening is one end of the TC is bolted to the engine (solid mount) and then the other end has the drive shaft coming out of it. Due to the gears changing the direction of rotation (from front to back over to side to side), this causes stresses inside the transfer case that try to rip it apart (kinda like when a baseball lands in your baseball glove). This essentially tries to stretch the metal casing apart. As mentioned above, the more you use the gas, the more stress the case sees. So, using the logic above, the case stretches, small cracks form, small cracks grow and many cracks come together to form bigger cracks and eventually you end up with a split in the TC housing. All metal exhibits these fine cracks. The trick is getting a metal that either doesn't allow the small cracks to grow or through heat treatment/process heat, the cracks have the ability to correct themselves.

Along this same idea, you will notice that most castings don't have a sharp edge to them. They all have rounded corners. Rounded corners help distribute the stress over larger areas so no one spot sees a lot of stress. You can prove this idea by taking two sheets of paper, one left whole, the other you cut through the paper an inch or so. Now, pulling on the side with the cut in it, see how much you have to work to make the paper rip. Now, grab the other sheet of paper and attempt to rip that sheet of paper using the same side of the paper. The cut paper should have ripped much easier.