AWD and 4WD

An AWD vehicle doesn’t have a transfer case. The center differential replaces the transfer case.

Tester

I kind of agree with Tester for the most part, if it locks the front and rear differentials together with no slippage, it’s 4wd. 4wd is also selectable, there is some type of shifter to go between 4wd and 2wd. Most 4wd vehicles are RWD in 2wd, but not all. I had an 86 Toyota Tercel that was FWD in the 2wd mode but had a locking transfer case for 4wd.

I seem to recall a neighbor of mine that had a vehicle that was AWD in the high range, but if you switched to low range, it locked the front and rear differentials together to make it a real 4wd. I think it was an exception to the rule though.

in the AWD paragraph it states some have a transfer case with a center dif. Maybe that’s what your neighbor had?

just a figure of what that paragraph was talking about.

A Tahoe with full-time AWD (center diff) would still have a transfer case, I think.

I just looked up that truck and the awd versions are able to switch to 4lo. I guess that’s where the transfer case would come in.

wesw Your 1990 Cherokee has Command Trac. It is a traditional 4WD transfer case with 2WD, neutral, 4WD High, and 4WD Low. The caution not to use 4H or 4L on dry pavement is absolutely correct. My 1991 Cherokee had Select Trac. Basically the same as yours with the addition of a center differential which gave the option of what Jeep called full time 4WD. I’m fairly sure this is the same system Jeep called Quadra Trac in the full size Cherokees and Wagoneers as power was distributed independently to the wheels unlike Subaru’s AWD which distributes power between front and rear wheels only. I also appreciated the option of 2WD. The climate in Western Oregon is normally mild with small amounts of snow and ice which are short lived. If you can stay out of the mountains and Eastern Oregon high desert in the Winter 2WD is all you need. I could have put it in full time 4WD and left it there year round but why put wear and tear on a very expensive to repair component if there is no need. I’m sure 2WD also saved a little fuel. I’m sure you know the Cherokee is not the best at fuel mileage. Mine got 18 city 22 highway with a 4 speed automatic in 2WD. If you have the 5 speed manual you can probably do better.

Db, I would argue that the portion of the drivetrain that changes the ratios is the transmission, and in many FWD cars is contained within the transaxle assembly. As is the differential. And the axles.

Re: the comment about the pumpkin being the differential, in a lot of people’s minds the pumpkin and its mechanicals IS the differential, Ergo, no pumpkin, no differential. I don’t agree, but I understand why they have this perception.

That’s why I try not to get hung up on nomenclatures. The can be confusing. Rather than simply telling somebody “you’re wrong”, I’d rather try to offer an explanation so they better understand. Then the nomenclatures become less a “driver” of their perception and more just a name.

@jmdomke37 - instead of concentrating on names, you might be better off reviewing each company’s AWD/4WD systems and identifying the common and different aspects of each. For example, Subaru uses 2 different systems (at least).

True texases. Thanks

Relative to the original question, it gets confusing when manufacturers start improvising their own definitions of drive trains. We used to think of 4 wd as a truck based drive train with a transfer case to transfer power to the front but with no differential. AWD commonly uses a differential allowing the front and rear wheels to spin at different speeds and be engaged at all times. Then, along comes Honda or someone else who apparently makes AWD cars and SUVs and plasters the term 4wd on the back.
From a drivers point of view, what mechanism a car manufacturer uses is less important then the limitations and advantages each has in use. In this day and age, a name is just a name.

mountainbike

Speaking of a typical FWD car . . .

The whole unit is still called a transaxle

If you want to remove the differential, and call the rest of it a transmission, that’s fine