Well, I finally got around to changing the fluid in my t-case this morning. Job went well overall... I was a little pissed, because the build sheet that Dodge sent me said that my truck came equipped with the 231-HD t-case, but the label on mine says 231-D, so that sucks. But anyway, the fluid that was in that thing looked like it was from a 1901 Ram instead of 2001...looked horrible! But I feel better now about it, especially since only about 1 qt of quite crappy fluid was in it. Just wanted to share...

In case anyone is doing this for the first time (as I was), the drain and fill fittings are removed with a #10 or 10mm hex tool and a little muscle. I thought it was 3/8" at first, but it is not. Also, I found that a squirt bottle (the kind like you put on a bicycle) is perfect for getting the fluid into the t-case.

 

YA, I use a squirt bottle now too. I used to use the plunger type, but the squirt just works so much easier. I also buy an extra quart or two, and squirt it in with the drain plug removed until the fluid runs out clean. Then I put the plug in and fill 'er up. ALso, to keep from overtightening the hex plugs when you are putting them back in, you can simply put some vinyl thread tape on, and that keeps it leak free without having to over tighten.

 

Just how often should the T-Case fluid be changed? My '01 has a little over 61000 miles on it.

 

I do mine once a year, but I think evey 25k is the service interval.

 

Yeah, I'm planning to do mine every year before winter. Next winter, I will be back in TN, so I won't use the 4WD as much as I do here in UT, but I will change it anyway. I agree with Silver_Dodge and say do it yearly for two reasons: 1) cheap & easy 2) peace of mind. Next on the list...change the tranny fluid/filter and install a trans pandrain plug and cooler.

 

"I was a little pissed, because the build sheet that Dodge sent me said that my truck came equipped with the 231-HD t-case, but the label on mine says 231-D, so that sucks."---Ram2K1

I was under the impression that the 'D' meant it was the heavy duty version of the 231. Not true?

 

No, D is for Dodge I beleive because Jeeps have a 231J.

 

It only takes 1 quart?

Thats sweet.
My truck has 92,000 miles and its never been done, I gotta get to it but I never get around to it. I have a feeling mine is horrible.

What type of fluid did you use? just atf4?

 

That is disappointing. Looks like I'm going to have to search for a replacement, soon.

 

After doing a quick search, because my memory ain't what it used to be, I found this. I was thinking there was more than one 231 out there besides between make/model.

Here's the link: http://dodgeram.org/tech/specs/tranfer_case.htm for what I'm going off of so far.

Here's the part that has me thinking the 'D' after 231 on the 1500s may be a heavier-duty version afterall.

Transfer case versions: NV231, NV231HD, NV241, NV241D, NV241HD The NV231 transfer case is used behind many V6 and V8 engines in pickups and sport utility vehicles. The NV231HD, used in the 1994+ Ram with V6 and V8 engines, features larger bearings and a wider chain than the NV231. All versions of the 231 cases use three gears in the planetary reduction set. The NV241 is essentially a NV231HD with six gears in the planetary set. The NV241D is a heavier duty Dodge version of the 241, with a larger input shaft and larger bearings to withstand the torque of the V10 and diesel engines. The NV241HD, an option on Ram 2500's and standard on Ram 3500's built after 1998, has a stronger case and wider drive chain to better withstand the shock of snow plow service, a PTO cover and drive gear, and an extra bearing to support the thrust to the main shaft created by a PTO adapter. Except for dimensional differences and the PTO port on the NV241HD, all of the cases are almost identical in appearance. An identification tag is attached to the rear case of every transfer case. The tag provides the transfer case model number, assembly number, serial number, and low range ratio. The transfer case serial number also provides the date of build. For example, a serial number of 9-10-93 would represent September 10, 1993.