Dorman 917-561 Rear Transfer Case Housing

I installed the Dorman 917-561 rear transfer case housing on my 2001 Chevy Silverado 2500HD that has the 6.0L gas engine, 4L80E 4 speed auto transmission and the NP246 transfer case. It was a very high quality die cast aluminum with no casting flash and was machined cleanly. Dorman actually included color photos and instructions that were pertinent and important. I highly recommend also installing the Merchant Automotive 10001 transfer case pump upgrade. It is machined billet alum plate to bolt onto your oil pump and it will stop the oil pump from wearing pin holes in the rear of your case. The case fit perfectly and all bearings were already installed in the case! Do not buy the other brand cases that have bad reviews on the internet of not fitting back together properly (2 guys pounding it back together with hammers and blocks of wood). I removed the transmission cross member, rear cross member for the torsion bars and removed the t-case from the truck to change out the rear case. There is a large snap ring that fits in a groove in the rear output shaft area in the case, and a mating groove in the rear output shaft bearing. It is located under a rubber plug on top of the tail housing of the case. This snap ring has to be expanded in order to separate the two case halves. It would be difficult to access the snap ring from the top with the t-case still in the vehicle and nearly impossible to correctly reinstall it. Do yourself a huge favor and buy the 11" lock ring / snap ring pliers to expand this snap ring. A typical 8" lock ring plier used to expand lock rings on transmissions will possibly expand the snap ring enough to separate the case halves, but it does not have enough spread to expand the snap ring far enough to engage it in both groves to correctly install the 2 t-case halves. I had to use screw drivers (inserted through the 2 holes for the vehicle speed sensors) to get in front of the rear output shaft bearing and pry it up or rearward enough to engage the snap ring between the rear case and the rear bearing groove. A plastic tool is recommenced, but did not provide enough leverage in my situation.

Worked great to replace the rear housing on my 1999 gmc Sierra NP261 transfer case. The rear output shaft was super tight on the housing. I couldn’t get it on at first, so I had to take my old bearing and put it in and take it out a few times to almost polish/sand the area so I could mate up the rear housing to the front. It wasn’t going on otherwise. Just a little TLC and it worked perfectly. The oil fill/drain plugs are not the same size as the OEM plugs. That is my only complaint. It’ll just make it that much harder to find a replacement if I ever need one. A seized drain plug got me into this replacement in the first place.

I just bought this 2005 Silverado 2500HD with 160,000 miles. Noticed a leak on the transfer case. I was aware of the pump rub issue but was hoping for just a leaking rear output seal. I ordered this Dorman replacement half case kit just in case and pulled the transfer case anyway to inspect. Good thing I did! Looks like someone was in there already and had installed 2 upgraded anti rattle clips. 1 was broken and half of it was stuck to the pick up magnet. The other was in place but was too big for the arm of the pump plate it was stuck on. Regardless, the pump plate ate notches in 3 of the 4 saddles. The 5 o'clock positioned saddle was the worst and when I shined a flash light from the inside of the case, I could see the pin hole that was leaking. Couldn't see it from the outside. Lucky I caught it before things got worse. I also installed the "Merchant Auto" case saver kit on the pump rather than using the 4 steel clips that come with this Dorman kit. Didn't feel comfortable with them and I don't want to have to do this shitty repair again. The speed sensor hole and everything was machined perfectly to match up with the original front case and accessories. 1 major tip. Get yourself an 11inch retaining ring/ snap ring pliers. Will need it for the main shaft access slot on top to release the rear case and the pump retaining ring if you choose to swap out the plate. Can buy one on Amazon for $20

Even though they'd like you to think differently, these are exactly the same case halves that Rigid Axle will send you when you buy one of their transfer case kits. It's Chinese made, but it's a nice unit from Dorman, and all went together without an issues. In my case, I installed a different, single piece "pump saver" than the clips that they sent with this kit, but both fit without issue. You can save some money by just buying it here.

Part fits fine and seems well built. I’ve run it over 1000 miles now and it’s holding up. I recommend you install the drain plug using Permatex High Temperature Thread Sealant and let it sit for two days. Then when it’s back on the car and you fill it with Auto Trak II fluid, let it drain out the fill plug as much as possible, then seal the fill plug with the same sealant. Let it dry for a day or two. I haven’t had the plugs leak yet so it seems to be working. I sealed the case halves with Permatex Grey gear lube sealant. Also, the speed sensors fit in fine with no rubbing in the reluctor wheels. I called Dorman and they confirmed that this problem was repaired years ago.

Fit my np261 transfer case in my 2000 silverado well. Have put a few hundred miles on it so far and some 4x4 use without issue. Only complaint is the drain plug holes are straight thread and not npt had to add copper washers to drain plugs so they would seal.

Reviewing, to possibly help someone else decide..01 2500 hd Silverado had the pump rub issue , installed pump rub kit, and this case housing. Went on smooth and have had no issues since installing. Everything lines up as should. The bearings are pressed in a bit deeper than original but highly doubt it’s enough to make much of a difference. Over all id recommend

The bearing that's installed into the case half is pressed to deep. It's out of spec and doesn't ride on the shaft correctly. I ordered 3 of these hoping it was just an error but all 3 were the same. Had to order an different brand.

This worked great for my 98 suburban np246. I used the merchant auto motive pump plate with zero issues. Sensor holes were correct depth. Buy some new bolts too mine were bad shape. Overall excellent part and great price

Fit perfect. I would recomend and use again

THIS CASE HALF, MADE IN CHINA, DOES NOT FIT LIKE THE ORIGINAL GM CASE HALF. Impossible to get Merchant Auto upgrade kit in or shim kit. Hopefully it will not eat this case half out again. Shipping was exceptionally slow, 3 weeks USA to Canada.