Remove/Replace GM 246 transfer case, 2000 Chev Suburban

A step by step video showing how I diagnosed, removed and partially tore down a damaged GM 246 (NP246) transfer case on a Chev 2000 Suburban 4X4 with the 4L60-E automatic transmission. The video shows details of removal and installation of the case, though full rebuild details are not shown.
For the best 246D disassembly I've ever seen, don't forget to watch this one:
• 246 GM Transfer case t...
For an excellent demonstration of the rebuild in a 261HD, go to the demonstration by Eric O, here
• New Process Gear 261HD...
Other videos showing the full rebuild are linked in the discussion thread.
If you decide to inspect your vehicle while in drive with rear wheels spinning, be wary for your personal safety, since sudden loss of life or limb may be only inches away.
This video is posted for entertainment purposes and is not an instructional guide. Do not attempt this at home without professional advice. I am not a professional mechanic, and any misadventure resulting from your attempt to repair your vehicle is your responsibility.

[@spelunkerd]

For those looking for more detail as to how to do the next step of a full rebuild, there are now a couple of excellent video sets that go into this in detail. The best one I've found so far is by Eric O at South Main Auto, here. kzbin.info/www/bejne/mZS6mZudgb9lZs0 Also don't miss the video linking to Briansmobile1's video, linked in the comment thread, below. An older set was done by Rickafix, here kzbin.info/www/bejne/iF6vpHmmhtCha68. Also just today I discovered an excellent demonstration of how to press in the seals and bearings, here kzbin.info/www/bejne/rWW6p2qprJqhgtU. Good luck!

[@danielbates9347]

O9k

[@bernocastro4310]

978

[@rletzgus]

It's great that there are guys like you taking the time to video all this work. So that people like myself, DIYer's, can do these kinds of jobs. Again, thank you!

[@calebpozsik2816]

I had to drop my NPG 246-NP8 transfer case so I studied your video and found it extremely useful. Now, I have a 2004 GMC Sierra so my transfer case is a little different but it really helped none the less. Thanks for posting a worthwhile video.

[@petecoots]

Have a 2001 GMC Yukon 5.3L- been battling the 4WD Service light going on 2 years now. I've tried changing the switch module, TCCM, front diff actuator, oversized fuses and lastly a fluid change out. Will sometimes switch into 4HI, but then the 4WD Service light comes back on and the fuse is popped. I finally got my hands on a used 246 t-case with all the numbers/codes that seem to line up. Great step-by-step procedure- was taking better notes than I ever did in any classroom! Also appreciate the spline count- going to check to make sure they are the same. Before I tear into it tomorrow! Thanks for your assistance

[@EddiCurrent]

Great video spelunkerd, you and others here on KZbin inspired me to not only rebuild my own NP246 TC, but to produce a few videos on the modifications I did as well as the assembly. After getting mine apart it was quite obvious these things were poorly designed and require some modifications to keep them from wearing themselves out prematurely.

[@spelunkerd]

Great, I'll have a look. Anybody who cares enough to give back to the KZbin community by recording experience is OK in my books. Thanks for stopping by to glance at my humble effort, which could easily be eclipsed by somebody who takes the rebuild right through to completion. I drove this car today, it was certainly worth the effort I put in.

[@spelunkerd]

Those are wise remarks. Yes, we repaired the seal leaking at the transfer case side. No more leaking since then, though I didn't do anything to the transmission end. I'll continue to watch that to the future. Thanks for your contribution!

[@TattereDX]

Thanks for putting up. After tearing into the the locking hubs and even opening the pumpkin to see if any gears were broken, I'm wishing I would've done this to see if the transfer case was shot first, which it is. New to 4x4's and learning the hard way to get things fixed. 1982 GMC 1/2 ton K1500.

[@Duststorm72]

this video is so helpful..i just got my transmission rebuilt...but wen i drove slow in a parking lot with the windows down i heard that noise...same clicking/grinding noise...i thought it was hard to take off and get it fixed....but thanks this vid...i feel more confiedant..and will be even cheaper to take off and put back on my self..save me money on labor...very helpfull..thanks for the video..

[@stumblein9]

that's the exact same noise i hear on my 2001 silverado. i notice it at low speeds, sounds like running over a beer can. so many shops have told me different things...gravel in my tires (lol!), u-joints..etc. finally a shop told me its the transfer case. told me the chain is stripped and shaft is worn. wants to do an overhaul. this video made me feel better. thanks!

[@semicrazy.neverlazy]

That's exactly what I said when I watched the first part of this video!

[@feverz28]

Thanks for the video. I got the transfer case out in 1 1/2 hours, went very smooth, now to open it up and see where the problems are at. I was quoted $1000 to trade my core for a rebuilt one which doesn't seem too bad. I don't need my truck for a while so i will mull it over and see what i end up doing. Thanks again.

[@RShakes]

Thank you for posting this video! I'm in the process of replacing the transfer case on my 2000 Chevy Silverado 1500 z71 and this definitely helped. I'm most likely going to go to a junkyard and pick one up off a wrecked vehicle and use that on my truck to save some cost.

[@spelunkerd]

Good luck!

[@noahvarca]

Great video, very informative, great camera clarity and placement. First automotive video I have no complaints about.

[@spelunkerd]

+Noah Arca Thank you.

[@OregonBigfootODA]

I am about to replace the NP246 on my 1999 Suburban and decided to get a rebuilt one on eBay for $729 with free shipping and no core charge. It is completely rebuilt: seals, bearings, chain, clutches, steels, pump and etc. As well as an upgraded rear case half. I couldn't justify doing it any other way.. Will be installing it this weekend. :-) Thanx for the good removal tips!

[@jasonjones313jj]

I like this video a lot. So many other videos were so full of blabber and fluff. You were straight to the point and hit all the critical points. Thanks again and I thumbs you up.

[@spelunkerd]

+Jason Jones Thanks!

[@wkl747]

You are very good communicator as well as technical skill. I learned a lot from you. You are very talented and good on financial justification. Great video.

[@thejnelson88]

Thanks, it does give me hope, I got the the tcase later in the day and once all the prep work was done and getting it under the truck it ate a lot of my time. I'll be giving it another shot in the morning. It just means I need to play with it some more to get it to go into place. Thanks for the advice.

[@filstoy]

And you were correct to do that. That's what they are called in the actual GM service and parts info. Also, thanks for taking the time to make this video. I usually like to do rebuilds myself but the cost of some of the special tools almost makes it a moot point . On mine the Kent-Moore puller for the rear output bushing is $400 alone. I lucked out and found a used one on ebay for $35 but sometimes it's cheaper to take it to a shop once you get it out.

[@g00se770]

Great video --I am right in the middle of removal / replacing my GM 246 transfer case ---wish I had seen your video before I started!

[@spelunkerd]

I'm sure that many of those who read the comments will find your remarks helpful. Thanks again for your insightful contributions.

[@spelunkerd]

And thank you back, for watching and participating.

[@spelunkerd]

Thanks for your input! For others who may be considering doing a case swap, they should know that there is added complexity if the diameter and the number of splines on the input and output shafts differ from the original case. Of course even if there is a problem, it's not insurmountable, just more work.

[@diesel2421]

this is definitely me right now. excellent video. thanks for diagnosing my sounds...

[@imnotviolent]

thank you for putting this video up.im changing the transfer case myself on my 99 yukon,this video helped me out so much.saved me prob$ 1500 thanks again man.

[@spelunkerd]

Thanks for documenting your experience. It's not easy to examine the system safely without a lift.

[@lancelot1953]

Thank you very much for taking the time and effort to put this video together and share your experience/expertise. I found it very helpful, Ciao, L

[@spelunkerd]

Thanks!

[@tjoyce81]

This is a great video - thanks and it has taken some anxiety out of my future tcase removal. I am going to try a rebuild myself, and to address the issue of leaks caused by holes - the fluid pump housing on these tcases wears a hole into the case over time. The best fix is to replace the pump housing with an improved housing...

[@spelunkerd]

+Tom Joyce Sounds like fun. You should do a video, ha ha. Thanks for watching!

[@spelunkerd]

Thanks for posting your experience here, it will help those who visit in the future.

[@spelunkerd]

Thanks for your comment and the extra info. This internet thing, it's all about paying it forward. Cheers!

[@spelunkerd]

For anybody reading this and considering a DIY rebuild, you will want to watch Rickafix1 do it without a lot of fancy tools. Great series!

[@CooganBear]

Thank you for the informative video. Still very useful in 2022. I'm driving a 2001 Yukon XL. No issues yet, but this is good info.

[@SignatureMind]

Very Wise!!! Very WISE INFORMATION!!! Thank you! I feel very confident for my task. God Bless!!!

[@mecheng81]

Great and thorough video, thank you for posting.

[@Turbo231]

That is a very neat video. Your truck is in very nice shape with very little rust to battle. I had front axle issues on my S-10 and I was unable to record it's repair but after watching you, wish I had. The 4x4 system on these trucks (S-10's being similar in design) is quite a beast but there are tricks to figuring out what's going wrong. I ended up setting the whole truck up on jack stands (with the front suspension loaded) to figure out the issues between 2 and 4 wheel drive.

[@spelunkerd]

@JScottRacing I'm glad it helped. Maybe you'll be lucky and it will be a universal joint rather than the case. Helping guys like you is my way of giving back, for all the help I've received from others here on youtube. Thanks for your comment. Dave

[@spelunkerd]

Oh, I'm glad you recorded your experience for the thread here. When I removed the encoder motor (while the case was on the bench) it came off perfectly, and putting it back on was easy too. But maybe in your case it needed more wiggling that wasn't possible in the confines of the vehicle frame. Nothing beats hands-on experience! Thanks again for your contribution.

[@spelunkerd]

Hey, thanks for your comment. Remarks from guys like yourself, with experience, make this thread more helpful for everybody.

[@spelunkerd]

Yes, that's the video I was referring to. It's not necessarily his problem, but it gives a good view of how to install and remove the encoder motor.

[@feverz28]

Thanks for putting the time into doing this video. I need a rebuild on my 01 Silverado without auto lock transmission. I figure it should be similar, just hope there is a way to salvage some of the transfer case. My truck was was at a jolting / grinding point and had it towed home.

[@FBIsurveillance62]

Wow what an amazing video break down all the information you really know how to make a KZbin video that's for sure thank you so much for all your help really made it a hell of a lot easier wish you the best hope all is well

[@spelunkerd]

Oh, I'm glad it helped. I wish I could have done the full rebuild, but there are other videos out there showing better detail regarding that step. Thanks for watching!

[@jeremyskookc4726]

First video I've came across of yours. I love the detail. Never seen someone go into such depth. Now I know exactly how to do the job on about to take on. Thank you

[@mcamp2013]

I will be using your video as a guide. Very thorough. Thanks for posting it.

[@spelunkerd]

Yeah, I understand. I wondered if it would be worth it for my vehicle, since it's old and other problems could have been coming. But it turned out to be the right decision for me -- the truck is still going strong and we use it every day. Cheers!

[@spelunkerd]

You're welcome, and I hope it works out for you. Don't underestimate how much work this can be, especially if you have inferior equipment such as no transmission jack or small jack stands. The case is heavy and awkward to manipulate from underneath, so there is some risk of it falling and injuring you or damaging sensitive parts. Thanks for your comment.

[@spelunkerd]

@dreamer2355 I really appreciate the complement, especially knowing you work in the industry. Thanks again for all of your insightful contributions on Ericthecarguy's forum. Dave

[@craigshiman1442]

Thank you so much. This has been a very helpful & instructional video. Thanks again

[@spelunkerd]

You're welcome, I'm glad it helped.

[@spelunkerd]

I'm glad it helped, thanks for the feedback.

[@vanstechcorral]

I attach the sliding ears on the trans jack from the bottom so the surface on the pan is smooth and they can be tightened and adjusted while supporting the trans weight. This is the correct way as the bolts are only long enough to remain flush. For the transfer case what is needed is a welded jig that supports it on the jack. It sure is tough getting it back up working alone as brother to the worm!

[@spelunkerd]

Yes, I'm told that is normal and your explanation is what I was thinking.

[@spelunkerd]

In response to Jason Palma's question, no I didn't have pump rub, but when it was rebuilt they installed redesigned clips to prevent that. The noise was the bad output shaft bearing shown in the video, and the rebuild was done as a kit including a new chain, new seals, etc. I still drive the vehicle every day, now well over 300,000 km. Good luck to you!

[@jasonpalma6209]

spelunkerd Thank you for the response. Ill be ordering the parts soon

[@crystelmangert7623]

1999 S-!) BLAZER LS,.. Driver side Front C-V axle won't stay in , When I lock it in 4 wheel drive It POPS OUT! the snap ring is getting chewed up , will inner barring fix issue? Tried longer axle , No Off Road package HELP! Steve

[@spelunkerd]

Those are wise words and I agree completely. The rebuild that I had done included replacing the clips that cause erosion through the wall of the casing, though I don't know if the full rebuild form Merchant was done. In any case, it's still working fine today.

[@jimmywells33]

Who were the idiots that downvoted this?! Thanks for a great no-nonsense video.

[@spelunkerd]

On mine I could feel the top one but not see it. The side ones were all easily seen. Fortunately they all were on with minimal torque, I was surprised how easily they came off. I used that ratcheting swivel box wrench that I showed in the video. It might help if you clean the area really well -- of course there is a risk to pressure washing but that might make it easier (disconnect battery). It's also a lot more comfortable to work on a clean surface when you lay underneath. Good luck!

[@fototropism]

i really appreciated the clip so thank you so much for posting

[@spelunkerd]

Nicholas Desrochers Thanks!

[@poeburgh]

After doing this repair I learned a bit. First thank you for your video , it was very helpful for the most part. However taking your suggestion to remove the encoder motor was a real mistake. It is very easy to get the mating shafts out of alignment and have real difficulty getting the encoder back on. I had to remove the electric motor from the encoder gear case and manually position it to the neutral position on the transfer case( which took some doing ) So Leave the motor on!

[@gordoncombine]

Very good and informative video. Thank you for taking the time to walk a guy (or girl. lol) through a transfer case job!

[@ianmcclelland9773]

Thanks... I really appreciate and enjoy your videos!

[@harryperry4328]

Thank you for putting this together.

[@spelunkerd]

You're welcome, thanks for the feedback.

[@cornell833]

Great content 👌 #I used a regular 🚗 jack no problems sat it on the jack got it high enough work it in place 👍 higherd jack to hold in place tighten nuts up plugged my plugs up then everything worked out great 💪

[@spelunkerd]

Yeah, I regret not trying, but that was a time when I couldn't afford to mess it up, and what was available on the net was not complete enough for me to risk it. Hopefully somebody will put together a video of the part I subcontracted, passing a baton for all of us. It's still working fine. Thanks for your comment.

[@spelunkerd]

The noise was definitely coming from that rear bearing. But with the case already opened it was only wise to replace the chain and also replace those metal clips that are notorious for wearing through the case and causing catastrophic failure. We replaced all the seals, not just the seal that was leaking a little at the front drive output shaft. Most of those parts come as a "minor seal kit" and so the simplest plan was to do all of that. The vehicle is still going strong today.

[@spelunkerd]

Yeah Steve, I was surprised, too. The reason I chose that terminology is that the manual I use (Alldata) uses the same word for that shaft, and I didn't want to confuse anybody by choosing a different word. It wouldn't have been my first choice otherwise (grin).

[@dreamer2355]

Awesome video! It was well worth the watch!

[@spelunkerd]

@Oldsmob455 Yeah, when the load is off center it's awkward, and lining up the bolts was time consuming. Thanks for your comment.

[@spelunkerd]

In the video you see the output bearing at the rear shows pitting of the ballbearings. Those steel bearings were bouncing and binding in their track, causing that clacking sound. The vehicle is still working fine now, and we use it every day. I wondered if it would be worth the effort to fix such an old vehicle, but in retrospect it was clearly a good decision.

[@Ezethede]

Good video, very informative. One thing worth noting, that I have read about frequently when dealing with this particular transfer case, is that the pump tends to wear a hole in the case due to the thin, sharp edges from the factory. A common pump upgrade kit is available from a company in the US (I think it's Merchant Automotive) which will prevent this.

[@spelunkerd]

Yes, you're right, the problem is well described all over the 'net. When mine was rebuilt they installed redesigned clips to prevent that from happening. It's still running strong with no problems.

[@Ezethede]

Good to know. Thanks for the video, I have isolated a drivetrain vibration to the transfer case area and have play in the output shaft along with fluid leaking out so I plan to undergo removing the transfer case soon. I think I will watch this video a few more times before I do..

[@brandongarcia7508]

Great video, thank you sir.. blessings

[@kenman1717]

great video. I rebuilt numerous GM 246 t-cases, but I am a licensed mechanic. they are not that bad to do, the big thing depends how bad they are on the inside. I have done a few that the chain stretched so bad it was digging into the case. but the biggest thing with these, auto ones being the worst, is a hole wearing through due to the clip on the oil pump. if you catch it in time, just the rear case half and a redesigned clip on the oil pump will work, but if it goes to long, pull the drain plug and nothing comes out except a chunk of metal.

[@spelunkerd]

It's great to have a pro stop by, thanks for your comment. You might get a few questions from people about the rebuild part. I believe the guys who rebuilt mine changed to redesigned clips, so the chain wouldn't wear through.

[@spelunkerd]

@Turbo231 Thanks for your reply, Ben. I watch all of your videos because I find them thoughtful and interesting.

[@spelunkerd]

@techgood Your welcome, thank you back.

[@spelunkerd]

You're welcome. If you want more detail on the actual rebuild, Rickafix1 did a very detailed set of videos showing that.

[@paulhaines5755]

Rebuilding these yourself is pretty easy. No special tools, really. In addition to bearings and seals, definitely replace tail housing and slip yoke to rear driveline if you've ever run it low on fluid. Likely some wear there that you may or may not see in both slip yoke and tail housing bushing. I found that getting them out is not a challenge but getting them back in is a bit. It's easier if you install the extension housing by itself with one, easy access bolt hand tight to the back of the tranny. You then bring the case in underneath the vehicle 90 degrees rotated then raise it and spin it into position. Get it close to the tranny shaft and take the bolt out of the extension housing. Install the extension housing on the transfer case at this time. You can spin the transfer case to easily gain access to all nuts. Now, slip the whole thing into place and install extension housing bolts. Easy money!

[@spelunkerd]

Thanks for an insightful note that will help many others who stop by.

[@tjs_welding_and_fabrication]

Thanks. My 98 Tahoe makes the exact same clicking noise. Time to get to work.

[@spelunkerd]

I'm glad it helped, thanks.

[@gregjames1423]

awesome in explaining ! you remind me of some cool cats I grew up with .

[@spelunkerd]

+greg james Ha ha ha, that's so funny. I'll have to save this, to show the cool guys from high school. Only in a different universe would I be part of that crowd. Thank you for watching!

[@spelunkerd]

@wishiniwasfishin27 I read about pump rub when I researched problems with this (and other) GM cases, and I was expecting to see something. But inside the case, even after 300,000 km, there was no evidence of pump rub at all. The mechanics did replace the clips with some kind of better pump support they were using, though I'm not sure it was made by Merchant. I can't say I expect very many years out of this vehicle, so we'll see.... Your input adds to this discussion, thanks!

[@spelunkerd]

The outer bearing that supports the output shaft to the rear wheels was badly damaged, and the pitted balls of that bearing were binding as the shaft rotated. I replaced that bearing, the chain and all seals, and I replaced those metal clips that are notorious causes of damage to the case. Thanks for your comment, and good luck!

[@rudysilva2713]

Amazing job.!!! Tnks for u time

[@spelunkerd]

As I recall there was a vent tube that just allows pressure to equalize with atmospheric air, but no vacuum line. The vent tube starts at the case and extends forward, with the forward tip held by a clip above the transmission somewhere.

[@spelunkerd]

In response to the remark by faclcom alkhair with the depleted oil -- One of the commonest causes of depleted tranfer case oil with this vintage chev case is a tiny hole eroded in the wall of the case that leaks from there. So, now that oil has been replaced, watch closely for recurrent leaking from the case wall. If the case has formed a hole you need to do an overhaul on it to replace the clips that are designed to protect the inner wall of the case. I've seen people use JB weld for that, but it usually doesn't work until the clips are replaced inside.

[@spelunkerd]

I don't know what the span was but I got them at a discount supply house, Princess Auto in Canada. That ring is about 6 inches in diameter, you need the largest you can find. I'm hoping somebody will do a thorough rebuild here on youtube, so that those details are clear as well. Thanks for your comment.

[@speubanks2250]

spelunkerd - thanks a bunch, you've helped me with my 2002 Tahoe. keep up the great videos & info. you are appreciated :-)

[@spelunkerd]

+Sp Eubanks Thanks, man!

[@spelunkerd]

@MileyCyrus192 That's eventually what I did to get more height. Unfortunately that wasn't my only problem since my little jack stands needed the same treatment, using several partial sheets of plywood. With all wheels on stands, risks are higher. I didn't want to be laying under the vehicle, unless it was broad based and rock solid. Ultimately I got it done, but not without a lot of unnecessary effort, compared to how one with quality tools would have done it. Thanks for you comment!

[@techgood]

Wow, wonderful Video, thank you very much Sir

[@glennrightsell1]

excellent thanks for alot of good info ,now to fix mine.

[@spelunkerd]

Good luck. There are some more high quality youtube videos of how to do the inside revision now, much better than there was a couple of years ago.

[@spelunkerd]

The frustrating thing about doing something like this the first time is not knowing how it goes together. Once I knew what was there, it was much easier. Of course those extra large snap ring pliers helped a lot. Thank you for watching!

[@spelunkerd]

Knowing how much work this is, I am not at all surprised at your bill -- it sounds very reasonable to me.

[@internalbeats6870]

Great video. Thank you for your time

[@redhorse554det1]

good vid. enjoyed yur explaning how u went about yur projct.

[@spelunkerd]

Thanks, Ian.

[@spelunkerd]

Yes, and after the fix that rotation continued, as you say.

[@spelunkerd]

(part 2). To remove the stainless steel straps you can pry them apart, and if you are careful you can reuse them. I cut mine so I had to replace it. There is a special tool you use to put the strap back on -- I have the tool so it was easy for me. If you don't have the tool, I have heard of some people using those plastic quickties that work almost as well. The thing that bothers me about plastic quickties is that plastic tends to expand with heat so they may not hold as well as steel.

[@chrisgunderson4651]

obviously degree in communications dang good job !

[@nickrodriguez7623]

Thanks for the info.. The GM Np246 had some issues.. Electrical issues like the 4x4 switch, encoder motor failure, front actuator motor failure. Test those out first before buying or rebuilding T-case. Other issues Pump rub on the shell and weak clutches.. I would have put the pump rub saver while the T- case was apart and changed the input and output seals.. If you need a stronger T-case go with the NP241 swap..

[@spelunkerd]

Excellent points, thanks for stopping by. Yes, all three seals were swapped and new clips were installed to prevent pump rub.

[@spelunkerd]

The fluid I used was what was sold and recommended to me by a GM dealer -- they use AC Delco for this.

[@brainsironically]

Great vid! Thanks.

[@briansmobile1]

I really appreciate your professionalism in editing and eloquent dialog. Your shop also looks very nice and clean. What is that you do professionally if you don't mind my asking?

[@ss109guy]

Excellent thanks

[@andersonrowland]

Great video!

[@spelunkerd]

No, it's working fine with 312,000 km on it. I did have the switch that controls the encoder motor fixed about 10 years ago under warranty.

[@dougtownley6748]

Thank you for the Video!

[@spelunkerd]

You're welcome, I drove the vehicle today.