One of the best how-to videos I've seen. But what I learned is, by the time I buy the press/spacers/blind hole puller/total rebuild kit, I'm probably better off getting a reman. Now If I already had the tool investment (have somehow managed to get by without that stuff to this point,) it might be worth the time/effort to do the job myself. Also, when you factor in in the "it jumped up and bit me in the ass" things, like the stripped/corroded allen head, combined with my general luck, which is usually around a 95 on the bad luck scale, I'm probably better off getting a reman! I'll have enough issues just with replacing that I'm sure. Plus will have to do the front shaft u-joints too while it's out... Cannot overstate the value in this video though. Well done. You make what I'm sure is a tougher job than it looks in the video, look easy.
I refilled my 05 yukon t-case after 52 ounces leaked out. It holds 64 ounces total. I ran out of auto trak fluid after 26 ounces and made a mix of 50/50 Dex3 atf to 10w30 motor oil for the rest. So far so good. I understand any ATF is fine to use. I put a little oil to add to lubrication since it ran short for an unknown time period.
@DrShock why not synthetic? Is it too slick or something? That's what everyone was saying they substituted...some kind of synthetic ATF. I hope the oil I added makes up for whatever wear it maybe had from only having 10 to 12 ounces of AT2 in it for an unknown time period. I recently got this a few months ago. The 4x4 wasn't used by me except to test it twice. Do you know if these NP246GM units spin the chain all the time even in 2wd, or does it disengage when it's not being used? My front shaft does not turn when in 2wd and rolling from what I can tell. The front driveshaft spins by hand when parked and off or on, in 2wd.
I don't know the specifics, just that GM issued a _do not use_ service bulletin around _not_ putting Dexron VI into these autotrak transfer cases. I showed this bulletin in part II of the reassembly video series.
I think you done a great and thorough job going through the entire disassembly. Thanks alot, you saved me some time and broken parts, by showing the potential trouble areas. Thanks again.
For thd clutch assy, most people skip the swimming procedure and just reuse the same shims, which seems to work every time. And it should if nit replacing any hard parts since the original shims already account for the tolerances of the hard parts.
Thankyou soooo much for your help!! Im currently rebuilding my factory installed np246gm in my 2002 gmc sierra with pushbutton 4wd. I didnt find a wavy ring between my reluctor wheel and oil pump...do you know if this was optional on some models?
I go over in the rebuild portion of this series the differences in the earlier and later designs. I believe that wave plate was one of the ones I covered. The description will have links to that vid.
Fantastic video. You gave me the confidence to tackle this job myself. What did you clean your internal parts with? I’ve heard mixed thoughts on using brake cleaner. You mentioned mineral spirits?
For jobs like this I use a parts washer basin, which uses a naptha based solvent (Crown PSC 1000) for the ferrous metal parts, mineral spirits also works. Non-ferrous metals, like the magnesium case, can be cleaned with engine degreaser or brake cleaner sprays. Non-metallic parts are hand cleaned with a water based degreaser like Simple Green, or similar. All internal parts should be spritzed with blue transfer case fluid to prevent flash rusting, or ease assembly in the case of non-metallic parts, after drying from cleaning.
I’m in the process of disassembling an np-246, can you please tell me what size Allen wrench fits the clutch lever pivot pin? I don’t have that size. I don’t want to go out and buy a whole set.
Hi, i have a 97 c1500 rwd i replace the speed sensor on the transmission and works fine for one day then start doing same ABS ANTILOCK light come out and dont shift correct any other sensor you know I can check? So is 3 speed sensor?on a c1500? 2 front 1 on the transmission?thanks for all the info on your video I hope U can help me with any advice for keep working on my c1500
No. The front output shaft splines to the front transaxle are statically lubricated, as are the rear output shaft splines to the driveshaft. Check out ruclips.net/video/lg4hLNzNm2Y/видео.html around 22:54 and 32:21
There's a link in the description where you might find the hardcopy TURM manual from GM. Alternatively you can print out the information, for a fee, from GM service information at www.acdelcotds.com
Does that book cover manual shift units? I believe it would be a NP241. I have a 2003 NP261 and hope the information would be helpful. There are no 2003 books that I could find (at least affordable)
Cant thank you enough, just what i needed. Are you planing to upload the assembling? If you do, there are torque numbers i would like to wait and see you do first. Thanks again.. EPIC
Where do i find what you printed out? Tried asking the chevy dealership and they had no answer for me. I want to print out the pages that you showed in the video and put them in a three ring binder like you did. How did you access them? Mitchell?
The books are printed by GM. They have not been printed in many many years now though. But there is a link in the video description where an used one may be found. The transfer case is covered in the _unit repair manual_ for the particular year and body style of the truck it was originally installed into. I showed these pages printed from my books. I also showed some service bulletins, online access to these can be purchased from GM at www.acdelcotds.com
No, _not_ the same otherwise they wouldn't have different model numbers. ;-) For example the input shafts are different, the TCC module is different, the encoder motor is different, the wiring harness connections are different, the front case halves are different as well, etc, etc. But they are similar enough that there are a number of shared parts internally between them too.
No, unlikely _I_ would _wing_ a published torque value. ;-) It's on the service manual page at time index 48:16 on the reassembly video linked in this disassembly ones description.
@@DrShock oh you're right. I think I got your video and another confused. It is 30 ft-lbs. I noticed you didn't put LockTite on the lower pin that oftentimes falls out. Wouldn't blue LockTite be a good idea? Also, I see there are two designs for the clutch fork, a 1st and 2nd design. How do I know which design I have? My Yukon is a 4x4 model, 2005 year. Thanks
What are the chances that automatic trans fluid was added at some point instead of the AutoTrax II fluid called for? Incompatibility of fluids may have been the cause of the caking inside the case.
Near zero. The owner has had the truck since 2001 and was quite positive it had *never* been changed. So it's likely the original fill from 1999. The original factory fill for the NP246 in 1999 was Dexron III ATF. It was only later it was changed to Autotrak II fluid when Dexron VI ATF was found to be incompatible with the clutch material used.
That _was_ the correct fluid when the vehicles were still relatively new. But GM superseded Dexron III decades ago, when they came out with Dexron VI which unlike with a transmission is incompatible with the clutch material in the auto shift type transfer cases this video covers. GM came out with the blue Auto-track fluid for the auto shift types (e.g., NP246), and continues to make the red Dexron III additive package for manual shift types (e.g., NP241C) separately.
Worst tc design. Auto mode is another way for lazy people to drive. Never use the auto part in that unit and you'll have no problems. Mine is 25 years old with 200,000 mountain miles that carried 2000 lbs consistently. Beat on it hard, not one transfer case problem.
This was the most descriptive disassembly I have ever seen. It really took the fear out of the process.
I'm about to tackle this project in my garage, transfer pump knocked a pin whole 🤕 Thank you for the Awesome tutorial for the DIYers!
How’d it go?
Outstanding video. great audio and video. wonderful teardown. Thank you for taking the time. Excellent!
One of the best how-to videos I've seen.
But what I learned is, by the time I buy the press/spacers/blind hole puller/total rebuild kit, I'm probably better off getting a reman. Now If I already had the tool investment (have somehow managed to get by without that stuff to this point,) it might be worth the time/effort to do the job myself.
Also, when you factor in in the "it jumped up and bit me in the ass" things, like the stripped/corroded allen head, combined with my general luck, which is usually around a 95 on the bad luck scale, I'm probably better off getting a reman! I'll have enough issues just with replacing that I'm sure. Plus will have to do the front shaft u-joints too while it's out...
Cannot overstate the value in this video though. Well done. You make what I'm sure is a tougher job than it looks in the video, look easy.
I refilled my 05 yukon t-case after 52 ounces leaked out. It holds 64 ounces total. I ran out of auto trak fluid after 26 ounces and made a mix of 50/50 Dex3 atf to 10w30 motor oil for the rest. So far so good. I understand any ATF is fine to use. I put a little oil to add to lubrication since it ran short for an unknown time period.
Just make sure it’s not synthetic ATF. The whole reason for the blue auto trak fluid is clutch material incompatibility with Dexron VI synthetics.
@DrShock why not synthetic? Is it too slick or something? That's what everyone was saying they substituted...some kind of synthetic ATF. I hope the oil I added makes up for whatever wear it maybe had from only having 10 to 12 ounces of AT2 in it for an unknown time period. I recently got this a few months ago. The 4x4 wasn't used by me except to test it twice.
Do you know if these NP246GM units spin the chain all the time even in 2wd, or does it disengage when it's not being used? My front shaft does not turn when in 2wd and rolling from what I can tell. The front driveshaft spins by hand when parked and off or on, in 2wd.
I don't know the specifics, just that GM issued a _do not use_ service bulletin around _not_ putting Dexron VI into these autotrak transfer cases. I showed this bulletin in part II of the reassembly video series.
I think you done a great and thorough job going through the entire disassembly. Thanks alot, you saved me some time and broken parts, by showing the potential trouble areas. Thanks again.
Thanks for your time and wonderful detail in your work
Good job. 👍
Thanks!
For thd clutch assy, most people skip the swimming procedure and just reuse the same shims, which seems to work every time. And it should if nit replacing any hard parts since the original shims already account for the tolerances of the hard parts.
I'm showing the professional approach, only follow the service manual.
Does a 2002 z71 Tahoe with a NP 246 get a wave washer between the pump and the tone wheel ? Mine didn’t seem to have one ??
Thankyou soooo much for your help!! Im currently rebuilding my factory installed np246gm in my 2002 gmc sierra with pushbutton 4wd. I didnt find a wavy ring between my reluctor wheel and oil pump...do you know if this was optional on some models?
I go over in the rebuild portion of this series the differences in the earlier and later designs. I believe that wave plate was one of the ones I covered. The description will have links to that vid.
@@DrShock thanks for your response!! I will most definitely be following that video to complete my rebuild. Have also suscribed to your channel
Fantastic video. You gave me the confidence to tackle this job myself. What did you clean your internal parts with? I’ve heard mixed thoughts on using brake cleaner. You mentioned mineral spirits?
For jobs like this I use a parts washer basin, which uses a naptha based solvent (Crown PSC 1000) for the ferrous metal parts, mineral spirits also works. Non-ferrous metals, like the magnesium case, can be cleaned with engine degreaser or brake cleaner sprays. Non-metallic parts are hand cleaned with a water based degreaser like Simple Green, or similar. All internal parts should be spritzed with blue transfer case fluid to prevent flash rusting, or ease assembly in the case of non-metallic parts, after drying from cleaning.
You use the term snap ring for lock ring or C ring. Snap rings have holes in the ends. Lock rings don't.
Sure, but this is more of a _potatoe, potatow_ situation tbh. ;-)
I’m in the process of disassembling an np-246, can you please tell me what size Allen wrench fits the clutch lever pivot pin? I don’t have that size. I don’t want to go out and buy a whole set.
Hi, i have a 97 c1500 rwd i replace the speed sensor on the transmission and works fine for one day then start doing same ABS ANTILOCK light come out and dont shift correct any other sensor you know I can check?
So is 3 speed sensor?on a c1500? 2 front 1 on the transmission?thanks for all the info on your video I hope U can help me with any advice for keep working on my c1500
Was feeling pretty confident about diy until the press and metric pressers were introduced.
Where can I get a instruction manual like yours for the 246
Out of print for many years now, but should be a link in the description where used ones pop up from time to time.
Does the fluid inside lubricates the output shaft splines?
No. The front output shaft splines to the front transaxle are statically lubricated, as are the rear output shaft splines to the driveshaft. Check out ruclips.net/video/lg4hLNzNm2Y/видео.html around 22:54 and 32:21
Thank you so much. This is awesome. I appreciate you posting this. Where did you get the manual that you are using?
There's a link in the description where you might find the hardcopy TURM manual from GM. Alternatively you can print out the information, for a fee, from GM service information at www.acdelcotds.com
Does that book cover manual shift units? I believe it would be a NP241. I have a 2003 NP261 and hope the information would be helpful. There are no 2003 books that I could find (at least affordable)
The GM manual will cover every transmission and transfer case used for the particular model year it covers.
Cant thank you enough, just what i needed.
Are you planing to upload the assembling? If you do, there are torque numbers i would like to wait and see you do first. Thanks again.. EPIC
Thanks, yes I'll be doing the rebuild very shortly with all genuine GM parts and service manual torque values.
@@DrShock Awesome!!! Thanks
Hello would you happen to have the brand or where you sourced the snap ring pliers that open up 1 1/2+ ?
I've added links in the video description to the tools used in the video.
@@DrShock Awesome, used your ebay link. thanks!
Where do i find the service manual that you printed out?
Long out of print, but should be a link in the video description for used ones.
Where do i find what you printed out? Tried asking the chevy dealership and they had no answer for me. I want to print out the pages that you showed in the video and put them in a three ring binder like you did. How did you access them? Mitchell?
The books are printed by GM. They have not been printed in many many years now though. But there is a link in the video description where an used one may be found. The transfer case is covered in the _unit repair manual_ for the particular year and body style of the truck it was originally installed into. I showed these pages printed from my books. I also showed some service bulletins, online access to these can be purchased from GM at www.acdelcotds.com
is this the same an an 263xhd transfor case for an 02 chevy 2500hd duramax 6.6
No, _not_ the same otherwise they wouldn't have different model numbers. ;-) For example the input shafts are different, the TCC module is different, the encoder motor is different, the wiring harness connections are different, the front case halves are different as well, etc, etc. But they are similar enough that there are a number of shared parts internally between them too.
Anyone know what the install torque is on the two clutch pivot pins?
I'm sure I went over that during the reassembly video series that followed this one (link in the description).
@@DrShock no, you just winged it. I found it lol
No, unlikely _I_ would _wing_ a published torque value. ;-) It's on the service manual page at time index 48:16 on the reassembly video linked in this disassembly ones description.
@DrShock I'll look again but that's what i saw the first time. Thanks!
@@DrShock oh you're right. I think I got your video and another confused. It is 30 ft-lbs. I noticed you didn't put LockTite on the lower pin that oftentimes falls out. Wouldn't blue LockTite be a good idea? Also, I see there are two designs for the clutch fork, a 1st and 2nd design. How do I know which design I have? My Yukon is a 4x4 model, 2005 year. Thanks
What are the chances that automatic trans fluid was added at some point instead of the AutoTrax II fluid called for? Incompatibility of fluids may have been the cause of the caking inside the case.
Near zero. The owner has had the truck since 2001 and was quite positive it had *never* been changed. So it's likely the original fill from 1999.
The original factory fill for the NP246 in 1999 was Dexron III ATF. It was only later it was changed to Autotrak II fluid when Dexron VI ATF was found to be incompatible with the clutch material used.
My 97 uses ATF dexron 3
That _was_ the correct fluid when the vehicles were still relatively new. But GM superseded Dexron III decades ago, when they came out with Dexron VI which unlike with a transmission is incompatible with the clutch material in the auto shift type transfer cases this video covers.
GM came out with the blue Auto-track fluid for the auto shift types (e.g., NP246), and continues to make the red Dexron III additive package for manual shift types (e.g., NP241C) separately.
how can I get a copy of the manual your using?
Links in the description.
@@DrShock yea my grandson showed me thx love the videos time to buy and put in the work
Cant find the manual man o man
Will you send me a copy of your instruction? I have a 1999 chevy suburban LT k1500.
There's a link in the video description to search for this, it's the GM transfer case unit repair manual for any given model year.
I'm allabout eye protection but I think the ear protection is a bit overdoing it.
Don't discount that some may have hearing impairments or sensitivities. I try to _not_ show any bias when going over these procedures.
Speed sensors are all the same.
Worst tc design. Auto mode is another way for lazy people to drive. Never use the auto part in that unit and you'll have no problems. Mine is 25 years old with 200,000 mountain miles that carried 2000 lbs consistently. Beat on it hard, not one transfer case problem.