Jump to content

Probably Need A New Transfer Case - Np 246, Gm Part# 24228403 Illinois

jrsavoie

By jrsavoie
in Classifieds (Buy/Sell/Trade)

Recommended Posts

jrsavoie Enthusiast

jrsavoie

Posted
Posted

 

 

Probably need a new transfer case - NP 246, GM part# 24228403

 

 

 

I crawled under to check the U joints today.

 

 

 

The good news is the U joints are fine.

 

 

 

The bad news is the transfer case output had movement up and down. About 1/16" I'm guessing.

 

 

 

Any good places to buy a low milage NP 246 tyransfer case?

 

 

 

Are they rebuildable?

 

 

 

Does anybody have a link to a parts explosion?

 

 

 

Is there a possibility that it's just the tail bearing?

 

 

 

How hard are they to work on?

 

 

 

Is there an alternative to Auto Trak II?

 

  • 2 weeks later...
BrockwayMT Enthusiast

BrockwayMT

Posted
Posted

Does it leak? It may just be play in the yoke splines. That rear output bearing is known to fail. It was updated at one point. They are usually noisy if they need to be replaced. Bearing is around $75 from GM. Should take a half hour or less to change once TC is out of the truck.

jrsavoie Enthusiast

jrsavoie

Posted
  • Author
Posted
Does it leak? It may just be play in the yoke splines. That rear output bearing is known to fail. It was updated at one point. They are usually noisy if they need to be replaced. Bearing is around $75 from GM. Should take a half hour or less to change once TC is out of the truck.

 

Thanks

Anything I need to know about dismantling the NP 246?

 

The vehicle was neglected for 30,000 miles & has 200.000 total miles on it. The transfer case was at least 1 1/2 quarts low.

 

I filled it and drove it for 4 miles with the Burb in 4 hi for half those miles. I noticed no drips when I got back to the shed.

 

There were couple of drips inside the rubber boot on the front output shaft. I took it off to change the input seal on the front differential.

 

I did not notice any noise from the transfer case but then I don't hear as well as I would like. Especially certain levels of sound.

 

I will get somebody else to listen and pay close attention to drips after I get the Suburban mobile again.

Currently doing front pinion seal, engine oil cooler lines, front and rear brakes. oil change, idler arm, pitman arm, FS2500 oil filter, Rear AC lines, tires & front axle assemblies.

 

Any further advice would be appreciated.

hd01chevy Enthusiast

hd01chevy

Posted
Posted

I just did a pump up grade on mine, and there is some play from factory in the splines for the most part, but you can use ur better judgement as to if it seems excessive by any means...1/16''...seems fine to me......i also do know that in the rear case half there is a brass or bronze bushing as well, as far as replacement goes not sure....

jkotila Enthusiast

jkotila

Posted
Posted

Thanks

Anything I need to know about dismantling the NP 246?

 

The vehicle was neglected for 30,000 miles & has 200.000 total miles on it. The transfer case was at least 1 1/2 quarts low.

 

I filled it and drove it for 4 miles with the Burb in 4 hi for half those miles. I noticed no drips when I got back to the shed.

 

There were couple of drips inside the rubber boot on the front output shaft. I took it off to change the input seal on the front differential.

 

I did not notice any noise from the transfer case but then I don't hear as well as I would like. Especially certain levels of sound.

 

I will get somebody else to listen and pay close attention to drips after I get the Suburban mobile again.

Currently doing front pinion seal, engine oil cooler lines, front and rear brakes. oil change, idler arm, pitman arm, FS2500 oil filter, Rear AC lines, tires & front axle assemblies.

 

Any further advice would be appreciated.

 

 

 

The 1/16 play is the yoke to spline slop. Take out the driveshaft and pack the yoke with syn grease. Do a search for yoke slop, you may find some details. If you really want to replace bushing and bearing in the tcase, the bushing can be pulled with the tcase in the truck, there is a tool to pull it. you can do a search for that as well (sorry, i dont have any of the numbers off hand). If you want to replace the bearing, you will need to pull the tcase, pull all the case bolts, then there is a rubber plug in the top that comes out and a snap ring that can be opened up and the case half pulled off. Then the bearing is held to the shaft via snap rings.

  • 2 weeks later...
jrsavoie Enthusiast

jrsavoie

Posted
  • Author
Posted

Does anybody know a part number for the puller?

I have a couple of internal bushing pullers and a slide hammer.

 

My front output seal is leaking profusely. Does this usually indicate anything more than that the seeal is out?

 

The U joints don't seem to have any twist or slop to them. How Long do the Ujoints last?

These have 200,000 miles on them.

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • Deadwood
      primary drive belt tensioner

      By Deadwood · Posted

      I bought belts and pulleys for my '20 L5P at Rock Auto a couple years ago. I have used them for many years, and almost always save significant money, especially when I buy maintenance stuff ahead of time.   They carry many OEM parts, which is all I use unless an aftermarket is shown to be same/superior, or if it is an insignificant part or unavailable OEM part anywhere else. RA is usually lower priced, often by a bunch, but parts are sometimes unavailable or out of stock, and I do shop around and sometimes find better prices at other sites.   Be aware that you pay shipping, and if you buy multiple items and they are coming from different warehouses, the shipping can kill the advantage. Planning ahead is best if possible.   If you have a transmission service in the near future, check out their OEM (AC Delco ULV) fluid, usually MUCH less than anywhere else.
    • Deadwood
      10L1000 anyone with High Mileage ? I hate Damocles....

      By Deadwood · Posted

      New member here, very long time occasional guest. Saw this thread, thought it would be a good time to contribute someting. It is only my experience and not a claim that everyone will have the same.   I bought my '20 3500 L5P new and have put 99.9% (literally) of it's current ~400k miles on it myself, with over 50% of that towing loads between 4k to 15k, and to me this truck has been nothing short of amazing. For the first 235k I had zero issues, and from there until 321k I replaced a NOx sensor, two failing glow plugs, and three of the notorious injector connectors. I believe this truck is in part, a testament to good luck, but also good care and following a decent maintenance schedule (I also keep meticulous records.) As a result, it looks as good as a well cared for 70k rig, up and down, inside and out.   At some point before that 321k mile mark I began to get a little spooked about the 10L1000, especially the valve body. Word of mouth about potential issues prompted me to jump on the net to sift through all the noise and determine what all the fuss was about. I routinely take long trips, coast-to-coast and points in between, so roadside breakdowns can be '...a thousand miles from nowhere' and a bit of a challenge, and though I had no issues, my guard was up and activated.   And then I stumbled across a chance to salvage some parts off a new 2025 that had been wrecked in transport. I grabbed a few wear items (alternator, pulleys, etc.) and on a whim asked what the ten speeder would cost me. It was cheap...really cheap. I knew some changes had been made in the '24+ version 10L and were supposedly not compatible, but I called service/parts at my local Chevy dealer and asked why and they didn't know. A call to a well known aftermarket transmission outfit revealed it was very likely it would be fine, but to them not 100% sure.   Because it was cheap (really cheap) and I was spooked, I took the chance. Had it installed by a local shop and it worked like a champ, shifted just like the original. At it's first service at 37k, I had the shop put in a Next Gen valve body kit, which after some initial hiccups and rough shifts, smoothed out though with somewhat firmer shifting.   All that said, I have a very serious concern about my newer transmission as just two weeks ago it suddenly began to exhibit a strong reluctance to engage forward or reverse. It was a bit past due anyway so I took it in for service. The reason it was sticking was due to 'glitter' in the fluid clogging the filter...not good folks, often indicates a converter giving out. We ended up going ahead with the new filter and fluid, first to see if it would move and shift, and then if so buy me a little time. It did, and I've driven it over a thousand miles and it is shifting smooth, no noises or slipping. Regardless, it looks like a third gearbox is in my future so I can resume taking long trips with some confidence. In the very short term, my curiosity will have me examining the fluid to check how much glitter has reappeared.   An earlier poster had alleged, in the context of 10L100 failures, that it is another example of how we seasoned citizens somehow descend into hysteria, lose control of our senses, and react irrationally after brief encounters with the idiocy of the internet infosphere. Let me say (and I have used and abused said internet since it's infancy) there is no segment of the populace that has a corner on over-reaction to digital garbage. Just as my offering of experience in this arena is purely anecdotal and should not be considered gospel or all-encompassing, I believe it is still worthwhile information to consider, along with other relevant anecdotal experiences about things like complex transmissions, especially when balanced with other sources.   So to answer the original question, yes I got high miles out of my first 10L, trouble free for 321,000. Now I really wonder how much longer it would have went. Did I 'overreact' to the internet ghouls by replacing a 'good' one with a 'bad' one? Maybe. Who knows, the thing might have taken a puke a 100 miles later. So I'll just fix it again, then move on and start thinking about all the other stuff that will eventually wear out. It still has the original brakes (they're at ~60%), original injectors/pump, turbo, water pump, etc....pretty much original everything. Knock on wood.
    • swathdiver
      6 Speed vs 8 Speed

      By swathdiver · Posted

      At peak temperature.  They get to cool down and warm up more, especially those with the external cooler.  I have three GMT900s and one of them has over 225K on its original transmission.  Fluid gets changed about every 36K miles, all of it.     It's not the bean counters, it was the government.  They had to meet CAFE standards and other government requirements.   To get around that, we tune them and modify them to our liking.
    • GMCustomerService
      Will not stay in Reverse

      By GMCustomerService · Posted

      Our customers' safety isn't something we take lightly. To ensure you get the proper assistance for your truck's repairs, please fill out the form at https://s.chevy.com/support-request with all pertinent details including your username.
    • GMCustomerService
      2026 Z71 Forward and Rear Park Assist help

      By GMCustomerService · Posted

      We appreciate you sharing your experience with your truck. To ensure we get you the proper assistance, please fill out the form at https://s.chevy.com/support-request with all pertinent details including your username.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...