Bearings inside a NP 203 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Jimma · 11-11-2007, 03:33 PM

I have a NP 203 transfer case in my truck. Recently the case developed a loud noise that sounds like one of the bearings is dry or bad. I replaced the bearing for the front yoke but the noise still developes after driving it for a while. I know that there are bearings up near the Trans and judging by where the fill plug is, it seems that the fluid line is lower then where the bearing is. Does anyone know what could be causing this sound and what I could do to make it go away?

bouncytruck · 11-11-2007, 04:50 PM

I had a similar noise in my truck with an TH350/NP203 combo. It turned out to be one of the clutch bearings inside the TH350 exploded and destroyed most of the internal parts as well as cracking the case. Ya might want to crack open the transmission pan and see if you have any fragments in there before you put it in gear again.

**jaros44sr** · 11-11-2007, 05:48 PM

Holy %$^&ing crap, Batman!! What a mess. Looks expensive...

Jimma, is the fluid level at the top plug?? Is it gear lube, or ATF in the transfer case?
BTW, welcome to the boards, J.

old man jimmy · 11-12-2007, 03:07 AM

Yep, oil level is to the top plug when setting level. Just like rear end. And uses 80 90 gear lub. same as rear end.

Sorry 44, I thought that was his question. Tried to delete it, but it was still their.

**jaros44sr** · 11-12-2007, 06:19 AM

No problem Old man jimmy, takes alittle while to get the hang of it. There's more to this computer thing then I know how to use....I wasn't sure what weight gear lube went in it anyway, so you did post up useful info.

After you submit your reply, go back into edit, I think the delete button is there... then save. J

Chevyman63 · 11-12-2007, 07:12 AM

Sorry I'm no help here, but welcome to the board.
Where in Michigan are you from?

Jimma · 11-14-2007, 09:05 AM

Thanks for the pictures, I will have to look into the trans. God I hope that isn't the problem...I am a student at GMI (Kettering) in Flint, MI and I live in an apartment right now, they don't take to kindly to people working on their trucks.

Chevyman63 · 11-14-2007, 02:09 PM

Cool, I'm only about a 1/2 hour away from there. My cousin's boy goes to Kettering as well.
Good luck with the transfer case. Let me know if you need a place to work on it, I may be able to help.

vtblazer · 11-14-2007, 02:57 PM

Why would there be 203's in your trucks?
Previous owner changed em out from the 205's?

BTW:
ATF is fine to run in a 4spd, can't imagine is wouldn't be fine for a T-case too.

bouncytruck · 11-14-2007, 04:03 PM

Mine was a swap from a 307/3-speed/Dana20 combo.

11-11-2007, 03:33 PM	#1
Jimma Registered User Join Date: Oct 2007 Location: Michigan Posts: 32	Bearings inside a NP 203 I have a NP 203 transfer case in my truck. Recently the case developed a loud noise that sounds like one of the bearings is dry or bad. I replaced the bearing for the front yoke but the noise still developes after driving it for a while. I know that there are bearings up near the Trans and judging by where the fill plug is, it seems that the fluid line is lower then where the bearing is. Does anyone know what could be causing this sound and what I could do to make it go away?

11-11-2007, 04:50 PM	#2
bouncytruck SKINNY TIRES RULE! Join Date: Sep 2001 Location: Bothell, WA Posts: 11,038	Re: Bearings inside a NP 203 I had a similar noise in my truck with an TH350/NP203 combo. It turned out to be one of the clutch bearings inside the TH350 exploded and destroyed most of the internal parts as well as cracking the case. Ya might want to crack open the transmission pan and see if you have any fragments in there before you put it in gear again. Attached Images __________________ bouncytruck 1972 K5 The Hauler 1994 K1500 Suburban The Daily2010 Kia Soul Wife's Ride2014 Fiat 500L

11-11-2007, 05:48 PM	#3
jaros44sr Senior Member Join Date: May 2006 Location: Philadelphia, Pa. 19454 Posts: 9,766	Re: Bearings inside a NP 203 Holy %$^&ing crap, Batman!! What a mess. Looks expensive... Jimma, is the fluid level at the top plug?? Is it gear lube, or ATF in the transfer case? BTW, welcome to the boards, J. __________________ Semper Fi...Uncle Sam, you da man All parts offered to help are free, unless otherwise noted Dont try this stuff in my build thread, unless you have 55 years of mechanical OTJ training SAFETY FIRST AS usual, off topic They say your mind goes second, can't remember the first Jim Last edited by jaros44sr; 11-11-2007 at 05:53 PM.

11-12-2007, 03:07 AM	#4
old man jimmy Registered User Join Date: May 2007 Location: texas Posts: 329	Re: Bearings inside a NP 203 Yep, oil level is to the top plug when setting level. Just like rear end. And uses 80 90 gear lub. same as rear end. Sorry 44, I thought that was his question. Tried to delete it, but it was still their. Last edited by old man jimmy; 11-12-2007 at 03:13 AM.

11-12-2007, 06:19 AM	#5
jaros44sr Senior Member Join Date: May 2006 Location: Philadelphia, Pa. 19454 Posts: 9,766	Re: Bearings inside a NP 203 No problem Old man jimmy, takes alittle while to get the hang of it. There's more to this computer thing then I know how to use....I wasn't sure what weight gear lube went in it anyway, so you did post up useful info. After you submit your reply, go back into edit, I think the delete button is there... then save. J __________________ Semper Fi...Uncle Sam, you da man All parts offered to help are free, unless otherwise noted Dont try this stuff in my build thread, unless you have 55 years of mechanical OTJ training SAFETY FIRST AS usual, off topic They say your mind goes second, can't remember the first Jim Last edited by jaros44sr; 11-12-2007 at 06:19 AM.

11-12-2007, 07:12 AM	#6
Chevyman63 Can't wait to retire!! Join Date: Feb 2003 Location: Corunna, MI Posts: 1,575	Re: Bearings inside a NP 203 Sorry I'm no help here, but welcome to the board. Where in Michigan are you from? __________________ 2009 4x4 Chevy Crew Cab 6.0 1989 4x4 Siverado (270,000 miles) 1972 4x4 Blazer 2007 Chevy Cutaway 1 ton 1970 Corvette (sons project) RIP - CLR 10/11/09

11-14-2007, 09:05 AM	#7
Jimma Registered User Join Date: Oct 2007 Location: Michigan Posts: 32	Re: Bearings inside a NP 203 Thanks for the pictures, I will have to look into the trans. God I hope that isn't the problem...I am a student at GMI (Kettering) in Flint, MI and I live in an apartment right now, they don't take to kindly to people working on their trucks.

11-14-2007, 02:09 PM	#8
Chevyman63 Can't wait to retire!! Join Date: Feb 2003 Location: Corunna, MI Posts: 1,575	Re: Bearings inside a NP 203 Cool, I'm only about a 1/2 hour away from there. My cousin's boy goes to Kettering as well. Good luck with the transfer case. Let me know if you need a place to work on it, I may be able to help. __________________ 2009 4x4 Chevy Crew Cab 6.0 1989 4x4 Siverado (270,000 miles) 1972 4x4 Blazer 2007 Chevy Cutaway 1 ton 1970 Corvette (sons project) RIP - CLR 10/11/09

11-14-2007, 02:57 PM	#9
vtblazer Registered User Join Date: Oct 2003 Location: Central Vermont Posts: 8,537	Re: Bearings inside a NP 203 Why would there be 203's in your trucks? Previous owner changed em out from the 205's? BTW: ATF is fine to run in a 4spd, can't imagine is wouldn't be fine for a T-case too.

11-14-2007, 04:03 PM	#10
bouncytruck SKINNY TIRES RULE! Join Date: Sep 2001 Location: Bothell, WA Posts: 11,038	Re: Bearings inside a NP 203 Mine was a swap from a 307/3-speed/Dana20 combo. __________________ bouncytruck 1972 K5 The Hauler 1994 K1500 Suburban The Daily2010 Kia Soul Wife's Ride2014 Fiat 500L



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