Click here to visit LS1Tech
Click here to visit Performance Trucks
Click here to visit Mod Motor Tech
Click here to visit Modern Hemi

PerformanceTrucks.net Forums  

Go Back   PerformanceTrucks.net Forums > GENERAL MOTORS SPECIFIC FORUMS > GM Engine & Exhaust Performance
Sign in using an external account
Register Forgot Password?
Register Albums FAQ Members Calendar Search Today's Posts Mark Forums Read VendorsUsed CarsGarageStore TSBs & Recalls
Welcome to PerformanceTrucks.net Forums

Reply
 
LinkBack Thread Tools Search this Thread
Old 07-13-2004, 07:53 PM   #1
Trader Rating: 0
TECH Apprentice
 
Join Date: Dec 2003
Posts: 377
Default exploded view of np246 ?

anyone have a manual with an exploded view of a np 246 transfer case ? i've been looking for one but found out i have to order it. i kinda need it now. so any help or links are appreciated. e p.s the reason i need it is my truck won't shift into 4wd all the way, suspect the auto trac thing in there is to blame.
__________________
02 - 1500hd - 4x4

whipple comp - 8.1 marine inj's - nelson tune

rcd - 35's
HAZE is offline   Reply With Quote
Old 07-13-2004, 08:34 PM   #2
Trader Rating: 0
TECH Apprentice
 
Join Date: Dec 2003
Posts: 377
Default

ok, sorry it's a nvg 246, it says right on the tag new process gear. but i guess that's the old name, nvg's site says np8=nvg246 anyway anyone got a picture that shows the clutch packs ? someone sent me an axle picture , have to figure out who that was. thanks e
__________________
02 - 1500hd - 4x4

whipple comp - 8.1 marine inj's - nelson tune

rcd - 35's
HAZE is offline   Reply With Quote
Old 07-14-2004, 08:34 PM   #3
Trader Rating: 0
TECH Apprentice
 
Join Date: Dec 2003
Posts: 377
Default

so i took it back to the shop today, we did basically the same test as last time, racked it, ran it in 4 hi and 4 lo , can't stop the wheel with your hands and it transfers power to the other wheel like it's supposed to, but under real trque loads it won't transfer enough power to turn the wheels. apparently it has a viscous coupler that transfers power gradually when in auto 4wd so it's either a bad sensor or the coupler is shot. everyone i talked to said they've never seen one fail in these trucks, so hopefully it's a sensor malfunction and not the computer or the coupler. hard to believe i could blow it in the sand when alot of guys are doing 4 wheel launches at the strip. e anyway, could still use the photo.
__________________
02 - 1500hd - 4x4

whipple comp - 8.1 marine inj's - nelson tune

rcd - 35's
HAZE is offline   Reply With Quote
Old 07-15-2004, 05:47 AM   #4
Trader Rating: 16
? ? ? ? ? ?
 
BigTex's Avatar
 
Join Date: Nov 2001
Location: East of Dallas
Posts: 7,043
Default

Are youhaving problems with the front wheels? Have you checked the front differential? The autotrac system uses a solenoid to engage the front wheels. The transfer case is put into 4wd and autotrac uses the front solenoid to engage or disengage the front wheels.

Here you go:



In the 4HI mode, the power flow to the rear propshaft (10) is the same as it is in the 2HI mode. To deliver power flow to the front propshaft (13) during the 4HI position, the transfer control module commands the encoder motor (15) to apply the clutch to a calibrated torque. The encoder motor (15) turns the control actuator lever shaft (14). A brake in the encoder motor (15) holds the control actuator lever shaft (14) in the full clutch position. The control actuator lever shaft (14) is cam designed and the cam action moves the clutch lever (4). The clutch lever (4) pivots on the clutch lever pivot studs and moves toward the clutch apply plate, to engage the clutch. As more pressure is applied to the clutch apply plate, the clutch discs are compressed. Using inner clutch discs, which are engaged with the clutch hub (5), and the outer clutch discs, which are engaged with the clutch housing (6), the power flow is delivered to the clutch housing (6). The clutch hub (5) is splined to the rear output shaft (9), and the clutch housing (6) rotates on a needle bearing on the rear output shaft (9). The chain drive sprocket (7) is splined to the clutch housing (6). The power flows from the drive sprocket (7), through the chain (11), to the chain driven sprocket. The driven sprocket is splined to the front output shaft (12). The power flow is delivered to the front propshaft (13) through the front output shaft (12).

During the Auto 4WD mode, the power flow is the same as it is in the 4HI mode. Except, during the Auto 4WD mode, the encoder motor (15) rotates the control actuator shaft lever (14) to the correct torque level positions. Rotating the control actuator (14) to the various positions changes the clutch torque level. When a difference of front propshaft (13) to rear propshaft (10) speed is recognized, the transfer case control modules command for more, or less clutch torque.
__________________
Richard-
2011 Z71 Avalanche
Current projects: 2002 Silverado RCSB, 1967 Chevy C10 LS conversion
Retired: 99 Excab Z71, 2003 Z71 Tahoe, 2003 Silverado SS, 2004 Avalanche, 2008 TBSS
BigTex is offline   Reply With Quote
Old 07-16-2004, 12:12 AM   #5
Trader Rating: 0
TECH Apprentice
 
Join Date: Dec 2003
Posts: 377
Default

thanks big tex, that's just what i needed. i'm not sure what you are getting at with the front axle ? the front axle is engaged with an actuator and is either on or off, it does'nt have anything else to do with the auto trac. from the tutorial there it looks like i either have a bad encoder motor or corresponding sensor or i blew the clutch pack. if the encoder motor is forcing the clutch lever to the full position, then it's more than likely the clutch. if it is not fully engaging the lever than it's either the encoder motor or sensor or just a plain mechanical part failure. i can't thank you enough for the picture and info, this will really help me troubleshoot this p.o.s. e
__________________
02 - 1500hd - 4x4

whipple comp - 8.1 marine inj's - nelson tune

rcd - 35's
HAZE is offline   Reply With Quote
Old 07-17-2004, 12:12 AM   #6
Trader Rating: 12
TECH Fanatic
 
Join Date: Nov 2002
Location: Minneapolis,MN
Posts: 1,976
Default

I have seen many of these with burnt up clutch packs under warranty. Pretty easy fix if its just the clutch packs. You can remove the rear half of the case and its basically right there in your face. There is also a shim that determines the preload on the clutches but usually the stock shim ends up being right. good luck
__________________
71 Nova- L33 5.3, PT76, 4L80E. 9.98 at 139
One-guys-garage
LS1NOVA is offline   Reply With Quote
Old 07-19-2004, 02:53 AM   #7
Trader Rating: 0
TECH Apprentice
 
Join Date: Dec 2003
Posts: 377
Default

nova, is there a fix ? any reason why i would blow a clutch pack spinning tires the sand ? if that's the case why aren't guys burning them at the strip ? i'd like to make it so the clutch is always locked when in 4x [no autotrac] any ideas ? never would have got this pos transfer case if i know it was so wimpy, hd my a$$. e
__________________
02 - 1500hd - 4x4

whipple comp - 8.1 marine inj's - nelson tune

rcd - 35's
HAZE is offline   Reply With Quote
Old 07-19-2004, 08:24 PM   #8
Trader Rating: 12
TECH Fanatic
 
Join Date: Nov 2002
Location: Minneapolis,MN
Posts: 1,976
Default

Not sure on how to keep it from happenening again. I only have experience with rebuilding them at work. Will look into it as I am interested myself.
__________________
71 Nova- L33 5.3, PT76, 4L80E. 9.98 at 139
One-guys-garage
LS1NOVA is offline   Reply With Quote
Old 07-20-2004, 12:01 AM   #9
Trader Rating: 0
TECH Apprentice
 
Join Date: Dec 2003
Posts: 377
Default

nova, the sensor on the side of my encoder motor got a groove worn it it when i shredded my output shaft boot. the dealer says i can only buy the whole assembly for $ 550, any idea where i can get the black shaft position sensor by itself [six prong plug]? i don't know for a fact that it's the only problem but it is the only part that appears to have any damage. thinking the sensor is reporting that it is in full locked position when it fact it's not. let me know if you can help. if not it's off to the junkyards i go. e p.s if you figure anything out on bypassing the auto trac let me know, i never use that anyway.
__________________
02 - 1500hd - 4x4

whipple comp - 8.1 marine inj's - nelson tune

rcd - 35's
HAZE is offline   Reply With Quote
Old 07-20-2004, 10:07 PM   #10
Trader Rating: 12
TECH Fanatic
 
Join Date: Nov 2002
Location: Minneapolis,MN
Posts: 1,976
Default

I can check at work on the price, since I can buy for 10% over cost. I have a used one but it is 3 hrs away at my storage building. I would sell it for $100 shipped.
__________________
71 Nova- L33 5.3, PT76, 4L80E. 9.98 at 139
One-guys-garage
LS1NOVA is offline   Reply With Quote
Old 07-20-2004, 10:07 PM
PerformanceTrucks
Ford F150




Paid Advertisement
Reply

Tags
246, assembly, autotrac, case, clutch, exploded, manual, np, np246, nvg246, pack, solenoide, transfer, valvula, view


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 07:18 AM.

 



Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
SEO by vBSEO ©2010, Crawlability, Inc.

PerformanceTrucks.net and InternetBrands, Inc. are not affiliated with the Ford Motor Company