NP205, no 4lo - The 1947 - Present Chevrolet & GMC Truck Message Board Network

shelby987 · 04-20-2007, 03:57 PM

My 70 K20 will not go into and stay in 4lo......if I force the shifter forward, and hold it there as I let out the clutch and creep really slow, it will move, but as soon as I let go of the handle, it springs out of 4lo and gives me a grinding noise as the truck comes to a stop......am I looking at a rebuild or an adjustment to the linkage?

Blazer1970 · 04-20-2007, 04:53 PM

There is probably something jammed in between the shift rails that is keeping them from going all the way back. 4 lo is both rails pushed all the way back into the case. Get under there and look. A good coating of hard mud will cause what you are seeing.

Burt4x4 · 04-20-2007, 06:00 PM

One thig is extra slop in the linkage can doit too. I used a big washer and ground one side so it would fit to fill the gap from the ware-n-tear over the years to remove the slop.
Good Luck

**special-K** · 04-21-2007, 10:44 AM

I`m thinking it`s in the linkage,too.

shelby987 · 04-23-2007, 11:17 AM

is this transfer case truely bullet-proof enough that you are all confident that I am just looking at a simple linkage problem, or is a potential rebuild in my future worst case scenario?
To look at my truck, I really don't think it spent all that much time doing any real tough 4x4 use (no lift, small tires, stock 250 when i bought it).

1969K10 · 04-23-2007, 11:34 AM

when I got mine (different X-fer), the PO had put it back together and "forgot" to tighten everything up. You'd be amazed at how much that helped the shifting...

**special-K** · 04-23-2007, 10:34 PM

Yes,bulletproof.Trans guys say they only see them for leaking,like the 4spd trannies.

eedgell · 04-23-2007, 11:45 PM

yes, bullet proof, and every one that I have been around is a bit hard to go into 4L. linkage, wear and mud are usually the culprit. Rarely the case its self. I have one in a 79 3/4 ton, 400,000 mi plus and still strong!

eedgell

snj8198 · 04-23-2007, 11:58 PM

Quote:

Originally Posted by eedgell

yes, bullet proof, and every one that I have been around is a bit hard to go into 4L. linkage, wear and mud are usually the culprit. Rarely the case its self. I have one in a 79 3/4 ton, 400,000 mi plus and still strong!

eedgell

I agree.

Wreckless_71 · 04-24-2007, 12:58 AM

Even If it is a rebuild it isn't hard to do. Factory rebuild and overhaul manuals help a lot!

1969 GMC · 04-24-2007, 03:38 AM

I don't know about bullet proof (has anyone ever tested that statment?

)
I've seen them go poof before. But it took over 500 hp, and some 44" boggers, on some not-so-friendly sandstone.

shelby987 · 04-24-2007, 08:25 AM

great to hear, I will check the linkage next time I get a chance.....big load off my mind!

04-20-2007, 03:57 PM	#1
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	NP205, no 4lo My 70 K20 will not go into and stay in 4lo......if I force the shifter forward, and hold it there as I let out the clutch and creep really slow, it will move, but as soon as I let go of the handle, it springs out of 4lo and gives me a grinding noise as the truck comes to a stop......am I looking at a rebuild or an adjustment to the linkage? __________________ 1969 SS 350 Camaro Sold 2008 1970 3/4T K20, stock height with 33's, 250 I6, 3 on the tree, and locked front and rear 4.10's 1980 Chevy Malibu 2 dr Sold 2007 1993 Olds. Cutlass Ciera Wagon Traded 2006 2003 Saturn L200 w/5pd. D/D My list spans 5 decades with One common thread.....GM!

04-20-2007, 04:53 PM	#2
Blazer1970 Registered User Join Date: Dec 1999 Location: Old Mission, MI, USA Posts: 2,507	Re: NP205, no 4lo There is probably something jammed in between the shift rails that is keeping them from going all the way back. 4 lo is both rails pushed all the way back into the case. Get under there and look. A good coating of hard mud will cause what you are seeing. __________________ Tim

04-20-2007, 06:00 PM	#3
Burt4x4 Registered User Join Date: Feb 2000 Location: Modesto, CA Posts: 1,842	Re: NP205, no 4lo One thig is extra slop in the linkage can doit too. I used a big washer and ground one side so it would fit to fill the gap from the ware-n-tear over the years to remove the slop. Good Luck __________________ 1972 K5 MPFI454/Sm465/Np205/D60/14FFd/Re-Centerd H1s w/Swamper Iroks

04-21-2007, 10:44 AM	#4
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,851	Re: NP205, no 4lo I`m thinking it`s in the linkage,too. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

04-23-2007, 11:17 AM	#5
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	Re: NP205, no 4lo is this transfer case truely bullet-proof enough that you are all confident that I am just looking at a simple linkage problem, or is a potential rebuild in my future worst case scenario? To look at my truck, I really don't think it spent all that much time doing any real tough 4x4 use (no lift, small tires, stock 250 when i bought it). __________________ 1969 SS 350 Camaro Sold 2008 1970 3/4T K20, stock height with 33's, 250 I6, 3 on the tree, and locked front and rear 4.10's 1980 Chevy Malibu 2 dr Sold 2007 1993 Olds. Cutlass Ciera Wagon Traded 2006 2003 Saturn L200 w/5pd. D/D My list spans 5 decades with One common thread.....GM!

04-23-2007, 11:34 AM	#6
1969K10 Senior Member Join Date: Jul 2004 Location: Clarks Hill, Indiana Posts: 733	Re: NP205, no 4lo when I got mine (different X-fer), the PO had put it back together and "forgot" to tighten everything up. You'd be amazed at how much that helped the shifting... __________________ 1969 K10 - V8, 465, 205, 12 bolt, D44 2002-current 1969 K20 - V8, 465, 221, Eaton, D44 2012-current Nothin' but drums on all 4 corners! past horses in the stable 72 C10-short step (97-02), 68 C10-long fleet (06-12)

04-23-2007, 10:34 PM	#7
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,851	Re: NP205, no 4lo Yes,bulletproof.Trans guys say they only see them for leaking,like the 4spd trannies. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

04-23-2007, 11:45 PM	#8
eedgell It's the air up here Join Date: Mar 2007 Location: Western Colorado Posts: 710	Re: NP205, no 4lo yes, bullet proof, and every one that I have been around is a bit hard to go into 4L. linkage, wear and mud are usually the culprit. Rarely the case its self. I have one in a 79 3/4 ton, 400,000 mi plus and still strong! eedgell Last edited by eedgell; 04-23-2007 at 11:45 PM.

04-24-2007, 12:58 AM	#10
Wreckless_71 Registered User Join Date: Apr 2007 Location: Kelso, WA Posts: 363	Re: NP205, no 4lo Even If it is a rebuild it isn't hard to do. Factory rebuild and overhaul manuals help a lot! __________________ 1972 K10 4" lift, 35’s, 383 stroker, 700r4, current project. 1971 C10 3"/5" static drop, 355/350. "La Bamba.” The current daily driver.

04-24-2007, 03:38 AM	#11
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	Re: NP205, no 4lo I don't know about bullet proof (has anyone ever tested that statment? ) I've seen them go poof before. But it took over 500 hp, and some 44" boggers, on some not-so-friendly sandstone. __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

04-24-2007, 08:25 AM	#12
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	Re: NP205, no 4lo great to hear, I will check the linkage next time I get a chance.....big load off my mind! __________________ 1969 SS 350 Camaro Sold 2008 1970 3/4T K20, stock height with 33's, 250 I6, 3 on the tree, and locked front and rear 4.10's 1980 Chevy Malibu 2 dr Sold 2007 1993 Olds. Cutlass Ciera Wagon Traded 2006 2003 Saturn L200 w/5pd. D/D My list spans 5 decades with One common thread.....GM!



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