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73-87 Chevy _ GMC Trucks => 4 Wheel Drives => Transfer Cases and Front Drivelines => Topic started by: Laderhosen on August 02, 2011, 05:56:13 pm

Title: Which bolts for NP205 front driveshaft
Post by: Laderhosen on August 02, 2011, 05:56:13 pm
I have this kind of front driveshaft mounting surface...

(http://tapatalk.com/mu/560b6b10-7ee5-e429.jpg)

I need to mount it to my transfer case, NP205, in an '87 K5.

Anybody know what size bolts I need?? I don't have the old ones.

Thanks...
Title: Re: Which bolts for NP205 front driveshaft
Post by: beastie_3 on August 02, 2011, 06:08:47 pm
9/16 or 5/8 i think, dont remember. pretty sure the bolts take a 3/4 socket.
Title: Re: Which bolts for NP205 front driveshaft
Post by: Laderhosen on August 02, 2011, 07:26:10 pm
9/16 or 5/8 i think, dont remember. pretty sure the bolts take a 3/4 socket.
Thanks, don't suppose you know how long???
I guess it doesn't matter too much.
Title: Re: Which bolts for NP205 front driveshaft
Post by: Irish_Alley on August 02, 2011, 09:30:43 pm
think i only used 1"
Title: Re: Which bolts for NP205 front driveshaft
Post by: beastie_3 on August 03, 2011, 03:23:17 pm
Ya, I think 1" or 1 1/4. I used washers and lock washers as well. Its ok if they are a little long, they wont be hitting anything.
Title: Re: Which bolts for NP205 front driveshaft
Post by: beastie_3 on August 03, 2011, 03:23:48 pm
Double the thickness of the driveshaft flange to figure out how long you need.
Title: Re: Which bolts for NP205 front driveshaft
Post by: Blazin on August 03, 2011, 07:43:27 pm
Length should be the same as the thickness of the two flanges, and enough room for a lock washer. If they stick out a shade thats okay, but no need to have them stick way out.
A bolt only needs to thread into a hole the diameter of said bolt to hold, any longer is a waste.
Bolt head size is 5/8" thread size is 7/16"
Title: Re: Which bolts for NP205 front driveshaft
Post by: Irish_Alley on August 03, 2011, 08:38:59 pm
lock-tight that also. ive had bolts on the yoke flange with lock washers back out then next thing you know snap
Title: Re: Re: Which bolts for NP205 front driveshaft
Post by: Laderhosen on August 04, 2011, 04:52:23 pm
Thanks a lot. Gonna get some tomorrow hopefully. My fitting kit for the other end of the shaft arrived in the post today.

Blazin... I know the length over the two flanges would be a waste, was only asking as I didn't want to get bolts too long in case they'd either
A.) conflict with something on the transfer case (though having inspected it, it didn't look like they would unless they were ridiculously long!!)
B.) upset the balance of the drive shaft. Though thinking about it this is also quite unlikely.
Title: Re: Which bolts for NP205 front driveshaft
Post by: beastie_3 on August 04, 2011, 05:26:50 pm
My bolts extend past the flange, only because I didnt know what length to get when my truck was on the side of the road. You wouldnt be driving fast enough in 4x4 to have a balance issue unless you have a stock 203, which you dont.
Title: Re: Which bolts for NP205 front driveshaft
Post by: Laderhosen on August 04, 2011, 06:02:49 pm
Thanks Beastie
Title: Re: Re: Which bolts for NP205 front driveshaft
Post by: Laderhosen on August 05, 2011, 12:45:03 pm
Dont suppose anybody knows what thread type. Have tried UNF 7/16 and it won't go in.
Title: Re: Which bolts for NP205 front driveshaft
Post by: Irish_Alley on August 05, 2011, 12:55:11 pm
Did you try all the holes
Title: Re: Which bolts for NP205 front driveshaft
Post by: Laderhosen on August 05, 2011, 01:51:30 pm
Did you try all the holes

Yeah it just ate the thread on the bolt!!! The one on the left is intact, the one on the right is the one I tried:

(http://tapatalk.com/mu/560b6b10-3b85-0f82.jpg)
Title: Re: Which bolts for NP205 front driveshaft
Post by: 1979C20 on August 05, 2011, 02:25:25 pm
Try 7/16s x 16 however long. Most stuff on our trucks is 16 thread. The only thing I have dealt with that is not course thread is the bolts on the back of the ac compressor which holds the lines on. To test if its right or not, pull a bolt out of your alternator bracket, the lart that bolts vertically into the front of the intake will work. Thread it into the hole without the drive shaft in place to see if its the right thread spacing and if it is go buy them in the proper length.
Title: Re: Which bolts for NP205 front driveshaft
Post by: Blazin on August 06, 2011, 07:51:50 am
16 should be the thread count. If the shaft has been out for any amount of time I would run a tap through the holes first.
Title: Re: Re: Which bolts for NP205 front driveshaft
Post by: Laderhosen on August 07, 2011, 05:19:02 pm
Found em. They're UNC (Unified Coarse), the ones I had were UNF (Unified Fine). Anyway all sorted now so thanks for the advise. Got the driveshaft on.

Next question!!!!...
Is there any way of telling if my locking hubs are engaging???
Title: Re: Which bolts for NP205 front driveshaft
Post by: Irish_Alley on August 07, 2011, 06:23:03 pm
if both are lock your front shaft will be locked with the transfer case in neutral
Title: Re: Re: Re: Which bolts for NP205 front driveshaft
Post by: Laderhosen on August 07, 2011, 08:38:15 pm
if both are lock your front shaft will be locked with the transfer case in neutral

So would I be able to tell by putting it in 4 HI, then put the transfer case in neutral, jack the front axle and try to rotate one of the wheels by hand. If it doesn't budge the hubs are locked???
Title: Re: Which bolts for NP205 front driveshaft
Post by: 1979C20 on August 07, 2011, 09:07:27 pm
Put your transfer case in neutral, lock the hubs, jack the front end up and turn the wheel. If the drive shaft turns then they are locked. Make sure the truck is not going to roll, too.
Title: Re: Which bolts for NP205 front driveshaft
Post by: Blazin on August 07, 2011, 09:37:33 pm
Or you can jack each wheel up separately. Lock the hub rotate the wheel. If the axles turns its engaged. Unlock the wheel should roll without turning the axle. Transfer case does not need to be in neutral.
Title: Re: Which bolts for NP205 front driveshaft
Post by: Irish_Alley on August 08, 2011, 05:44:31 am
for my way it does or in 4x2 and you dont have to jack it up
Title: Re: Which bolts for NP205 front driveshaft
Post by: thirsty on August 08, 2011, 10:16:43 am
If they are manual locking hubs just lock one and reach around the tire and try to rotate the axle.
Title: Re: Which bolts for NP205 front driveshaft
Post by: Laderhosen on August 08, 2011, 12:54:23 pm
How does the actual locking hub engage??
Title: Re: Which bolts for NP205 front driveshaft
Post by: Irish_Alley on August 08, 2011, 03:50:41 pm
the lock pushes a sleeve with spines on both sides inward and that in turn locks the wheel hub to the axle shaft. its more simple than most would think
(http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/04/c6/c5/large/0900c1528004c6c5.gif) thanks ej
it pretty much pushes 11 into 12
Title: Re: Which bolts for NP205 front driveshaft
Post by: beastie_3 on August 08, 2011, 06:23:05 pm
11 and 12 mesh together when locked, and 13 pushes 11 out when unlocked. 11 grabs the axle shaft, 12 grabs the hub.
Title: Re: Which bolts for NP205 front driveshaft
Post by: Blazin on August 08, 2011, 11:00:45 pm
Thirsty's way works too, but have had them have a bad spot in the hub. They could be locked in that postion, but partly, or completely disengaged in others.
Title: Re: Re: Which bolts for NP205 front driveshaft
Post by: Laderhosen on August 10, 2011, 05:55:08 pm
the lock pushes a sleeve with spines on both sides inward and that in turn locks the wheel hub to the axle shaft. its more simple than most would think
(http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/04/c6/c5/large/0900c1528004c6c5.gif) thanks ej
it pretty much pushes 11 into 12

Thanks, so presumably when the drive shaft rotates, by 4wd being engaged, it locks the hub.
Title: Re: Which bolts for NP205 front driveshaft
Post by: beastie_3 on August 10, 2011, 05:59:18 pm
its gets locked when you turn the dial. when you turn the dial, it pushes #12 in, which meshes with #11. #13 spring pushes #12 out when the hubs are unlocked. #11 is stationary.
Title: Re: Which bolts for NP205 front driveshaft
Post by: Laderhosen on August 10, 2011, 10:47:02 pm
its gets locked when you turn the dial. when you turn the dial, it pushes #12 in, which meshes with #11. #13 spring pushes #12 out when the hubs are unlocked. #11 is stationary.

Mine are auto locking hubs though??
Title: Re: Which bolts for NP205 front driveshaft
Post by: Irish_Alley on August 10, 2011, 11:46:28 pm
lol well thats a different ball park then. i have no ideal how they work. never used them had them on my buds blazer removed them because you just didnt know if they worked till you got in the mud. but it has to do with the axle shafts turning and that will engage the auto hubs. if it was mine i would ditch them, the way i see it since they arnt locked solid and if you have one wheel thats spinning and it catches it will put all that power to the free hub and it should slam it and lock it, but with that force i dont think it will last for long
Title: Re: Re: Which bolts for NP205 front driveshaft
Post by: Laderhosen on August 11, 2011, 01:50:02 am
lol well thats a different ball park then. i have no ideal how they work. never used them had them on my buds blazer removed them because you just didnt know if they worked till you got in the mud. but it has to do with the axle shafts turning and that will engage the auto hubs. if it was mine i would ditch them, the way i see it since they arnt locked solid and if you have one wheel thats spinning and it catches it will put all that power to the free hub and it should slam it and lock it, but with that force i dont think it will last for long

Yeah precisely what I've been thinking. Been looking at Warn locking hubs. Any recommendations???
Title: Re: Which bolts for NP205 front driveshaft
Post by: beastie_3 on August 11, 2011, 11:29:40 am
Warn premium hubs. they are stronger than their other ones. Its what I have on mine.

Dunno about auto hubs.
Title: Re: Which bolts for NP205 front driveshaft
Post by: Irish_Alley on August 11, 2011, 02:13:10 pm
I have only broke one manual but it seams every time something breaks now its the axle shafts. From what I know and understand I would much rather break a hub before a shaft I just buy the cheapest warn manual hubs I can find
Title: Which bolts for NP205 front driveshaft
Post by: Senck243 on November 01, 2012, 07:30:11 pm
Bringing this back guys. Need the bolts that hold the front drive shaft in the yoke of the axle... Any ideas?


Sent from heck
Title: Re: Which bolts for NP205 front driveshaft
Post by: pholliday1 on November 19, 2012, 10:12:14 am
7/16 course thread getem tight, if thats not the treads for your application then somebodys changed it
Title: Re: Which bolts for NP205 front driveshaft
Post by: pholliday1 on November 19, 2012, 10:13:59 am
sorry i gave transfer case end not pinion flange end i just relized my error