Which bolts for NP205 front driveshaft

[Laderhosen]

I have this kind of front driveshaft mounting surface...



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...

[beastie_3]

9/16 or 5/8 i think, dont remember. pretty sure the bolts take a 3/4 socket.

[Laderhosen]

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.

[Irish_Alley]

think i only used 1"

[beastie_3]

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.

[beastie_3]

Double the thickness of the driveshaft flange to figure out how long you need.

[Blazin]

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"

[Irish_Alley]

lock-tight that also. ive had bolts on the yoke flange with lock washers back out then next thing you know snap

[Laderhosen]

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.

[beastie_3]

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.

[Laderhosen]

Thanks Beastie

[Laderhosen]

Dont suppose anybody knows what thread type. Have tried UNF 7/16 and it won't go in.

[Irish_Alley]

Did you try all the holes

[Laderhosen]

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:

[1979C20]

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.