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73-87 Chevy _ GMC Trucks => 4 Wheel Drives => Topic started by: 1976er on April 04, 2012, 09:23:51 AM

Title: NP203--Anyone know what this is?
Post by: 1976er on April 04, 2012, 09:23:51 AM
On a few of the mid-70s pick-ups I have noticed something different.  I recently had to rebuild my 203, the donor TCase, on the extreme right side of the chain case portion there are two external holes for a mount of some sort.  I went to the scrape yard and found this "mount"; it is a rod that bolts to those two holes and then runs up to where the tranny bolts to the engine block and is secured by one of those bolts (tranny to engine block).  Is there a purpose for this "rod" and if so what is it?  I have noticed several other vehicles with the holes for the rod, but it is not installed.  To me, when looking at it installed it does not appear to have any function; seems too light for any kind of support.  Ideas???
Title: Re: NP203--Anyone know what this is?
Post by: snibook7537 on April 04, 2012, 09:47:10 AM
I have seen them too. I kinda thought the same thing, they were too dinky to actually do any kind of support. Id be curious to see if they had a different role or just a dinky support piece.
Title: Re: NP203--Anyone know what this is?
Post by: Captkaos on April 04, 2012, 06:26:17 PM
It provides stability to the transfercase/drivetrain. 
Title: Re: NP203--Anyone know what this is?
Post by: bake74 on April 05, 2012, 06:57:14 AM
It provides stability to the transfercase/drivetrain.

     Not that it is much, but it is for support.
Title: Re: NP203--Anyone know what this is?
Post by: 1976er on April 05, 2012, 10:15:54 PM
Being that I have only saw 1 truck with it installed (scrape yard), I won't worry about installing one.  Thanks
Title: Re: NP203--Anyone know what this is?
Post by: Blazin on April 06, 2012, 06:05:00 AM
I have seen several 208 cases crack over the years, none of them had this rod installed. Have been told by a guy that rebuilds transmission, and transfer cases that this prevents them from cracking. From what I have experienced in my Blazer wheeling with the a 208 I think that if the front suspension compresses all the way, and the front shaft slip yoke bottoms out. It pushed backward on the case, and cracks it. Or in my case with the Blazer broke the right side of the transfer case completely off!!!  :o
As far as a 203 they are cast iron vs the aluminum 208. I would think they would be less prone to cracking.
Title: Re: NP203--Anyone know what this is?
Post by: Engineer on April 07, 2012, 07:07:44 PM
I am running a 550HP big block in my 4x4 sled puller, and I don't have one.