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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Jon87V20 on February 26, 2017, 04:20:28 pm

Title: Transmission Crossmember Diagram?
Post by: Jon87V20 on February 26, 2017, 04:20:28 pm
Hi, Everyone:

I'm in the process of putting my truck back together after a transmission swap. Now I usually thread bolts back into their spots after removing things so I don't lose them, and I know where they go. When I removed the transmission crossmember, I threaded a couple of the mounting bolts back in, but I thought I might have lost a few washers, but I'm not sure if I'm imagining that or not. I've been pulling my hair out trying to find an exploded view of the crossmember or something to help me figure out how the bolts go back in. If I remember correctly, doesn't the capscrew head go on the bottom side of the crossmember with a washer up against the head, then it goes through the crossmember, through the collar, then through the frame rail and then the nut after going through the frame? Or is there supposed to be a washer before the nut on the frame side as well?

Thanks!
Title: Re: Transmission Crossmember Diagram?
Post by: Jon87V20 on February 26, 2017, 04:52:37 pm
So I was able to gather from a video I found that the bolt head goes on the top side of everything, but I'm still not sure what is going on washer wise.
Title: Re: Transmission Crossmember Diagram?
Post by: dphipps on February 26, 2017, 05:23:53 pm
Generally, washers always go under the nut.
Title: Re: Transmission Crossmember Diagram?
Post by: Jon87V20 on February 26, 2017, 06:50:45 pm
Ok thanks. I think I have it figured out except I don't know if I need washers on both ends of them.

Does anyone have a diagram of this area?

Anyone with a K/V truck have a picture I can look at, or possibly take one for me? I'd really appreciate it.
Title: Re: Transmission Crossmember Diagram?
Post by: 1967KaiserM715 on February 26, 2017, 07:19:40 pm
 If it's a flanged bolt and nut, I don't worry about washers, I'll add a SAE washer to either side that is not flanged. SAE washers tend to fit tighter then standard washers.

Unless your going for concourse quality and awards, I wouldn't worry all that much about it. Just check the tightness after 50 or so miles and again after another 100 or so miles.


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Title: Re: Transmission Crossmember Diagram?
Post by: Jon87V20 on March 12, 2017, 12:35:52 pm
So here's what I'm worried about still. I'm not sure if I should be using these spacers or not in the crossmember. I don't remember for sure, but I thought when I took it apart, it was set up like this, with the spacers just on the bottom not actually spacing anything.

It just doesn't make sense that they would put these in here if they didn't serve a purpose right?

Should I be running these in between the crossmember and the frame? I can't find any diagrams or pictures of other trucks on Google where I can see this part of the truck. I'm just worried that something could get damaged if the angles are off etc.

Thanks!
Title: Re: Transmission Crossmember Diagram?
Post by: 1967KaiserM715 on March 12, 2017, 03:20:03 pm
Is the truck lifted? If not, it just may be that during its life course, some one lost the right length bolts and replaced with longer ones and a spacer.


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Title: Re: Transmission Crossmember Diagram?
Post by: bd on March 12, 2017, 03:45:39 pm
The spacers are OEM K frame parts (GM P/N 343179).  They are correctly installed in the image.  Flat washers fit under the bolt heads on the top side of the framerail flange.
Title: Re: Transmission Crossmember Diagram?
Post by: Jon87V20 on March 12, 2017, 06:45:29 pm
Thanks, bd. Why are they there if they aren't actively spacing something? Seems like an unnecessary expense for GM, right?
Title: Re: Transmission Crossmember Diagram?
Post by: bd on March 12, 2017, 07:10:47 pm
It decreases rigidity of the cross member attachment to allow for frame flex and prevent cracking and tear out.
Title: Re: Transmission Crossmember Diagram?
Post by: 1967KaiserM715 on March 13, 2017, 06:31:58 am
It decreases rigidity of the cross member attachment to allow for frame flex and prevent cracking and tear out.
That's good to know, think I'll put some spacers on mine now.


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Title: Re: Transmission Crossmember Diagram?
Post by: gunrac on March 13, 2017, 09:26:52 am
It decreases rigidity of the cross member attachment to allow for frame flex and prevent cracking and tear out.
That's good to know, think I'll put some spacers on mine now.


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I wondered also after having to make room to drop trans. pan. I knew my cross member had not been touched before....thx for info