Please help with Porterbuilt Mild Dropmember notch placement.

[Artikgrau325is]

Hello everyone, I was hoping I could get a more specific answer as to where the notch is supposed to sit on the frame. It is a longbed fleetside and I have the complete Porterbuilt Mild rear dropmember.

The instructions say that the center of the wheel well is 26.5" from the third bed mounting hole from the cab. Simple enough, I got out the tape measure and marked accordingly.

I understand that the center line of the dropmember notch is supposed to be in line with the wheel well center line. This is where I run into some issues and want to ask those with experience before I go crazy with the sawzall.

Where do I find the notch center line? I could measure the top of the cap (something like 9 inches), the valley of the cap where it rises from the frame, or the entire notch assembly end to end (38 inches or so). Obviously, this gives me 3 different numbers, and the instructions weren't too clear on it, at least not to a first time truck builder as myself.

I could bring the notch more towards the rear of the truck to get the "center" to match with my 26.5" mark I made earlier...but then I noticed something else, the notch sits almost perfectly where it currently is, the bottom contour of the notch fits awesome with the bottom contour of the frame. In any case, I'm about 1.5" to 2" off of that centerline, so I really need to find some other way to do this.

I even went as far as mocking up the trailing arm crossmember and dragging the rear end out of the storage to see if it would help. Here's some photos:

NCL = the middle of the top of the notch cap. I'm not sure if this was the correct place to get that measurement.

26.5" CL = Center line from third bed mounting hole from cab. This line is about 2" short of the NCL line above.

Black half circle = where the rear end hits the frame.



As the notch sits now, it flows with the countours of the frame REALLY nicely. I don't think it would do this is I were to move the notch forwards or backwards. I still have to trim down the bottom of the frame rail to get it to sit flush though.





Excuse the mess, it has been cleaned up since then. NO MORE RIVETS YESSSSS!!!!




So to sum things up:

My notch center line (if I measured it correctly) sits 2 inches forward of the wheel well centerline I marked on the frame. If I need to bring it back, then so be it, but I wanted to be double sure on it. I already contacted Nate from Porterbuilt and got an automated text, so I figured it would be easier to ask here as well.

If anyone has any tips to help me correctly place this notch, I would GREATLY appreciate it. Thanks in advance,

-Mike.

[2002yanks]

i just installed my extreme rear. i used the bump stop hole on the bottom side of the notch to locate it. i measured that hole and it was dead center of the notch. i lined that up with the mark 26.5 from the mount. ended up perfect.

[Artikgrau325is]

If the frame was originally a leaf spring truck, would it have that bump stop hole? I don't recall seeing it when I was disassembling everything. =/

Or did you mean that the hole is on the bottom of the notch itself? Thanks for the quick response too bud.
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[vegadesign]

iv always centered it at the center of the bump stop bracket

[PBFAB.COM]

I just returned from vacation.... so here we go!

The 26.5" measurement will put the center of the notch in the center of the wheel well opening... we do that so when the suspension is deflated, the axle lands on the bumpstop in the center of the notch.... landing in the center of the wheel well opening.

If you are measuring from the center of the bolt hole of the second bed mount from the cab (the flat one that sits close to the top of the frame) then you are good to go.

I do recognize that the notch seems to fit better a little further forward on your chassis.... this could be due to some of the manufacturing descrepencies and tolerances that vary from truck to truck. Don't let that concern you, as you will see that the notch will snug up to the chassis nicely as you install it.

Feel free to ask us any and all questions that arise as you continue your installation. Also, don't hesitate to send me a text if necessary. I may not be available at some times throughout the day, as I also do a lot of the welding here. You could also call or text the shop 480-297-2621 and will likely get a quicker response.

Nate

[PBFAB.COM]

I just noticed that you are measuring from the THIRD bedmount.... this is correct if you have a Long Wheel Base chassis. I said "SECOND"... but that is for the Short Wheel Base.

Nate

[Artikgrau325is]

Yup, it's a lwb. Where do I measure the center of the notch itself to match up with the frame measurement though? As mentioned before there's 3 points I can measure which give me 3 different measurements.
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[PBFAB.COM]

Originally Posted by Artikgrau325is

Yup, it's a lwb. Where do I measure the center of the notch itself to match up with the frame measurement though? As mentioned before there's 3 points I can measure which give me 3 different measurements.
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Use the hole in the bottom plate where the bumpstop goes for your centerline measurement.

Nate

[Artikgrau325is]

Originally Posted by Porterbuilt Street Rods

Use the hole in the bottom plate where the bumpstop goes for your centerline measurement.

Nate

Heck yeah! I didn't know about that one, I skimmed through the instructions and didn't see anything about bumpstops, must have missed it. This sounds like a real good reference to use. Thank you and everyone else who helped me out here, I'll keep you guys updated.
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[2002yanks]

Originally Posted by Porterbuilt Street Rods

Use the hole in the bottom plate where the bumpstop goes for your centerline measurement.

Nate

That's the one I was talking about.
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[Artikgrau325is]

Originally Posted by 2002yanks

That's the one I was talking about.
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I totally didn't even look underneath the notch, so I never noticed the hole, nor knew what it was. Found it after you guys mentioned it, and now I really feel dumb.

Thanks SO much guys, this helped tremendously. Fortunately I asked first before I started cutting things up and wondering why I was having problems. A new frame isn't something I can get at the local Ace Hardware, afterall.

[2002yanks]

dont feel dumb. glad you asked. thats what this forum is for.

[Artikgrau325is]

Originally Posted by 2002yanks

dont feel dumb. glad you asked. thats what this forum is for.

Yessir, helpful folks abound.

Also the update, as promised.


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