Problems with Porterbuilt rear shock mount lining up

[fastpace]

I've already sent these pictures to Travis at Pro Performance and he's talked with the guys at Porterbuilt and we're planning on mailing the lower shock mount back to Porterbuilt tomorrow to have them double check it in the jig. I just want to check and see if maybe someone on here recognizes maybe an issue somewhere else.

When going to install the rear shocks the angles of the top and lower shock mounts.


Right now the trailing arms are in the hole second from the bottom with the heims all the way in. The rear end is pretty well centered in the notch and the pinion is tilted up just a little from horizontal, visually it looks to be about the right angle and we're estimating our ride height. Here's a couple other pictures of the install:





Everything else has seemed to line up pretty good so far except for this one piece. Any suggestions?

[sduckworth13]

Here is link with a ton of pictures to compare your setup to.
http://67-72chevytrucks.com/vboard/s...d.php?t=406186

[fastpace]

Originally Posted by sduckworth13

Here is link with a ton of pictures to compare your setup to.
http://67-72chevytrucks.com/vboard/s...d.php?t=406186

Thanks that's a great link and after staring at all the pics for about 15 minutes I still can't figure it out.

[mac808]

Not sure if its just the angle of the camera but your axle looks a tad closer to the front of the truck than towards the back and not exactly centered in the notch.

Looks ok in the last pic though.

[fastpace]

Originally Posted by PGSigns

Not sure if this will help but here is what I noticed from the two sets of pictures. Yours does not have the bracket under the shock upper cross member that the one in the other pictures has. This may roll the bracket back and into a little better alignment. Also the other pics are of the system fully aired out and that will improve your angles also. If the design was done with the trailing arms in a lower hole the would more than likely line up just fine. All other positions will be a little off. If you plot the travel with the shock bolts facing forward and back you will find they are only parallel at one position. It's a little hard on the shock bushings but that is the price we pay for having a lot of options on ride height with an air ride system. I think if you ran it with the trailing arms in the lower holes for a low instant center with power plant you have the shock angles will be better and I think you will like the way the truck drives.
Jimmy

Yeah it's only going to line up perfectly in 1 spot, but you want that spot to be near your ride height. It's fine if the shocks are a little off when it's laid out because it's in a static position. Also if I put the trailing arms in the lowest hole then my pinion angle will be too low and the rearend will be sitting too far back.

Originally Posted by mac808

Not sure if its just the angle of the camera but your axle looks a tad closer to the front of the truck than towards the back and not exactly centered in the notch.

Looks ok in the last pic though.

When the rear is move up into the notch it sits pretty close to the center of the notch, if anything it sits a little back on the notch.

[mac808]

Maybe back off the threads on the trailing arm at the cross member to 'extend' the length of the arms so the axle can be centered...?

[PGSigns]

Not sure if this will help but here is what I noticed from the two sets of pictures. Yours does not have the bracket under the shock upper cross member that the one in the other pictures has. This may roll the bracket back and into a little better alignment. Also the other pics are of the system fully aired out and that will improve your angles also. If the design was done with the trailing arms in a lower hole the would more than likely line up just fine. All other positions will be a little off. If you plot the travel with the shock bolts facing forward and back you will find they are only parallel at one position. It's a little hard on the shock bushings but that is the price we pay for having a lot of options on ride height with an air ride system. I think if you ran it with the trailing arms in the lower holes for a low instant center with power plant you have the shock angles will be better and I think you will like the way the truck drives.
Jimmy

[PBFAB.COM]

Fastpace-

I didn't notice anything else that stands out as being a concern.

Do me a favor and simulate ride height to compare the tabs. It does look to be off a little more than desired in the pics.

I just want to compare it to the fixture that locates the tabs before we send another one out to ya. I apologize for the delay/inconvenience I just don't want to send you an identical bar if it isn't lining up on your set-up to begin with. By having it in hand we can make sure you get one that will work better than what you have.

Nate

[fastpace]

Originally Posted by Porterbuilt Street Rods

Fastpace-

I didn't notice anything else that stands out as being a concern.

Do me a favor and simulate ride height to compare the tabs. It does look to be off a little more than desired in the pics.

I just want to compare it to the fixture that locates the tabs before we send another one out to ya. I apologize for the delay/inconvenience I just don't want to send you an identical bar if it isn't lining up on your set-up to begin with. By having it in hand we can make sure you get one that will work better than what you have.

Nate

Nate,

I think that picture should be close to ride height. That's basically the height of the bag as it naturally sits with no pressure and no weight on it and the axle tube sits probably 2 inches below the point that would be the bottom of the factory frame rail. I'll be honest I'm not really sure where ride height should be but by looking at and estimating from other peoples pictures I would think we're pretty close. Also, we're mounting the bag directly to the frame rail/notch so there's no cup or additional plate.

The lower mount is boxed up and Travis just sent me the shipping label so we'll probably get it sent out tomorrow. Thanks to both you and Travis for the customer service, both me and the shop doing the install were very happy with the fitment of everything.

Jared

[PGSigns]

The pinion is easily shimmed and if you lower the front it will bring the rear ever so slightly forward. You are going to want to match the pinion angle up once the engine is fully bolted in place.
Jimmy

[aggie91]

One thing I noticed in comparing the pictures, yours does not have the stud for the upper shock mount in place. that stud spaces the shock away from the mount about 1/2" rearward on the top. Its hard to tell in the pictures but does the lower use a stud mount too? If so, that would space the shock about 1/2" forward on the bottom too.

If those are installed, how well does the shock line up at ride height?

[PBFAB.COM]

This missing brackets in question for the upper shock bar should not change its angle.

[aggie91]

I was thinking the angle of the shock was the problem, not the angle of the stud mount. I see that in the picture now....