POL 4 link install tips wanted

[Kevin Mac]

I have been doing some reading and watching videos on intalling a 4 link but would like some do's and don't from someone who has done this. It is a bolt in kit like some others.
This is a compleated 1948 3100 short box truck with stock springs lowered with blocks. I will measure the ride height before I remove the bed and after I remove the bed to see how much it moves. I also will check angle of rearend, measure CL of diff side to side and from back to CL. I am hopeing to get it all done from Friday night to Sunday afternoon. I will have help from my brother and Dad. Do you think it can be done in this time frame? We have good tools and work well together. Here is the kit. I will take pictures and post.
One other question is about how/where to install the panhead bar. I have read to intall it level at ride height, but do most go behind the rearend or on top or does it matter as long as it is level?
Thanks Mac

https://www.performanceonline.com/19...-KIT-COMPLETE/

[Jesse Z]

Looks like an excellent kit.

I have designed, fabricated and installed several rear 4-links. Depending on the vehicle, I've had to mount panhards in different places dictated by the available space and type of differential. You didn't mention what your rear end is, but generally panhards should be as long and straight as possible for better leverage. Also as vertically centered on the differential as possible so they don't put weird torque on the rear end or the mount. And lastly, you are absolutely correct that the most important thing is they should be horizontal at ride height to minimize side-to-side movement inherent with more extreme angles.

[mongocanfly]

do go ahead and do all your measuring..triangulated measurement is best...once you get the axle where you want it and you got ride height where you want with the bed on,tires/wheels on.. then weld some metal from the axle tube to the frame good enough to hold the axle from any movement..needs to be solid and out of the way of your new brackets...then install your kit.....and like you said...keep the panhard bar level

[idbeast]

I'm in the process of doing one in my '56, do you know if you need to c-notch your frame for clearance? My rear end was already flipped on top of my springs so I only had 3 inches of clearance, but it had the rear end in the position I wanted. So I bought the c-notch kit and did it also.

[Kevin Mac]

I don't plan on the c notch. I like where it sits now and looks to have good clearance , but I will measure it. How much should it have, 4"?

[idbeast]

I don't know how much you should have, however 4 to 5 inches should be fine so long as you don't plan to jump curbs! Speed bumps are 3 to 4 inches and if you usually cross them at an angle, you will need that much movement. If you already drive yours then all you need to do is adjust your rear shocks for that height.

[Kevin Mac]

Yes I drive it now but it's pretty stiff that's why I'm changing it. It is a cruiser with the occasional rubber slinger.

[idbeast]

Ok, then measure either top of axel to bottom of frame, or ground to center of rear wheel well marked with a piece of tape, just adjust your rear shocks for that height!

[dsraven]

dont forget to install a nice thick rubber suspension snubber so if/when you bottom out the snubber will take the brunt of it and not your neck/back. I like the urethane ones from the newer style vehicles. mine are from an S10 and are honeycomb shaped. if you look under a newer vehicle you will likely see the snubbers sit pretty close to their impact seats at ride height, like an inch from touching. they get "snubbed" more than we all realize. that is why the shape they have, it makes them progressive so they get harder to compress as they get more weight applied to them.
check google for info on 4 link geometry and how it affects traction, handling etc so you get it right the first time. remember that the link bars are usually adjustable so you can get the diff centered and the pinion angle correct
like said, keep the panhard bar level at ride height
level and block frame at ride height you like
center diff in wheel openings and at the correct pinion angle
tack weld some blocks so the diff stays where you need it
remove all the old stuff
install all the new stuff
remove the tacked in blocks
take pics and post as you go so the experts on here can help steer you right if you get off course a bit. or at least give advice that you can disregard as you see fit, haha

[mr48chev]

It would be nice if they had put in a link to the instruction sheet pfd as that would probably have answered most of your questions.

Panhard bar wants to be as long as possible and as level at static ride height as possible. I've seen issues on some builds where the shorter bar that was mounted at an angle wanted to pull the axle sideways when the springs flexed. If you have ever owned a 58/64 Chevy car you are probably with the tire clearance to fender issue depending on ride height because the bar tends to want to push or pull the axle one way or the other.

[Kevin Mac]

Mr. 48 I have the instructions but sometimes first hand experience is the best. thanks for all the insight.

Mac

[Fiftee3]

Hey Kevin,
Like most "bolt in kits", there is sometimes welding required. From the photo, it
looks like those coil mounts have to be welded to the rear axle. May slow you down a little. Nice looking kit though. Good luck and post finished pics!

[b-mac]

Originally Posted by mongocanfly

do go ahead and do all your measuring..triangulated measurement is best...once you get the axle where you want it and you got ride height where you want with the bed on,tires/wheels on.. then weld some metal from the axle tube to the frame good enough to hold the axle from any movement..needs to be solid and out of the way of your new brackets...then install your kit.....and like you said...keep the panhard bar level

Came here to say this. I've also heard that you can warp the axle tube by welding on it. Leave it full of oil, and move from side to side, leave plenty of time to cool between welds.
I did mine myself, with a universal, triangulated, all weld in kit. And I had to flip the angles of the brackets, since the axle was so narrow. It's not on the road yet, but it cycles up and down, either axle independently, with no binding.

Plenty of guys on this forum have built theirs from scratch too. You may be over complicating it.

[Kevin Mac]

Thanks b-mac, I will jump around on the welding, and I was wondering if I should drain the oil or not. I will bring new to change out when done. Looks like yours turned out nice. I had wanted to build my own but not knowing this and that, I thought I should just buy a kit. I have done a lot of reading and internet searching and have a good handle on it, just thought if I get 1 tip that would help or save time it's worth it. My next project will be hydro boost. I wil have questions on that too, even though I have read and read and read on that also.
I will have to drive north of me an hour Friday night to get to my fathers place, hope it don't rain, no wipers LOL.

Mac

[mongocanfly]

thumbs up on hydroboost...you'll love it...

[tmoble]

if you do the the style with the upper arms running forward at a 45 degree angle you can skip the panhard bar thing altogether. you'll notice there's not one on b-macs truck. If all four bars run parallel to the frame you'll have to have the panhard bar.

[b-mac]

Originally Posted by Kevin Mac

I will have to drive north of me an hour Friday night to get to my fathers place, hope it don't rain, no wipers LOL.

I'm sure you're just joking, but a little RainX can go a long way when you don't have wipers...I know from experience.

[Kevin Mac]

The kit and before pic.

Attachment 1756935

Attachment 1756936Well guys and gals I got the 4 link in by about noon today. Strarted on it Friday night at about 6pm. I went to dad's shop and my brother came over from KC to help. The front mounting bracket did not fit well at all. Had to cut them apart and drill new holes in the frame. Because the frame gets wider as you go towards the back the bracket made the link rods spread also, not run parallel. Keep scrolling for photos.
Kevin

[Jesse Z]

Originally Posted by tmoble

if you do the the style with the upper arms running forward at a 45 degree angle you can skip the panhard bar thing altogether. you'll notice there's not one on b-macs truck. If all four bars run parallel to the frame you'll have to have the panhard bar.

Personal choice, but I've always preferred parallel 4-links; they remain aligned with the frame and out of the way, whereas triangulated configurations run diagonal through an area where you need space for exhaust, etc.

[b-mac]

Link doesn't work for me. Glad you got it in. Good to know about the kit. Seems like it was still plenty of work.

[mongocanfly]

you can post pictures straight to this site.....http://67-72chevytrucks.com/vboard/s...sting+pictures

[Kevin Mac]

[Kevin Mac]

OK it worked, let me get a few lined up.

[Kevin Mac]

The first picture is the tool bench dad had all ready when I got there. He probably fooled around all day getting ready ha ha.
the 2nd and 3rd picture is before teardown.
The 4th picture is the new shock mount in place, you have to cut lower flange to get it to fit. That was called out in the directions.
The 5th picture is tearing apart the springs and getting ready to cut off old spring perch.

[Kevin Mac]

1st pic after cutting off front spring bracket
2nd pic, this is where the problems started, the holes on the bottom lined up but, as you can see, the side holes are not close. We drilled through the frame and bolted them on. Then we installed the link bars and they were not parallel with each other. The problem is the frame gets wider as you go toward the back and the bracket was on that angle. So the bars were on an angle also. You would have to pull hard to try and get them parallel. After making a bar to try and bend the bracket we decided that was not going to work so we cut the bracket, slotted the bottom holes so we could twist the bracket and then bolted the side plate back on and tacked it place.
3rd pic is cutting bracket apart
4th pic is slotting the holes
5th pic back on frame in 2 pieces

I hope you all like pictures now that I have this figured out thanks to friendly fourm members, I know I do.












Mac