BioMax's 4-link Article

I think maybe you and chris are in agreement about the pinion, looks to me like he was just putting it in words those that dont already might understand?

Max, I apologize for the first post, after I re-read it to myself I seen that it is worded alot like a question. Michelobe is right, I think that we are both on the same page but wording it different. As for the pinion, when you accelerate the wheels will rotate forward but the axle housing will try to rotate, twist, or spin rearward slightly. So you point the pinion down 1 degree more than what your ideal pinion setting would be (if the tranny is at -3 degrees then the rear end should be +3 degrees, equal but opposite angles). By preloading the rearend it would be at +2 degrees then under acceleration it will put the axle in the idea setting of +3 degrees. I hope it makes more sense now. Also you hit the nail on the head with this statement "But the more I learn, the more I realize I don

so um max do u need an apprentice? or just a helper cuz i'd be more than happy to work for u

Well...

Sence you can't just come by every now and again, I would have to say no. Not right now.

Max...Slap steve for me...k, Thanks.

Fo' sho'

Originally posted by BioMax



Just had to post this pic of my shop cat, it makes me laugh every time. She is drinking the mist coming from the hose.



I think it's eating a Fruit by the Foot!

So I just got my 4 link done, but my drive shaft binds up, when I lift it real high. With the drive shaft in it binds up at 19 inchs of lift and with the drive shaft out it will go to 21 and I know it would go higher, but I cant get the truck any higher. The pinion angle is at 0 degrees all the way through the travel. The upper bars are like 1 inch longer than the lowers if you look at it from the side and they are both parrell to each other from the side. Is there anything I can do to get more travel?

What you have done is built a long-travel system with out taking all of the asociated systems into consideration.

The driveshaft needs to be addressed much like you would consider the steering and bumpsteer on the front suspension. Once you relate the 4-link to the driveshaft you start to really complicate things. You now have to place the transmission tailshaft inline with your desired instant-center. What the off-road guys do is run a carrier bearing. That way you can mount the engine/trans package where you want and put the carier bearing in line with your i.c.

The easy way to cure your particular issue is to have a driveshaft built that is fixed at the trans (or carier bearing) and have the rear section telescope. This alows you to have some things out of line and keep the plunge loads fron being transmited into the transmission. We broke a transmission tailshaft housing learning that one.

I hope that makes some sence...

so when setting up your 4link you want the bars parallel to the ground at ride height. but with an instant center would you want the lower or upper bars to be parallel to the ground at ride height? or somewhere in between? also on a triangulated setup if the lower bars are say 26" long and the uppers are 23" is there going to be a dramatic difference in pinion angle change through travel? last but not least my most confusing query, when the upper bars are set up triangulated they do not mount as far foward on the frame as the lowers even if uppers and lowers are the same length, as the uppers would be at an angle, does this cause any dramatic effects? front mounting to the frame of the upper and lower bars will be closer together than on the axle as per i.c. but...if the uppers do not come as far forward on the frame do you consider the mounting difference only in height or strictly distance between the two points?