When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
2 piece driveline angles and 5” rear drop...cliffs notes
So after many adjustments and basically just moving a slight vibration to a different mph but never completely getting rid of it I dove 100% in last week to fix it once and for all. I had probably 5 hours total adjusting, measuring, running numbers through the Spicer calculator etc but in the end it was worth it.
We have 3 working angles calculated from 4 points. The trans, 1st shaft, 2nd shaft and pinion...all working angles should be 3° or less and the angle of the 2nd shaft needs to match the angle of the pinion...or so say the experts. No matter what I did I couldn’t get those to work out. If the 2nd shaft and pinion matched the working angle was too great and vice versa...I attribute this to the 5” drop changing things so much. I settled on getting the working angles < 3° As it seemed like the lesser of 2 evils and the difference between the 2nd shaft and pinion was still less than 1°
Getting there was the hard part. I had to shim the trans tail shaft up 1/2”, shim the carrier bearing down 1/4” (I have the McGaughys carrier bearing bracket installed so a stock one would be different) then dial in the pinion angle with the DJM flip kit bracket I put in a while back...all while keeping in mind that the 2nd shaft and pinion angles need to form a downward V. You can achieve that even with the pinion angled up...so it gets a bit confusing.
I’m attaching a pic of the Spicer calculator and where I wound up. I’ve driven it for several days including acceleration tests at 25% throttle, 50%, 75% and WOT through 3rd gear. No vibrations I can detect at any speeds so I think it’s finally good.
Keep in mind no working angle can be less than .5* or the u-joint needles won’t spin and lubricate themselves...the joints will wear out just as fast as too much angle.
Here’s a couple of pics for reference. At one point mine was like the bottom...about as bad as it can get. Now I’m more like the 2nd one down just not quite parallel. Once you have the trans and 1st shaft set you can treat the 2nd shaft and pinion like a 1 piece driveline.
The lower pic is a reference of how things should be...except the trans and 1st shaft centerlines need at least .5* of angle to lubricate the u-joints.
I just finished the drop on my 18 F150 and I need to check modify the stock carrier bearing and check all of the angles.
I currently have the Maxtrac flip kit but might change it out to the DJM if I need some more adjustment.
I will compare the stock angles of my wife's 18 F150 to what I have and what you listed.
That would be awesome. I’ve been curious what the stock working angles are.
I completely spaced it. My wife's f150 is a 4x4 with a single piece driveshaft, so that didn't help at all.
I was able to remove the stock carrier bearing bracket and bolt the carrier bearing directly to the frame and that helped me a lot. Runs smooth now. I plan on taking it to a driveline shop if I can find a good one and see what they say about it before I put the supercharger on.
I have a RCSB with one piece driveshaft and I used a BellTech 4" flip kit. Their supplied shims did nothing for the driveshaft hop so I ordered up enough to get rid of it and I ended up at a -1 pinion angle. Remember that the pinion rises under acceleration so I am probably going +1 or more under hard acceleration or with a load in the bed. It is all a compromise. The problem with the extra shims to get to -1 was the locating pins on the springs were too short. I hopped on McMaster-Car ordered up the correct hardness and thread in a cap screw to replace the factory pins. Some slight machining on the cap screw head to decrease diameter and then shortening one of the heads so it would not contact the axle tube and I was all set. If you have to add more than one shim to a BellTech flip kit you need to build new locating pins. Most of the flip kits will be like the BellTech.
Ok so hears my question. Would a reputable driveline shop be able to make it work for me? I am currently without a workspace and would most likley have the shop install everything as well. Never dealt with lowering and dont want to drive away with vibrations and be sol. Thanks
04-21-2018, 06:20 PM
2 piece driveline angles and 5” rear drop...cliffs notes
