Chasing driveline vibration.

Gnarvan · 03-16-2021, 10:08 AM

I've got what I think is a driveline vibration starting around 68mph. I've eliminated a driveline component issue. I think I have a driveline angle problem causing a harmonic vibration at certain speeds. My van is a 1992 E350 5.8L that was converted by Advanced 4WD systems. Since I live in the Salt Lake City area now I drove to Advanved 4WD and talked to them. They are going to look at it next Tuesday. It will probably need new blocks to change the driveline angle.

carringb · 03-16-2021, 10:47 AM

That’s pretty common. JSWEEZY had a similar issue with his advanced conversion, and ended up putting in shims in his garage. The angle was only a little out of spec but that was enough.

Gnarvan · 03-16-2021, 11:33 AM

Thanks Brian

The old guy (been there forever) guy said they didn't like to shim them. The shims crush over time. He said they literally have 100s of blocks they can use to dial in the driveline angle.

Are you still hitting the whitewater? Is your V10 duelly still on the road? If so have you passed 500k yet

John

carringb · 03-16-2021, 01:37 PM

I’ve never seen a shim crush. A proper one is wedge shaped and made form spring steel. If somebody tried to cut their own out of mild steel, I could see it having issues. A block could do the same thing I suppose.

FWIW Ford sells spring alignment shims. They are used stock on the F650/750 and motorhome chassis. That are not expensive and they do fit the e-series rear springs.

Unfortunately I haven’t been on the water much lately. The Smith River festival was the only one in 2020 that we got in, before things shut down.

The van is doing great though. Only at 496,000 miles though. I’ll post when I hit 500!

Pntyrmvr · 03-20-2021, 09:42 AM

My Advanced 1984 conversion has rear axle lift blocks. When I updated the engine it gave me the opportunity to set the driveline angles. I ended up having a spring shop replace all the rear spring bushings, hangers, and rear shocks. They put in new u bolts as well as new spring clamps. While they were at it I went underneath and checked the rear axle to driveshaft angle with my digital angle gauge. I had already bought the shims as I had that thrushy drone that bad u joint angles make and figured out what angle change was needed. They threw them in on reassembly and voilà drone was gone.

Critical thing to remember with lift blocks is that they push axle center line further from the leaf spring and thereby increase the lever effect of the spinning axle shafts. Check for videos of rear axle wrap on line. It’s a lot of angle change at the u joint.

When setting the angle up with shims take into account that cruising down the road will lift the front of the rear axle housing up 1-1.5° just from the torque of the engine pushing the truck forward.

Good luck getting Advanced to figure that all out. My interactions with them have been like talking to a wall. Congratulations your conversion was done by the lowest bidder.

Gnarvan · 03-20-2021, 11:41 AM

Over the years I've heard a few not so complimentary comments about Advanced. They were quite helpful to me when I showed up at their shop. By the number of vans in their lot and shop they are super busy. After talking to whom I assumed to be one of the owners I have high hopes they will be able to dial in my driveline angle issue. I'll make my own assessment of their customer service abilities next Tuesday when they work on my van. I will keep everyone posted on my driveline vibration issues.