Pinion angle with Adams 1-piece and Fusion 60

[Muddyape]

Installed Fusion 4x4 D60 rear end with 5.13’s 2 weeks ago and Adams 1 piece 1350 driveshaft came in this week and its installed. Been going easy on it to break it in, 150 miles now. Hit the highway today, first time of 60 mph and getting a low frequency drone when on the gas, and its goes away when i let off. So….my pinion angle to driveshaft is like 0 degrees at rest. Perfectly straight. Should I be nosing it down? Cant find anything anywhere. Ill just wait to call vendors on monday but was hoping to resolve over weekend.

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[kevman65]

IIRC it's like 2 or 3 degree difference.

*** Just checked my install instructions for RK lift, pinion should be 2-3 degrees DOWN from driveshaft center line.

 

[ShadowsPapa]

IIRC it's like 2 or 3 degree difference.

*** Just checked my install instructions for RK lift, pinion should be 2-3 degrees DOWN from driveshaft center line.

Makes sense as the pinion wants to climb the ring gear when under load/torque, and that raises the front of the diff a bit, probably ending up under load at about 0 degrees if it's down a bit at rest.

And shaft that has 1 SINGLE cardan joint without a 2nd on the same shaft needs that joint to run close to 0. A couple of degrees off won't bother.

 

[Muddyape]

Thank you gents…gonna make some tweaks

 

[JeepOfTheseus]

My Adam's 1-piece is now a 2-piece.

 

[Muddyape]

Ummmm…..

 

[JeepOfTheseus]

Yea, I've been battling a similar drone above 60-65. I took it to a shop who sent it to a driveshaft specialist who said it was bent, and they did "the best they could" to straighten/fix it. It was actually better till about 68-70, but would still start vibrating. Finally came to a head when I took it over 80 (had to pass a car to get out of the passing/left lane).

Craziest part is this isn't how I expected it to go if it were to: if you can tell, the spline slid out of the slip yoke entirely intact.

 

[Muddyape]

Thats insane. Sidenote: I adjusted the uppers and added 2 degrees of separation. Just took it for a test spin and it would seem the issue is no more. But time will tell.

 

[JTenn]

Thats insane. Sidenote: I adjusted the uppers and added 2 degrees of separation. Just took it for a test spin and it would seem the issue is no more. But time will tell.

I also finally got around to adjusting my pinion angle over the weekend. I took my UCA's out 3 turns which moved the pinion 4 degrees. The pinion and drive shaft are now at zero alignment at rest. I was getting a vibration @70 mph. That is now gone. After installing the Adam's shafts, I was pretty unimpressed but too deeply invested to back out. Maybe as a preventive measure they're worth it but clearly they break too. I don't know, I could have spent those dollars on other mods and got alot more bang for my buck. The biggest pro for me is the u-joints are much easier to source than the Rzeppa joints if needed. Just my 2 cents.

 

[ShadowsPapa]

Yea, I've been battling a similar drone above 60-65. I took it to a shop who sent it to a driveshaft specialist who said it was bent, and they did "the best they could" to straighten/fix it. It was actually better till about 68-70, but would still start vibrating. Finally came to a head when I took it over 80 (had to pass a car to get out of the passing/left lane).

Craziest part is this isn't how I expected it to go if it were to: if you can tell, the spline slid out of the slip yoke entirely intact.

I had a racing shop do a total rebuild on my Eagle's rear drive shaft. We had a nice talk while I was there - and he explained they get a whole lot of factory and after-market replacement shafts that are either out of balance, bend/curved, or out of phase (those with a single cardan joint at each end)
they have some of them hanging on the wall behind the counter as you walk in.
Brand new GM shaft with the yokes welded to the tube, out of phase, was the most obvious.
They did racing shafts, jeep shafts and axles and so on. (maybe they still do.....)
Made my Eagle drive shaft better than new and perfectly straight and balanced.

 

[Janster]

I never hear anyone talking about Tom Woods Driveshafts? They were the premiere shaft back in our younger years. We had one on our YJ….. totally beefy. I’d never heard of anyone damaging a TW driveshaft.

 

[Wheelin98TJ]

I never hear anyone talking about Tom Woods Driveshafts? They were the premiere shaft back in our younger years. We had one on our YJ….. totally beefy. I’d never heard of anyone damaging a TW driveshaft.

Tom Woods was always great for me. Last time I ordered a driveshaft, it was at my door in a few days.

 

[Rusty PW]

I had a racing shop do a total rebuild on my Eagle's rear drive shaft. We had a nice talk while I was there - and he explained they get a whole lot of factory and after-market replacement shafts that are either out of balance, bend/curved, or out of phase (those with a single cardan joint at each end)
they have some of them hanging on the wall behind the counter as you walk in.
Brand new GM shaft with the yokes welded to the tube, out of phase, was the most obvious.
They did racing shafts, jeep shafts and axles and so on. (maybe they still do.....)
Made my Eagle drive shaft better than new and perfectly straight and balanced.

When I had my 572 ci Dart. Had a 4" driveshaft from Direct Connection (remember them?). About half way through the season. I started to get a vibration. The driveshaft was never painted. I was under the car looking around. I noticed the weld seam on the driveshaft had a twist in it. The driveshaft had about an 1/8 of of turn of twist in it. Time for a new driveshaft.

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