I have noticed that also, how smooth the engine runs greatly affects the roll-over noise. But I believe a diesel engine with the mechanical injection will always have some roll-over noise at idle. Some of these newer diesels are pretty smooth, they may not have a problem with it, though it's hard to even get a newer truck with a manual trans?
another ZF5 roll over thread.... with excessive roll over noise.
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Black dawg
Registered User
It only does it on decel....correct? The engine isn't turning the trans at that point, the trans is turning the engine. This really sounds like angle issues to me.....if the rear diff isn't falling apart.
Booyah45828
Full Access Member
Sounds like angle issues to me too.
I fixed a gmc sierra a few years ago with something similar. The PO installed a 4" suspension and a 4" body lift kit and didn't measure/correct the driveline angles. After doing that, and installing a double cardan shaft up front, the truck was whisper quiet.
Before doing that though, I replaced every u-joint in the thing, rebuilt the front axle and transfer case, and was about to tear into the rear axle, before I took a step back and started checking stuff.
The noise was 100% like what you're hearing, a bearing/gear grind noise that was coming from the trans/transfer case area, primarily on decel.
I fixed a gmc sierra a few years ago with something similar. The PO installed a 4" suspension and a 4" body lift kit and didn't measure/correct the driveline angles. After doing that, and installing a double cardan shaft up front, the truck was whisper quiet.
Before doing that though, I replaced every u-joint in the thing, rebuilt the front axle and transfer case, and was about to tear into the rear axle, before I took a step back and started checking stuff.
The noise was 100% like what you're hearing, a bearing/gear grind noise that was coming from the trans/transfer case area, primarily on decel.
been raining like a **** lately, caught a break today.
i will be repositioning the leaf pads before it goes back in and ordering yet, again, another driveshaft lol
i will be repositioning the leaf pads before it goes back in and ordering yet, again, another driveshaft lol
Booyah45828
Full Access Member
So I'm assuming it was drive shaft/u joint related?
Regardless, I'm glad you found the issue.
As an addition to my story, that sierra made the noise all the time. Much worse in 4wd though. I probably could have cut and welded the leaf pads, but I found some angle shims that I put between the pads and the spring blocks to bring the pinion up in line. The front shaft angle adjustment was hopeless, so a double cardan shaft and pointing the pinion straight was the fix.
I want to say the rear shaft joint difference was 5 or so degrees with the axle at rest, with it nosing down worse under decel. Front axle was 10+ out.
ttman4
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'90 LBCC Dually.
Several yr ago I got tired of crawling underneath with my fat belly so I did 4" Frame & 4" Body lift.
About 3-4 yr ago I put D60 under front, BG 1356 transfer. Had it aligned & luckily was spot on. Had rear drive shaft shortened, front driveshaft fabed that I used from the parts truck, just regular front driveshaft ujoints.
Ever since in 2wd its OK. But I can only lock front hubs in & I get a howl/growl. Put it in 4x4 with hubs unlocked & get same howl/growl. Lock hubs in & use 4x4 & get same howl/growl. This noise pretty well, mostly, stays same sound-pitch pulling, letting off, or coasting.
I assume I should have come up with a double cardan joint for the front D60 axle??? That's what on my list soon. Where good place I might find one???
Also what is a usual-good driveline/ujoint angle? IIRC about somewhere around 5* but not sure.
I need to remeasure front driveline angles, don't recall rite now, but its pretty short & steep.
Each time I get under the 4x4 truck I take a gander at the front driveline and I still haven't figured it out yet.
I get the rear angle thing. The engine/tranny is tilted down toward the rear, the nose of the rearend is tilted up about the same. But does that mean the front 4x4 pumpkin needs to be tilted down toward the rear to match the engine/tranny? That's what I tried with mine and it didn't work. And when I look at factory setups, it seems the front diff pinion is tilted up. There is something here the driveline people are not telling us.
I have a little Bronco II I have been driving. On the rear shaft it has a double cardan joint at the transfer case. The engine trans are tilted down like all others, about 3 degrees. The rear diff pinion though, is tilted up 9 degrees according to the manual, and it looks like it also.
ttman4
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Well I remember from my semi trucking days the alignment shop would "wedge" the steer axle to give it few * of positive caster, if level or neg then it wouldn't hold the road as well. (Visualize leaning forward over the steering wheel driving, or walking all leaned forward trying to walk straight."
Anyway, on my '90 with the D60 front axle my pinion is somewhat slightly down. The output of BG1356 to front driveshaft looks slightly up, need to measure with angle finder Either way front driveline is pretty short I'm pretty sure I need to redo get double cardan joint.
Just got to find out which one I need & try to bit into my $$$Budget.
Anyone know what I need to be looking for matches my BG 1356?
As I recall; the tranny and rear differential should be close to the same angle if running a single piece driveshaft. I shimmed my dif and it worked great. A cardan driveshaft dose not need to be the same angle.
Booyah45828
Full Access Member
Lima clutch and joint in Lima, Ohio built the custom front shaft. They actually had what I needed in stock, so I assume I wasn't the first person to come in with the issue. They cut it to size, welded, and balanced it while I waited. The counter guy was pretty smart and I recommend them if you're needing work.
I was told, that for any driveshaft to work, the joint angles on each side need to match within a half of a degree, and be in opposite directions. So for a single rear driveshaft to "work", most vehicles have the transfer case/transmission angled down, requiring the pinion to be at an up angle the same amount. You can also run into leaf spring flex under accel/decel, allowing the rear joint angle to change, which needs to be considered too. I mention that because that sierra didn't make noise under power, only decel. Pointing the pinion angle up higher, lowered the angle difference when the truck was under decel, which eliminated the noise. Truthfully, installing a set of traction bars or anti-wrap bars probably would have worked on the rear of that truck too.
Front shafts are a different scenario, as the transfer angle is now pointed up, requiring the front pinion to be pointed down in order to cancel the difference out. I couldn't do that on the sierra without the joint angles being out to lunch, so installing a double cardan joint on the rear of the shaft eliminated the need to have the front joint # match the rear joint #. Then, all I had to do was get the pinion-driveshaft angle as near to zero as I could.
Spicer has a calculator and smart phone app you can use https://spicerparts.com/calculators/driveline-operating-angle-calculator#more
And here's a video on driveline angles, velocities, and the issues they present
I was told, that for any driveshaft to work, the joint angles on each side need to match within a half of a degree, and be in opposite directions. So for a single rear driveshaft to "work", most vehicles have the transfer case/transmission angled down, requiring the pinion to be at an up angle the same amount. You can also run into leaf spring flex under accel/decel, allowing the rear joint angle to change, which needs to be considered too. I mention that because that sierra didn't make noise under power, only decel. Pointing the pinion angle up higher, lowered the angle difference when the truck was under decel, which eliminated the noise. Truthfully, installing a set of traction bars or anti-wrap bars probably would have worked on the rear of that truck too.
Front shafts are a different scenario, as the transfer angle is now pointed up, requiring the front pinion to be pointed down in order to cancel the difference out. I couldn't do that on the sierra without the joint angles being out to lunch, so installing a double cardan joint on the rear of the shaft eliminated the need to have the front joint # match the rear joint #. Then, all I had to do was get the pinion-driveshaft angle as near to zero as I could.
Spicer has a calculator and smart phone app you can use https://spicerparts.com/calculators/driveline-operating-angle-calculator#more
And here's a video on driveline angles, velocities, and the issues they present
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i have not cured this issue yet. but im going to swap rear diff's.
today i prepped the other 10.5
i took the 1350 yoke off the rearend installed, and changed it on the new diff.
super duty rearends have a flange, and im swapping to a yoke
did a crush sleeve eliminator, and a new pinion seal.
bearing preload is on point and i have .013" backlash..
im cutting the perches off tomorrow so i can get the pinion angle dead nuts with the trans.
may even drop the trans a inch or so, dont know yet...
till tomorrow
Black dawg
Registered User
Are you trying to run a 2 joint shaft with that lift and wheel base? It will be very difficult to get useable if so.
I ask for pictures, because this is stuff I deal with almost daily.
I ask for pictures, because this is stuff I deal with almost daily.
well, i had some time to work on this today.
cut the spring perches off, and ive almost got the angles dialed in.
looks like im gonna need yet another driveshaft.
i had to go pick the boys up, so i didnt weld anything.
here are the pics you asked for
cut the spring perches off, and ive almost got the angles dialed in.
looks like im gonna need yet another driveshaft.
i had to go pick the boys up, so i didnt weld anything.
here are the pics you asked for
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