Deceleration/light throttle growl/noise help!!

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

fudalad

fudalad

Joined
Aug 17, 2025
Threads
1
Messages
21
Location
Virginia
I have combed this site and still and have not found my exact issue so sorry to start another noise thread but I need help!!

When I let off the gas, and really just lighten my foot on the gas pedal I get a growling cyclical possible vibration noise. At all speeds. Sounds like it’s coming from front of the vehicle.

3” lift, delta arms, new drive shafts front and rear, new wheel bearings up front, new birfields, front pinion bearings replaced (which is really what I thought it was, noise went away briefly and now is very much back).

Noise goes away when I take front shaft out, but the drive shaft is new and the angles look very slight, and I have video of the front shaft into pinion and the noise cannot be heard. Have taken rear shaft out and left front in and still get the noise.

It is driving me nuts and is very pronounced so I won’t rest until I have pinned down. Help!! Please
 
Dbl cardan shaft? With 3 inch your right at needing it . The noise/vibe on decel points to worn loose part or bad drive shaft angle . I would start looking at the drive shaft making sure everything is tight and phasing correct (ive seen brand new shafts with bad joints and Dlb- cs) . Then I would check your pinion bearing for any play same with the t case.. Best way Install a Known good shaft see if the noise goes away.

500743634_122234109110220118_7124400182500998507_n.webp


in_phase_1024x1024.webp
 
My guess is it's your drive line angles based on my experience of fighting the same thing.
Your new drive shaft skips the step where you worry its old U-joints operating at new angles.
Measure the drive line angles with a digital protractor. You'll find they are are out.
The only fix is to rotate the front axel. More $$$

I had no vibes with the 3 inch lift. I put new u-joints in when I did the lift because old joints don't like to run at new angles.
My vibes started when I regeared and spun the drive shafts 16% faster. (411 to 488)
The fix was a double-cardan AND new radius arms, because the front axle needs to rotated to with-in +/- .5 degree pointed up the DC shaft at the transfer case.
Don't skip the step where you just put in the DC shaft and don't rotate the axle. I thought, "1.5 degrees out, that's at the top range of spec according to the inter webs. It'll be fine"...

No. It wasn't.

I had a critical speed vibe that would start around 65 MPH and get bad at 70 through 75 then calm down a little at 80. So I drove everywhere at 65 MAX for two plus years. What a PITA.
This fall, after conversing with Dave at Delta to determine which radius arms where needed to correct the drive line, I put new 2degree radius arms in (sold the 4degree set to a buddy) and it was much better, but not perfect, for about a week, then the vibes started again but now at all speeds. :mad: Remember that part above where U-joints don't like running at new angles, (Rick / @landtank was kind enough to remind me of that) well the CV part of the DC is REALLY sensitive to that and I destroyed the CV and the u-joint on the front side of the DC. Pulled the front shaft and drove around in RWD for a month or so till I had time and $$ to rebuild the DC drive shaft.

Its been about 2 months since the DC rebuild after the axle rotate and everything has been wonderful, truck goes down the road at any speed I willing to run it at.

This has been kind of a rambling mess, but my point is, you can't skip steps. Its going to be expensive to do it all at once. But it will be more expensive if you don't get all the steps completed correctly the first time.
 
raisinhell2 said:
Dbl cardan shaft? With 3 inch your right at needing it . The noise/vibe on decel points to worn loose part or bad drive shaft angle . I would start looking at the drive shaft making sure everything is tight and phasing correct (ive seen brand new shafts with bad joints and Dlb- cs) . Then I would check your pinion bearing for any play same with the t case.. Best way Install a Known good shaft see if the noise goes away.

View attachment 4054371

View attachment 4054372
Click to expand...

I hesitate to buy another shaft as I have been throwing money at this for 6 months to fix it. Has new shafts in it.
Rusty Marlin said:
My guess is it's your drive line angles based on my experience of fighting the same thing.
Your new drive shaft skips the step where you worry its old U-joints operating at new angles.
Measure the drive line angles with a digital protractor. You'll find they are are out.
The only fix is to rotate the front axel. More $$$

I had no vibes with the 3 inch lift. I put new u-joints in when I did the lift because old joints don't like to run at new angles.
My vibes started when I regeared and spun the drive shafts 16% faster. (411 to 488)
The fix was a double-cardan AND new radius arms, because the front axle needs to rotated to with-in +/- .5 degree pointed up the DC shaft at the transfer case.
Don't skip the step where you just put in the DC shaft and don't rotate the axle. I thought, "1.5 degrees out, that's at the top range of spec according to the inter webs. It'll be fine"...

No. It wasn't.

I had a critical speed vibe that would start around 65 MPH and get bad at 70 through 75 then calm down a little at 80. So I drove everywhere at 65 MAX for two plus years. What a PITA.
This fall, after conversing with Dave at Delta to determine which radius arms where needed to correct the drive line, I put new 2degree radius arms in (sold the 4degree set to a buddy) and it was much better, but not perfect, for about a week, then the vibes started again but now at all speeds. :mad: Remember that part above where U-joints don't like running at new angles, (Rick / @landtank was kind enough to remind me of that) well the CV part of the DC is REALLY sensitive to that and I destroyed the CV and the u-joint on the front side of the DC. Pulled the front shaft and drove around in RWD for a month or so till I had time and $$ to rebuild the DC drive shaft.

Its been about 2 months since the DC rebuild after the axle rotate and everything has been wonderful, truck goes down the road at any speed I willing to run it at.

This has been kind of a rambling mess, but my point is, you can't skip steps. It’s going to be expensive to do it all at once. But it will be more expensive if you don't get all the steps completed correctly the first time.
Click to expand...
Gah!! I have delta radius arms on. Thought that would fix it. I’m worried that I spend money on the dc and it doesn’t fix the problem. I put a camera on the shaft and didn’t pick up anything unhappy in the video. Additionally the shaft is barely at an angle now. Not even remotely severe.
 
fudalad said:
I have combed this site and still and have not found my exact issue so sorry to start another noise thread but I need help!!

When I let off the gas, and really just lighten my foot on the gas pedal I get a growling cyclical possible vibration noise. At all speeds. Sounds like it’s coming from front of the vehicle.

3” lift, delta arms, new drive shafts front and rear, new wheel bearings up front, new birfields, front pinion bearings replaced (which is really what I thought it was, noise went away briefly and now is very much back).

Noise goes away when I take front shaft out, but the drive shaft is new and the angles look very slight, and I have video of the front shaft into pinion and the noise cannot be heard. Have taken rear shaft out and left front in and still get the noise.

It is driving me nuts and is very pronounced so I won’t rest until I have pinned down. Help!! Please
Click to expand...
Vibration when coasting at speed is usually a worn slip yoke or loose universal in a driveshaft.
There should be ZERO rotational play in the slip yoke or universal of a driveshaft.

What happens is when the torque unloads, the 2 halves will flop around until torque is applied in either direction. This is very common and usually happens when the driveline is neglected.
 
Post a photo of the front shaft installed and from the end of the axle with the tire removed. You can use an angle finder to determine the working angle of the shaft and also the difference in companion flange angles from perfectly vertical (90* from a flat floor surface). This difference needs to be no more than 1*.

The forward companion flange of the transfer case is normally about 1- 2* pointed upward. Knowing that Delta arms correct castor angle heavily for the given lift size arm, I will predict that the third member companion flange is too low to be parallel with that of the transfer case. This means that a DC shaft won’t correct the issue and would probably be worse.

Another possibility is that your 80 is actually lifted more than 3”. As posted before, 3” lift is the cut off point for a standard shaft to work. How about measuring the castor angle by place a steel ruler, or similar, across the bolt heads on the top of the steering knuckle.

You can buy a cheap digital angle finder or download an app to your phone. Don’t give up, this is not uncharted territory.
 
"Additionally the shaft is barely at an angle now. Not even remotely severe."

You do have considerable front shaft uj angles and for sure with a 3" lift, not sure why you say you don't. The output of the front of the transfer case is quite a bit higher than the input into the front diff. See post #2.

The off-accelerator growl is typical of the problem. Removing the front shaft and the noise goes away confirms the issue. No saving pennies in this case.

You aren't the first going down this path and there are an enormous number of posts throughout this site about this issue and how to resolve it.

Time to spend the money. You have new Delta arms. Now you need a DC front shaft. The combo cured my off-accelerator growl (new uj on the stock shaft did nothing to help) and all is wonderful now, just cost a bunch of $$.

Summary: there's no way to lift 3" or more without spending a whole bunch more addressing ALL the issues.

cheers,
george.
 
I’ve had the same issue, very hard to trouble shoot, but it turned out the delta 3L’s modified my angle just enough to need a DC driveshaft. I retrospect I wouldn’t have got the radius arms and would keep rocking the stock arms. I thought I would improve handling but not that much to stop 1500.

EDIT: The issue is not necessary the lift angle of the truck, but the angle of the pumpkin to that of transfer case. With 3” lift and stock radius arms, the caster is less, so the diff housing is facing the transfer case differently, and stock drive shaft works fine. If you add delta radius arms, it moves the caster bald by twisting the axle, which changes just enough that the driveshaft no longer works.

PeterTheBeater

Thread 'Loose Suspension/Rattle Noise - Can’t Figure It Out'

I’ve got a 1997 fzj80 with about 255k miles.

35’s, fox shocks no bypass, dobinsons 3” - 3 1/2” heavies.

Recently, decided to splurge out and get delta control arms to fix the caster, got 3L’s which brought my caster back to +2.5*. As well as rear panhard bracket.

I’ve pressed the bushes in myself. (Rubber bushes, not Toyota ones, but look very close and they are pretty soft). Used all new Toyota bolt hardware, torqued at ride height to spec.

After install and drive, noticed my front panhard bar had a crack in it, so I’ve removed:

Steering stabilizer, front steering arm, steering...
 
jonheld said:
Vibration when coasting at speed is usually a worn slip yoke or loose universal in a driveshaft.
There should be ZERO rotational play in the slip yoke or universal of a driveshaft.

What happens is when the torque unloads, the 2 halves will flop around until torque is applied in either direction. This is very common and usually happens when the driveline is neglected.
Click to expand...
As stated in my post I have two new drive shafts
 
george_tlc said:
"Additionally the shaft is barely at an angle now. Not even remotely severe."

You do have considerable front shaft uj angles and for sure with a 3" lift, not sure why you say you don't. The output of the front of the transfer case is quite a bit higher than the input into the front diff. See post #2.

The off-accelerator growl is typical of the problem. Removing the front shaft and the noise goes away confirms the issue. No saving pennies in this case.

You aren't the first going down this path and there are an enormous number of posts throughout this site about this issue and how to resolve it.

Time to spend the money. You have new Delta arms. Now you need a DC front shaft. The combo cured my off-accelerator growl (new uj on the stock shaft did nothing to help) and all is wonderful now, just cost a bunch of $$.

Summary: there's no way to lift 3" or more without spending a whole bunch more addressing ALL the issues.

cheers,
george.
Click to expand...
Only state that cuz visually it’s not much of an angle. Where at the rear is a very steep angle and doesn’t appear to have any issue. Not a mechanic I just figured that it looked to be very slight. Which dc do you recommend?
 
^ yep, forever if you wish.

cheers,
george.
 
fudalad said:
is it ok to drive with front shaft out and cdl on for an extended period?
Click to expand...
Absolutely, it'll do doughnuts like a MoFo too.
 
If your current driveline displays any angle of the forward U-joint more than 1* a DC shaft will not fix your problem. The pinion shaft needs to point directly at the transfer case output. If that be the case, then your castor angle is less than it should be. Once the 80 is lifted like yours is lifted (which we don’t really know for sure but you say 3”) if the pinion does point directly at the transfer case output, you are at nearly zero degrees positive castor angle.
 
baldilocks said:
If your current driveline displays any angle of the forward U-joint more than 1* a DC shaft will not fix your problem. The pinion shaft needs to point directly at the transfer case output. If that be the case, then your castor angle is less than it should be. Once the 80 is lifted like yours is lifted (which we don’t really know for sure but you say 3”) if the pinion does point directly at the transfer case output, you are at nearly zero degrees positive castor angle.
Click to expand...
Guess I need to measure the angle? I have the delta arms meant for the 3” lift.
 
fudalad said:
Guess I need to measure the angle? I have the delta arms meant for the 3” lift.
Click to expand...
I’d measure the angles and make sure your front diff flange is no less than +\- one degree off from pointing directly at the TC flange before buying a new DC shaft. FWIW, I had the same issue and ended up with the DVS4 arms and a Landtank shaft with about of 3.5” lift. Smooth and quiet since then.
 
fudalad said:
is it ok to drive with front shaft out and cdl on for an extended period?
Click to expand...
I ran like this for a month or so while figuring out vibrations's etc. ended up with a tom woods DG shaft. also converted to part time 4wd.
 
baldilocks said:
If your current driveline displays any angle of the forward U-joint more than 1* a DC shaft will not fix your problem. The pinion shaft needs to point directly at the transfer case output. If that be the case, then your castor angle is less than it should be. Once the 80 is lifted like yours is lifted (which we don’t really know for sure but you say 3”) if the pinion does point directly at the transfer case output, you are at nearly zero degrees positive castor angle.
Click to expand...
Best way to check the angles? I have delta 3” arms and 3” front dobinson springs.
 
You must log in or register to reply here.

Share this page

Back
Top Bottom