Possibly another solution for driveline decel noise

[Luke]

Even if your driveshaft angles are all the same already, I personally would still try either lowering the rear or front carrier bearing. I would suggest trying both, but not at the same time.
I am no longer certain if the proper adjustment is to make all the angles equal.

 

[Terry Posten]

Quoting Armitage:
I measured my driveshaft's angles last weekend, but they were all within .5 degree of eachother, so I didn't change anything. I have very bad driveline decel noises. I also tried swapping to a different xfer case with no luck.



I agree with Luke.

Mine were within spec but I lowered the front bearing starting at 1/8" and working my way to 3/8" and it got rid of 90% of the noise. I did notice a slight vibration at cruising speeds for about a day but after that, things are pretty good.

 

it works!
most of the vibration is completely gone.
I just put 3 washers each on the front bolts.
its well worth it for a cheap fix. Thanks for sharing this info!

 

[Armitage]

Bringing this back from the dead with an update. I finally got around to giving this a try after eliminating pretty much everything else I could think of.

To date, I have replaced or rebuilt the following trying to eliminate the decel noise:

Tranfer Case
Rear Diff
Lobro Joint/Carrier Bearings/All U-joints/Yoke
Various halfshafts

Even though all three segments of my propeller shaft were within 1* of each other as measured with the magnetic angle finder, I tried shimming the front carrier as recommended to me. Doing so maybe made a 10% improvement, but almost all of the decel grumble was still present. I removed those shims and did the same for the rear carrier. 0% improvement that way.

Basically I'm thinking there's only one possibility left here and that's the Transmission itself. I'd like to hear if anyone else has run into or solved this decel noise issue lately.

 

[bazeng]

This might sound silly, but I had an issue with this also.

Have you checked under your carpet?
I had some coins / nuts etc vibrating under the carpet.

Also have you ever lost and nuts / bolts / screws within the chassis?

I lost a socket in my bootlid!! I still don't know where it is!

 

Brilliance! Can't wait to get my driveshaft back in so I can try this out...

 

Guys, finally another alternative. Click for more info

 

[deez]

Mine had an issue similar after a new transmission and clutch were installed. Turned out the new transmission had a bad bearing.

 

[belize1334]

I feel like a dummy for asking...but these are metal bushings for what exactly? To my memory the carrier bearings bolt up to studs in the floor pan. Where do these come into play?

 

[CSMShaun]

The mounting plates in the carrier bearing have large holes in them that rubber bushings sit in. These metal bits will replace the rubber bits.

 

[belize1334]

Ah, that makes sense. Still, the carrier bearing itself allows for shaft excursion of nearly an inch. Given then, would these really make much difference?

 

[4thStroke]

Its one step closer to having a further controlled driveshaft. The stock bushings wear and deteriorate and allow for slop. Mine are ugly.

Most people opt to fill the carrier bearings, taking care of the excess play there.

When I have $40 to spare, I'll be sure to pick these up. Thanks Garfield.

 

[JNR]

won't it transfer vibrations elsewhere and/or be more prone to breaking other parts of the driveline?

 

[Muskrat]

1) Yes, definitely. That's what those bushings are for.

2) Probably not. Any play in the system is taken up by the LoBro and carrier bearings.

 

[4thStroke]

It might transfer a little more vibration, but if the driveshaft is properly set up, it should be minimal.

I highly doubt it would cause something else to break.

 

[CSMShaun]

If you have set the correct angles and your carrier bearings are in good order the DS shouldn't vibrate bad. It is definitely a pain in the rear to deal with but you are rewarded with better driveability of the car.

 

[evo8ya]

I had a decel noise since I installed my coilovers last month. Guess the ride height I set them at, put the DS at just the right angle to make a decel noise and a slight vibration. So, I made some spacers out of a old A/C compressor bracket. About 6mm, and installed them on the rear carrier. Huge improvement. It alleviated about 95% of the noise and vibration. I'll probably have to remove or re-shim the DS when I lower the car back down for the summer, but we'll see. BTW, I think this should be in the "how to" section, being that it's helped a large percentage of people that has tried it.

 

[Barnes]

Changing the height of the car does not affect the drive shaft angle. /ubbthreads/images/graemlins/wink.gif

Unless you are doing a body lift. /ubbthreads/images/graemlins/uhh.gif

 

[turbowop]

Quoting evo8ya:
I had a decel noise since I installed my coilovers last month. Guess the ride height I set them at, put the DS at just the right angle to make a decel noise and a slight vibration. So, I made some spacers out of a old A/C compressor bracket. About 6mm, and installed them on the rear carrier. Huge improvement. It alleviated about 95% of the noise and vibration. I'll probably have to remove or re-shim the DS when I lower the car back down for the summer, but we'll see. BTW, I think this should be in the "how to" section, being that it's helped a large percentage of people that has tried it.



/ubbthreads/images/graemlins/bowrofl.gif

 

[Brianawd]

Quote:
I had a decel noise since I installed my coilovers last month. Guess the ride height I set them at, put the DS at just the right angle to make a decel noise and a slight vibration. So, I made some spacers out of a old A/C compressor bracket. About 6mm, and installed them on the rear carrier. Huge improvement. It alleviated about 95% of the noise and vibration. I'll probably have to remove or re-shim the DS when I lower the car back down for the summer, but we'll see. BTW, I think this should be in the "how to" section, being that it's helped a large percentage of people that has tried it.









/ubbthreads/images/graemlins/uhh.gif