Rear end vibration

xterraminator

xterraminator

Wheeling
Location
Maple Ridge,BC
So as you know the sas is done and so I was able to drive it for a bit. About 2 days ago when I drive down the street at a speed(human running slow speed ~5-10km/hr) I can hear a noticeable vibration that has a pattern to it. It sounds like if I had huge 44" knobby mud tires making noise but almost like a binding sound. When I checked the angles of the transfer case drive shaft and the angle of the rear pinion they were out by 2.5 deg. Because of this I added 2.5 deg shims under the leafs and that corrected it. Right now the rear pinion and front transfer case angles are at ~ 5.8 deg each. The drive shaft was lengthened, balanced and u joints inspected for the sas project. Right now I am puzzled because it never did this when it was stock. If anyone has any suggestions they are welcome. Thanks.
 
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granitex

granitex

Skid Plates
Founding Member
Location
Columbus OH
are the u-joints in the same orientation as they were originally? Having them out of phase can cause binding. Thay is why you want to mark them when you drop a shaft for any reason.
 
xterraminator

xterraminator

Wheeling
Location
Maple Ridge,BC
The drive shaft was lengthened and balanced. The cv joints are in phase and the only way to change that is of you cut the yoke off the drive shaft. One end of the drive shaft is splined and the other is a flange mount. Both yokes at each end of the shaft are lined up with each other. I was also reading that brakes drums/shoes if repaired incorrectly can bind as well. The brake shoes were replaced.
 
xterraminator

xterraminator

Wheeling
Location
Maple Ridge,BC
granitex said:
are the u-joints in the same orientation as they were originally? Having them out of phase can cause binding. Thay is why you want to mark them when you drop a shaft for any reason.
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With a stock rear axle there is no way of messing up the u-joint orientation because they are part of the axle, splines on one end and the other end has a 4 bolt flanged connection. Not sure what you mean, maybe I am missing something.
 
T

TJTJ

Skid Plates
Founding Member
Location
NJ
xterraminator said:
With a stock rear axle there is no way of messing up the u-joint orientation because they are part of the axle, splines on one end and the other end has a 4 bolt flanged connection. Not sure what you mean, maybe I am missing something.
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You had the shaft lengthened, correct? Any chance the re-welding re-aligned the joints to be balanced but out of phase?

Its possible of course that the vibe is from something else. For example, COULD it be the tires or rims? The Axle or Diff? Warped/Sticking Brake? Exhaust, etc, interference with drive train?

Does it get louder, or does the frequency change when you go faster?

Is it different when coasting than when under power or using engine braking?
 
xterraminator

xterraminator

Wheeling
Location
Maple Ridge,BC
TJTJ said:
You had the shaft lengthened, correct? Any chance the re-welding re-aligned the joints to be balanced but out of phase?

Its possible of course that the vibe is from something else. For example, COULD it be the tires or rims? The Axle or Diff? Warped/Sticking Brake? Exhaust, etc, interference with drive train?

Does it get louder, or does the frequency change when you go faster?

Is it different when coasting than when under power or using engine braking?
Click to expand...
I am sure the joints are in phase but I will double check tonight. Brakes shoes were replaced(brand new) and I have no muffler at this time. the vibration gets louder as I go faster. I am just going slowly in the culdesac in a straight line for now because there is no insurance on it yet. The way it is I would not dare go faster than 30mph. I will see if the frequency changes.
 
T

TJTJ

Skid Plates
Founding Member
Location
NJ
Also clarify when you report back about what part is vibration, and what part is sound...as you've been referring to it as both.

If you can drive past someone/have them drive it past you while its doing it...sometimes its easier to tell what's doing what when you have a line of sight/sound to it.
 
xterraminator

xterraminator

Wheeling
Location
Maple Ridge,BC
Speaking of out of phase, tonight I am going to check the front drive shaft. It has a slip yoke and when they lengthened that one they could have put it out of phase when the two halves are put together. I am also going to see how much further I can push the rear drive shaft into the transfer case. Should be at around 1 inch or less at ride height. All good points and suggestions. :)
 
T

TJTJ

Skid Plates
Founding Member
Location
NJ
xterraminator said:
Speaking of out of phase, tonight I am going to check the front drive shaft. It has a slip yoke and when they lengthened that one they could have put it out of phase when the two halves are put together. I am also going to see how much further I can push the rear drive shaft into the transfer case. Should be at around 1 inch or less at ride height. All good points and suggestions. :)
Click to expand...

Hopefully, the front can telescope in/out too...most of the ones I see have unused grease fittings from the factory...and never a drop since.
 
T

TJTJ

Skid Plates
Founding Member
Location
NJ
Actually, if it might be in front that's doing it...check the motor mounts and other potentially moving parts as mentioned for the rear too, etc..
 
xterraminator

xterraminator

Wheeling
Location
Maple Ridge,BC
So I found out two things.

1. I need to reduce the driveline shaft about 1 inch. At ride height I will not push any further into the transfer case. It can be made shorter no problem.

2. The stock u joints don't support high angle that it is running. The bind and will need to be replaced where the u joints can rotate at a high angle.

Because of this what other options do I have?
 
Prime

Prime

Shut up Baby, I know it!
Admin
Location
Denver Adjacent
Wow that's a lot. Sounds like you need a slip yoke eliminator, and then a double cardan or CV driveshaft with a slip in it.

The SYE kit will move the mating surface of the driveshaft further away from the axle so it'll give you more room to work. And it also eliminates the ability of the driveshaft to pop out of the transfer case.

That is if we're talking about the rear. The front should already be on a u joint and have a slip driveshaft.
 
xterraminator

xterraminator

Wheeling
Location
Maple Ridge,BC
Would the slip on the splines as the shaft goes into the transfer case act as a SYE? If I use a Cardan then I have to redo my rear axle angle to match the drive shaft. I will see what my local drive guys have to offer. Thanks for the feedback.
 
Prime

Prime

Shut up Baby, I know it!
Admin
Location
Denver Adjacent
The slip on the splines in the back of the transfer case is the definition of a slip yoke. An SYE kit will replace the back half of the transfer case with a regular u-joint mount instead of a slip. Which does two things, it moves the slip to the driveshaft so that it's in line with the rotation of the shaft and it pulls the mounting surface of the driveshaft closer to the transmission so you have more room to work with.
 
BEEFY

BEEFY

I Smile when Gasoline Can Freeze
Location
Prince George, BC, Canada
Some thing else to consider that might fix a couple of your problems is moving your rear diff back. By doing that you may not need to get you shaft shortened. Also it will decrease the angle on your rear drive shaft. On mine I used adjustable spring purches from TMR customs that allowed me to move my diff back 1 1/2". So for your it would mean pulling the rear diff out. And drilling new holes 1"-1 1/2" forward on the purches and u bolt plates. And also I see you are running used tires. Do they have a weird wear pattern that could be sending a vibration up your drive line. I have had that happen.
 
xterraminator

xterraminator

Wheeling
Location
Maple Ridge,BC
So here is the update. 1. rear driveshaft was shortened about 1 inch so now it moved freely on the splines into the transfer case. 2. Offset joints were added to the stock yokes on the drive shaft to get more anlge. 3. The angle of the transfer case(~6.5 deg down) and diff yoke(~6.5 deg up) are the same at ride height. 4, Driveshafts were balanced and good. Now when I drive sometimes around 5 mph it vibrates then as I speed up it goes away. I can feel a slight vibration at about 40 mph. When I accelerate the vibration does not increase or decrease. Sometimes when I slow down back to the 5-8 mph then it vibrates noticeably. Ideally it should have a double cardon on top and the dif yoke made to be inline with the driveshaft(future upgrade). As it is now the driveline shops feels it should be ok but this is not the case. Kind of running out of ideas.
 
Fromfrontier2Xterra

Fromfrontier2Xterra

I bought a Taco
Super Moderator
Supporting Member
Location
All over PA
Hmmm...how much suspension work was done after the rear cut? Is it possible with the weight difference the rear is now sitting slightly higher and just high enough that you need shims? Sent via my walkie talkie
 
xterraminator

xterraminator

Wheeling
Location
Maple Ridge,BC
Fromfrontier2Xterra said:
Hmmm...how much suspension work was done after the rear cut? Is it possible with the weight difference the rear is now sitting slightly higher and just high enough that you need shims? Sent via my walkie talkie
Click to expand...
By cutting off the back and adding in the new rear boxed tail gate it evened out. I went back to the stock rear shackles. The truck is sitting nice and level. I added 2.5 deg shims under the leafs to make the yokes on each end at the same angle. Geometry speaking its all lined up.
 
xterraminator

xterraminator

Wheeling
Location
Maple Ridge,BC
Found out the problem was the front driveshaft. When the modified the front they added a Tom woods offset ujoint at the top and then the bottom one near the dif is a standard ujoint with no offset. That might explain why. Will take it to the driveline shop to get it repaired under warranty.
 
xterraminator

xterraminator

Wheeling
Location
Maple Ridge,BC
Because of the angle of the front driveshaft had to use a double cardon on the shaft. This will allow it be very flexible and not bind. Shakedown ride is this weekend.
 
1stGENXterra

1stGENXterra

Test Drive
I have a question about the rear end on my first gen Xterra, I put it in drive and start driving. When it shifts into gear it sometimes vibrates and/or sounds like it’s bogging down?


Any thoughts
 
granitex

granitex

Skid Plates
Founding Member
Location
Columbus OH
could be a number of things, but an actual problem with the rear end is really unlikely, it would be much more likely to be a universal joint. It will be a spicer 1310, and every parts store in town will have them on hand.
 
1stGENXterra

1stGENXterra

Test Drive
granitex said:
could be a number of things, but an actual problem with the rear end is really unlikely, it would be much more likely to be a universal joint. It will be a spicer 1310, and every parts store in town will have them on hand.
Click to expand...

Damn, ok. Thank you
 
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