Chasing a drivetrain noise.. (1 Viewer)

[VinSil]

So I've been hearing this noise in the drivetrain. It only happens at 50+ mph and when very light throttle or no throttle (coasting or driving down a very flat piece of highway).


I figured I'd start with the front driveline after feeling a tiny bit of play in the u-joints. All four need to be replaced. So I pull the front driveline, lock in the center diff and take off. Noise is gone. Cool. I go to turn around and wanted to see what would happen if I unlocked the center diff.

It drove like normal. Now, this is my first 80 and I was under the impression in high range unlocked diff, it would just send power to the least path of resistance. So, taking a front or rear driveline out would make the vehicle inoperable correct?



Just a puzzling situation.


Oh and my question about the front driveline. There is no play in the slip splines, but I suspect that is the problem and the u-joints are compounding it.


The truck is lifted on J springs. Is that tall enough to warrant a CV driveline? Honestly, the angle doesn't look that extreme. Do any of you have a max degree angle these work best at?

I will start by replacing the u-joints but I was just curious to your experiences. Thanks!

 

[Tools R Us]

...
The truck is lifted on J springs. Is that tall enough to warrant a CV driveline? Honestly, the angle doesn't look that extreme. Do any of you have a max degree angle these work best at? ...

J+ is in the range where you can have issues, depending on your caster correction method. If your u-joints have play that is the first step, genuine Toyota joints are the best replacements.

 

[VinSil]

Thanks. I kinda figured that I'm at the point of "maybe" with some things. The local Toyota dealer wants $70 a piece for the joints. Ouch when your doing 4.

 

[OGBeno]

Thanks. I kinda figured that I'm at the point of "maybe" with some things. The local Toyota dealer wants $70 a piece for the joints. Ouch when your doing 4.

Call 1.800.432.6668 ext. 8 and talk with Dan. Your $70 per joint will decrease substantially.

 

[NaterGator]

Or just bite the bullet at give slee a call and grab a double cardan shaft, get it balanced and worry not next time you need to add a bit more lift

 

[landtank]

It drove like normal.

Did the CDL light on the dash go out? There could have been enough load on the T-case that the motor couldn't disengage locker. But if the light went out then you might have a VC problem.

 

[OGBeno]

Or just bite the bullet at get a slee dual cardon shaft, get it balanced and worry not next time you need to add a bit more lift

Just a CV joint won't always cure issues.

If the front pinion is not facing directly at the front output of the xfer case, you are still going to get nasty vibrations and noises. By correctiny caster like Tools mentioned, you are also placing the pinion in the correct angle in relationship with the front output.

As you well know Mr. Gator , for a DC shaft, pinion has to be pointing straight up at the front output. On a regualar DS, angles should be as parallel as possible between front output and front pinion...

 

[NaterGator]

As you well know Mr. Gator , for a DC shaft, pinion has to be pointing straight up at the front output. On a regualar DS, angles should be as parallel as possible between front output and front pinion...

I plead ignorance, honestly!

My previous lifted SUV was IFS and did not have the aforementioned problems...

To the best of my knowledge the slee shaft compensated both for the increased length of the driveline when one considers the new angles, as well as a CV joint to butter up more extreme angles.

I guess I assumed caster correction was already in place... and I knew not of the DC shaft issues.

 

[VinSil]

I will give Dan a call on Monday, thanks.

The light did go out and always does when going from low to high and depressing the switch on and off. Could the VC be stuck on full time and the light operating normal?


The PO had the lift done. Drop brackets were used on the front arms and degree bushing used. The pinion looks to be setup for a regular DS.

 

[OGBeno]

I plead ignorance, honestly!

My previous lifted SUV was IFS and did not have the aforementioned problems...

To the best of my knowledge the slee shaft compensated both for the increased length of the driveline when one considers the new angles, as well as a CV joint to butter up more extreme angles.

I guess I assumed caster correction was already in place... and I knew not of the DC shaft issues.

I know you're a technical dude. Spend some time here and many of your driveline questions will be answered (or at least illuminated):

http://pirate4x4.com/tech/billavista/PR-shaft/index.html

 

[OGBeno]

I will give Dan a call on Monday, thanks.

The light did go out and always does when going from low to high and depressing the switch on and off. Could the VC be stuck on full time and the light operating normal?


The PO had the lift done. Drop brackets were used on the front arms and degree bushing used. The pinion looks to be setup for a regular DS.

J's need more than bushings. Slee's plates might work--also, give Landtank PM. I think he's making some cool plates.....

 

[landtank]

The light did go out and always does when going from low to high and depressing the switch on and off. Could the VC be stuck on full time and the light operating normal?

With either drive shaft removed and the t-case unlocked the truck would only move if you rev'd the engine enough to have the VC engage. If it drove normally with the T-case unlocked I think you have a VC failure and might be one reason the truck is making noises.

 

[NaterGator]

I know you're a technical dude. Spend some time here and many of your driveline questions will be answered (or at least illuminated):

http://pirate4x4.com/tech/billavista/PR-shaft/index.html

Thanks.

I just read the 80 series driveline thread too, and all the slee bashing aside, it was a helpful read. It sounds like a cut-and-turn is the "proper" way to run a DC shaft, which makes me wonder how people get away with 4-4.5" lifts and standard shafts without cutting and turning.

More reading material. Delicious.

 

[VinSil]

Interesting. VC failure. Off to the FAQ for me then. Thanks.

 

[Tentsontop]

4 new U-joints from Mr. T will run you about $180 through CDan. Not bad really.

 

[VinSil]

That isn't that bad. I need a new EGR modular anyway, so it'll be all inclusive. Ah...I can't really find anything in the FAQ regarding the VC failure.


Anyone care to point me in the right direction?