Great! - A new noise from the driveline!

Cacher123 · **Posted:** Fri Jun 30, 2006 1:24 am

Ok, this is gettin worse. Ever since I've had it I get an occasional clunk from the driveline when I step on the brakes. Long story short I've gotten a new driveshaft, and had the slip yoke joint greased a couple times. Each time the noise goes away for a while. Now it's back and so bad that my GF is complaining and worried something is gonna grenade while we are driving. Of course every time I bring it to Jeep they find nothing wrong. When I accelerate it seems to "load" whatever is making the noise and when I hit the brake there is this loud "CLANG" that sounds like something is breaking free. And I can feel it! Sounds/feels like it's either coming from the center or right rear. Worse when the Jeep is really hot or after a long highway ride when I hit local streets. I think it gets worse when I make a full lock turn but can't be sure. 54k miles, 03 Rennie. Any thoughts?

This is what someone on here told me a while back:

Quote:

Clunking when stopping

Here is what the Jeep dealer told me:

When you brake the vehicle rotates forward (even if you have anti-lock brakes, which includes a two axis accelerometer to reduce vehicle dip). This 'dip' causes the driveshaft slip yoke (a fore-aft slip joint at the transfer case) to extend. The grease in this joint dries up or is displaced over time. Without grease the slip yoke does not move as freely. After the vehicle stops (no more deceleration) it rotates back to level. To rotate back the slip yoke must compress. There is more friction in the slip yoke due to the lack of grease. This extra static friction (and possibly binding) cause a momentary delay in the vehicle rotating back (leveling) .
When the slip yoke finally releases you hear a pop.

After greasing this joint the problem went away. Looks like this is going to be a regular maintenance item for some of us until Jeep provides a permanent solution.

Jeepjeepster · **Posted:** Fri Jun 30, 2006 7:43 am

Cacher123 wrote:

Ok, this is gettin worse. Ever since I've had it I get an occasional clunk from the driveline when I step on the brakes. Long story short I've gotten a new driveshaft, and had the slip yoke joint greased a couple times. Each time the noise goes away for a while. Now it's back and so bad that my GF is complaining and worried something is gonna grenade while we are driving. Of course every time I bring it to Jeep they find nothing wrong. When I accelerate it seems to "load" whatever is making the noise and when I hit the brake there is this loud "CLANG" that sounds like something is breaking free. And I can feel it! Sounds/feels like it's either coming from the center or right rear. Worse when the Jeep is really hot or after a long highway ride when I hit local streets. I think it gets worse when I make a full lock turn but can't be sure. 54k miles, 03 Rennie. Any thoughts?

This is what someone on here told me a while back:

Quote:

Clunking when stopping

Here is what the Jeep dealer told me:

When you brake the vehicle rotates forward (even if you have anti-lock brakes, which includes a two axis accelerometer to reduce vehicle dip). This 'dip' causes the driveshaft slip yoke (a fore-aft slip joint at the transfer case) to extend. The grease in this joint dries up or is displaced over time. Without grease the slip yoke does not move as freely. After the vehicle stops (no more deceleration) it rotates back to level. To rotate back the slip yoke must compress. There is more friction in the slip yoke due to the lack of grease. This extra static friction (and possibly binding) cause a momentary delay in the vehicle rotating back (leveling) .
When the slip yoke finally releases you hear a pop.

After greasing this joint the problem went away. Looks like this is going to be a regular maintenance item for some of us until Jeep provides a permanent solution.

Not to sure what they are talking about. When I brake, I do not nose dive everytime I hit the brakes. Anyway, its only slack in the drivetrain. Mine has always done it. Ive learned to be very easy when going from brake to gas and gas to brake. I let off the gas very slowly and it will not do it. If im giving t gas then let off real fast, or let off the brake and give it gas, my entire jeep will jump. The powertrax also made this much worse for me.

Jeepin Al · **Posted:** Fri Jun 30, 2006 9:56 am

Check your ball joints and CV joints. Check all five ball joints the four in the front and the top rear one to see if they are loose. The cv joints will clunk on braking also. Make sure the bushings on the a-arms are in ggod shape.

Al

asgates · **Posted:** Fri Jun 30, 2006 10:16 am

my '03 sport makes a similar clunking under heavy braking. i've checked over my joints and driveline and find no problems. i've asked others in my area if they expierenced a similar sound with thier KJs. some said yes, others no. i don't believe that it is anything to be ultra concerned about. does it occur only under heavy braking for you too, or all the time?

Cacher123 · **Posted:** Fri Jun 30, 2006 10:47 am

I'm not talking about a little clunk. I'm talking about a noise that has a metallic "snap" to it so loud that other drivers look at me like "What the hey just exploded?!" It happens almost every time I hit the brake, easy or hard, as soon as the pedal gets past about 1/4 travel. Worse when the vehicle is hot or wet.

Quote:

Check your ball joints and CV joints. Check all five ball joints the four in the front and the top rear one to see if they are loose. The cv joints will clunk on braking also. Make sure the bushings on the a-arms are in good shape.

Al

Thanks Al, gives me something to tell them to check. Gonna take it in on Wed since this would be covered under my 7/70 and I've complained about it before.

Jeepin Al · **Posted:** Fri Jun 30, 2006 12:26 pm

Sounds like you are talking about your CV joints. My old ones made a snaping noise on accel and decell. I don't think you can tell if they are bad by just looking and pullimng on them. Jack it in the front oneside at a time and leave the KJ in park, try to rotate the whell in the air by hand see what kind of movement their is in the cv's and shaft. See if you get them to make the noise

Al

Cacher123 · **Posted:** Sun Jul 02, 2006 12:37 am

Dlr won't have a free appt slot till the 11th. Of course there was not one clunk today when I was trying to isolate it. Then I hit the car wash and sure enough "clunk". Funny how it happens w/o fail whenever the KJ is wet. i wish I could pin it down.

Great! - A new noise from the driveline!

Who is online