[TJ-Q8]

Hi all
When i stop the jeep then let go of the brakes and accelerate there is a big thump from under. A mechanic said i have to grease the driveshafts, but then when i wanted to the joint have no nipples. There is a rubber boot only and no body wants to touch it i dont know why. any help on how to grease? and please confirm when the driveshafts need greasing thats wat happens.

 

[jasonwrangler]

I think you need new U joints. theres nothing you can grease.

 

[TJ-Q8]

I think you need new U joints. theres nothing you can grease.

so you confirm that the thump comes from the driveshafts? thats not good news from what i heard wrangler u joints are expensive especially the front one where there are to joints in one piece.

 

[Undefinedskillz]

My jeep does the same thing if I let off the clutch to fast. Nothing serious. Just a little jump. But I know it's not my u-joints. I recently changed those and the,"thump" never stopped.

 

[jgano23]

so you confirm that the thump comes from the driveshafts? thats not good news from what i heard wrangler u joints are expensive especially the front one where there are to joints in one piece.

i replaced the rear joints in my 05 tj 2 years ago. i don't know how parts pricing is where you're from, but the new u joint was under $20 from napa and it took only about a 1/2 hour to do.

 

[TJ-Q8]

My jeep does the same thing if I let off the clutch to fast. Nothing serious. Just a little jump. But I know it's not my u-joints. I recently changed those and the,"thump" never stopped.

What do you think it is? should i forget about it?

 

[TJ-Q8]

i replaced the rear joints in my 05 tj 2 years ago. i don't know how parts pricing is where you're from, but the new u joint was under $20 from napa and it took only about a 1/2 hour to do.

I think its the front one next to the transfer case that soo pricy.

 

[jgano23]

oh, got ya. the rear is the more common one to go bad, so i assumed that is the one you meant.

 

[TJ-Q8]

oh, got ya. the rear is the more common one to go bad, so i assumed that is the one you meant.

yeah thats true but iam kinda getting the thump from the front of the jeep so iam assuming its the front, but anyways if il replace i will replace all 5 i think in jeeps case? 3 in front and 2 in back?

 

[TjTheo]

Start by letting the clutch out slower and see if that's your problem, dont start replacing things just yet haha.

 

[TJ-Q8]

Start by letting the clutch out slower and see if that's your problem, dont start replacing things just yet haha.

still an auto. It even happens on slow acceleration after a harder stop.

 

[TjTheo]

Oh sorry, my moms automatic chevy monte carlo does that sometimes. When you dont stop fully and get back on the gas the transmission will slam into gear and basically shake the whole car.

 

[Schmo]

Should be easy to diagnose . . . first check for any play in the U-joints while the DS is on the Jeep, there should be zero so if you have any, you'll need to replace the U-Joint. Next step would be to pull the rear DS, shift into 4x4 and drive around . . . if the noise has gone away then it would point to an issue in the Rear . . . good chance it would be the DS vs. diff, etc and that would be where I would start as replacing U-Joints is cheap. If you think U-Joints are costly, then it's probably time to sell your Jeep and get a Toyota Camry or something that doesn't need much maintainence. You won't get off much cheaper than replacing U-Joints . . . just about everything else is going to cost 10x to 100x the cost of a U-Joint to repair. If you really think the noise is coming from the front DS, then just pull it off and if the noise is gone, then you've found the culprit, but I'd expect it to be the rear as unless you are driving around in 4x4, there is no power going to the front DS to make the big thump noise.

 

[jeepjones]

What do you think it is? should i forget about it?

Never,never forget about it!!! Keep up on the maintenance it's part of owning a JEEP. The u joints,ball joints etc from the factory are not able to be greased but they do wear out and need to be replaced. Replace them with ones that can be greased. If you blow a Drive shaft the damage that can result can be devastating depending on how fast you are going, it can completely take out tranny's, t -cases, diff's and quite possibly the entire jeep (accident).

 

[Schmo]

x2 on what jeepjones said. Figure it out or you could have something like this to look forward to (not my Jeep)

This is what can happen if the front DS lets go on you . . .

. . . you thought a U-Joint was expensive!!!

 

[My89yj]

When it was said that there was no nipples on the drive shafts are there any that are broken off or removed? There has to be at least 11 or 12 all together on a stock yj and even if Tie Rods and BJ's are sealed from the factory then you would atleast have 1 on the slip yoke and 3 on the drive shaft u joints never mind the pitman arm and drag link and steering connection but you should always grease regularly I perfer to use the needle grease gun fitting makes things smother and easier to grease old rusty grease zerc's or zerc's that were installed backwards on drive shaft u joints.

 

[Schmo]

TJ's don't have zirks on the stock DS or U-Joints, so don't bother crawling under the jeep looking for busted nipples.

 

[Ggg]

From the initial description I would suspect a slip yoke is sticking. I doubt it is the rear because it is lubed with t-case oil. I bet the front is the issue. The slip yoke is inside the rubber boot. You need to mark the DS for spline alignment, then remove the front joint, then cut the metal clamp and the slip yoke will pull apart. I use Ford PTFE spline grease (blue), apply a thin coating on the splines and reassemble. Remember to align the marks so the two DS sections are in proper phase. replace the metal boot clamp you cut off.

 

[Ggg]

Man I hate this stupid edit time limit.
Correction on the Ford grease.
It is Ford XG-8 3oz tube
or Ford D2AZ-19590-A is a large can.
The 3oz is plenty for one vehicle.

 

[aelwero]

U-joints are easy to check... put it in park, crawl under it, have a friend push it back and forth (IN PARK) a few times while you try to turn the driveshafts. If anything gives then it's prolly a -joint, and if you'r under there checking em, you'll know which one. back, front, left, right, you can see it and feel it.

If a u-joint is clunking, all the grease in the world won't help. replace it. it's cheap (even the ones on the cardan), it's not that hard, and if you wanna get all fancy, you can ask for joints with grease fittings and the guy at the parts store will probably have em in stock.

If all the u-joints are good, read GGG's post on slip yokes.


as a "quick check"... go push the jeep foward and back in park and see if you hear the clunk... if not, find a parking lot, do a hard stop, don't move it anywhere, put it in park, shut it off, get out and go lift up on the front bumper as hard as you can... if that makes the clunk, then go straight for the slip yoke