VTJeep

there is somebody on here whoes tag reads
"whats that noise?"
"idk, its a jeep.. it makes noise.."

well, yea, i guess thats true. so what is this new noise that has developed?

it went from kinda like 35-40ish and slushy to kinda cold and frozen the other day. i drove around in the warm slushyness for a little while then when i went to work, i had to put it into 4wd. so i parked and left it, still in 4, for the day. that evening i took off, still in 4, and there was a clunk like diveline play that would happen both on acceleration, and when i took foot off of pedal. it was more noticable when decelerating. it seemed like the noise got a little quiter after a bit, but even now (2 days later) it will still do it. my 4wd has been working well and i assume all fluids to be ok, though i havent actually checked... so you guys tell me... idk if its anything to really be worried about, usually never seems like it is with a jeep!! haha. it needs a little shop time anyways; last time wheelin i had to throw a chain around the rear axle and i pinched a break line a little. also one of my lower control arms is "peeling" apart around the eyelet. and my drag link is slightly bent. and my belts been squealing. and... well ****, maybe thats it... well, aside from the weird electrical stuff like my (i think) resistor switch for my fan, the rear wiper rocker switch wont do just the wipe, you have to push it all the way down to the spray setting for it to work, i just discovered that my horn isnt working, and my airbag light wont go off. so yea, standard jeep stuff. ok, im done now. peace.

VTJeep

what, was i excessivley wordy, or something? idk, just hate the waiting game...

XJeepWerks

Check your front driveshaft for play. Get under the Jeep with it in park and try to move the front driveshaft in every direction possible. Be rough with it... Act like your trying to rip it off. You won't break anything doing so.. And if you do, it needed to be replaced anyway. A good driveshaft shouldn't have any play in it. If it does, it's most likely a bad u joint.

VTJeep

i will go check now... recently replaced the u joints, so they are good. the noise seems like it is all in the rear... idk, ill brb...

VTJeep

o, so i got down there and checked the front driveshaft, there is some play when i spin it, but nothing else. so in being new to all this, forgive my newb question: there are u joints (or somthing of equivelent) in driveline?

XJeepWerks

It could be many things. Driving the Jeep in 4wd puts more strain on the drivetrain and can make loose parts "Clunk" easier. These steps are in no particular order.

1. Visually inspect your trans mounts and make sure they are in good condition. Cracking or breaking in the rubber would indicate a bad mount.
2. Make sure your transmission crossmember is bolted down tight.
3. Check your rear driveshaft the same way you checked the front.
4. Check your motor mounts. (If you need info on how to do this, ask. You will need another person to help you)
5. Check your front axle u-joints. To do this, reach behind your tire and find the u-joint at the end of the axle tube. Checking this goes along the same lines as checking your driveshaft u joints... Check for movement. They shouldn't move much, if anything at all.
6. Check your wheel bearings, front and rear. To do this, grab your wheel/tire on the top from the side of the vehicle and try to move it up and down. (Push in and out on the top of the tire) It should have little to no play in it. Grab the tire from the sides and try to turn it side to side. There should be little to no movement in this aswell.
7. Check all steering components. Also do this by attempting to move them. (Check trac-bar specifically)

XJeepWerks

Sounds like your front driveshaft is in decent shape. Driveline is a universal term that refers to the entire system that delivers the power from the engine to the ground. Driveshafts have u-joints on either side and the front axle of your Jeep has them on either side.

VTJeep

ok, ty for the info. i guess i should run thru the list of poss. issues and see what i get. i would guess that i couldnt get more that 1/8-1/4" play on front driveshaft, is that cool?

XJeepWerks

Less could be desirable, but that sounds ok. Is your Jeep lifted?


Here's a basic diagram of your Jeeps driveline and all of its' driveline u-joints. http://www.jeep4x4center.com/jeep-un...herokee-xj.htm

VTJeep

well... its got a 2" bb... so no, its not lifted

XJeepWerks

Even that 2" BB can cause some problems in the driveline. That 1/8-1/4" play in your front driveshaft could cause a problem.

VTJeep

huh. didnt realize that, what kinda issues would the bb cause?

VTJeep

marky mark and the BUMPy bunch

XJeepWerks

When you lift a vehicle, it also pulls the transmission and transfer case up, which is what your driveshaft is connected to. Your axle remains on the ground, which is what the other end of your driveshaft is connected to. Doing this increased the angle of the driveshaft in proportion to the ground and the vehicle. This increase in driveline angle puts more strain on the driveline, which would make loose components show their face easier.

Here's a picture to explain it a little better:


The blue line is the driveline angle. When the Engine/Transmission is raised while the axle stays on the ground, the angle is increased.

VTJeep

i see... so my best/cheapest fix? (ty in advance)