Safe? Unsafe? common practice? sounds stupid

[kbeefy]

I've ran vehicles on jackstands. Never got under any of them.

I second the ujoint diagnosis. Noise changes with speed means it's somewhere between the wheels and t-case.

I check ujoints by putting the vehicle in neutral, grabbing the driveline and checking them for play. Rocking the vehicle in gear is a good way also, and can point out control arm issues as well.

 

[91 PBP 5079]

You think its spooky laying under a 4000lbs truck try laying under a 20000lbs fork lift and try not to think how flat you will be if the jack stand collapses runing or not.:ack:

By the way is ther any vibration. Also ask the neighbor if your truck makes a rythmic squeek as you go up the street.

 

[n8thgr8]

I can hear a bit of a rhythmic squeak, but only at slow speeds. I probably just can't hear it at higher speeds, due to road noise and such.
I"ll be under the truck in a few minutes to check for play in the u joints...

 

[n8thgr8]

Musky, it's a 98 d1 and it has a rear ujoint. At least i don't see anythint that looks like the rotoflex couplers I've read about.
Ok, so I was just under the truck rocking away, and I noticed a couple of things, but I don't know what they mean.
First of all, zero play in the rear. Only moved a little bit when rocking the truck back and forth. I'm guessing it's not the rear
Second, there was a lot of play in the front. Even when not rocking the truck.
I noticed that when I moved the prop shaft back and forth that the transfer case was allowing it to do so. Is this normal?

 

[jymmiejamz]

I can hear a bit of a rhythmic squeak, but only at slow speeds. I probably just can't hear it at higher speeds, due to road noise and such.
I"ll be under the truck in a few minutes to check for play in the u joints...

Does it do it when you are putting on the brakes? I'd check the bearing preload on the front wheel bearings. To see if the is excessive play jack up the front tires and grab the top and bottom of the tire and shake it back and forth. If there is any play then that is too much and you should re pack your wheel bearings and adjust the preload.

 

[MUSKYMAN]

Musky, it's a 98 d1 and it has a rear ujoint. At least i don't see anythint that looks like the rotoflex couplers I've read about.
Ok, so I was just under the truck rocking away, and I noticed a couple of things, but I don't know what they mean.
First of all, zero play in the rear. Only moved a little bit when rocking the truck back and forth. I'm guessing it's not the rear
Second, there was a lot of play in the front. Even when not rocking the truck.
I noticed that when I moved the prop shaft back and forth that the transfer case was allowing it to do so. Is this normal?

ok now we are getting somewhere.

what type of play did you see when not rocking it?

if there is no play in the rear for now we will focus on just the front.

when you say back and forth are you rotating the shaft or is the shaft moving forward and back? does the front out put shaft comming out of the transfercase seem loose? can you grab it and wiggle it in any way?

 

[Blue]

I KNOW I'm going to get ripped on for this, but there is sort of a serious question in here somewhere...
So I'm experiencing some noise under the ol' truck, but I can only hear it when I'm driving 30+ mph.
The only thing I can think of is putting all 4 axels up on stands, removing the wheels (you know, for safety!), and laying under the truck to help diagnose this as a buddy is in the car...
Maybe it's just the common sense in me, but this just sounds ridiculously unsafe and goes against my better judgment as a reasonably intelligent human being. :ack:
Please tell me that this is in the same category as driving with a friend under the hood, or strapping someone underneath.
What do you guys do to diagnose those mystery sounds underneath that show up when you're driving?

The problem is obvious - you have two extra axles rattling around under there. Duh.

 

[bri]

That's why my belts are horsehide

Yeah, but what about the loops?

 

[n8thgr8]

Jymmie, It's probably not the wheel bearings, I've recently redone those.
Musky, Good question, the front shaft is rotating side to side, not front to back.
No, I don't believe that the output shaft from teh TC is loose, but I will check again to be sure.
I also greased only 1 zerk to see if I could isolate the problem. I didn't grease the u joints, just the rear side spline zerk. This morning while still there, the noise was quieter.

 

[MUSKYMAN]

Jymmie, It's probably not the wheel bearings, I've recently redone those.
Musky, Good question, the front shaft is rotating side to side, not front to back.
No, I don't believe that the output shaft from teh TC is loose, but I will check again to be sure.
I also greased only 1 zerk to see if I could isolate the problem. I didn't grease the u joints, just the rear side spline zerk. This morning while still there, the noise was quieter.

ok there should be some slack/lash/rotation in the front shaft as that is the lash in the center diff lock you are feeling and that is normal.

Dont assume that just because you have just done the wheel bearings that there isnt a problem with them. I just had a front wheel bearing spin on the spindle on my disco only about 500 miles after all brand new timken bearings where installed in. I have done hundreds of these so I know I got them right but a bad bearing can fail at any time.

 

[n8thgr8]

I'll check the wheel bearings again then.
I think I'll also get one of the mechanics from the hobby shop here on base to help me take a look this evening.

 

[n8thgr8]

Sorry, I think I used the wrong term to discribe the zerk I greased, I believe it's the "slip joint" not the spline.

 

[MUSKYMAN]

close enough ...

now go back to your original idea.

running the car on jack stands isnt a good idea but putting it up on jacks stands both front and back and then putting the transfercase in neutral you will be able to turn all the different parts of the drivetrain.

do this slow and careful and you may be able to hear where the issue is.

 

[RVRSRVC]

Just curious, did the noise start after you fitted the taller springs?

 

[91 PBP 5079]

The up and down play in the front out put flange is somewhat normal. Is the squeek in time with wheel revolotion or drive shaft. If it in time with drive shaft you may have a dry or failing Ujiont. If in time with wheel it could just be squeeky brakes. Just drop the drive shafts and and check the UJs that way. What the heck most of us on here can take a drive shaft off in our sleep because we have had them off so much.

 

[n8thgr8]

No, the noise started long after the springs.
I think what I'm going to do tonight is take the front shaft off, lock the dif and see if the noise comes back during a little drive.
I'll clean up the shaft while it's out and inspect it really well. I may just put some new u joints in because of the milage on them. I'm pretty sure I'm nearing around 60k or so.
I'm not experiencing any vibration, now, and I'm worried about messing with too much and not getting the re-install right and messing things up more.
Is there a NAPA part # that I should ask for? or can I just ask for a replacement for my year rover?

 

[n8thgr8]

The problem is obvious - you have two extra axles rattling around under there. Duh.

I should have THOUGHT about that one! I may have 2 extras for sale in the parts section...

 

[gmookher]

I've run my d2 on jack stands, using all the common sense and safety precautions

doesnt tell ya much, TC keeps kicking in...

with 3 jack stands per axle, I've felt totally safe, with tire removed of course

its un nerving when you see the shaft spinnin and all, but we drive 80mph, that shaft spins alot faster than i can get to on stands

thats three 6 ton stands

 

[n8thgr8]

Yah, the idea just still sounds freaky to me.

 

[66rover99]

If you leave the wheels on you need to have load range D tires on your creeper as well.