[OAS]

Should the rear driveshaft have any "play" or "give" to it if you twist it?

Sometimes it doesnt move at all, sometimes enough to make a "clink-clink" noise when twisting it real hard. (maybe 1/8-1/4 inch play??)
And no it's not the u-joints.
I noticed the front driveshaft does this also, but all the time.
(and more play in it than the rear.)

My son's '96 sport does the same thing.
But my old Bronco2 with 180,000 miles on the original 7.5 rear does not.
Ive searched the forums a bit, and there seems to be conflicting answers.

It seems to drive o.k..
Maybe i'm just being paranoid?
(i have been accused of that before! LOL!)

 

[Kyle]

Could be a stretched chain:dunno:

Mine does that a very small amount aswell but I have no problem as far as drive ability goes.

 

[littleblackxj]

How are you sure it's not your U-joints? It really sounds like it is because drive shafts should be solid. Does the output shaft on your tcase turn as well or just the drive shaft? Can you "wiggle" the driveshaft?

 

[OAS]

Doesnt wiggle, just when you twist it.
Like twisting the throttle on a motorcycle.

I bought 2 hd u joints from Napa anyways, just in case.

It also has a "base" sounding noise occasionaly at speeds of 40 and slower.
Like a car a few lanes over was cranking up their sterio.
The noise does not change pitch with speed though.
It stays the same (when it does it) at 4 mph or 40, after that it dissapears.

Does it take special tools to swap out u-joints on the rear driveshaft?

 

[BowtieGuy3]

You can buy one or rent one down at the local parts store. Get a ball joint press, it has all the sleeves for doing ball joints, or set up without them it works as a u-joint press. keep some pene fluid and a torch handy just in case... Oh, some needle/snub-nosed pliers and a few screwdrivers too.

 

[2000XJ]

Play in the font driveshaft is normal (as you described 1/8-1/4"). Just make sure to keep it greased.

However, it is possible that the u-joints may be tired and worn out, and if you do swap them, you will probably still have the same amount of play in the driveshaft.

 

[OAS]

A question on the rear driveshaft.

I removed the 2 straps holding the rear u-joint to the pinion flange.
And went to pull it out............but.....
there are these goofy little thin "clamps" (kinda looks like a one time use hose clamp) that are on the front & rear of this accordian "dust cover".

Do you have to remove just the rear one?
or both?
And what do you use to resecure the boot when your done?
Ive never seen a hoseclamp that thin.
What else works? zipties?
And will tranny fluid come out when removing the driveshaft?

Don't see how as it comes out of the trans.case. And i just changed trans.case fluid today. (dexron 3 , right?)

 

[finneys98xj]

pics

 

[2drx4]

Guess I'll say it... Play is normal and acceptable as long as it is not through the u-joints. To check the u-joints, you have to isolate them... So, hold off the yoke then try to turn the driveshaft back and forth (wiggle). If the driveshaft turns any without turning the yoke - ya need new u-joints.

Replacing ones that aren't bad is a bit of a 'waste' IMHO.

 

[OAS]

pics

and yea, ive held the slip yoke and the rear pinion still, and cant get any movement out of the u-joints.
In fact i popped the caps out of the rear ones when i had the pinion straps off, and they still had grease in them.
not gobs of it, but enough. i added a bit to them anyways.

 

[JeepGodXJ]

Mine does the same thing. I know it's not the U-Joints so I just called it being "normal". And I think hose clamps should work just fine.

 

[OAS]

Your prolly right about the hose clamps.
The gaps on the boot is pretty narrow though.
So i found a way to reuse them.

Loosened them up with needlenose & a screwdriver.

Then used a pair of old blunt wirecutters to squeeze them back together.

The slipyoke was almost dry of grease, so i stuffed a bunch of RP's best in there.

 

[4.3L XJ]

The twisting you refer to is normal. When the gears in the differential are set up they have a small amount of play called backlash. Normally this is only about .008" of movement on the ring gear when set up new. As the gears wear, the amount of free play or backlash increases. If the gears are not growling, don't worry too much about it I would suggest however that you change the oil in it.

Steve

 

[whowey]

There doesn't need to be any grease inside of the dust cover.... There is nothing in there that will stay greased. The seal at the back of the transfer case nose will wipe off any grease that was on the slip-yoke anyway.

 

[OAS]

It also has a "base" sounding noise occasionaly at speeds of 40 and slower.
Like a car a few lanes over was cranking up their sterio.
The noise does not change pitch with speed though.
It stays the same (when it does it) at 4 mph or 40, after that it dissapears.

Is this what you mean by "growling"?

The noise is not constant, it sounds literally like another car a few lanes over with the base in the sterio turned up.
A deep muffled base sound.
(and a very slight low frequency vibration. maybe my imagination?? LOL)
Kinda like a tire road noise. But ive had them balanced.
And it doesnt change pitch with speed.
And at speeds above 40 (ish) i cant hear it at all.
Even under hard acceleration.

I changed the diff oil (rear & front) a few weeks ago.

Didnt notice any odd wear patterns or chips in the gear teeth.

Ive also changed out the transfer case oil, and greased the slipyoke.

 

[OAS]

Well, i broke down and took it to a local shop.
(prolly should have done in the first place)

Ironicly right next door to where i work.
An auto / fab shop that specializes in Jeep / offroad / custom built rockcrawlers no less.
The guy took it for a drive and then put it on jacks/ lift and ran it up to 40 mph.

He told me this is "fairly common" on XJ's and more common on TJ's.
Said it was "normal gear wear".
He said unless it gets REALLY loud, to not let it bother me.
They told me that it would probably not give me any problems as long as i owned the Jeep.

If they were to rebuild the rear end he said it would take a couple days and cost around $700 to $800.
But he said this is a fairly normal occurance, and that i'd be wasting money by getting the rear rebuilt.

I do admire the guy's honesty, as he could have told me it's gonna grenade, and make $800.

So, IS this fairly common? (Jeep forum'd be the place to ask.)
I think i saw a post or two on these boards about this kinda thing.

Maybe i'm just too used to smooth, quiet Fords! ha ha!

 

[Kyle]

Honestly poor gear wear would have been the last thing I would have thought of.

 

[2000XJ]

I'd say it's normal play, and that you really don't have to worry about it.

 

[OAS]

Well, the guy didnt say "poor gear wear".
More like "normal gear wear".
He said it could prolly go another 100,000 like it is.

He didnt even pull the diff cover to look.
He recognized the sound from driving it. They just put it on ramps and ran it at speed to confirm that it wasnt something else.
(glad they didnt pull the diff cover. RoyalPurple 75-140 is $15 a quart!):bow:

I did take a few real good digital pics of the gears when i changed diff oil.
And i took a disc over to them to check out just in case.
(fuji 9.3mp camera)
Waiting to see what they say about them.

I dont think they'd steer me wrong.
My buisness and theirs have a good relationship going.
We lend them our forklift from time to time when they get a big load of steel.
And they give us a good deal on brakes & repairs on our shoptrucks when its needed.
Theyr kinda the local offroad "gurus" around Farmington.
We always see lots of cool rides over there getting worked on.
Old Bronco's, Jeeps, rockbuggies and such.
They even fabricate tube framed buggies and racers there.
I envie them, they always have cool toys to play with!:rofl::bow::rock: