pmtg

go figure, i had some plans for the truck as far as the fun factor, but now i have noticed a bad vibration at certain throttle positions and leaking diff fluid (front and rear).

the vibration: mainly noticeable above 65mph. if im holding speed or completely off the throttle, no vibration. if i let off just enough where the engine is neither accelerating the truck nor compression braking, it will give off a good humm...makes the mirrors shake. feels like it is towards the rear. rear u joint? rear transfer case bearing?

leaking diff fluid: leaking out of the pinion on the rear axle. the culprit might be helping cause the vibration problem? pinion bearing? the vibration started a week ago, no highway driving during the week so it left my mind. leak started this sunday after some four wheeling this weekend. when i drove home on sunday, the vibration wasnt noticeable until 40 miles into the trip. also, leaking out of the front axle on driver's side, axle tube side. i hope that makes sense.

i have NOT done any work with axles before. u joints dont seem bad, would i be correct in saying that? the bearings i described (transfer case, pinion, front axle), what type of work do they sound like? all day, bloody knuckles? im trying to get a feel of what i can do myself on a saturday and what i should look into getting fixed by the experts.

lets hear what you have to say and where i should locate the parts...


thanks in advance, Pat

G1625S

Could be any number of the things you mentioned...in my experience, the further fron the t-case, the more pronounced the problem for a given amount of wear/damage. For instance, my rear t-case output bearing has tons of play and a shot seal, yet it produces no noticible vibration at any speed. However, I just banged a new u-joint into the back of the rear driveshaft yesterday cause it had one cracked cap. When the cap went, it was obvious that something was wrong right away. As for the time a given repair may take, it all depends on your experience. It's pretty easy to pull the driveshaft and at least check the caps for play and whatnot...that'll give you a quick answer for about an hours worth of time. If there is a bad joint and you've never done 'em before, it may be worth the 1/2 hour shop charge to have the local garage bang one in. While the shaft it out, grab the pinion and check for play....a bad u-joint can take out the pinion seal, so don't panic right away--the pinion bearings very well could be just fine. Axle work is definitely not for the faint of heart. It's one of those mechanical anomolies that requires both a dial indicator AND a 5 pound dead-blow hammer FWIW, these drivetrain components are not for kids, so there will be some inherent play/slack that might be scary on an explorer or even a 1/2 ton truck, but is just part of the program for these beasts. Good luck finding the source of the vibe---keep us posted!
g

Big Perm

I say bad u-joint.

It sounds like your leaky pinion seal may have been caused by a bad u-joint.

All my experience is in Jeeps and I do all my own work and I'm sure as hell no machanic. The trouble with pinions is the the nut and when you start looking at crush sleaves and whatnot. Then you are required to put the **** thing back the way you found it or you throw off the pinion depth which impacts the gears.

I would follow TK421's advice and pull the driveshaft off and check the u-joint. If it's screwed, then if you don't want to do the work yourself put it back together and take it to a shop. If it's the pinion bearings... well.. it's not an impossible job by any means, but you will want to read up on it... but axles, tcases, driveshafts.. those aren't too bad.. Gears is what I stay away from like the plague

I'm happy to pay for that work

bgilbert

Or loose pinion yoke nut.

pmtg

to add a little...

i never let it run for extended periods during the vibration (i will either speed up or slow down to drive around it).

it does not squeal in any way.

it gives a good "clunk" when engaging the tranny into any gear.

front axle diff fluid leak, any thoughts?

thanks, Pat

Big Perm

Where's it leaking from? If it's also from the pinion then did you drive over some rocks and whack both your front and rear DS?

apwatson50

block your wheels and put the trans in neutral and go turn the drive shaft back and forth by had and see if your u-joints are worn. you'll be able to tell pretty easy no need to remove anything

wannadiesel

The clunk is probably a worn cross pin in the differential (assuming the u-joints are OK).

Like apwatson said, you can check the u-joints on the truck. Make sure it's out of Park, then go under and try to find anything loose. If the u-joints feel the slightest bit loose, they are toast. Try to wiggle the pinion shaft, if it doesn't move the bearings are most likely fine and you'll be able to just replace the seal. Still not fun, but less involved than the bearings.

Where's the front axle leaking, or did I miss that?

92DIESEL

I think he said the tube by the drivers side.

apwatson50

I wouldn't worry about oil leaking out of the tube on the front axle, he said he was 4-wheeling and when you get on much of a camber oil will leak out. there's not much of a seal on the axle shaft and to change them you have to take the carrier out. pretty much you have to disassemble the front axle. This is assuming its the same design as a dana 44. I don't know why it would be different. Just make sure its full.

Also for the vibration. Did you land on a rock with the driveshaft and bend it?

pmtg

not my pic, found this on the web...its the first picture displayed.

pic of leak

pmtg

the vibration started before i went wheeling and i know i never hit anything before the wheeling weekend. but hitting something during the weekend could have sped up the ending to what was starting to go wrong.

the driveshaft had to have been on the ground at some points, not much clearance down there. mud and weeds mixed with the spinning of the driveshaft sounds like potential to take out the seal and possibly the u joint.

i will replace the pinion seal. i just hope those bearings are OK. i think u joints are in order, but i still need to check them...


thanks for the help so far, Pat

DODGE 92

my guess is u joints and leak cause by vent blocking if it looks like pic i saw its a blown seal

timb

If it clunks when you put it in gear, then I would say you have a bad u-joint. as for the front axle tube leaking fluid, mine does every time I change the fluid, till it gets to a level that it does;nt want to any more.

pmtg

rear u joint has a 1/4" of play in one direction...can you say toasted?