Front diff leaks? (1 Viewer)

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Went out to check the mail today and saw a puddle of fluid under the 100....

I had just changed the oil so that was my first thought. took the skid plate off and saw it was coming from the output shaft on the driver side where the CV connects. I checked the breather but I can't tell if it's clogged. The cover on the top the breather did not want to pop up at first I had to work it a little.

about a week ago I did start to cross a creek but I backed out once water started coming over the hood. Didn't start leaking until today though.

What are my options here?

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its a 12 dollar seal. if toy know what you're doing you can pull the axle without taking the hub apart using the quick method. what's your skill level?

Maybe 7 out of 10? ok maybe a 6.5 but I can usually figure things out.

I've replaced thermostats, wheel hubs, spark plugs, brake jobs. basic stuff
 
Also check the front diff breather for clogs. Mine was doing the same, seal probably wasn't replaced when PO did front drive shafts. Replaced seal with new OEM, which helped substantially, but still have small leak because of aftermarket driveshaft fitment. So, could be the driveshaft too, in my experience.
 
well then the steps are these:
jack up and remove wheel.
remove grease cap from hub.
remove snap ring from axle shaft.
remove 2 caliper bolts and hang caliper out of the way.
separate the upper ball joint and tie rod end. (careful when doing ubj, it can fall forward on you. best to leave nut slightly on to catch it)
now turn push the knuckle away and down and slide the axle out from the hub. if this is difficult then just remove lower ball joint and get the whole knuckle off.
use two long screwdrivers or medium sized pry bars to pop axle out of diff. protect seal and dust shield that is located on the outboard axle.
confirm your seal is correct size. they are different for driver side and passenger side.
then pry old seal out. take note of its seated depth.
drive new seal in. don't drive too far or it won't seal properly. there is an inner lip that the seal fits flush with.
pop axle back in. careful to not damage new seal.
attach knuckle again, torque the balljoints and TRE properly. they are all different. replace cotter pins with new stainless pins. (home depot 1/8" by 1.25 inches or so)
use a bolt to pull axle out as far as possible and fit a never used snap ring. probably 2.4mm unless excessively worn.
replace grease cap.

I'll try to edit with part numbers and torque values.
Lower Ball joint 117ft-lbf
TRE 90 ft-lbf
Upper ball joint 81ft-lbf

diff oil seal (driver side)..9031147013..13.25
diff oil seal (passenger side)..9031147027..12.18
snap ring sizes with part numbers. $2 ea.
9052031005 (2.8mm)
9052031006 (2.6mm)
9052031007 (2.4mm) * probably need this size
9052031008 (2.2mm stock size just in case)
this video is step by step. just replace the seal when you get there. has torque values.

different sized seals depending on side
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snap ring order extra. order this when you order your seal.
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here's the bolt i use to thread into axle to pull on it. you don't need to pull so tight since you aren't repacking bearings.
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these caliper hangers are super useful. got them from rock auto
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there's the seal you're after. if you jack up only one side only you won't lose much oil at all.
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finally here's a how NOT to do it. but it does give the idea behind the "quick" method.


2001LC is where i learned most this stuff. if you need more reading or more details:
 
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wow thanks for all that dude, that's crazy helpful. I think I'm going to re run my breather lines to while I'm doing this as well since I'm in there.

I'm wondering if I should do both seals?
 
wow thanks for all that dude, that's crazy helpful. I think I'm going to re run my breather lines to while I'm doing this as well since I'm in there.

I'm wondering if I should do both seals?
naw. save it for the next time you do rotors. no need to get into it out you don't have to. just solve the leak for now.
 
I looked under the truck and since I popped the top of my breather it hasn't seeped anymore. I'm going to drive it a little tomorrow and see if it leaks anymore before I order the seal. Or would the pressure build up cause the seal to fail anyway?
 
As a precaution; I'd drain gear lube inspect for water.
 
As a precaution; I'd drain gear lube inspect for water.

That sounds like a good idea. Do you think the seal needs to be replaced regardless at this point? Or can I safely refill and rerun my breather?
 
These seals do not often just go bad on their own. So I'd be inclined to watch for seepage after breather cleared and gear lube flushed. If seal still weeps, I'd add 2.35 oz. of AT-205. Watch for seepage again, after 5 or more hours driving time. If still leaking/weeping, I'd then go ahead and replace the seal. If close to wheel bearing service, combine with diff tube seal job. Doing a knuckle service at same time.

If doing just the diff tube seal. You can do without disconnection the TRE.

Note: If any signs of water in gear lube. I'd use some cheap gear lube and re-flush after a short drive to warm up. Then add the quality gear lube and AT-205.
 
I would drain and fill your diff, verify the breather is breathing, and then inspect for leaks. If it still leaks, you can pull the cv and replace the seal in under two hours if you watch some videos before you get started.
 
Well s***, it was still dripping slightly this morning. Looks like I'm going to have to replace that seal.

The bearings haven't been done in a long time (service records just say "inspect or repack" at it's service at 97k miles. Diff fluid looks like it was changed at that time as well. I'm at 185k now.


Why do you need different size snap rings?
 
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Well s***, it was still dripping slightly this morning. Looks like I'm going to have to replace that seal.

The bearings haven't been done in a long time (service records just say "inspect or repack" at it's service at 97k miles. Diff fluid looks like it was changed at that time as well. I'm at 185k now.


Why do you need different size snap rings?
Overtime the gap between cv axle and housing/hub can increase. The stock c-clip is thinner, but over time more wear and tear occurs and that gap widens, resulting in needing a thicker c-clip.
 
How do you know if you need a thicker C-clip?
 
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measure
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since you haven't done a bearing repack in some time it's probably time to just do it. you got some reading to do.
it's really not that bad. my project thread has all the possible related part numbers if you need it. and i insert many related YouTube videos that show the details. my thread is not a how to but does give a relatively quick overview for someone who hasn't done it.

 
Thanks for that info. I ordered the seal and all the snap rings you recommended.

I'm going to re-run my diff breather, and try refilling and adding some AT 205 first just to see if that stops it. If that doesn't work I'll go ahead and swap the seal.

Where can I find the specs for the clearance on that clip?
 
this is 2001LC method.


his related thread.

basically you pull out the axle as far as possible and put the biggest snap ring that will fit. they come in .2mm increments.

btw do you have a driveline clunk from reverse to drive? hopefully not. and by using propper snap ring you can help prevent the clunk. clunk comes from worn splines in the cv shaft. if you have a little play, a new flange can help tighten it up. too much play and you'll need a new cv shaft. ask me how i know!
 
this is 2001LC method.


his related thread.

basically you pull out the axle as far as possible and put the biggest snap ring that will fit. they come in .2mm increments.

btw do you have a driveline clunk from reverse to drive? hopefully not. and by using propper snap ring you can help prevent the clunk. clunk comes from worn splines in the cv shaft. if you have a little play, a new flange can help tighten it up. too much play and you'll need a new cv shaft. ask me how i know!


I do have driveline clunk that I suspected was the bushing on the diff. mounts since I saw them shift when moving from P to D. Seemed to be where the noise was coming from. I may have to look into new hub flanges
 

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