Reasons my rear diff vent tube is leaking gear oil? - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Cherokee & Comanche Forums > XJ Cherokee Technical Forum > Reasons my rear diff vent tube is leaking gear oil?

Dual Color LED Light Bars White/AmberTJ 5.25" Speaker Adapters - NalinMFGAlloy USA Still Available

Reply
Unread 11-01-2011, 07:16 PM   #1
phmaris
Registered User
1999 XJ Cherokee 
 
Join Date: Oct 2008
Location: Harrison, Oh
Posts: 384
Reasons my rear diff vent tube is leaking gear oil?

All of a sudden, my rear differential vent tube is leaking gear oil pretty bad. It is pouring down the frame rail and leaving a baseball size puddle on the driveway after sitting for the day.

I have no clue why this would happen all of a sudden. I have changed the oil less than a year ago. I have not driven through water at all recently.

My seal is leaking very minimally. Just a trace of oil about two inches down the diff from the seal.

Anyone have any ideas?

phmaris is offline   Reply With Quote
Unread 11-01-2011, 11:08 PM   #2
EricsXJ
The Post man
 
EricsXJ's Avatar
2000 XJ Cherokee 
 
Join Date: Apr 2001
Location: Reno, Nevada
Posts: 8,564
What rear end, D35 or 8.25? Have you done any work to it or added anything like a locker or different carrier other than stock?
__________________
Eric
2000 XJ "PROJECT RUBICON" 3-link front / 4-link rear / coilovers / running 37's on Dana 60s
My website - EricsXJ.com

EricsXJ is offline   Reply With Quote
Unread 11-01-2011, 11:40 PM   #3
Wearingthin
Registered User
2001 XJ Cherokee 
 
Join Date: Apr 2008
Location: Florida
Posts: 1,406
Positive it's diff fluid and not brake fluid leaking from the hose near the frame rail?
__________________
Patriot Blue XJ 4x4
RE 4.5" | 305/70/16 MTR K

My Build Thread
Wearingthin is offline   Reply With Quote
Unread 11-03-2011, 11:04 AM   #4
phmaris
Registered User
1999 XJ Cherokee 
 
Join Date: Oct 2008
Location: Harrison, Oh
Posts: 384
Its a stock 8.25 now with a rockcrusher diff cover. Im pretty sure its not brake fluid. It smells and looks like gear oil to me and its pretty easy to trace the leak up to the vent tube.

Going to throw it up on a lift and look at it more tonight but Im pretty sure its coming out of the vent tube... and a lot of it
phmaris is offline   Reply With Quote
Unread 11-03-2011, 11:16 AM   #5
Wearingthin
Registered User
2001 XJ Cherokee 
 
Join Date: Apr 2008
Location: Florida
Posts: 1,406
Quote:
Originally Posted by phmaris View Post
Its a stock 8.25 now with a rockcrusher diff cover. Im pretty sure its not brake fluid. It smells and looks like gear oil to me and its pretty easy to trace the leak up to the vent tube.

Going to throw it up on a lift and look at it more tonight but Im pretty sure its coming out of the vent tube... and a lot of it

I'm not sure why it would happen all of a sudden, but when you put your new diff cover on, did you put the stock amount of fluid back in or did you fill it up to the fill plug?
__________________
Patriot Blue XJ 4x4
RE 4.5" | 305/70/16 MTR K

My Build Thread
Wearingthin is offline   Reply With Quote
Unread 11-04-2011, 07:49 AM   #6
EricsXJ
The Post man
 
EricsXJ's Avatar
2000 XJ Cherokee 
 
Join Date: Apr 2001
Location: Reno, Nevada
Posts: 8,564
I believe this will fix your problem....

Unscrew the breather tube fitting from the axle housing. (You do not need to disconnect any brake lines.) It will look like this:



Then with a hacksaw, dremel, or suitable cutting tool, cut off the lower section of the fitting that has no threads. It will shorten it about 1/4". Then thread the fitting back in the housing and you should be good to go.
__________________
Eric
2000 XJ "PROJECT RUBICON" 3-link front / 4-link rear / coilovers / running 37's on Dana 60s
My website - EricsXJ.com

EricsXJ is offline   Reply With Quote
Unread 11-19-2012, 10:15 PM   #7
Gonzo99XJ
Registered User
1999 XJ Cherokee 
 
Join Date: Nov 2012
Location: Phoenix, AZ
Posts: 12
I have this exact same issue going on with my XJ as well and its driving me nuts!... Phmaris, did this fix your issue? if so, so I can do it too.. Hey EricsXJ, how did you figure this out?
Gonzo99XJ is offline   Reply With Quote
Unread 11-20-2012, 01:41 PM   #8
phmaris
Registered User
1999 XJ Cherokee 
 
Join Date: Oct 2008
Location: Harrison, Oh
Posts: 384
Quote:
Originally Posted by Gonzo99XJ View Post
I have this exact same issue going on with my XJ as well and its driving me nuts!... Phmaris, did this fix your issue? if so, so I can do it too.. Hey EricsXJ, how did you figure this out?
It did stop. But all I did was change the fluid again and re-seal the cover with RTV again making sure it was super clean and made a good seal. Waited about 6 hours to ensure the RTV dried. Then refilled just up to the bottom of the fill hole. It hasn't leaked from the drain tube since. Still a mystery to me why it was leaking in the first place?
phmaris is offline   Reply With Quote
Unread 11-21-2012, 09:31 AM   #9
Gonzo99XJ
Registered User
1999 XJ Cherokee 
 
Join Date: Nov 2012
Location: Phoenix, AZ
Posts: 12
Quote:
Originally Posted by phmaris View Post
It did stop. But all I did was change the fluid again and re-seal the cover with RTV again making sure it was super clean and made a good seal. Waited about 6 hours to ensure the RTV dried. Then refilled just up to the bottom of the fill hole. It hasn't leaked from the drain tube since. Still a mystery to me why it was leaking in the first place?
I took off that fitting that Eric showed us, cleaned it thoroughly with brake cleaner, I put everything back together and it started leaking again after driving it for 10 miles... I drained and filled my rear diff like 2 months ago thinking that what would stop the leaking but no... it still did ever since.... i didnt overfill it or anything... I dont know what action to take next... any ideas?
Gonzo99XJ is offline   Reply With Quote
Unread 11-21-2012, 10:28 AM   #10
EricsXJ
The Post man
 
EricsXJ's Avatar
2000 XJ Cherokee 
 
Join Date: Apr 2001
Location: Reno, Nevada
Posts: 8,564
The root of the problem should be that gear oil is not draining out of the tubes back into the differential housing. It collects in the tubes and pressure is forcing it out of the vent tube.

This is usually more of a problem when aftermarket carriers (ARB, Detroit) are installed. They recommend cutting additional drain passages to allow the oil to drain out of the tubes. If you have a stock open carrier it shouldn't be a problem. I wonder if the limitted slips are prone to this however.... What do you have?

Not that its a guaranteed fix but did you try trimming the vent tube fitting that I showed in the photo? Just curious, because I had seen that as a fix/remedy before. I trimmed mine as a preventative measure but didn't have this problem to begin with.
__________________
Eric
2000 XJ "PROJECT RUBICON" 3-link front / 4-link rear / coilovers / running 37's on Dana 60s
My website - EricsXJ.com

EricsXJ is offline   Reply With Quote
Unread 11-21-2012, 10:46 AM   #11
bigbadduck
Registered User
1987 XJ Cherokee 
 
Join Date: Sep 2012
Posts: 83
I have a D44 with a trac lock and just regeared and I am a little bit of an issue with venting
bigbadduck is offline   Reply With Quote
Unread 11-21-2012, 10:57 AM   #12
Gonzo99XJ
Registered User
1999 XJ Cherokee 
 
Join Date: Nov 2012
Location: Phoenix, AZ
Posts: 12
Quote:
Originally Posted by EricsXJ View Post
The root of the problem should be that gear oil is not draining out of the tubes back into the differential housing. It collects in the tubes and pressure is forcing it out of the vent tube.

This is usually more of a problem when aftermarket carriers (ARB, Detroit) are installed. They recommend cutting additional drain passages to allow the oil to drain out of the tubes. If you have a stock open carrier it shouldn't be a problem. I wonder if the limitted slips are prone to this however.... What do you have?

Not that its a guaranteed fix but did you try trimming the vent tube fitting that I showed in the photo? Just curious, because I had seen that as a fix/remedy before. I trimmed mine as a preventative measure but didn't have this problem to begin with.
I have a Dana 35 stock... so if I trim the fitting... do u think itll fix for sure? Or is it a 50/50 situation?
Gonzo99XJ is offline   Reply With Quote
Unread 11-21-2012, 11:00 AM   #13
Paradise XJ
Registered User
1990 XJ Cherokee 
 
Join Date: Jan 2007
Location: Paradise, CA, Northern California
Posts: 2,068
Quote:
Originally Posted by Gonzo99XJ View Post
Or is it a 50/50 situation?
Yes...it either will or it won't
__________________
1990 XJ Laredo - White & Chrome
1988 MJ Pioneer - Metallic Green and Black
Paradise XJ is online now   Reply With Quote
Unread 11-22-2012, 06:38 AM   #14
94beachxj
Registered User
1994 XJ Cherokee 
 
Join Date: Nov 2012
Location: Surry, va
Posts: 237
They say that vent tube was the main culprit on those "mystery" Nissan Titan Rearend Issues
94beachxj is offline   Reply With Quote
Reply
Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.