[SOLVED] Gear oil pushing out overflow

eslaski · 12-27-2008, 02:55 PM

Hi, new to forum so thanks in advance for any help. I just purchased a 95 Jeep Cherokee Limited. 134K miles and the (front) rear had just been replaced. When I drive it for a long period, the pumpkin gets so hot I can not touch it. It also pushes gear oil out the overflow tube which ends up on the exhaust and smells really bad. I just replaced all the bearings and races in it and it still happens. Any idea what the problem may be?

2strokedetroit · 12-27-2008, 08:55 PM

Quote:

Originally Posted by eslaski

Hi, new to forum so thanks in advance for any help. I just purchased a 95 Jeep Cherokee Limited. 134K miles and the (front) rear had just been replaced. When I drive it for a long period, the pumpkin gets so hot I can not touch it. It also pushes gear oil out the overflow tube which ends up on the exhaust and smells really bad. I just replaced all the bearings and races in it and it still happens. Any idea what the problem may be?

2strokedetroit · 12-27-2008, 08:57 PM

when u say front rear had just been replaced wats do u mean?

2strokedetroit · 12-27-2008, 09:22 PM

if you were saying the rear diff was just replaced or rebuilt then it does requrie a proper break in time!!! usually we tell customers even after a diff fluid change to drive it 20 miles then let it cool then drive it 20 more and let cool again sounds dumb and all though ive never seen a problem with people not breaking it in u could be or the man u bought u from could be a a rare case! iam unaware of the effects that not breaking it could cause but i would imagine over flow, over heating, and failure could be the only 3. If u dont let it cool after 20 miles once or twice u can over heat the spider gearsi belive doubt u could over heat the pinnion gear! also ir it was rebuilt was pinnion gear runout checked? or backlash? unfortantly i dont see how it could be fixed without taken it out as i would assume the problem is internal! a cheaper non correct way to possibly keep it from over heating and over flowing would beee to get a a bigger diff case cover however all youd be doing is temporaily covering up a greater problem!
before doing anything make sure your using the correct fluid!!! and if its limited slip it may requrie and additve also make sure its at the correct level! if your not a do it your selfer your local lube place could do that for you

2strokedetroit · 12-27-2008, 09:49 PM

welll i was watching tv and just had a thoughttttt! are all your tires the same brand and size? and worn similar? sounds crazy but u should always at least replace 2 tires at a time on 4x4 however all 4 should be replaced if possible! make sure the rear tires are the same size! make sure they are the same brand and tread pattern and that they are worn evenly! if they are not this could be the cause of your problem belive it or not! tires that are not vey close in diameter can cause extreme over heating problems in a diff and even cause parts inside to weld toghter
and check your tire pressure make sure they are evenly filled!
doubt its your problem but just a thought!

eslaski · 12-28-2008, 07:26 AM

Hi 2strokedetroit. Thanks for the responses. First off, the complete rear was replace just before I bough the car and not driven until I had it. The garage had gotten the rear out of a junk yard used. So I have no idea what kind of milage it had to begin with. I did replace all the guts except for the gears. Took it to the store yesterday which was about that distance. Got there and there was a little fluid. When I got home, it was much worse. There is a loud whine in the gears when I do drive it. I also just went and looked at the tires. Three different brands. One tire is different in size. And one tire has much less ware than the other three. Do you think the difference in tires would cause the whine as well? Thanks again!

dai · 12-28-2008, 08:17 AM

check the breathers are not blocked

eslaski · 12-28-2008, 08:31 AM

Hi dai. If the breather is blocked, can it still push gear oil out like mine is? Thanks!

dai · 12-28-2008, 08:37 AM

it blew past the seals when i had it happen,i did't know the breathers were there at the time they were buried in crap

eslaski · 12-28-2008, 08:40 AM

dai, thanks again. I will be looking at all these solutions today. I will post back on anything I find out.

cardoc · 12-28-2008, 10:21 AM

Hi All
If the tires on the same diff are noticably differant sizes it could wreck a good diff.Your whine could indicate that.The side gears will be working way overtime.Also a wine can be caused by excess bearing preload,wrong pinion depth etc.My guess is the frt tires are differant sizes and the excess side gear(differantial gear) use is causing the heat.If you have matching tires it would be worth a try.Or you could try safely jacking all 4 wheels of the ground and running it at road speed to see if the whine is still there.
Be safe,Cardoc
PS The breather is usually a nipple on one of the axle tubes with a hose attached runiing up to the frame to keep it above the water.

eslaski · 12-28-2008, 02:19 PM

Thanks to all for the suggestions. I have made sure the breather is open. I don't think it was blocked. However, I think the issue was with different size tires! Tires are supposed to be P225/75 R15. The left rear tire was a P225/70 R15 but was a good 2" taller than the others. I replaced it with the spare and now all tires are very close. Took it for a long test ride up the highway and back. 95% of the whine is gone and no fluid out the overflow tube!!! Pumpkin was a little warm, but I was able to touch it. Funny how it was the rear tires that were different, but it all transferred the problems to the front. Now I just need to keep an eye on it. I'll know what's wrong as soon as I smell that aweful burnt gear oil... Thank you again for all the responses. I appreciate the help...

Ed

2strokedetroit · 12-28-2008, 04:31 PM

glad we could help sounds like the tires were the problem i learned about it in school however never had actually seen it till now!!!! prolly a cheaper fix then u thought? If your doing ok finacially u realy should get 4 new tires on it or at least get it down to only two brands of tires on it

12-27-2008, 02:55 PM	#1 (permalink)
eslaski Registered User Join Date: Dec 2008 Posts: 5 OS: xp	[SOLVED] Gear oil pushing out overflow Hi, new to forum so thanks in advance for any help. I just purchased a 95 Jeep Cherokee Limited. 134K miles and the (front) rear had just been replaced. When I drive it for a long period, the pumpkin gets so hot I can not touch it. It also pushes gear oil out the overflow tube which ends up on the exhaust and smells really bad. I just replaced all the bearings and races in it and it still happens. Any idea what the problem may be?

12-27-2008, 08:57 PM	#3 (permalink)
2strokedetroit Registered User Join Date: Dec 2008 Location: Minnesota Posts: 23 OS: xp	Re: Gear oil pushing out overflow when u say front rear had just been replaced wats do u mean?

12-27-2008, 09:22 PM	#4 (permalink)
2strokedetroit Registered User Join Date: Dec 2008 Location: Minnesota Posts: 23 OS: xp	Re: Gear oil pushing out overflow if you were saying the rear diff was just replaced or rebuilt then it does requrie a proper break in time!!! usually we tell customers even after a diff fluid change to drive it 20 miles then let it cool then drive it 20 more and let cool again sounds dumb and all though ive never seen a problem with people not breaking it in u could be or the man u bought u from could be a a rare case! iam unaware of the effects that not breaking it could cause but i would imagine over flow, over heating, and failure could be the only 3. If u dont let it cool after 20 miles once or twice u can over heat the spider gearsi belive doubt u could over heat the pinnion gear! also ir it was rebuilt was pinnion gear runout checked? or backlash? unfortantly i dont see how it could be fixed without taken it out as i would assume the problem is internal! a cheaper non correct way to possibly keep it from over heating and over flowing would beee to get a a bigger diff case cover however all youd be doing is temporaily covering up a greater problem! before doing anything make sure your using the correct fluid!!! and if its limited slip it may requrie and additve also make sure its at the correct level! if your not a do it your selfer your local lube place could do that for you

12-27-2008, 09:49 PM	#5 (permalink)
2strokedetroit Registered User Join Date: Dec 2008 Location: Minnesota Posts: 23 OS: xp	Re: Gear oil pushing out overflow welll i was watching tv and just had a thoughttttt! are all your tires the same brand and size? and worn similar? sounds crazy but u should always at least replace 2 tires at a time on 4x4 however all 4 should be replaced if possible! make sure the rear tires are the same size! make sure they are the same brand and tread pattern and that they are worn evenly! if they are not this could be the cause of your problem belive it or not! tires that are not vey close in diameter can cause extreme over heating problems in a diff and even cause parts inside to weld toghter and check your tire pressure make sure they are evenly filled! doubt its your problem but just a thought!

12-28-2008, 07:26 AM	#6 (permalink)
eslaski Registered User Join Date: Dec 2008 Posts: 5 OS: xp	Re: Gear oil pushing out overflow Hi 2strokedetroit. Thanks for the responses. First off, the complete rear was replace just before I bough the car and not driven until I had it. The garage had gotten the rear out of a junk yard used. So I have no idea what kind of milage it had to begin with. I did replace all the guts except for the gears. Took it to the store yesterday which was about that distance. Got there and there was a little fluid. When I got home, it was much worse. There is a loud whine in the gears when I do drive it. I also just went and looked at the tires. Three different brands. One tire is different in size. And one tire has much less ware than the other three. Do you think the difference in tires would cause the whine as well? Thanks again!

12-28-2008, 08:17 AM	#7 (permalink)
dai Manager, Hardware Forums Join Date: Jul 2004 Location: west australia Posts: 56,753 OS: win 7 32x 64x rtm	Re: Gear oil pushing out overflow check the breathers are not blocked __________________

12-28-2008, 08:31 AM	#8 (permalink)
eslaski Registered User Join Date: Dec 2008 Posts: 5 OS: xp	Re: Gear oil pushing out overflow Hi dai. If the breather is blocked, can it still push gear oil out like mine is? Thanks!

12-28-2008, 08:37 AM	#9 (permalink)
dai Manager, Hardware Forums Join Date: Jul 2004 Location: west australia Posts: 56,753 OS: win 7 32x 64x rtm	Re: Gear oil pushing out overflow it blew past the seals when i had it happen,i did't know the breathers were there at the time they were buried in crap __________________

12-28-2008, 08:40 AM	#10 (permalink)
eslaski Registered User Join Date: Dec 2008 Posts: 5 OS: xp	Re: Gear oil pushing out overflow dai, thanks again. I will be looking at all these solutions today. I will post back on anything I find out.

12-28-2008, 10:21 AM	#11 (permalink)
cardoc Registered User Join Date: Apr 2007 Location: Ct. Posts: 198 OS: win xp sp2	Re: Gear oil pushing out overflow Hi All If the tires on the same diff are noticably differant sizes it could wreck a good diff.Your whine could indicate that.The side gears will be working way overtime.Also a wine can be caused by excess bearing preload,wrong pinion depth etc.My guess is the frt tires are differant sizes and the excess side gear(differantial gear) use is causing the heat.If you have matching tires it would be worth a try.Or you could try safely jacking all 4 wheels of the ground and running it at road speed to see if the whine is still there. Be safe,Cardoc PS The breather is usually a nipple on one of the axle tubes with a hose attached runiing up to the frame to keep it above the water.

12-28-2008, 02:19 PM	#12 (permalink)
eslaski Registered User Join Date: Dec 2008 Posts: 5 OS: xp	Re: Gear oil pushing out overflow Thanks to all for the suggestions. I have made sure the breather is open. I don't think it was blocked. However, I think the issue was with different size tires! Tires are supposed to be P225/75 R15. The left rear tire was a P225/70 R15 but was a good 2" taller than the others. I replaced it with the spare and now all tires are very close. Took it for a long test ride up the highway and back. 95% of the whine is gone and no fluid out the overflow tube!!! Pumpkin was a little warm, but I was able to touch it. Funny how it was the rear tires that were different, but it all transferred the problems to the front. Now I just need to keep an eye on it. I'll know what's wrong as soon as I smell that aweful burnt gear oil... Thank you again for all the responses. I appreciate the help... Ed

12-28-2008, 04:31 PM	#13 (permalink)
2strokedetroit Registered User Join Date: Dec 2008 Location: Minnesota Posts: 23 OS: xp	Re: [SOLVED] Gear oil pushing out overflow glad we could help sounds like the tires were the problem i learned about it in school however never had actually seen it till now!!!! prolly a cheaper fix then u thought? If your doing ok finacially u realy should get 4 new tires on it or at least get it down to only two brands of tires on it