So how screwed is my Jeep?

[Zundfolge]

Fired up the Jeep this morning ('70 CJ5) since it hadn't been started in a while. Figured I'd go top the tank off while the gas was cheap too.

So I put it in 4x4 high (since I have to drive out of a valley) and headed to get gas. Soon after I was on the road I noticed that the front diff was loud ... much louder than I remember it so when I drove the couple of miles to the gas station I decided it would be best to put it back in 2 wheel drive. When I got out I noticed a noise under the Jeep that sounded like sizzling grease in a frying pan and there was oil coming out of the back of the diff where the drive shaft goes into it and it was obviously very hot (sizzling and all).

So is the diff fried? Or is it just a bad seal?

Thing worked just fine last time I drove it (back in October) so I'm wondering if the intense cold caused some damage (maybe some water got into it, froze and broke something?). Also last time I drove it I checked the diff oil and it was fine.

Stuff like this makes me wish I'd stuck with the Porsche ... at least I would know what was wrong with it.

[henpecked]

Sounds like a bearing went out and took out the seal. Could be worse

[Hound]

4x4 on the road is a big problem with these older 4x4 systems (and even in some newer ones). It should only be used off-road or in snow, etc. Basically anywhere it allows the tires to slip and not bind the front diff with the rear. I rebuilt a 77 CJ5 from the frame up, they are pretty simple all around and part of why Jeeps get thier reputation for being good off-road. You can replace the seal pretty easily depending on which Dana axle you are running (30 vs 44). Drain the diff, pull the cover and see what is on the bottom or anything missing on the teeth. If there is damage there it should be obvious. This will let you know if you are "screwed". Also check the universal joints, they are even easier to fix. To check the u-joint just look for slop between the drive shaft and the diff. If you want to ask more questions feel free to PM me and I will give you my phone.

Rough guess, the front over heated for some reason and started pushing diff oil out the back. It may be a problem...... It may not. There is not enough information here.

[MED]

4x4 on the road is a big problem with these older 4x4 systems (and even in some newer ones). It should only be used off-road or in snow, etc. Basically anywhere it allows the tires to slip and not bind the front diff with the rear. I rebuilt a 77 CJ5 from the frame up, they are pretty simple all around and part of why Jeeps get thier reputation for being good off-road. You can replace the seal pretty easily depending on which Dana axle you are running (30 vs 44). Drain the diff, pull the cover and see what is on the bottom or anything missing on the teeth. If there is damage there it should be obvious. This will let you know if you are "screwed". Also check the universal joints, they are even easier to fix. To check the u-joint just look for slop between the drive shaft and the diff. If you want to ask more questions feel free to PM me and I will give you my phone.

Rough guess, the front over heated for some reason and started pushing diff oil out the back. It may be a problem...... It may not. There is not enough information here.

Good post. This was my first thought. If it was binding in 4 high on dry asphalt, it would certainly be cooking when you stopped.

[Zundfolge]

Good post. This was my first thought. If it was binding in 4 high on dry asphalt, it would certainly be cooking when you stopped.

Road was covered with snow and I never got over 20mph, so that (and the god-awful noise the front end was making) makes me think its probably just the outer pinion bearing.

Waiting for the weather and my schedule to come together so that I can get out there under the thing and start looking at it better.

[Zundfolge]

I believe its a Dana 27. Based on the noise it was making I bet henpecked is right, the bearing went out.

[Hound]

I believe its a Dana 27. Based on the noise it was making I bet henpecked is right, the bearing went out.

Take the drive shaft off and see if there is play at the pinion shaft. Easy check.

Here is a link for axle id'ing http://www.jeepz.com/forum/drivetrai...ification.html

It could very easily be a D27 for a 70 CJ. Most get changed out for a D44 or at least a D30 due to the lack of strength on D20 and D27's.

[Zundfolge]

I have a second front axle that came with the Jeep that is I believe a D30 (or maybe even a 44) off a later model CJ ... its also got calipers and rotors (but no pads). Often thought about just installing it so I'd have front disk brakes, this might be the opportunity to do just that.

[blackford76]

I have a second front axle that came with the Jeep that is I believe a D30 (or maybe even a 44) off a later model CJ ... its also got calipers and rotors (but no pads). Often thought about just installing it so I'd have front disk brakes, this might be the opportunity to do just that.

Make sure the gear ratios match, new front and original rear, if they do, I wouldn't even bother with checking the broken one. Disc brakes alone are worth the swap.

[Hound]

Ya, they were probably planning on the swap and you came along. Blackford is correct, check the ratios but if it came with the Jeep, the odds are they will match. This will make the fix even easier.

I have a second front axle that came with the Jeep that is I believe a D30 (or maybe even a 44) off a later model CJ ... its also got calipers and rotors (but no pads). Often thought about just installing it so I'd have front disk brakes, this might be the opportunity to do just that.