Been flat towing the CJ once a year for about 250 miles for 10 years now. This was the last year. I'd never heard you weren't supposed to flat tow with the rear driveshaft connected, now I know better.

Me and my cousin were following behind my dad who was towing the jeep. We saw something fly off and bounce about 10 feet up in the air. Luckily we were far enough behind that it didn't hit us. We pulled over to find the rear driveshaft of the CJ laying in the middle of the road. Then we look over and see a fire on the other side of the highway. Rear output bearing burnt up, ate the output shaft, dropped the driveshaft, and the molten bearing went into the dry grass. The fire spread real quick because of the wind, but luckily there was a green wheat field, some guy pulled over with a fire extinguisher so we were able to get the end out that was spreadin before the fire department got there.

Here's the damage:

http://i87.photobucket.com/albums/k124/glp86/DSC00004.jpg
http://i87.photobucket.com/albums/k124/glp86/DSC00005.jpg
http://i87.photobucket.com/albums/k124/glp86/DSC00006.jpg
http://i87.photobucket.com/albums/k124/glp86/DSC00009.jpg

I feel retarded, because it makes total sense how the rear bearing doesn't get any lube now that I think about it. My dad had been towing it for about 5 years before I took over and started working on it, so I had no reason to think anything bad of it.

So do you guys link my Low-Max gears are trashed? I won't get to check it out for 2 weeks when I get home from college for christmas break. I really hope I don't have to buy another kit. I have a spare dana 300 so hopefully I can get all the parts to fix it from that.



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Been flat towing the CJ once a year for about 250 miles for 10 years now. This was the last year. I'd never heard you weren't supposed to flat tow with the rear driveshaft connected, now I know better.

Me and my cousin were following behind my dad who was towing the jeep. We saw something fly off and bounce about 10 feet up in the air. Luckily we were far enough behind that it didn't hit us. We pulled over to find the rear driveshaft of the CJ laying in the middle of the road. Then we look over and see a fire on the other side of the highway. Rear output bearing burnt up, ate the output shaft, dropped the driveshaft, and the molten bearing went into the dry grass. The fire spread real quick because of the wind, but luckily there was a green wheat field, some guy pulled over with a fire extinguisher so we were able to get the end out that was spreadin before the fire department got there.

Here's the damage:

http://i87.photobucket.com/albums/k124/glp86/DSC00004.jpg
http://i87.photobucket.com/albums/k124/glp86/DSC00005.jpg
http://i87.photobucket.com/albums/k124/glp86/DSC00006.jpg
http://i87.photobucket.com/albums/k124/glp86/DSC00009.jpg

I feel retarded, because it makes total sense how the rear bearing doesn't get any lube now that I think about it. My dad had been towing it for about 5 years before I took over and started working on it, so I had no reason to think anything bad of it.

So do you guys link my Low-Max gears are trashed? I won't get to check it out for 2 weeks when I get home from college for christmas break. I really hope I don't have to buy another kit. I have a spare dana 300 so hopefully I can get all the parts to fix it from that.



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I would guess the gears are junk. And even if not I would think their strength has been compromised from an incident like that.

Wow thats crazy!

wow nice carnage and burning up some grass nice.
jason

Call up lomax, you may be able to get the gears normalized and have them heat treated again.

yep, their junk, how much you want for em?:D

newb question, if everything in the case is spinning weather it be from the tires spinninf it or the engine spinning it, how does it not get lube?

newb question, if everything in the case is spinning weather it be from the tires spinninf it or the engine spinning it, how does it not get lube?

when you're towing the rig, the transfer case is in neutral, so only the output shaft is spinning, not the rest of the gears that sling the gear oil.

I would guess the gears are junk. And even if not I would think their strength has been compromised from an incident like that.

Hum yeah I hope not, I need to get in there and check them out. Sucks I have to wait 2 weeks. What's your reasoning behind them being junk? To much heat?

Call up lomax, you may be able to get the gears normalized and have them heat treated again.

From the pics, I'd say those gears have had enough heat for one lifetime..

Hum yeah I hope not, I need to get in there and check them out. Sucks I have to wait 2 weeks. What's your reasoning behind them being junk? To much heat?

You hit the nail on the head ... I would guess they are pretty brittle .. And with that heat I would guess it ate through heat treat..

yep, their junk, how much you want for em?:D

I'm with him if you think there junk let one of us know. The heat was concentrated it the output hopefully everything didn't start spinning when the bearing started to fail. I would be worried about physical damage. Not material. I would first check for color change it there was no change at the base of the gears where it attaches to the shaft and would have been transferring heat from, there shouldn't be a problem. You could always get a hold of lowmax and get hardness requirements or material condition and have the hardness checked, non-destructive and good piece of mind.

why would you guys waste your money on used gears that might be fine. i mean if your going to drop 300-350 dollars ( im guessing if he sells them ) why not just pony up for new one's. what are you saving to chance that the gears "might" be ok.
im sure there ok, but if i was the OP i would call lomax and let make them make the decision. they may say send them in for a small fee and they can make them right, reinstall them, BAM now your all set agin.

but for all the seagulls lining up for cheap set of gears let the OP decide what he's doing and then decide if you want to take the gamble to save a few hunderd.
jason.

... I would guess they are pretty brittle .. And with that heat I would guess it ate through heat treat..

Unless he through water on it when hot, wouldn't the metal be annealed by the heat?...

:eek: Holy crap! I say run 'em.

The gears being allowed to naturally chill they should be fine, I doubt they reach temps above anything that will actually change the molicules, which would weaken/strengthen them.

Your fine, replace the output shaft and have fun....

i would call lomax and let make them make the decision. they may say send them in for a small fee and they can make them right,

x2...I think Lomax would have the best answer/solution seeing as they would know exactly how their gears are heat treated, annealed,etc...

Since the t-case was in nuetral at the time I would think only the rear output gear was subjected to the very high heat, the front drive gears would have been in the oil and input gear would not have been connected.

so should you leave the T case in gear with the trans outta gear? or just not flat tow at all?

Since the t-case was in nuetral at the time I would think only the rear output gear was subjected to the very high heat, the front drive gears would have been in the oil and input gear would not have been connected.

but the heat will travel up thru the shaft and into the case. if there is enough to melt a 1 3/8'' shaft in half there was enough to travel into the case and maybe do some dammage. is there any dammage who's to say but let the OP figure it with lomax. then he can base his decision on what they say.

zuki 06 just remove the rear drivshaft and it will be fine, PIA yes but no harm will come to your case.
jason.

Rear shaft removed is proper.

if there is enough to melt a 1 3/8'' shaft in half there was enough to travel into the case and maybe do some dammage.

I don't think that shaft melted, it looks like it snapped due to bearing seizure...

so should you leave the T case in gear with the trans outta gear? or just not flat tow at all?

The best option for flat towing is a clocking ring for the 300.

Clocked near flat - the bearing (rear) is already partially immersed in oil.

I towed like this for years before I got my low-boy.

I don't think that shaft melted, it looks like it snapped due to bearing seizure...

got to admit eather way thats alot of heat there.
jason.

Dang! That's a nice little fire you got going there! haha:eek:

Things that make you say HOLY SHIT!:eek::eek:

I just got off the phone with JB Conversions who make the Low-max kit. They said that they doubted I messed up the heat treating on the gears and that as long as the gear still spun freely on the output shaft and that that the output shaft wasn't blue where it met the gear I should be fine. So it looks like I'm in the clear! Shouldn't cost me to much to fix, just a major PITA having to pull the tcase apart.

I thought the hot ticket was to put some kind of a slinger ring inside the case to oil when flat towing

I just got off the phone with JB Conversions who make the Low-max kit. They said that they doubted I messed up the heat treating on the gears and that as long as the gear still spun freely on the output shaft and that that the output shaft wasn't blue where it met the gear I should be fine. So it looks like I'm in the clear! Shouldn't cost me to much to fix, just a major PITA having to pull the tcase apart.


X2, As long as you don't see any temper marks on the gears (like you had on the bearings and output shaft) they should be fine to run. I would check the needle bearings between the input shaft and the rear output shaft however. There is a possibility of those getting chewed up if the t-case was in neutral.

In the future, pull the driveshaft or buy a trailer. Flat towing sucks.

I don't think that shaft melted, it looks like it snapped due to bearing seizure...

Word. Why hadn't it melted before if he has been towing it for so many years?

X2, As long as you don't see any temper marks on the gears (like you had on the bearings and output shaft) they should be fine to run. I would check the needle bearings between the input shaft and the rear output shaft however. There is a possibility of those getting chewed up if the t-case was in neutral.

In the future, pull the driveshaft or buy a trailer. Flat towing sucks.

Yep that or I'll just drive it. That way I will hear something going weird before the shat hits the fan. Lost an axle and tire back when the AMC 20 was in there due to a wheel bearing going bad a few years back while flat towing. Didn't notice it for about a mile being pulled behind that diesel. Made quite a spark show to say the least.

Word. Why hadn't it melted before if he has been towing it for so many years?

I guess I've been lucky. Although the Low-max has only been in there for about 3 years so maybe that had something to do with it. Bigger gears = less lube to bearing while in nuetral??? Just a guess.

This is why the manual says to stop and run the engine for a while every 200 miles (I think). This helps sling oil and relube the output.

This is why the manual says to stop and run the engine for a while every 200 miles (I think). This helps sling oil and relube the output.

Yeah I have heard it says something like that after looking it up on the net. Although we had only gone about 150 miles when this happened...hum

My money is on the gears being alright. I'd run them.

The hot ticket for flat towing was to tig weld some little oil slinger paddle things onto, uhh, something.

Jason Bunch of Tri-County gear was doing this mod for a while I believe, back in the 90's, haven't seen any media on it for a long time since then though.

so should you leave the T case in gear with the trans outta gear? or just not flat tow at all?

You may have tranny issues if you do this. I know an NP-435 cannot be flat-towed(spins the part of the tranny not in oil), others may.

pull rear driveshaft when towing.

this is goodnews! pull the rear when flat towing til the trailer is bought...check.

Thats scary, sounds like no one was hurt, but still could have been a lot worse. We recently had a fire on the freeway near me from a similar incident, but it burned small patches off and on for like 50 miles of freeway.

On happier note, it sounds like your t-case is still good, well as good as can be expected considering. Good luck rebuilding.

At least you just broke the TC, when this happened to my Dana 18 years ago, the driveshaft hit the pavement and snapped the pinion off of the 44 rear. We were flat towing it behind a Winnabego and we heard the rear tires lock up. It was time to upgrade anyway. :D

i flat towed my old d20 a few times in 150mile stretches and never had a problem. I left the driveshafts in place, put the tcase in neutral, trans in gear, and locked the front hubs. with the front hubs locks the front tcase gears spin inside the tcase and help keep the oil moving around in there. A little extra oil in the tcase also helps too.

another trick- rotate the tcase flat so that the outputs are on the same level- this keeps the oil level high enough to keep the rear bearing lubricated and you also benefit with a flatter bellypan.

I have read on here before that the Dana 300 gets its oil from the transmission spinning and when only the rear driveshaft spins it does not get oil to the case and gears, thus carnage. We always put the transmission and tcase in neutral and remove the rear driveshaft. Overkill, but have had no problem doing it this way.

I have read on here before that the Dana 300 gets its oil from the transmission spinning and when only the rear driveshaft spins it does not get oil to the case and gears, thus carnage. We always put the transmission and tcase in neutral and remove the rear driveshaft. Overkill, but have had no problem doing it this way.

Yep I'm just gonna pull the rear driveshaft from now on. Plus I'll go ahead and clock the t-case flat while I have it out since I have a clocking ring collecting dust in the garage. :grinpimp:

Picture of flat tow oil slingers I found a few years ago. Look easy enough to do.

http://www.rocktaxi.com/tech/dana300/300flattowoilslingers.jpg

Ed

I towed mine from cali to MD with the rear DS pulled, but left the front (no problems)... Would this cause problems also or are the internals different for the front/rear shafts?

This is why the manual says to stop and run the engine for a while every 200 miles (I think). This helps sling oil and relube the output.

And to lock in the front hubs. Having the front output spinning helps lube all of it in the D300.