Axle grease melting?

[bones1]

Not happy.About a year ago I replaced all the brakes and rear axle inner and outer seals and corks when I flipped the hubs and installed MRAPs. I had no leaks for a year. I was amazed and very happy about this. Every time I drive the truck, when I park it in the garage at home, I would without fail would look underneath it for oil leaks on the backing plates. I just knew they would leak. None. Happy, happy, happy. Been busy getting daughter married off etc and the last time I remember driving it was in early April, it was just sitting in my garage. Been stationary since.Now in the summer this building gets hot during the day 90+ or so and sometimes I don't go out in it. Anyway, yesterday, I looked under the truck, as usual and all 4 rear backing plates are wet with oil. I checked, it's not brake fluid.I wish it was, easier fix than the "hope it don't leak again seal guessing game". And they will. So my question is:
Can heat make the gear oil expand and come through the seals sitting still? I removed the vents a while back so that's not it.
Could the wheel bearing grease actually be "melting" in the hubs? I use red high temp Valvoline grease.
Has anyone come up with a positive way to seal these Rockwells yet?.

 

[clinto]

I don't think the cork lasts very long. I've had pretty good luck with RTV and I've probably done no less than a hundred (hubs, not trucks) at this point.

I've had 3 fail and 2 were the same hub, same truck; which leads me to think it had a bad hub or something.

 

[welldigger]

The ambient temperature isn't melting the grease. Your gonna have to pull the hub apart and have a look.

 

[rmgill]

I've tried in my last axle service a hand cut piece of medium soft rubber shoved up in the slot. We'll see how that works. So far so good with a bit of driving....50 miles or so.

 

[m16ty]

Like Clinto, I use RTV and never had a problem.

Seeing as how the truck has been just sitting and not driven with oil in the hubs, you may get by with just pulling the axle and replacing the outer seal. You may want to pull at least one hub though to make sure the oil hasn't washed the grease out of the bearings.

 

[budman67]

I am looking to do this to my soon to be my M35,I have so many TM's now,I get lost looking
for certain things. Could someone please tell me the TM# for the axles. Thanks

 

[MWMULES]

I am looking to do this to my soon to be my M35,I have so many TM's now,I get lost looking
for certain things. Could someone please tell me the TM# for the axles. Thanks

This is a great step by step with pictures and tool list for the front that Banshee365 did years ago. http://www.steelsoldiers.com/showth...s-and-boots-stepXstep&highlight=front+rebuild

 

[bones1]

Thanks for the help. This time I think I will just use rtv and leave the cork out of the equation and see what happens.Might get lucky.

 

[bones1]

The ambient temperature isn't melting the grease. Your gonna have to pull the hub apart and have a look.

I quess I kinda knew that, just so darn frustrating to keep doing the job over.

 

[brianp454]

My sympathies bones1. I haven’t had my truck that long and am planning to bleed the brakes this morning before going to work. I’ve been going through a few iterations of using engine degreaser and pressure washing, but still have some caked-on crud on some of the backside of the hubs. Probably should try a different degreaser…

I’ve read about the oil separating out of grease, yet not sure how much I would think this is plausible with modern grease just sitting in the garage. I just cleaned out an old grease gun and the stuff inside was clean, homogeneous, looked like new. I had that grease gun sitting outside for years through the worst of weather. I think that indicates the grease is better than we sometimes give it credit for.

I’ve never liked cork gaskets. I’ve seen so many split and such on valve covers and spent too much time scraping them off. My preference is Viton (vs. buna nitrile) or RTV. When I get around to tearing mine all apart I want to make sure I do it once and forget about it for a long time. Hope to learn all I can from you guys. Will be interested in learning along with you, thanks for sharing!

 

[silverstate55]

I haven't had any problems with the cork gaskets. I've noticed this problem on my Deuce as well when it sits for long periods. Drive your Deuce more often to get everything warmed up & that should keep everything where it should be...works on my Deuce anyway, in severe triple-digit heat temperatures.

 

[Flyingvan911]

You also might do the axle vent mod. I am going to do that to mine. Member "Stagg" put up a post about it on his truck.

 

[silverstate55]

Did that to mine already, still have a similar problem if mine sits too long...when I drive it enough to warm everything up, the leaks/drips go away from the axles/drums/hubs.

You also might do the axle vent mod. I am going to do that to mine. Member "Stagg" put up a post about it on his truck.

 

[budman67]

WOW!! That is an amazing thread, Thanks for the links.

This is a great step by step with pictures and tool list for the front that Banshee365 did years ago. http://www.steelsoldiers.com/showth...s-and-boots-stepXstep&highlight=front+rebuild

 

[m16ty]

I just did a seal on a deuce today and it had a rubber wedge piece in the slot instead of cork. It came this way from the government and is the first time I've seen rubber instead of cork. It looked like it would seal better than cork but I left it out and went to my tried and true method with RTV.

 

[bones1]

I haven't had any problems with the cork gaskets. I've noticed this problem on my Deuce as well when it sits for long periods. Drive your Deuce more often to get everything warmed up & that should keep everything where it should be...works on my Deuce anyway, in severe triple-digit heat temperatures.

Maybe I'm not crazy after all.I had no leaks when I parked it in the garage in April, really. I quit drinking in 2008.

M16, which rtv do you use. I think I will just use rtv this next time.

 

[welldigger]

I just did a seal on a deuce today and it had a rubber wedge piece in the slot instead of cork. It came this way from the government and is the first time I've seen rubber instead of cork. It looked like it would seal better than cork but I left it out and went to my tried and true method with RTV.

I have been tempted to get some square viton cord of the correct size and give that a try. Rtv works, but if there is an easier and less messy way, I'm all for it.

 

[bones1]

There may be some correlation between the amount ( quantity) of grease placed in the hub on re assembly and the leaking of differential oil. I remember when I first did this job that there was a huge amount of wheel bearing grease inside the hub. I did not put near that amount back in the hubs.
Maybe that grease in large quantities helps to block differential oil from reaching the seals?.
Any takes on this?.

 

[clinto]

There may be some correlation between the amount ( quantity) of grease placed in the hub on re assembly and the leaking of differential oil. I remember when I first did this job that there was a huge amount of wheel bearing grease inside the hub. I did not put near that amount back in the hubs.
Maybe that grease in large quantities helps to block differential oil from reaching the seals?.
Any takes on this?.

I have read that the large quantities of excess grease are a military thing so that if you have to repack bearings in the field, you can scoop some excess out and use it.

I see that as 50% likely. The other thing that's 50% likely is the novice 19 year old mechanic thinking better to be safe than sorry and just filling it up with grease.

 

[budman67]

I might be misunderstanding you guys,I am looking at the TM,where is this cork plug,
or do you mean cork gasket?

Is there a way to let the rear bearings be dif oil bathed instead of just grease?