Im running 6.17's with 38 sx's. The rear diff gets super hot after a trip to the trail. Have any of you checked how hot your diff gets if you drive them on the street? Does not seem to hurt anything, but I cant imagine the ARB orings like it too much.

I have only checked mine back when i had pinion bearing problems(on a criser axle) After about 30 min on the freeway i could still hold my hand to it but it was good and warm.
I think the ARB's are designed to deal with the heat.

You got the tow rig Get a trailer ya Bum. then ya don't have to wory about it

Ian-

Originally posted by KrustyKruiser
I have only checked mine back when i had pinion bearing problems(on a criser axle) After about 30 min on the freeway i could still hold my hand to it but it was good and warm.
I think the ARB's are designed to deal with the heat.

You got the tow rig Get a trailer ya Bum. then ya don't have to wory about it

Ian- no he just needs to pimp the powerstroke to me!!!!!!!!!!!!!!! jiMMy

Yeah, I know. Just dont have a place to store one right now.

I can't even hold my hand on it for a second. Granted, I have little fragile wussy hands, but I think it is way to hot.

they can get real warm...not like cant hold you hand on it but warm....

hows the pinion angle?
possibly not getting lubed sufficiently due to excessive angle?
~John

It sits at 18*. I know it has enough juice, because I filled it when the housing was out and on jack stands. I filled it will it level. When I pull the plug to check it while it is in the jeep, lube flows from the hole. When I am at cruising speed, it is turning about 3100 rpm. Man, it has a lot of miles on it now, probably 8 trips from the valley to various sierra trails. If it was going to burn up a bearing, I think it would have by now. (who knows, maybe it has!) I am serious when I say I cant even hold my hand on the cover for a second.:eek:

Also, when I was running 4.88's in it, it never got that hot. Gearman set these up, so I have faith it is not something to do with the install. Could possibly the breather be blocked and causing he juice to foam up. Would that get it hot?

come awn Austin, I know you have some smart ass thing to say about this.

Originally posted by Keith
It sits at 18*. I know it has enough juice, because I filled it when the housing was out and on jack stands. I filled it will it level. When I pull the plug to check it while it is in the jeep, lube flows from the hole. When I am at cruising speed, it is turning about 3100 rpm. Man, it has a lot of miles on it now, probably 8 trips from the valley to various sierra trails. If it was going to burn up a bearing, I think it would have by now. (who knows, maybe it has!) I am serious when I say I cant even hold my hand on the cover for a second.:eek:

Also, when I was running 4.88's in it, it never got that hot. Gearman set these up, so I have faith it is not something to do with the install. Could possibly the breather be blocked and causing he juice to foam up. Would that get it hot?

come awn Austin, I know you have some smart ass thing to say about this.


A:If the breather were blocked, you would be puking oil out of the seals. (pinion, wheel seals, cover gasket)
B:How much of a load are you running/carrying/towing? If you are not at any kind of a full load for that particular axle, a heavier load would probably burn it up.
If you are not using it now, look into a synthetic oil to better withstand the high temperatures.

you need 44's for over drive :D then it won't have to spin so fast generating less friction over time eqauting to the need for new fuel injuected steel braided brake lines w/ a side of twice pipes :D

Mine gets worm to i only have 5.29;s in a toy but it heatsup in the freeway not hot enought to burn my hand but warm. I have no clue why and it has not hurt anything yet let us know if you figure nything out.:usa:

I ran 7.17s in a 60/70 with 39s ran 50mph for 45min at a time. The temp would get to 170 deg. This was a 1 to 1 trans at 3000 rpm. I bought a infrared temp gun and would check diffs, power steering and eng oil. It was cool to have on a big trail ride and when we stopped checked other rig temps.
Dan

Originally posted by Keith
It sits at 18*. I know it has enough juice, because I filled it when the housing was out and on jack stands. I filled it will it level. When I pull the plug to check it while it is in the jeep, lube flows from the hole. When I am at cruising speed, it is turning about 3100 rpm. Man, it has a lot of miles on it now, probably 8 trips from the valley to various sierra trails. If it was going to burn up a bearing, I think it would have by now. (who knows, maybe it has!) I am serious when I say I cant even hold my hand on the cover for a second.:eek:

Also, when I was running 4.88's in it, it never got that hot. Gearman set these up, so I have faith it is not something to do with the install. Could possibly the breather be blocked and causing he juice to foam up. Would that get it hot?

come awn Austin, I know you have some smart ass thing to say about this.

how long have they been setup?? if it's a fairly new set of gears it makes more sense they're heating up more.. make sure to break 'em in right.. if they're broke in and old, then disregard...

A buddy of mine a had troubles like this on his axle - anywhere over an hour away at freeway speed and his rear axle would get hot and start pissing gear oil out the breather. He had an ARB as well.

We never figured it out - just keep it topped off and ran it. He did look into a catch can with a return line for the gear oil - but I don't know what he ended up doing.

Diff should heat up to about 100 degress above ambient temp.
Get a cooking thermometer and check the case with it before you drive, stop about 1 mile and check it again. then drive about 10 miles and check it again. you might have a bearing going.

Keith

a thought is to drain the gear lube and send it in for analysis. This should tell you if the bearings or R&P are breaking down, it might tell you if the heat is destroying the O rings.

Also you might call arb @ (206) 264 1669 and ask them how much heat the O rings can take, I heard they were good to ~ 300 F, but that may be crap.

no he just needs to pimp the powerstroke to me!!!!!!!!!!!!!!! jiMMy It must have been close to jimmy's bedtime when he wrote this as there is a misprint...I'm betting he meant he would pimp the trailer to you.


good luck

- Keith

You guys ever see the cooling system the NASCAR guys have for their rear diffy's? Doubt it would survive a trail trip, but pretty cool all the same. The low ratio is definitely contributing to the heat. That pinion has to make a LOT of revolutions at highway speeds.

TEX

I'm not sure 6.17:1 was never intended to spin that fast. :(

Coupla suggestions in order of expense:
* fab up an 'air scoop' to feed air to the diff when you're at speed on the highway
* use some 'climbing lube' in your pig to make sure the oil gets up to the pinion and sticks up there (Moroso makes it, others, too, likely)
* use synthetic, since it is more tolerant to overheating
* call Mag-Hytec and get one of their finned aluminum housings and fab up a serious skid to protect it! :eek:
* adapt a differential oiler kit from a Mustang or Viper. $$KACHING$$

Regardless of what you do, find some way to measure the temperature reliably (some of those infra-red pistol-grip therms are under a hundred now, or if you wanna go real cheap, Harbor Freight has a digital meat temp therm).

Randii (not even gonna tease about that RC rearend)

If you are looking for reference on the hand to metal temps:

Nice and warm = 40C = 105F
Wow that’s hot = 50-55C = 120-130 F
Holy! $^(*& = +60 = +140 F

I use thermocouples a lot at work, but I use my hand first often for reference. :D

If you can hold your hand on it for more then a second then it’s less then 60C, or you are a mechanic or welder with leather instead of skin.

I was curious, so I googled...

I wasn't kidding on my :eek: $$$KA-CHING :eek: comment, above.
$1,449.00 http://www.viperconnection.com/parts/parts.html (scroll down)
...the one I've seen advertised in print is for a Mustang Cobra -- couldn't find a link. About a grand IIRC.

The ones I've seen on the 'net seem to all use the Tilton pump, but I saw a prototype Mark Williams one, as well. You need one that can survive a heavy gear lube.
http://emporium.markwilliams.com/prodinfo.asp?prodid=2024
http://www.tiltonracing.com/pdf_files/pg29.pdf
The Tolton pump is kinda big and clunky, but they make good stuff for everyday racers, so it is likely about 50% of the MW cost. MW makes great stuff, but they are proud of it.

Decent home-built diffy cooler setup: http://www.planetmustang.com/how_to_install_a_diff_cooler.htm

Bitchin' random link: http://www.turbokart.com/turbokartII.htm

Randii

:flipoff2:

Imo 18 degrees is to much..

even if you fill the fluid level at normal hieght and level when you tilt it that much you get alot less fluid on the slinger..

cheapest and easiest test is to get some gear fuild stuff .. lucas makes some good stuff...

you need the thick/sticky additive so it clinks up in the pinion bearing..you're prolly getting so little fuild up in your bearing, and getting hot it just runs right out cause its so thin..

if this don't work take that fawker out and reset it...
gearman knows his shit, but everybody has a fluke, or an employee of his installed it..it may not be eighter, cause it may not be wrong..

checking the temp in a acurate way is key to..as you know new gears get hot, some more than others, but borderline hot to the diff, is different than borderline hot to your hands..
do you know what gearman set your backlash to? he could have set it up like a race pattern (like 5-7 thousandths) and that would make it run hot to..ask him


without knowing is this a 1st generation tera 60 rear?

My D70 with 5.13's and Detroit gets HOT to the touch after long freeway trips. I just keep the fluid clean and full and have no problem. My pinion angle is right around 18* also.

Originally posted by slotoy


how long have they been setup?? if it's a fairly new set of gears it makes more sense they're heating up more.. make sure to break 'em in right.. if they're broke in and old, then disregard...

They have plenty of miles on them. :D

Randii, thanks for the links, but that is more than I want to spend.

Austin, I am going to give Sean a talking to.

Keith, you must be right about JiMMy.

JiMMy :flipoff2: you cant handle the P-stroke


Lots of good ideas guys, I think I will try the climbing lube, and the synthetic. (assuming they can be mixed together).
What brand and flavor would you guys recommend on the synthetic?

Thanks........

Is your fill hole in the diff cover? If so, it is rotated down & you may not be getting enough fluid into it. Mine has another hole placed above the original one.

Randii, thanks for the links, but that is more than I want to spend.
Yup -- for $1449, you could replace bearings each season for MANY moons....

The $200 Tilton pump, though.... that has some promise. If using better juice doesn't help, I bet you could set up a simple axle-mounted circuit for under $300... but only if you've running through bearings.

Any metal in the oil?

Randii

Originally posted by Keith


They have plenty of miles on them. :D

Randii, thanks for the links, but that is more than I want to spend.

Austin, I am going to give Sean a talking to.

Keith, you must be right about JiMMy.

JiMMy :flipoff2: you cant handle the P-stroke


Lots of good ideas guys, I think I will try the climbing lube, and the synthetic. (assuming they can be mixed together).
What brand and flavor would you guys recommend on the synthetic?

Thanks........ STRAWBERRY!!!!!!!!!!!!!!!!!!!!!!!!!!!!