My Rear end is smokin hot!

[shmoov69]

Ok, it's in my car because I ain't got a rearend! Lol
first off, 9" rear with 3.00 gear and a Locker.
last weekend at the MMCC event my car puked out rear end fluid/grease out of the vent tube after around 9 laps or so around the road course. It dis it twice after about the same amount of laps, so I think it is legit. I jacked it up answer it on stands for about 15 minutes. Then I got under it to spray it off with brake cleaner. The tubes were fine, the mufer was even fine. But I sprayed the pumpkin and it sizzled it was STILL so hot! After a minimum of 15 minutes!!
Now my questions, is the fluid junk now? It had Castrol Syntec fluid in it.
What should I be running? And does anyone have a good idea for an overflow tank that will fit? Or ideas on anything else?

Thanks!

[MrQuick]

any whining or grinding noises coming from it?



maybe its time for a cooler with vent can?
vince

[Ron.in.SoCal]

Middle of the page:

http://www.artmorrison.com/2006cat/48.pdf

[David Pozzi]

How hot was it really? Isn't the boiling point of Brake Clean pretty low?

[CarlC]

According to MSDS the intial boiling point is 250*F. Could you touch the center section with your hand? 150*F is about the limit for touching.

The center section has enough mass that it will take a lot longer to cool down vs. lighter components.

However, if it was at 250*F after 15 minutes and a cool-off lap the temps on-track may have been pretty high. I'd be very concerned about component damage, such as bearings, since the heat treatment is affected after reaching 275-300*F. Excessive bearing preload, gearing mesh, and too much oil may be likely contributors to the problem. A internal inspection should be done.

[zbugger]

How is your exhaust set up too?

[6'9"Witha69]

A title like this and Allen's question may actually be pertinient to the conversation? I think I may faint.

[John Wright]

I'd pull the cover and peek at the teeth on the ring gear...if they have turned straw or blue....Hmmm...it may have hurt the gear.

whoops!...I read a bit closer...9" rear...pull the punkin' to see

[John Wright]

A title like this and Allen's question may actually be pertinient to the conversation? I think I may faint.

Bwhahahaha

[MrQuick]

A title like this and Allen's question may actually be pertinient to the conversation? I think I may faint.

I think its safe to assume that no joke means he either agrees or thinks its a trap. wait....I think the exhaust comment might have been an attempt as a subtle come on.


Vince

[shmoov69]

Lmao!

Well, it was too hot to touch for sure, but that don't tell me how hot it was. Just hot! The exhaust (4" single) dumps right on the right side in front of the pumpkin with a turndown. I know the level was correct because I checked before we left, so it wasn't overfull. It wasn't making any different noises than the normal locker clanking and clunking. Is it normal for a rear to get that hot when road racing?
So it sounds like I need to check it and change the fluid and put a resivoir/breather on it correct?

Thanks!

[JRouche]

Lmao!

Well, it was too hot to touch for sure, but that don't tell me how hot it was. Just hot! The exhaust (4" single) dumps right on the right side in front of the pumpkin with a turndown.

Ohh, thats the problem. Not the gears heating up the rearend but the exhaust heating it up. Got a non contact thermometer? If not get one. They have come way down in price and have many useful purposes.

You could easily see what the temp of the housing is with it. The gear oil wont be much lower. You could check that with a thermometer poked down into the level check plug. But I dont think you would need too. The gear oil will get as hot as the case.

The non contact temp meters are great for checking for "cool" cylinders too. Say one or two that are running 20-50 degrees cooler than the other cylinders. Shoot the exhaust tubes.

Find hot spots in a radiator. Tire temps. Shock temps. Tranny case temps. Rearend temps. Bearing temps. Good for a really quick trailer wheel bearing check. A/C clutch bearing temps. Engine intake temps. Like a before and after check when troubleshooting and installing a heat insulator. Floor pan temps before and after insulation. Ignition wire temp checks.

I could go on and on. There are so many temperatures that I need to see or some that Im just curious about. With a non-contact thermometer it is quick and easy. Not to mention ALL the other stuff around the shop and house that I want to know what is going on with the temp.

Oh, and I dont think you did any heat treating damage to the gears or bearings. You would have to be up there in temp, around 400*. I dont think you were that high. You would have seen alot of smoke before the tempering range of the hardened steel components got warm enough. JR

[shmoov69]

Thanks man. I'll try to get a thermometer and check stuff out. I'm not sure tho on what will be exhaust heat and what will be gear heat. But I do know that when I had dual 3" dumping there, the tank got SUPER hot, so I suppose alot could be exhaust. Never thought of that.

[Gitter Dun]

I seen a gal today with a smokin hot rear, Didn't get to feel it tho.

[Roadrage David]

any whining or grinding noises coming from it?



maybe its time for a cooler with vent can?
vince

Annybody running a cooler?? on there rear axle. if so pictures please..........

[shmoov69]

How would a cooler work? Just an electric oil pump to a cooler?

[JRouche]

I seen a gal today with a smokin hot rear, Didn't get to feel it tho.

Get a NON-contact thermometer and you can check her heat also. Definitely dont wanna reach out and take a contact temp feel though. You might get some added heat that will cook you but quick. JR

[JRouche]

How would a cooler work? Just an electric oil pump to a cooler?

A rear gear lube cooler helps with some folks. But thats after they have already removed the outside heating sources. Like an exhaust dump on the rear.

And yes you can get a rear gear oiling system. Driven mechanically (NOT cheap) from the rear end. Alot of issues though. Not just a simple oil pump. Pumping cold gear oil isn't easy. Then when it warms up the pump needs to change. Pumping cold gear oil needs some serious PSI. Think about sucking mud through a straw. There are better ways to cool the rear. Remove the exhaust dump is one.. IMO you dont even need a rear end cooler. You need to remove the heat that you are applying. JR

[Roadrage David]

So nobody hase any ecsp with a oil cooler for the rear??. couldend we just aply 2 holles in the caseing below the oil line. tap wire in it and plug it to a smal oil cooler that is being fikst on the casing.?? wouldend de oil flow from the ring and pinion find its way into the oil cooler some way??. thinking out loud here.......

[MrQuick]

So nobody hase any ecsp with a oil cooler for the rear??. couldend we just aply 2 holles in the caseing below the oil line. tap wire in it and plug it to a smal oil cooler that is being fikst on the casing.?? wouldend de oil flow from the ring and pinion find its way into the oil cooler some way??. thinking out loud here.......

I see some track cars with it. There is a project or two out there but they escape me right now? Mr. Stielows Blue bomber perhaps? Jakes 70' Track rat?
I know Mr Shipka's one lap has a over level vent system.

A rear gear lube cooler helps with some folks. But thats after they have already removed the outside heating sources. Like an exhaust dump on the rear.



And yes you can get a rear gear oiling system. Driven mechanically (NOT cheap) from the rear end. Alot of issues though. Not just a simple oil pump. Pumping cold gear oil isn't easy. Then when it warms up the pump needs to change. Pumping cold gear oil needs some serious PSI. Think about sucking mud through a straw. There are better ways to cool the rear. Remove the exhaust dump is one.. IMO you dont even need a rear end cooler. You need to remove the heat that you are applying. JR

Good points JR, but pumping hot oil is easier...by using a oil thermostat set to say 180 degrees would allow the circulation. The question would be, what would your optimum operating temperature be for a hard running 9 inch?

I believe Jimmy has found his issue.


I remember the idea of having a driveshaft run pump or internal ring gear pumping system that pressurizes fluid into a channel built into the housing that feeds into a line then to a trunk mounted air/fluid heat exchanger then semi/gravity feeds back to the top of the ring gear. Sounded crazy at the time but now, without my coffee...it just might work. What do you think David?
Vince