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Differential cooler

It's not bolted to the diff, its merely a cross brace tying the two pipes together.
I suppose that cross brace stays at outside ambient temp and transmits absolutely no heat to the diff cover, right? I think not. It's gonna transmit some heat to the diff cover is what it looks like to me.

And ken, why ya want my thread locked?:-P

Durrrr now you get it. See post 23.

You took my statement the wrong way. I KNOW the finned covers help cool diff oil. Give me a break duder.

It was said it had no cooler/cooling of diff. I pointed out that is what the finned cover does.

And if you can find me a finned cover like that for a 91 240 diff w/ elec. speedo hook up, I'd appreciate it. But no one makes them. At least I cannot find anyone who does. So looks like buying a finned cover for mine is pointless advice. Why I was trying to come up with something else.

most of the aftermarket BMW covers have more fins and allow more fluid.... supposedly the one above lowered the race temp 55? over using the factory aluminum finned cover...
Interesting info. but unless it'll fit my diff, it's not gonna do me any good.:lol:

Again, this why I'm was trying to come up with something else to do same job.


If you want it to work at all you should consider making a finned aluminum cover like I posted on the last page, or like the MB or Datsun one above. Not just a "ribbed" one, but one with actual heatsink fins on it.
Well, if I had my own Brideport & a CNC milling machine, and my own foundry, I guess I could. But alas, I don't. Would be extravangantly expensive to have one custom made also.

I guess I'll just have a hot diff.:lol:
 
It's not bolted to the diff, its merely a cross brace tying the two pipes together.
I suppose that cross brace stays at outside ambient temp and transmits absolutely no heat to the diff cover, right? I think not. It's gonna transmit some heat to the diff cover is what it looks like to me.

And ken, why ya want my thread locked?:-P

Durrrr now you get it. See post 23.

You took my statement the wrong way. I KNOW the finned covers help cool diff oil. Give me a break duder.

It was said it had no cooler/cooling of diff. I pointed out that is what the finned cover does.

And if you can find me a finned cover like that for a 91 240 diff w/ elec. speedo hook up, I'd appreciate it. But no one makes them. At least I cannot find anyone who does. So looks like buying a finned cover for mine is pointless advice. Why I was trying to come up with something else.

most of the aftermarket BMW covers have more fins and allow more fluid.... supposedly the one above lowered the race temp 55? over using the factory aluminum finned cover...
Interesting info. but unless it'll fit my diff, it's not gonna do me any good.:lol:

Again, this why I'm was trying to come up with something else to do same job.


If you want it to work at all you should consider making a finned aluminum cover like I posted on the last page, or like the MB or Datsun one above. Not just a "ribbed" one, but one with actual heatsink fins on it.
Well, if I had my own Brideport & a CNC milling machine, and my own foundry, I guess I could. But alas, I don't. Would be extravangantly expensive to have one custom made also.

I guess I'll just have a hot diff.:lol:
 
"And the diff gets pretty hot on a 100F* day after 100 miles of 65+ MPH driving." How hot? Putting your hand on it and concluding it's really hot isn't - uh - scientific. Black paint sitting in the sun gets too hot to put your hand on it for very long - but it won't hurt anything. Lots of stuff under the hood gets too hot to put your hand on it -- without being hot enough to cause any problems. Cooling the fluid is going to solve a problem that doesn't exist.

Now -- if you just want to do it -- that's a whole other deal. And I can appreciate that --- lots of stuff on mine that I just wanted to do. I just think you should be intellectually honest with yourself about it, that's all. Short of a pump and heat exchanger -- a finned cover is about your best bet. I don't think your original suggestion will accomplish much of anything in the way of cooling. And if your Panhard sits as close as mine did (move from Dana 30 to Ford 8.8" required modifying things to clear the Panhard on mine) you'll have to move it to clear the cover.
 
TB has the most talented troll.

Color me amazed that so many of you actually responded to this thread seriously.

HAHA, I was just thinking of a scientific awsner. One needs to get a used watertemp guage, or a oil temp guage since they may read a little lower temp....do a before (and to at least see what the diff is running at for normal temp and then do a test after some sort of cooler is added.

One could also use an old school MS1 and use a water temp guage for more accurate lowend resuslts.

Ive always meant to do the MS trick for pre and post IC temps using a gm airtemp for water and air and watch them in real time.
 
I suppose that cross brace stays at outside ambient temp and transmits absolutely no heat to the diff cover, right? I think not. It's gonna transmit some heat to the diff cover is what it looks like to me.

In free air, the transfer of heat is going to be piss poor...think of it this way...you can stand outside naked in 50? if you had to for a while...in water you'd be dead in a short time.

Air is a decent insulator, it has an R value of approx R-5 , not too bad

That and figure when the mufflers are going to be the hottest, air will be flowing past them, at idle, they won't be as hot to transfer any heat to items off to the side (most heat will travel up


You took my statement the wrong way. I KNOW the finned covers help cool diff oil. Give me a break duder.

It was said it had no cooler/cooling of diff. I pointed out that is what the finned cover does.

And if you can find me a finned cover like that for a 91 240 diff w/ elec. speedo hook up, I'd appreciate it. But no one makes them. At least I cannot find anyone who does. So looks like buying a finned cover for mine is pointless advice. Why I was trying to come up with something else.

Find a cheaper aluminum on, have a bung welded to it, does not matter if cast or billet, still weldable.

Interesting info. but unless it'll fit my diff, it's not gonna do me any good.:lol:

Again, this why I'm was trying to come up with something else to do same job.


Well, if I had my own Bridgeport & a CNC milling machine, and my own foundry, I guess I could. But alas, I don't. Would be extravagantly expensive to have one custom made also.

I have all 3, just no desire to make something like that..too many other useless projects to work on 1st.


I guess I'll just have a hot diff.:lol:

see above :)
 
I'll see if I can get an infrared temp reading on our diff housing at the 24hr lemons race @ charlotte.
 
$39 at Harbor Freight, is within 2? of my Cole-Palmer K-Type Thermocouple Thermometer and 1? of my neighbors DeWalt infrared unit. Can be used in the kitchen as well so the wife shouldn't complain about more tools since she too can use it !!!

I'll definately check into HF IR heating reading gun. Thanks!


I'll see if I can get an infrared temp reading on our diff housing at the 24hr lemons race @ charlotte.

I'd really appreciate it if you would do that towerymt.:nod: That would give a good indication of a 24 hour constant run temp at hi speed. And would be an "extreme use" temp to judge/gauge by when I get the HF IR heat reading gun and take readings of my "street use" temps.

I'm curious to see what/how much difference in those two types of readings actually are .
 
$39 at Harbor Freight, is within 2? of my Cole-Palmer K-Type Thermocouple Thermometer and 1? of my neighbors DeWalt infrared unit. Can be used in the kitchen as well so the wife shouldn't complain about more tools since she too can use it !!!

I'll definately check into HF IR heating reading gun. Thanks!


I'll see if I can get an infrared temp reading on our diff housing at the 24hr lemons race @ charlotte.

I'd really appreciate it if you would do that towerymt.:nod: That would give a good indication of a 24 hour constant run temp at hi speed. And would be an "extreme use" temp to judge/gauge by when I get the HF IR heat reading gun and take readings of my "street use" temps.

I'm curious to see what/how much difference in those two types of readings actually are .
 
Get a multimeter that does logging (cheap) and plug a thermocouple in it. Run the wire through the ebrake cable pass through and drive around.
 
Nope, not just a finned rear cover.but that is part of what gave me this weird idea. But....no one makes Volvo diff rear covers for the electric speedo diff cover anyway.
Let me explain my idea. And keep in mind, it's just an idea that crossed my mind when I noticed those holes in mtg flanges on the diff.

Now... on pass side of diff. hsg. on my 91 244 there are two mounting flanges with drilled & tapped holes in them. One hole on each flange.

I was wondering .....what if i made a thick steel plate to bolt to one or both mtg flanges.Drill & tap it for small bolts to screw into said plate. (if floorpan clearance will allow it)

Then cut some short 1/8" long or so ,small diameter sleeves for spacers.
Find, or fab some thin sheet aluminum.
Cut them into same size pieces.
Drill holes in a pattern, so as to allow them to be stacked(like fins on an oil cooler) 1/8" apart.
Bolt the bottom plate to the thick mtg plate that'll attach to diff mtg holes.

I'll end up with a series of stacked aluminum fins to use as a convection cooler that'll maybe dissipate heat away from diff hsg, thereby (possibly) cooling the diff & diff oil temps.

Only problem is, not sure how large said cooler would have to be ,to do the job. I'm thinking not enough room under there for this thing to actually do any cooling of diff. But I'm thinking it might be worth investigating?

I need to read up on heat loss/heat gain formulas I suppose. I doubt this idea of mine will be very feasible/worth the effort.

And I'd have to investigate on exactly how to mount it for proper clearance/air flow. Like I said, just a weird idea that "popped" into my head.

See pic below and notice the star drivers are inserted into the threaded holes where mounting flanges are already cast into the diff hsg.

Now..look at this pic. This is a pic of my 91 240's diff.

100_6660.jpg

That still isn't convection, it's conduction, then radiation.

Hmm, cast iron engine block gets hot & so does the cam cover. Must be some cast iron to aluminum heat transfer going on there I'd think. I know the engine oil is part of it
Even on a Harley engine, the old ones had cast iron cylinder & aluminum head. Both had fins. Both dissipated heat.

While my idea surely isn't as effient as a pump & oil cooler, seems like it'd do some cooling if the fins were big enough & placed in decent airflow.

But maybe not..........and like I said, it was just an idea I came up with.....
The block and cam cover materials are..immaterial, since the liquid cooling going on by far surpasses the radiation of heat from those parts.
Except for the case of old air-cooled stuff, like the harley mentioned.


And, now, the important part:
And folks before suggesting all sorts of silly solutions we really ought to concentrate on the supposed problem and if it needs a cure...
First things first and all

See Towery post, wait for temps report, yadda.
 
Crazy idea time , I'd add a bolt on fin assembly to the rear of the drive shaft to "blow" air across the diff housing

Kinda like a boat propeller? Interesting angle, although foward vehicle motion will have a similar effect.

And, you could replace all the door seals so she floats and you will have marine propulsion.:oogle:

I did install an aftermarket aluminum cover on my F250 after the stock one rotted thru, but I also tow an 8000lb boat in the summer so I figured it couldnt hurt. The cover has fins and only really gets too hot to touch after towing.
 
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