What is the safe rear differential temperature? Was about 90* out today and unloaded was driving around parked the truck and was working under the truck and noticed the pumpkin wasn't scorching hot, but just hot enough to put my hand on for a few seconds...I know it will get warm, but what is the max temp??

 

most large truck axles redline at 180 degrees. not to sure about the ranger.

 

At a Prevost Bus service seminar the printed material stated, "When talking about differential oil temperature, nomal reading should not exceed 250F, 120C." It should be remembered that the rear axle on a 54k GVWR bus is under greater load than the twin screw axles on an 80k GVWR truck/trailer. Hence whenever a truck dealership has to service a bus rear axle they are always impressed at how much beefier the bus axle is when compared to the truck. My personal experience has been that the rear axle temp on the bus usually ranges between 180 at no load, level ground conditions to 230 full weight load and climbing numerous grades. Usually it settles in around 200 F at highway speeds with mile to no grades and rising slightly with grades. The temperature is much more dependent on load, grade, and speed than ambient temperature. Usually our load is constant. Of interest at the same seminar, Allison ATEC transmission oil temps normal readings were listed as 160-250 F (70-120 C). This was pre transmission cooler temps. Again, my concern was for the protection of the bearings, oil, and seal components. I think the bearings, oil, and seals in the Ranger can probably tolerate a temp of 250 F, but I suspect the temperature would be less than that simply as a matter of load.

 

If you could hold your hand on the pumpkin for a couple of seconds, You're well below the above stated limits. But the cooler the diff runs, the longer the lube runs and better the protection etc. Lots of guys put a cast aluminum cover on it with the fins. There's some straight take-offs from other Ford 8.8 and maybe the 7.5. I remember a couple of threads about them.

Fred

 

You mean one of these badboys Adds capcity, aiding cooling, Supports main caps, and looks good This is for my Roadmaster. Had the words milled off the top for the smooth look. It's being powdercoated right now. Many places sell them. Around $160. BTW an electric sending temp gauge would work good if you were concerned about temps. Run the wire up along the brake line, and give it a little slack.

(Forgive the cell phone pics)

 

Yep, that's the ticket. Buffman, was that the stock replacement for the Roadmaster?

Fred

 

well the stock replacement is just a crappy steel cover. Thats the summit brand rear end support cover. They make them for many applications.

 

just to show off a tad, got my cover back from the powdercoater today. Will go on my roadmaster when it gets back from the body shop.





Matt

 

Wow. That cover is really good looking... Kind of hard to tell but is that a light hammertone powdercoat finish?? Either way looks great! I will try to get one of those eventually but in the mean time it sounds like my temperatures arent too far out of line.... thanks all for the help!

 

They even kept the threads clean... Did you use a clear non pigmented clear coat powder to reduce corrosion possibility, or is that the base by itself?? Looks like the powder had good flow characteristics.... Eastwood powder by chance??

 

it's called silver vein which I think is just the same as hammertone. I'd have to ask my friend but everything is usually clear coated.

My friend is very **** about powdercoating. He won't do something he wouldn't put on his car. He's been doing it for a few years. A lot of what he owns is higher end professional equipment. I think at one point he told me he had 60K worth of equipment.