Rear Differential Lubricant's Temp Range

Discussion in 'transmission and Drive train' started by Grumpy, Jun 30, 2021.

  1. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    I got asked what the ideal rear differential lubricants differential temps should be?
    Changing the lubricant's and additives in the differential if its of unknown age or it looks overly black may help durability, and perhaps order a magnet to place on the outside surface of the rear differential too trap and hold metallic debris,
    that naturally comes off the gear wear surfaces to help reduce the wear,
    will be helpful, but it certainly helps to check your rear differential coolant temps and occasionally verify fluid levels in your differential, after about 30 minutes of drive time

    Mark Williams recommends Torco RGO 85W140.
    Another good choice is Schaeffer’s Extreme Performance 75W140 part number 170.
    as a lube in the read differential,

    that fine metallic crap floating around suspended in that differential gear oil could cause thats very easily reduced.

    [​IMG]
    [​IMG]
    [​IMG]

    http://www.magnet4less.com/product_info.php?cPath=3_27&products_id=254
    if your towing temps generally run about 20F higher than general cruising due to the increased load on the contact surfaces and bearings
    the general temp range most cars see is in the 175F-200F range, higher gear ratios, like 3.73:1-4.56:1 tend to run about 15 F degrees higher than the more common 2.87:1-3.36:1 rear gear ratios
    differential lubricant temps above about 175F over time tend to degrade the bearing surfaces and increase wear on the ring and pinion gear teeth surfaces, and much to most people surprise, lubricants based on petroleum rather than newer synthetics are just as effective at lubricating surfaces , but something most people tend to ignore is the fact differential lubricants should be drained and replaced with new lubricant at about every 75K miles from what I've read in several places over the years.
    adding a differential cooler is a good idea if you are going to be driving at high speeds and under higher loads such as during road racing or towing a trailer .
    now obviously that is also something effected by vehicle weight and the cruising speeds, generally Id consider the differential temps be measured after about 30 minutes of street driving which might include some highway cruising in the 55 mph-70 mph range.
    [​IMG]
    http://www.testequipmentdepot.com/e...1100200223789&utm_content=All Extech Products

    http://garage.grumpysperformance.co...-synthetic-oil-and-trans-lube.718/#post-93459

    INFRARED TEMP GUN

    Wide temperature range from -58 to 1832°F (-50 to 1000°C)
    any time that your dealing with a potential temperature issue or a trouble issue where , knowing the exact temperature vs what a gauge might say, it helps to have a handy and accurate infrared temp gun handy to locate and confirm heat, levels.

    rear differential coolant temps can be significantly reduced with a differential cooler, that has an external lubricant pump and hear exchanger, much like an oil cooler, but those aftermarket rear differential covers with the fins don,t do much more than slow the rate at which rear differential lube reaches the peak operational temps.

    https://www.speedwaymotors.com/Dera...MIzKfRlc3A8QIVS21vBB2VpQcHEAQYAyABEgL3UfD_BwE

    https://www.summitracing.com/parts/...MIloDMuMzA8QIVVG5vBB0JtArREAQYASABEgJCofD_BwE

    [​IMG]
    [​IMG]



    EAR DIFFERENTIAL LUBES
    http://www.lastgreatroadtrip.com/wp-content/uploads/2010/11/gear-oil-comparison.pdf


    https://www.summitracing.com/parts/der-51008
    viewtopic.php?f=71&t=10690&p=46305#p46305

    http://garage.grumpysperformance.co...ans-cooler-on-a-c4-corvette.10514/#post-44498

    http://www.carid.com/dorman/radiator-fan-assembly.html

    http://garage.grumpysperformance.com/index.php?threads/valve-spring-cooling-via-engine-oil.6491/


    [​IMG]
    related info
    (DON,T SKIP OVER READ THE LINKED INFO):rolleyes::D


    https://bobistheoilguy.com/forums/threads/typical-rear-differential-temperatures.250049/

    http://garage.grumpysperformance.co...ear-axles-and-differentials.11848/#post-99450

    http://garage.grumpysperformance.co...nd-composition-is-important.15807/#post-94667

    http://garage.grumpysperformance.com/index.php?threads/rear-differential-cooler.10005/#post-94668

    http://garage.grumpysperformance.com/index.php?threads/differential-rebuild.257/#post-307

    https://www.streetmusclemag.com/tec...-ffr-cobra-challenge-gets-diff-trans-coolers/

    http://garage.grumpysperformance.co...luid-flow-and-composition-is-important.15807/
     
    Last edited: Jul 7, 2021

Share This Page