1964 Daytona · Part 10 of 15

Rear Differential

The Daytona’s rear differential with its new chrome cover Rear Differential with new Chrome Cover

Normally a 259 V-8 powered 1964 Studebaker will come from the Factory with a Dana 27 Rear Differential

The Dana 27 differential cover with its bolt pattern Dana 27 Bolt pattern

With a 289 V8 it will normally come with a Dana 44 with sometimes Twin Traction (Non-Slip)

The Dana 44 differential cover with its bolt pattern Dana 44 Bolt Pattern

Covers are different but they use the same gear oil 75w90

I replaced the cover as it was old and very rusty with a Chrome aftermarket variety from EBay vendor

Tools/Parts Required

  • 1/2 inch 6 sided box end wrench
  • Liquid wrench or equivalent
  • Gasket scraper
  • Thin flat tipped screwdriver
  • Oil Drip Pan & rags

Parts Required

  • 1560245 Dana 27 Diff Cover Gasket
  • Permatex Gasket Maker - Black
  • 194839 Dana 27 Rear Diff Cover (if required)*
  • 2.5 Pints 75w90 Gear Oil

*Dana 27 cover & gasket is the same as a Dana 30 Optional: Car can be up on jack stands or on hoist to better enable you to remove diff pan and change gear oil easier

Task: Remove Differential Cover

  1. You will need to spray some Liquid Wrench on the bolts - let stand for 30 mins
  2. Slightly loosen Diff oil level access plug to ensure it can be removed - leave on cover
  3. Remove cover bolts (10) & diff ratio tag leaving the top one last - note where they go as some are longer then others and need to go back in the same hole
  4. Pry the cover off gently ensuring the oil drip can in position to catch all of the gear oil
  5. Remove last bolt and after all of the oil is emptied remove cover
  6. Inspect cover and if in rough shape replace
  7. Inspect Diff tag and note Gear Ratio and the bolt it was mounted on*

* Gear ratios: This Daytona has a gear ratio of 3:07 which will get you good gas mileage with reasonable acceleration

Other Gear ratios will be 3:31 (most common with Auto Trans) 3.54 and 3.73 if you want faster acceleration

Task: Reinstall Diff Cover & Add Gear Oil

  1. Thoroughly clean all gasket surfaces
  2. Put a coating of Gasket maker on the different housing surface where the gasket is mounted
  3. Then mount the new gasket on the Diff cover using gasket maker - not too much
  4. Reinstall the diff cover inserting the old bolts or new tempered steel bolts ensuring they are not cheap ones as they may snap off and then you will have to drill them out and use a Tap & Die
  5. Reinstall Diff ratio tag on assigned bolt
  6. Tighten all bolts firmly - 13-17 ft lbs
  7. Pour Gear oil into the Access Drain plug hole until it comes out - reinsert access drain plug firmly
  8. Check all bolts and if done properly there should be no leaks