Experience Using Doctor Diff "Sure-Trac II?"
- Thread starter piver
- Start date
piver
Active Member
Thank you all for sharing feedback on Doctor Diff's 8 3/4" Helical Gear Sure-Grip ("Sure-Trac II").
I ordered the Sure-Trac II from the Doctor for my '68 Coronet R/T (747 trans, 742 case, 3.23 ratio now, originally no Sure-Grip) and will report back on installing & running it.
Doctor Diff (Cass) only accepts email and form submissions on his website, but he called me when I asked. He was knowledgeable, authoritative, polite, and helpful. He no longer carries Eaton's Detroit Truetrac for Chrysler 8 3/4" because he's found the side gear fitment inside the carrier is sloppy loose, causing the axles to pivot during use (and even affecting toe etc.). He has a video showing that looseness. His discoveries were a few years ago, so he did acknowledge it's possible Eaton has made improvements since then (but who knows). Regardless of Truetrac comparisons, he persuasively argued for superiority of the Sure-Trac II (includes belleville springs, more helical/ worm gears...basically stronger, smoother, more responsive to low traction, etc.). And at $595 it is less expensive that Truetrac and other differentials out there.
FYI, also ordered from Doctor Diff:
> 8 3/4" bearing rebuild kit
> 8 3/4" Ring and Pinion (for 3.55)
> 8 3/4" Inner Axle Seal (2)
> Green Bearings (PAIR)
> Sending Unit
> Fuel Pump to Carburetor Line(s)
I ordered the Sure-Trac II from the Doctor for my '68 Coronet R/T (747 trans, 742 case, 3.23 ratio now, originally no Sure-Grip) and will report back on installing & running it.
Doctor Diff (Cass) only accepts email and form submissions on his website, but he called me when I asked. He was knowledgeable, authoritative, polite, and helpful. He no longer carries Eaton's Detroit Truetrac for Chrysler 8 3/4" because he's found the side gear fitment inside the carrier is sloppy loose, causing the axles to pivot during use (and even affecting toe etc.). He has a video showing that looseness. His discoveries were a few years ago, so he did acknowledge it's possible Eaton has made improvements since then (but who knows). Regardless of Truetrac comparisons, he persuasively argued for superiority of the Sure-Trac II (includes belleville springs, more helical/ worm gears...basically stronger, smoother, more responsive to low traction, etc.). And at $595 it is less expensive that Truetrac and other differentials out there.
FYI, also ordered from Doctor Diff:
> 8 3/4" bearing rebuild kit
> 8 3/4" Ring and Pinion (for 3.55)
> 8 3/4" Inner Axle Seal (2)
> Green Bearings (PAIR)
> Sending Unit
> Fuel Pump to Carburetor Line(s)
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