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8/20/2019 4:28 PM  #1


True Trac or Traction Lock rear differential

Anyone have experience with the newer True Trac differential as opposed to a Traction lock?  The guy at Currie recommended one.


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
 

8/20/2019 5:06 PM  #2


Re: True Trac or Traction Lock rear differential

i used the True Trac in my Cobra replica (replacing a traction lock) and was very happy with it.  No smelly additives and smooth sharp turns.  Still left 2 stripes when necessary. No clutch replacements.  I liked it so much that I just installed one in my truck with the 10.25 Sterling.  Cost is a bit higher than some other options but worth it to me.

 

8/20/2019 5:50 PM  #3


Re: True Trac or Traction Lock rear differential

I'am planning on doing mine next and so far my pick for my  8"  is This Eaton Truetrac 912A616
 Helical worm gear design, no clutches to wear out
 or  ​love to here any reference or experiences anyone has on this subject !!  THANKS 

Last edited by Vkt-66 (8/20/2019 5:51 PM)


66 PonySilverBlue-289/gt40/roller/650cfm/ram air-T-5-cable-w4way.disc/4-245x50x16"
 

8/20/2019 6:11 PM  #4


Re: True Trac or Traction Lock rear differential

Apparently Eaton, who now owns Detroit, states that the part number you reference will work with 3.25 or numerically higher ratios.  There is potential interference with the pinion on lower numeric ratios.  I trying to remember if it was Alesandro that might have had a problem with fitment.  But most reviews I saw on Summit and others for the 8" rear were positive.  It sounds like you may need new ring gear bolts to match the flange thickness and you will also need new bearings - they provide the required bearings and I saw them listed on several searches.  The standard 8" carrier bearings for the ford center section do not fit.  One guy mentioned that it jumped around corners and was noisy in reverse - not my experience at all.  Maybe he was describing a Detroit Locker.  But it was on the internet so it could be true.

 

8/20/2019 8:39 PM  #5


Re: True Trac or Traction Lock rear differential

I forgot to state, but this is for a 9”.


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
     Thread Starter
 

8/20/2019 8:53 PM  #6


Re: True Trac or Traction Lock rear differential

I figured your's was for a 9".  The literature also shows that the 9" 28 and 31 spline units are compatible with 3.25 and numerically higher ratios as well.  One stated that it may work with 3.0 gears in some cases.  So, if you are going under 3.25 you probably need the trac lok.

 

8/21/2019 6:00 AM  #7


Re: True Trac or Traction Lock rear differential

These guys seemed pretty helpful when I called about replacing my 9" center section.   https://www.quickperformance.com/Ford-9-Inch-9-Ford_c_37.html

 

8/21/2019 6:40 AM  #8


Re: True Trac or Traction Lock rear differential

I put an Eaton Truetrac in the 9” on my 64.5 vert. Haven’t driven it out of the driveway yet, so can’t give you any real feed back, but all reports I’ve read are that they work well.

 

8/21/2019 8:12 AM  #9


Re: True Trac or Traction Lock rear differential

After exhaustive research I will be putting a TrueTrac in the rear of my '06 F250.  The factory Ford Traction Lock was wasted in about 20-30k miles.  I replaced it with a Yukon LSD, which lasted a lot longer, but is now starting to fade, and occasionally I get chatter in a corner.  The truck makes massive power (660HP and over 900lbs/ft.) so I just don't think any clutch based LSD is going to be as effective as something that uses gears.  All the forum posts rave about them across model lines too.  Guys with trucks love them, guys with cars love them.  Its rare to see that, usually the truck guys are screaming full Detroit while the car guys say they're too harsh, etc.  I don't think you can go wrong.

 

8/21/2019 11:50 AM  #10


Re: True Trac or Traction Lock rear differential

I have a tru trac in my mustang.  My driveway has twin patches on it to prove function.  Torque biasing differentials are pretty awesome in my opinion.  I had one in my diesel pickup and it held up well.

Only thing I have ever heard is to not run synthetic with one, as the helical torque biasing magic needs conventional oil to have the small amount of friction it needs to function.  I do not know how true this is, but I run dinosaur oil just in case.

 

8/21/2019 1:38 PM  #11


Re: True Trac or Traction Lock rear differential

A lot of guys I race with use the newer TrueTrac and love them. I would not waste time on a Trac lock. I remember all the diff testing at the Eaton Proving Grounds back in the day which was the early design TrueTrac stuff along with the Locker. The early ones were not what the newer ones are.

 

8/22/2019 10:01 AM  #12


Re: True Trac or Traction Lock rear differential

Not a newer True Trac, but have been running a unit in a Curry 9+ for approximately 15 years with no issues; however, the shear pin in my case are the narrow tires (235/17). Good traction to both tires, even on uneven pavement, but one wheel spin can be induced if significant friction difference from one tire to the other.

 

8/22/2019 11:21 AM  #13


Re: True Trac or Traction Lock rear differential

Thanks for all the feedback.  Looks like true trac is the way to go.


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
     Thread Starter
 

8/23/2019 4:49 AM  #14


Re: True Trac or Traction Lock rear differential

Bentworker wrote:

I have a tru trac in my mustang. My driveway has twin patches on it to prove function. Torque biasing differentials are pretty awesome in my opinion. I had one in my diesel pickup and it held up well.

Only thing I have ever heard is to not run synthetic with one, as the helical torque biasing magic needs conventional oil to have the small amount of friction it needs to function. I do not know how true this is, but I run dinosaur oil just in case.

Its not true.  You can run synthetic oil with them.  In my research I happened upon a video from the manufacturer explaining operation, and in it they stated that the oil type used doesn't matter.  They don't really work on friction; they work because a worm gear can drive a spur gear, but a spur gear can't drive a worm gear.  In the locked mode the spur gears are trying to drive the worm gears and they just can't.  No amount of friction reduction is going to change that. 

However, what might happen is that the time it takes to achieve lockup may be lengthened with synthetic as opposed to conventional.  This would be a split second difference that some may or may not find objectionable. 
 

 

8/23/2019 2:30 PM  #15


Re: True Trac or Traction Lock rear differential

Quick, someone contact Eaton because obviously their website is the victim of malicious hackers. Their website states to use GL5 mineral based oil and the use of synthetic oil is discouraged.....this so confusing...what expert should we trust???

 

8/23/2019 2:57 PM  #16


Re: True Trac or Traction Lock rear differential

This if from their product manual, enjoy:

Detroit TruetracHigh quality mineral gear lubes are required for use in Detroit Truetrac differentials. Regardless of the lube type, always use a GL5 rated lube with the least amount of friction modifier. Mineral lubes lacking friction modifiers (limited-slip additives) were historically recommended for all Truetrac applications because friction modifiers can slightly reduce the bias ratio (limited-slip aggressiveness) of Truetrac differentials. However, to address the continually increasing power outputs of modern powertrains, many vehicle manufacturers have switched to synthetic lubricants as a counter measure for increased axle temperatures and prolonged service intervals. In general, consult the vehicle owner's manual for the manufacturer's recommendations for lubrication type, weight and fill volume. This will ensure lube compatibility with the seal materials and bearings used in the axle. Eaton Performance technical support is available for any concerns in lube selection.
 

Last edited by TKOPerformance (8/23/2019 2:58 PM)

 

8/24/2019 10:06 PM  #17


Re: True Trac or Traction Lock rear differential

Gotta love it when the manufacturer gives conflicting info.

https://www.eaton.com/Eaton/ProductsServices/Vehicle/Differentials/FAQforDifferentials/index.htmDetroit TruetracQ: What kind of oil should I use? Can I use synthetic? Do I need friction additive/modifier?A: A quality petroleum/mineral based oil works best in the Truetrac units. We do not recommend synthetic oil. Friction additive/modifier is not required.

 

8/25/2019 6:07 AM  #18


Re: True Trac or Traction Lock rear differential

When I ordered my new rear axle from Strange, they shipped the fiction modifier with it and said to use it, so that is what I did.

 

Board footera


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