Detroit Truetrac 3.55 in Chrysler 8 3/4

[inviolet]

Whats up guys,,,

I just installed my rear the past week. I did a Detroit Truetrac with 3.55's in a Chrysler 8 3/4. Needless to say the car has woken up..coming from 3.23's. The Detroit Truetrac is an excellent posi unit....I LOVE THE BITE.

Anyway, So far so good, Only thing that I still can't figure out is why rear end fluid blows out my breather at high speeds and hard accelerations. I had the same issue before with my last Differential. I tried a new stock breather..and that was no good, I tried a 5/16 hose leading off the old breather and running it to the top of the frame rail and that helped a bit but still the same issue...now some might say I'm over filling the rear but I don't think so. Any suggestions?

[Chryco Psycho]

I assume the breather is in the stock location about 1/3 of the way down the top of the axle tube ?
 The diff should only be full to the bottom of the fill plug in the side of the carrier . I cannot think of any other reason why oil would be pushed out the breather unless it is in a different position than the original factory location

[72cudamaan]

So , which is it. A Detroit Locker or a Truetrak?  I only ask because I had heard that a locker was awfully aggressive for street use. Lot's of scuffing on tires in tight turns.

[inviolet]

So , which is it. A Detroit Locker or a Truetrak?  I only ask because I had heard that a locker was awfully aggressive for street use. Lot's of scuffing on tires in tight turns.

Its a Detroit Truetrac,

http://www.eaton.com/EatonCom/ProductsServices/PerformanceProducts/Products/Differentials/DetroitTruetrac/

    * Smooth operation
    * Performs open until needed
    * Fully automatic limited slip

I assume the breather is in the stock location about 1/3 of the way down the top of the axle tube ?
 The diff should only be full to the bottom of the fill plug in the side of the carrier . I cannot think of any other reason why oil would be pushed out the breather unless it is in a different position than the original factory location

Yes the breather is in the stock location,, and I do fill it till it empties from the fill hole.....Could it be that I'm using a narrower rear from a 68 charger?

Currently I have a 5/16 hose leading off the stem of the old breather running to the top of the frame rail with a little plastic air filter on top. Should I just buy another stock breather and try that again?

[Chryco Psycho]

I have no clue why it would be pressurizing enough to push fuild out the breather , never seen it on any other diff & a Chrger diff should make no difference at all

[inviolet]

When I compare the location of the stock breather from my stock 70 E body rear housing it's in a totally different location than the stock 68 charger rear housing I am currently using. I assume Both breathers are in their original location.

Does the 68 charger rear have the breather mounted in a different spot because of the width difference or was it tampered with?

[SBDave]

I just did the same upgrade about 6 months ago.  I haven't had any breather issues however I didn't fill it as much as recommended.  I used 2 quarts of LAT 75W140.  I believe it was recommended to fill it with 2.2 quarts but I can see that the fluid is just below the drain plug.  Don't some road racers use catch cans off their axle vent tubes?  What type of fluid did you use?

Dave

[inviolet]

Lucas Heavy Duty 85W-140 Gear Oil

http://www.lucasoil.com/products/display_products.sd?iid=44&catid=12&loc=show&headTitle=%20-%20Lucas%20Heavy%20Duty%2085W-140%20Gear%20Oil

No additive need because of True Track.

The catch can idea sound interesting............