Truetrac by Eaton

[Hendrix-Engineering]

Originally Posted by blazzin1

I asked Redline what I should use with this Eaton Truetrack and new gears, and they highly recommended their Redline 75W90 GL-5 (synthetic), and use a bottle of their friction modifier just for "break-in". Then change out the fluid again without the friction modifier after 500-800 miles. But now I'm hearing all this stuff about not using synthetic gear oil, so now I don't know what to do!?!?!?!? Maybe I should use their 80W140 instead??? Is the Lucas stuff you mentioned, is that a synthetic-based gear oil???

Or maybe this would be good stuff to use (link below). Although, Redline did not recommend this "shockproof" stuff for my application, they said it was for "racing" differentials only. I'm so confused, I thought with the 6-speed manuals being so hard on the rear ends, that this stuff would be perfect....but maybe I'm wrong?!?!? Can anyone give a definitive....."this is the best stuff to use with the Eaton Truetrac" recommendation????

http://www.redlineoil.com/product.aspx?pid=43&pcid=8

I never use synthetic in rears,always dino oil for me....lucas is dino oil

[blazzin1]

Originally Posted by Hendrix-Engineering

I never use synthetic in rears,always dino oil for me....lucas is dino oil

Thanks!.....It's hard to question anything about differentials coming from you guys!!!!

I'm assuming then this is the stuff you're recommending:

http://www.lucasoil.com/products/dis...how&headTitle= - Lucas Heavy Duty 85W-140 Gear Oil

[JTRJSS]

The Lucas 85-140 is what I use. I tried other diff oil and the Lucas seems to keep the noise down.

[blazzin1]

Originally Posted by JTRJSS

The Lucas 85-140 is what I use. I tried other diff oil and the Lucas seems to keep the noise down.

Thanks for the confirmation on the oil. I'll have to see if I can find it around here! Did you do any kind of special "break-in" procedure for the Truetrac? I know supposedly for the gears, you're supposed to do a few heat-cycles on them, like 20 minutes of driving, and let them cool, and then 20 minutes more driving, and let them cool, etc. And I've also heard about doing figure 8's for breaking in the traditional clutch-type posi units, but not sure what to do for the Truetrac. Any suggestions?

[JTRJSS]

Yes I was also told to do the heat cycle. There is no break in period for the posi unit. There are no clutches to break in. I was also told to change the gear oil after 1000 miles.

I have about 8,000 miles on the unit and no problems. Are you changing the diff bushings? I do hear more noise because of the stiffer bushing that were installed.

[blazzin1]

Originally Posted by JTRJSS

Yes I was also told to do the heat cycle. There is no break in period for the posi unit. There are no clutches to break in. I was also told to change the gear oil after 1000 miles.

I have about 8,000 miles on the unit and no problems. Are you changing the diff bushings? I do hear more noise because of the stiffer bushing that were installed.

Yes, I am in the process of installing new gears (3.91's), JRE billet caps, Pfadt "Race" differential bushings, Pfadt Solid Subframe bushings, and Pfadt upper control arm bushings. So, yes, I do expect to hear considerably more "noise" than what I had before!!! But I'm just hoping this thing doesn't ride like a freakin' dump truck after all this?!?!?!?

Did you notice that Pfadt no longer sells their differential bushings on their website!?!?!? I wonder if they were getting too many complaints about NVH??? And I am installing their "race" version which is even stiffer, I'm really afraid this thing is going to sound like a freight train now!!!!

[bthibodeaux]

Thanks for the additional input guys. I will go with mineral oil instead.

[Motion427]

Here at the shop, I use either Royal Purple or Redline.
For your application,I would use Redline shock proof.

The True trac does not like the Royal Purple when the True Trac is brand new.

I tried it on my truck.I ran the Royal Purple for a few months,then I changed to Lucas oil.It was OK with Lucas,then I changed again to Royal Purple.It's OK now. (I tried a couple of different gear ratio's in my truck,that's why I changed the oil often)

To be honest, the front diff has Redline and the rear has Royal Purple.lol.....

[blazzin1]

Originally Posted by Motion427

For your application,I would use Redline shock proof.

Hey Ron, thanks for the recommendation. I'm still kinda "wishy-washy" on this, but IF I was to use this Redline Shock Proof stuff, which one do you think I should use, the "Heavy" or "Lightweight"???

http://www.redlineoil.com/product.aspx?pid=44&pcid=8

http://www.redlineoil.com/product.aspx?pid=43&pcid=8

[Motion427]

I use the heavy.You should see the thing stick on the gear. lol....

When you do the break in period.Heat will kill the gears, new gears run alot hotter.
Premium oil and short trips are key for the first 500 miles.

[bthibodeaux]

Originally Posted by Motion427

I use the heavy.You should see the thing stick on the gear. lol....

When you do the break in period.Heat will kill the gears, new gears run alot hotter.
Premium oil and short trips are key for the first 500 miles.

Would a 50 mile trip be in the "short trip" range? Thanks again for the smokin deal on the gears.

[Motion427]

Would it be the very first "short trip" with the new gears?
If so,I would take a break in between.
After the 2nd or 3rd short trip,you can go further.
The AAM is a great gear,some will say that you can hammer it after 2-3 heat cycles,but why take the chance.

No Problem Brian.Glad I could help.Thank You.

[Awesome_SS]

Interesting. I am running Royal Purple w/ my new Tru Trac. No problems here...so far.

Originally Posted by Motion427

Here at the shop, I use either Royal Purple or Redline.
For your application,I would use Redline shock proof.

The True trac does not like the Royal Purple when the True Trac is brand new.

I tried it on my truck.I ran the Royal Purple for a few months,then I changed to Lucas oil.It was OK with Lucas,then I changed again to Royal Purple.It's OK now. (I tried a couple of different gear ratio's in my truck,that's why I changed the oil often)

To be honest, the front diff has Redline and the rear has Royal Purple.lol.....

[bthibodeaux]

Originally Posted by Motion427

Would it be the very first "short trip" with the new gears?
If so,I would take a break in between.
After the 2nd or 3rd short trip,you can go further.
The AAM is a great gear,some will say that you can hammer it after 2-3 heat cycles,but why take the chance.

No Problem Brian.Glad I could help.Thank You.

It should not be the first or second trip. I am out of town for 20 days or so, and my wife will take delivery of the car when completed. She will likely just be taking it for short joy rides and grocery store trips till I get back. Then we will want to make the 50+ mile trips to see family. So we should be good. Thanks for the info Ron.