Detroit Truetrac worth the extra cost?

[L92 OLDS]

Pretty simple.

They're the most expensive option, so are they worth the added cost?

Getting ready to buy.. only ever had Auburn, and never had an issue running way more HP than this GP ever will.

-Gonz

Same here. I have 2 Auburn pro's going on 25 years + with no issues. Those that say Auburn's suck likely have units that have been clapped out, abused or lubed improperly. Mine always leave 2 solid black marks on the road

 

[Supercharged111]

The answer is no you can’t. But you’ll hear otherwise very shortly.

Same here. I have 2 Auburn pro's going on 25 years + with no issues. Those that say Auburn's suck likely have units that have been clapped out, abused or lubed improperly. Mine always leave 2 solid black marks on the road

My crappy Auburn was disassembled, inspected, and scuffed per their instructions. It was in excellent condition and still sucked from day 1. Sure it left 2 stripes in a straight line, but incessantly unloaded that right wheel around a corner. Even the "good" one I borrowed unloaded on the corner curbing. The Truetrac doesn't do this. I'm only putting 260whp through mine, so that's worth considering as well.

 

[64nailhead]

So, what's the deal with the 7.5 rears? I get that everyone says they're weak but what's the weak link? Gears, carrier, axles... Can the limitation be reduced to allow a 7.5 to survive in a well powered street car that see's the occasional trip to the drag strip. Can a 7.5 survive a 12 second car??

The answer is no you can’t. But you’ll hear otherwise very shortly.

Sticky tires and hard launches don’t mix with a 7.5. Can you make one live, absolutely. Street tires and 4-500 hp is ok - need good 28 spline axles - factory Torsen or aftermarket posi.

The weak link - all of it if you’re making any kind of power.

 

[Streetbu]

Stick shift cars are hard on them too. I've literally stripped teeth off the ring gear on the last two setups I had. And before anyone says they were setup wrong, I set one up, had the other professionally done at a driveline shop and those were Richmond gears. I drive hard and the stick doesn't help.

 

[UNGN]

So, what's the deal with the 7.5 rears? I get that everyone says they're weak but what's the weak link? Gears, carrier, axles... Can the limitation be reduced to allow a 7.5 to survive in a well powered street car that see's the occasional trip to the drag strip. Can a 7.5 survive a 12 second car??

The Stock Axles will break at 13.9. With Forged Axles, auto trans and a Footbrake leave against a loaded converter, it should be fine in mid 12's. They hate shock loads, so no manuals and no throttle punch take offs, no on-off-ons. Even the burnout should be gentle... don't let it roll backwards and floor it forwards. Any lash that allows the pinion to smack the ring gear will shorten the life.

 

[olds307 and 403]

Don't forget soft, tiny, exploding spider gears! Mine took out a perfectly good pinion gear.

 

[L92 OLDS]

My crappy Auburn was disassembled, inspected, and scuffed per their instructions. It was in excellent condition and still sucked from day 1. Sure it left 2 stripes in a straight line, but incessantly unloaded that right wheel around a corner. Even the "good" one I borrowed unloaded on the corner curbing. The Truetrac doesn't do this. I'm only putting 260whp through mine, so that's worth considering as well.

I’m not sure how to explain that. In my Olds I can do left hand or right hand donuts in a parking lot with both tire smoking. No issues with unloading as you put it. Did you use limited slip additive or synthetic gear lube?

 

[Supercharged111]

I’m not sure how to explain that. In my Olds I can do left hand or right hand donuts in a parking lot with both tire smoking. No issues with unloading as you put it. Did you use limited slip additive or synthetic gear lube?

I used dino oil and with/without additive didn't seem to make a difference. I started with additive.

 

[Gonzo1970]

Drop another $300 and jump up the axle size up to 30 or 31 spline.

How much power you making'?

The car will never see more than 350hp/350tq

-Gonz

 

[64nailhead]

The car will never see more than 350hp/350tq

-Gonz

No worries as an automatic and no drag radials/slicks.