mzoomora

iTrader: (36)

http://www.tractech.com/docs/TT-List-LTPM1004.pdf

Here is a link to the Tractech catalog online. They list the 33 spline 12 bolt locker and true-trac, but they are not available yet.

matts22

iTrader: (2)

If you look at the notes at the bottom, it says that the truetrac is not the same as the soft locker. It is an option for the Detroit Locker. Just to clear up any confusion. The Truetrac is just a clutchless, coneless posi and I don't know if it would be stronger than an Eaton or similar unit. Would the soft locker be as strong as a regular locker? It says it just has a dampening device installed into the inboard end of each side gear.

mzoomora

iTrader: (36)

A true-trac is a limited slip or torque proportioning diff, similar to a Gold-trac, diamond-trac or Torsen. It works off of gear pressure applied under power. They can actually be weaker than Eaton's, etc. A soft-locker is ever bit as strong as a regular detroit locker, and most applications are only offered in one or the other. The soft-locker npart numbers have a "SL" in the part number, like 187SL17B 31 spline 9". The regular lockers dont have the "L". The c-clip style units have a "C" in the part number like 187c198a, and are not available as a soft locker. All the soft lockers have is an additional spring to dampen the the locking effects. The Nascar guys use a locker without the dampening springs and stiffer apply springs for faster reaction. That part number is 187n158a.

matts22

iTrader: (2)

So if he is looking for something stronger, he should be looking soft locker, regular locker, or spool. Have you installed any soft lockers? I have talked to PSJ via pm about this but would like other opinions. What do you think of them? Are they good for the street? Is there one out for a 12 bolt? If not, will there be any time soon? I am thinking that if I am going to spend that much money on a rear, I am going with a soft locker most likely because I don't want to break a posi. I would like to stick with a 12 bolt if possible, but if I have to go 9 inch, that's what I'll do.

mzoomora

iTrader: (36)

I have installed lockers before, but most of them go into trucks/ 4x4's. The only people that ever complain either dont like the noise, or have short wheelbase vehicles like Jeeps. The cars that I have put them into are usually happy, but most of those had slicks and loud exhaust. The slicks absorb some of the shock from the locker, and you can hardly hear anything over the exhausts. They were originally designed for larger trucks, and then worked their way into smaller trucks and then cars. They work well in track vehicles and street strip vehicles, but the noise can be annoying for daily drivers. Another thing to consider is that the F-body cars are hatchbacks, so the diff sits under the passenger compartment. So, rather than the noise echoing into the trunk, it echoes into the car. This also comes into play with people complaining about gear whine. They are making a locker for 12 bolt car diffs, but only 3 series, and they are not soft lockers. The 9" by far has the most options available of all the diff's out there, and can upgraded in so many ways. I am pretty sure that they are considering a 4 series 12 bolt locker for cars, but are waiting to see how well the 3 series sells. The only good reason not to use a 9" is the extra power loss, but even that is minimal(around 3%). With all the aluminum components and lightweight gears, etc, you can even undo some of that.

blue66

Put a spool in and be done with it. I also have a pile of 12bolt posi parts in a box.
66 Chevelle, BBC footbraking, with 30x12.5 ET Streets. Called Eaton and they told me I would keeep braking their stuff.

pewterta

iTrader: (6)

what is strong enough then...imean wheni had a ten bolt ..you all say go with a 12 bolt..then I hear that they canbreak...what is a solution that works?

02WS6Bird

iTrader: (2)

it sucks to hear....the way i see it is if your that seruious about stirp racing and slicks get the damn 9" theres nothing like it...otherwise if its street jsut get a 12 bolt...even if its for all around spool or posi ou decide...

i mean if im not mistaken ZL1's only have the 10 bolts...some mayb with 12's but no 9" rears and look at them over 600 hp at the crank...so its gotta be how crazy people are going

im planning SLP 12 bolt with eaton posi and 3.73's dumping at 5000 rpms 33 spline 1350 yoke 8.875" axles and engineered by moser...sounds like a winner to me...same price if not 100 cheaper then moser alone...so mayb ill have luck with a performance built T56 and a 455 stroker afterwars...will have a drop so Forget the slicks

jamnut

iTrader: (4)

I've got a 12 bolt with a 33 spline True Track in it. I will be installing it this week & going to the track on the 5th, so we'll know how they handle 6k rpm dumps after the 5th. They are supposed to be better than the Eaton's is my understanding.

HumpinSS

iTrader: (1)

where did you get the 33 spline truetrac from?

1fastWS6

iTrader: (3)

HumpinSS: Randy's Ring and Pinion has them. $405

Jamnut: Let us know how it works next time out.

HumpinSS

iTrader: (1)

Is this the 45* pressure angle differential or is it the old one