How about a sticky with pics and need help identifying 8" third member

[Guest]

[ochohill]

Can the stellar staff at SBFTech.com create a sticky to help the masses identify third members?

I got a new 8" third member as part of a deal of used parts.  I would like some help identifying if it is a trac loc or locker differential. I need to know if it needs the special clutch additive.

[SteveL]

Does it still have the little metal tag under one of the mounting nuts?

What does it say??

[frdnut]

A stock type trac lok will have the ring gear bolts recessed into the carrier a little..This is because the side of the carrier is bulged out a little to allow room for the clutch plates..If you do a google search you can find lots of images online to see the differences in the two...If in doubt just add the friction modifier..It won't hurt it anyway if its a locker.

[68mustang405]

umm.. can't you just turn the wheel on one side and if the other wheel turn the same direction it's a locker?

[ochohill]

No metal tag, this appears to be a new unit. I knew about the recessed holes. That info is at other locations on the web. What I haven't found is a definitive this is what a XXXXXX looks like etc.

On the spinning thing, there are times with an open diff both axles will spin the same direction. The real test there is if you can spin one side by hand with the other side stationary. A trac lock or locker should not spin by hand in that case (assuming the clutches are still good).

I couldn't get my fat ass off the couch last night. I will get it done tonight, St Valentine willing.

[ochohill]

[69 Merc]

 

[frdnut]

That is a trac lok.

[68mustang405]

That is a trac lok.

What I was thinking, there would be anything between the two spider gears.

[69 Merc]

That is a trac lok.

How can you tell?     

[frdnut]

Just by the look of the carrier...It is "thicker" so it can house the clutch plates inside..That is why the ring gear bolts appear to be recessed.

[frdnut]

That is a trac lok.

What I was thinking, there would be anything between the two spider gears.

Huh?..Not sure what you are saying or asking?
Here is a link with some good info on 8 and 9 inch rears.
http://www.kevinstang.com/Ninecase.htm

[68mustang405]

the open carriers i've seen haven't had anything between the two verticle spider gears is what I meant. Usually if there's some type of device there it's a trac lok. IMO.

[frdnut]

the open carriers i've seen haven't had anything between the two verticle spider gears is what I meant. Usually if there's some type of device there it's a trac lok. IMO.

That "block" sort of piece in between the spiders doesn't necessarily mean its a trac lok..It is a support for a 4 pinion setup..What that means is it has 4 little gears instead of 2..The block supports the ends of the two pins that the extra two gears run on..

[68mustang405]

Oh i see what you're saying..