# Limited Slip ID needed



## denrael (Apr 7, 2018)

I am not that familiar with the various types of LSD and lockers out there, so asking for some help. Can you tell by this photo what type (and brand) of limited slip/locker I have here? And the real question, therefore... exactly what lubricant should I use with it?


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## BLK69JUDGE (Jun 10, 2010)

it looks like a factory four-pinion ,safe T trac, limited slip ,cone style , from a nodular rear differential
installed in a 66-70 pontiac GTO with a 8.2 ring gear ......


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## denrael (Apr 7, 2018)

BLK69JUDGE said:


> it looks like a factory four-pinion ,safe T trac, limited slip ,cone style , from a nodular rear differential
> installed in a 66-70 pontiac GTO with a 8.2 ring gear ......


Thanks! Now... about that lubricant?


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## michaelfind (Dec 14, 2018)

denrael said:


> Thanks! Now... about that lubricant?


I am eager to see some responses on this as well. I have a similar differential. I have some old non-synthetic Napa gear oil and a bottle of additive for limited slip that I may use. I have not changed out the fluid yet because I'm waiting for advice on the forum here. When I first called Ames to see what they had, the person on the phone told me they only had a synthetic gear oil and that they had received many complaints about it. He suggested I leave the differential alone if it is not giving me trouble. Obviously, yours is already opened up so you need an answer soon. I'm still debating whether or not to open mine to change out the 30 year old fluid and check for debris. It has been run very hard and then sat for 15 or so years. I plan to run it hard again in the near future so thought fresh gear oil may be a good idea. Still thinking it over.


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## GTOJUNIOR (Aug 7, 2011)

I prefer the real oil/lube made for these differentials, Your service manual should have the oil spec.
You can still get the ACDelco Posi additive and/or I use 80W90 with CRC Posi additive which is good stuff.


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## PontiacJim (Dec 29, 2012)

michaelfind said:


> I am eager to see some responses on this as well. I have a similar differential. I have some old non-synthetic Napa gear oil and a bottle of additive for limited slip that I may use. I have not changed out the fluid yet because I'm waiting for advice on the forum here. When I first called Ames to see what they had, the person on the phone told me they only had a synthetic gear oil and that they had received many complaints about it. He suggested I leave the differential alone if it is not giving me trouble. Obviously, yours is already opened up so you need an answer soon. I'm still debating whether or not to open mine to change out the 30 year old fluid and check for debris. It has been run very hard and then sat for 15 or so years. I plan to run it hard again in the near future so thought fresh gear oil may be a good idea. Still thinking it over.



Do not use a synthetic gear oil in the older rear ends - it is used in later model cars. Use an 80W90 gear oil, store brand or other. I use Lucas products for gear oils. You will want to add a bottle of the posi additive for proper operation. Most forums say you may experience "chatter" from the posi unit if you don't add it.


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