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Hi guys,

My gto is supposed to have the Safe-T-Track diff but I cannot find any codes to identify it. Where am I supposed to look? Also, the car does one leggers................:icon_bs: did the previous owner put a non-lsd on the goat, or is the diff worn out?

Let me know,
Martin
 

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When jacked up off the ground and with the trans in neutral both tires should turn in the same direction if it is a LSD. If the turn in the opposite direction then it is open. If you want to tell for certain, take the rear diff cover off and look to see for yourself. If you see spider gears in there then somewhere along the line someone switched rears or diffs on your car.
 

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I am betting that the rear was changed. If the gears and or clutch pack was worn enough to make your car lay rubber on one side only you wouldn't be driving it long. Someone changed it if it was born with a Safe-T- Track
 

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Martin,

There is a letter code found on the axle tube that will identify the assembly as either being original to your car or if it has been swapped. Just went through this in another thread on axle ID.

Best way, to find out for sure if its a posi would be to take off the rear end cover and look. Never hurts to put on a new cover seal and some fresh gear oil.

If it is not a posi, I would leave it that way. If it is, the posi could be rebuilt. A posi can be trouble on wet roads, curves, loose gravel, etc. if you put too much power to it in these conditions. The posi will engage and you can easily kick the rear end out sideways and many cars have been wrecked or destroyed in this way. The actual percentages of posi units installed in GTO's is actually low. Not only was it an extra cost option, it can get a little sideways in a hurry in anything more than dry road straight line acceleration. I'd rather do a good controlled & smokey single legger burn out than have that rare car make a quick sudden kick out that you cannot recover from. Just my opinion with a little burn out experience (or many burnouts) thrown in for good measure.
 

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Martin,

There is another way to check for a posi. Next time you're out driving your car find a Mustang at a traffic light. Line up next to him and when the light turns green NAIL IT! After a short distance look in your rear view mirror to see how far back the Mustang is. Then glance down at the road behind you, if you see two equal stripes of smoking rubber chasing your GTO you have a posi.
 

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I have to butt in here and respectfully disagree with SCG. With these cone type LSD units, and even with the clutch type, when they become worn and no longer grip, the rear end becomes an open rear and no real damage is done. It'll run virtually forever like that. All the clutch does is link the axles together. Pontiac Jim speaks with wisdom in his post, IMO. A good tight posi can lead to hijinks out on the road if you are not experienced. I have 360'd my '65 on a freeway on-ramp. It was a little damp out and off-camber. Got my attention. I have a true locker rear end in my Toyota 4X4. Even worse than a posi in the rain or on a side slope. The best way to tell if it's a posi or not is to remove the inspection cover and look at the carrier unit. Only way to be sure if it is or not, if it's only doing peg leg burn-outs.
 

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It depends on what the source of the failure is. I agree that you can have a worn posi that just becomes open but I promise you they don't all go quietly.

Personally I would want a LSD in any performance car. Most if not all single car accidents that are caused by the LSD was actually caused by the DRF (drivers right foot)
 

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SCG, I'll give you that. Back in about '93, I picked up a '66 Dodge Coronet 440 4 speed with a Dana 3.23 Sure-Grip for $1500. The owner was driving it from San Jose to Washington, had a flat on the freeway, and installed the 14 inch spare on the right rear. The left rear was a tall 15" on a mag. Burnt up the clutches in the rear in about 20 miles and sheared a roll pin...the car came in on a hook. So on that Dana 8.75, yea, it failed. But the way the GM 10 bolts are set up with a cone clutch, they just stop being a posi, and nothing else bad happens. The OP is asking about the stock rear end, which is a cone clutch ten bolt.
 

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My build sheet on a '71 pontiac firebird formula has a 331 code next to the safe-t-track option.....it was $46.34 for the option if this helps
 

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I was just looking at the window sticker on my '64 LeMans sport coupe. It lists a "G80 DIFFER-SAF-T-TRACK 701" option for an extra $37.66. I guess it did not require a 389 because I have a 326.
 
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