Do I have a sure-grip or not?

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DartGTDan

DartGTDan

'71 Dart GT Fan
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Trying to verify whether or not the 8 3/4" rear end in my Dart GT is a sure-grip. With the rear axle up on jack stands and the transmission is in neutral. When I rotate the passenger side wheel, in the forward direction, the driver side wheel also rotates in the same forward direction. If my memory is correct, this means it IS a sure-grip. Correct?
 
If they rotate in the same direction it's not an open (pegleg) rearend. What type sure grip or other clutch/cone/locker type still unknown? 65'
 
DartGTDan said:
Trying to verify whether or not the 8 3/4" rear end in my Dart GT is a sure-grip. With the rear axle up on jack stands and the transmission is in neutral. When I rotate the passenger side wheel, in the forward direction, the driver side wheel also rotates in the same forward direction. If my memory is correct, this means it IS a sure-grip. Correct?
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That's not necessarily correct. Sometimes in neutral, the opposite tire will rotate the same direction as the one you're turning simply because of friction of gear oil and that it's in neutral. The best way to tell is in park with the wheels in the air. Grab one wheel and try to turn it. If it turns and the opposite wheel turns the opposite direction, it's an open differential. If you cannot turn the wheel, you have a sure grip.
 
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RustyRatRod said:
That's not necessarily correct. Sometimes in neutral, the opposite tire will rotate the same direction as the one you're turning simply because of friction of gear oil and that it's in neutral. The best way to tell is in park with the wheels in the air. Grab one wheel and try to turn it. If it turns and the opposite wheel turns the opposite direction, it's an open differential. If you cannot turn the wheel, you have a sure grip.
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What if it's a Posi ?
 
if its a posi it must be a chebby expect lots of wheel hop and watch the wheel fall off :)
 
RustyRatRod said:
That's not necessarily correct. Sometimes in neutral, the opposite tire will rotate the same direction as the one you're turning simply because of friction of gear oil and that it's in neutral. The best way to tell is in park with the wheels in the air. Grab one wheel and try to turn it. If it turns and the opposite wheel turns the opposite direction, it's an open differential. If you cannot turn the wheel, you have a sure grip.
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How's that play out with a stick shift?
 
Get a 150lb friend to hug one tire as tight as he can then turn the other. If he flips over the unit is good LOL
 
Hellrats said:
Then break the clip and spit the axle out. :)
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Back in the mid 80’s I ran a Chevy circle track car with a stock 10” rear and we never broke a C-clip but we did break a right side axle once. After that happened we would replace the right side axel halfway through the season. The real problem is twisting an axle since there’s nothing to hold in the housing after it breaks. I would have rather ran a Mopar but we couldn’t afford to build a new race car and always ran used race cars. Also spare Mopar parts at the racetrack were non-existent since everything was Chevrolet.
 
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mcodecuda said:
Back in the mid 80’s I ran a Chevy circle track car with a stock 10” rear and we never broke a C-clip but we did break a right side axle once.
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Where was that at? I raced dirt track in Pa and Ohio in the early 90's and Chevy differential were banded because they broke so many of them. I saw one come off while on the track and it went through the pits. Axle, brake drum, tire and all. Lucky no one got hurt but it did go into a trailer and boy was it ugly! That put an end to any Chevy differential at Wayne county speedway.
 
OK, I'll try turning the passenger wheel, with the transmission in Park, tomorrow.

Thanks!!
 
one other thing to consider is it could be an open diff with the spider gears welded to the cross pin due to lack of lubrication -- abuse at some point in its life -- seen this too many times pull the diff to confirm what you have to be sure ,, its 50+ years old time to look.
 
You would know that right away as soon as you tried to go around a tight corner.
 
Hellrats said:
Where was that at? I raced dirt track in Pa and Ohio in the early 90's and Chevy differential were banded because they broke so many of them. I saw one come off while on the track and it went through the pits. Axle, brake drum, tire and all. Lucky no one got hurt but it did go into a trailer and boy was it ugly! That put an end to any Chevy differential at Wayne county speedway.
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We ran Shangra-La Speedway in Owego NY and Spencer Speedway in Williamson NY weekly. We also ran In special events at Pocono Speedway on the 3/4 mile inner track and Oswego Speedway in Oswego NY.
These were all asphalt tracks. My only dirt track experience was in a Dwarf Car once at Brewerton Speedway. I also had an opportunity to drive a dirt modified which would have been interesting since it was powered by a 305 cu in Mopar.
 
Interesting. Yeah I ran dirt pro stock and late model. Some people on this site don't understand the punishment a car goes though on dirt. Really one weekend it about equal to a year of drag racing. We don't get to take them apart after every race. Plus the on and off RPM's are killer.
 
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