489 Sure-Grip head scratcher

[Chipstar]

Howdy all - have a bit of a head scratcher here. Just had my 62 Fury at my mechanic to finally have the "once over" and when listing off for him what I was told came with the car, we wanted to "trust but verify". I had made mention when I went to do a burnout it seems I do a one-wheel squeal and only see one patch, rather than what I would expect to see with a SG setup.

Car listed "8.75 inch 489 housing with 3.55 gears and is a sure grip setup". However, after the car was on the lift, we rotated the rear passenger wheel forward, the driver's side wheel moved in the opposite direction. Also, he marked a line on the driveshaft and 3rd member and one of his techs counted the rotations when rotating the wheel and he came up with 2.5 rotations. I suppose it is possible they missed counting a rotation, but considering the wheels spun in opposite directions, it gives me cause for concern this isn't what was described as being sold, regardless of what is stamped on the housing. That along with the original sales documentation which had the listing as a 440 out of a 69 Roadrunner, when the block is clearly from a 66 something-or-other (still trying to track that down).

Anyone here able to help clear this up for me/us? Not sure there is anything I can do since I bought this on consignment, but it would give me a better idea of what I have moving forward.

Sorry for the long post and here are pictures for the curious:
Rear housing casting:

Engine block casting and stamp:

 

[69 Sleeper Bee]

I think there should be a tag on one of the carrier bolts showing SG & ratio.
Others can verify.

 

[R413]

When wheels turn opposite direction you have any open rear end. There is no sure grip. You can not rotate and count on an open rear end with both tires lifted off the ground, it doesn’t work.

Do it like this for an open rear axle. lift one rear tire. Count the driveshaft revolutions and turn the tire exactly 2 revolutions. Now you have the ratio.

You have a 1966 440, assembled on 8-5-1965

 

[Chipstar]

When wheels turn opposite direction you have any open rear end. There is no sure grip. You can not rotate and count on an open rear end with both tires lifted off the ground, it doesn’t work.

Do it like this for an open rear axle. lift one rear tire. Count the driveshaft revolutions and turn the tire exactly 2 revolutions. Now you have the ratio.

You have a 1966 440, assembled on 8-5-1965

Thank you @R413 appreciate the input. Could there be something mechanically wrong causing this to behave like an open rear regardless of no noises being present? Seems odd to me that they would use an SG casting, but not have it contain SG functionality.

 

[R413]

No it is an open rear end.

What is a sure grip casting? All you can see is the housing, and they are. All the same from the outside. A 489 housing is nothing special

this is nothing new, some sellers tell lies about their products. And you were lied to.
there is no head scratching here. You have presented all the needed facts.
You don’t have a 69 road runner 440
You don’t have a sure grip rear end

 

[Chipstar]

No it is an open rear end.

What is a sure grip casting? All you can see is the housing, and they are. All the same from the outside. A 489 housing is nothing special

this is nothing new, some sellers tell lies about their products. And you were lied to.
there is no head scratching here. You have presented all the needed facts.
You don’t have a 69 road runner 440
You don’t have a sure grip rear end

My mistake, I was under the impression the 489 meant it was a sure grip; bit of a newbie here. Thanks for clearing things up for me.

 

[MoparLeo]

Not all "489" were Sure-grip.

 

[DeltaV]

Howdy all - have a bit of a head scratcher here. Just had my 62 Fury at my mechanic to finally have the "once over" and when listing off for him what I was told came with the car, we wanted to "trust but verify". I had made mention when I went to do a burnout it seems I do a one-wheel squeal and only see one patch, rather than what I would expect to see with a SG setup.

Car listed "8.75 inch 489 housing with 3.55 gears and is a sure grip setup". However, after the car was on the lift, we rotated the rear passenger wheel forward, the driver's side wheel moved in the opposite direction. Also, he marked a line on the driveshaft and 3rd member and one of his techs counted the rotations when rotating the wheel and he came up with 2.5 rotations. I suppose it is possible they missed counting a rotation, but considering the wheels spun in opposite directions, it gives me cause for concern this isn't what was described as being sold, regardless of what is stamped on the housing. That along with the original sales documentation which had the listing as a 440 out of a 69 Roadrunner, when the block is clearly from a 66 something-or-other (still trying to track that down).

Anyone here able to help clear this up for me/us? Not sure there is anything I can do since I bought this on consignment, but it would give me a better idea of what I have moving forward.

Sorry for the long post and here are pictures for the curious:
Rear housing casting:
View attachment 1134479
View attachment 1134480

Engine block casting and stamp:
View attachment 1134485
View attachment 1134489

You'll have to check the ratio yourself.

Edited to delete other stuff.

See post#3 above and post #10 below.

 

[oldkimmer]

Up to and including the 1964 line up the clutch type sure grip didn’t have any beveled/concave clutches in them so the did infact act the same as an open rear when both wheels were off the ground. Or 1 wheel on and the other wheel off the ground. The pins had to climb the ramoo on s to apply pressure to the clutches. Thus was accomplished by putting torque to both wheels thru the drive shaft with both wheels on the ground. This unit was from 1957 to 1964. 1965-1968 had the beveled/concave clutches that preloaded the clutches some so they did turn both in the air also. But I agree the op either has an open diff or the cone type unit is no good. Kim

 

[33 IMP]

To get the true ratio with an open rear, which you have, lift ONE rear tire, turn it TWO rotations, (because of two to one spider gear/side gear relationship) and count the drive shaft rotations. Lots of you tube videos on how to do this.
(If the seller lied about the sure grip [he did] then he might have lied about the ratio too.)
Edit: a 489 pig would likely be a cone type sure grip, if it has a sure grip, but it would have to be unbelievably wasted to act open with both tires in the air.

 

[69 Sleeper Bee]

If it is a cone type I saw a link to a video another member posted not long ago of a way to rebuild them.
Seemed pretty straight forward but did require machining the face of the cone.

 

[Darter6]

you were lied to.

Sad to say but it happens all the time.

 

[R413]

Everyone has 3.55 envy. So,that’s what’s sellers say they have,

I bought a car and several times he said it was 3.55 SG.
Well it is a SG, but It’s a 3.23

 

[Cranky]

Edit: a 489 pig would likely be a cone type sure grip, if it has a sure grip, but it would have to be unbelievably wasted to act open with both tires in the air.

I've seen them wasted enough to not spin both rear tires off the ground........several actually.

I think there should be a tag on one of the carrier bolts showing SG & ratio.
Others can verify.

IF it's a SG, there should be a tag but since it's plugged into and older car, you never know if they just forgot to transfer the tag or left it off on purpose or there wasn't one because it wasn't a SG

If it is a cone type I saw a link to a video another member posted not long ago of a way to rebuild them.
Seemed pretty straight forward but did require machining the face of the cone.

They are not hard to fix if they are not totally wasted inside. Many will keep on hammering it in trying to make it lock up but it never will if worn and the spiders and side gears along with the cross shaft pay the price for doing that. If you have a SG and it's not locking up anymore, don't keep on trying to make to make it work because you'll only trash it much worse. The clutch type has small spiders and don't like being single wheeled and the same goes for the cone type even though the spiders and side gears are bigger.