489 suregrip pin wear

[mycuda]

What is prognosis of pin hole elongation on cone style suregrip?
Bearings, gear pattern good. For street use, will there be noise or vibrations?

Thanx,Dave

 

[SGBARRACUDA]

Not sure what you mean?

 

[mguner]

A big bang when shifting from drive to reverse! If the retaining pin/bolt isn't broken yet it will be and can allow the cross pin to slide out and destroy your pumpkin! Maybe even lock up your driveline at speed.... Nasty things like that....

 

[SGBARRACUDA]

Do you have it out? Can you post a picture of what your talking about.

 

[mguner]

Pretty sure he's talking about the cross shaft hole in the carrier.....

 

[SGBARRACUDA]

Maybe so. When he said cone sure grip, I was thinking 8 3/4.

 

[mycuda]

On the train.
can't send pics
Suregrip conestyle unit

But main pinhole going thru unit
is oblong on end so pin can move about 1/ 8
Inch or do

 

[SGBARRACUDA]

On the train.
can't send pics
Suregrip conestyle unit

But main pinhole going thru unit
is oblong on end so pin can move about 1/ 8
Inch or do

What rear end do you have? 8 1/4, 8 3/4 or?

 

[mguner]

Picture is just for reference....

Here is one of an 8.75 with the same pin visible just no pointer...

 

[Daves69]

What rear end do you have? 8 1/4, 8 3/4 or?

"489" (Case = 8-3/4") in the thread title.

 

[SGBARRACUDA]

"489" (Case = 8-3/4") in the thread title.

Duh, I missed that. lol
What has happened is the cones bottom out, causing the two small spiders to spin all the time. Sooner or later the spiders seize on the shaft, then rip the .250 x one inch cross shaft keeper out of the case. After that the shaft spins in the case wearing the hole bigger and bigger. At this point you have a 25 lb paper weight!

 

[john-9]

What is prognosis of pin hole elongation on cone style suregrip?
Bearings, gear pattern good. For street use, will there be noise or vibrations?

Thanx,Dave

as stated in other posts -- sure grip will be junk ----

just for the record ,,, it has nothing to do with the cones bottoming out in the case and then the spider gears " spin all the time " --spider gears are in constant mesh with the side gears and they do spin all the time or you would not have a working differential --

it is strictly a lack of lubrication which seizes the spider gears to the cross shaft which breaks the 1/4 inch locating pin for the cross shaft and then rotates the whole shaft wearing into the case .or in a worse case scenario the pin works its way out and locks up the diff destroying it completely.

 

[RedFish]

I've seen the cross pin in some gearboxes marked in the middle where the cir-clipped axle(s) has pushed on it which tries to turn it eventually breaking the little bolt.

 

[Daves69]

Rather than just run it or scrap it, what's the possibility for redefining the hole center, open it up, and steel bush it or sleeve the pin?

 

[john-9]

Rather than just run it or scrap it, what's the possibility for redefining the hole center, open it up, and steel bush it or sleeve the pin?

Dave

first off you have to find out if the spider gears and cross shaft can be saved ----they may be permanently welded to the cross pin --if so, you are sol as no one makes replacement spider gears or cross shaft and finding a good used set is ??????
if you can remove the spider gears from the cross pin if they are not too tore up the bore can be polished to make them serviceable again and you can use a cross shaft from an open diff to replace the damaged one.
if you can save the spider gears and get a shaft from a open diff -- finding a good machine shop to bush the case or weld up the holes and rebore them to size may be costly.

best bet is to buy a new aftermarket unit -- Power Lock , Auburn , True Trac , or a good used Power Lock clutch style unit to rebuild

 

[mycuda]

Rather than just run it or scrap it, what's the possibility for redefining the hole center, open it up, and steel bush it or sleeve the pin?

You were reading my mind!!!!
Never had one apart, but sure ill figure it out.


After I figure out the "in house" repair/rebuild
ill update.


D.

 

[mycuda]

Dave

first off you have to find out if the spider gears and cross shaft can be saved ----they may be permanently welded to the cross pin --if so, you are sol as no one makes replacement spider gears or cross shaft and finding a good used set is ??????
if you can remove the spider gears from the cross pin if they are not too tore up the bore can be polished to make them serviceable again and you can use a cross shaft from an open diff to replace the damaged one.
if you can save the spider gears and get a shaft from a open diff -- finding a good machine shop to bush the case or weld up the holes and rebore them to size may be costly.

best bet is to buy a new aftermarket unit -- Power Lock , Auburn , True Trac , or a good used Power Lock clutch style unit to rebuild

Thanks John

 

[mycuda]

Pics of damage.


I will fix this. But cast metal cant weld.
Drill out 1/8" find brass bushing reem to fit pin.


Sugestions???/



thanks dave

 

[RedFish]

Only way to do it right is bush both sides. A naval bronze would be my choice.
Wouldn't the cut ends of bushings need to be machined to inside and outside diameters also ?

 

[mycuda]

Thanks RF.

I'll update as I go.
Going to ohio this weekend.

I'll figure something out next week and post.

D.

 

[SGBARRACUDA]

as stated in other posts -- sure grip will be junk ----

just for the record ,,, it has nothing to do with the cones bottoming out in the case and then the spider gears " spin all the time " --spider gears are in constant mesh with the side gears and they do spin all the time or you would not have a working differential --

it is strictly a lack of lubrication which seizes the spider gears to the cross shaft which breaks the 1/4 inch locating pin for the cross shaft and then rotates the whole shaft wearing into the case .or in a worse case scenario the pin works its way out and locks up the diff destroying it completely.

ok

 

[SGBARRACUDA]

What do the bottom of the cones look like and the case halves at the bottom.

 

[oldkimmer]

..........I have had a few welded up by a machinest that says he's not a welder, but none have broken in the 10-20 years since the weld job, but I can say I don't torture them...........kim.....

 

[RustyRatRod]

as stated in other posts -- sure grip will be junk ----

just for the record ,,, it has nothing to do with the cones bottoming out in the case and then the spider gears " spin all the time " --spider gears are in constant mesh with the side gears and they do spin all the time or you would not have a working differential --

it is strictly a lack of lubrication which seizes the spider gears to the cross shaft which breaks the 1/4 inch locating pin for the cross shaft and then rotates the whole shaft wearing into the case .or in a worse case scenario the pin works its way out and locks up the diff destroying it completely.

Sorry John, but you are wrong. The only time the spider gears turn is when the car takes a corner and the axles turn at different speeds. Period. Over and out. Roger wilco. Other than that, in a straight line, they simply rotate with the case and do not spin. Roy was right in his description.

There are some good videos on youtube of how a differential works. I suggest you watch some of them. They are very informative.

 

[mycuda]

pics of cone surfaces.
Not sure how much meat on collar is considered good or not.
Can I rough surface up?

Thanks for suggestions.