Sure grip spider gears broken

[Beechwood45789]

Well I dropped my third member to fix the leak that had just recently started, finished scraping the old gasket and went to clean out the gear oil that didnt drain out of the bottom of the housing and was shocked to find chunks of teeth at the bottom. I have a 489 case 3.55 cone style sure grip that had no noticeable issues. Sure grip worked fine with no whine or weird noises. I have no idea how long they've been like this, but I cant imagine it can be good to go back together like this. I'll attach a picture of how many chips of teeth were in there. Are there replacement gears out there for it or is it toast? If so would it better better to switch to the clutch style sure grip unit?

 

[davek]

I was pretty sure the 489 were all clutch style but I could be wrong,Time to call DR Diff and order some parts.

 

[PRND21]

741 and 742 cases had clutch type, 489s had cone type sure grip. I prefer the clutch type over the cone type, just my opinion. You might also look at the Truetrac type differential.

 

[chtampa]

Case numbers do not necessarily mean that a certain friction assembly is in it. They are interchangeable.

 

[davek]

741 and 742 cases had clutch type, 489s had cone type sure grip. I prefer the clutch type over the cone type, just my opinion. You might also look at the Truetrac type differential.

Is it not the other way around?

 

[PRND21]

Is it not the other way around?

From the factory, no. But as chtampa said any case could have any style sure grip in it now. -as far as I know-

 

[Beechwood45789]

Is it not the other way around?

Mine is the Borg Warner

 

[66Satellite47]

To OP, you do need to replace the differential. If you have a cone style, which I presume would be in the 489 case, I understand they are complicated to rebuild, machine work involved. That's a big advantage of the Dana clutch style which are very simple. There are several options and the prices seem to vary widely.

 

[john-9]

there are NO replacement parts available on this planet for the cone style 8-3/4 suregrip -- someone on here may have a a torn up sure grip that the spider gears are ok and maybe be willing to sell them - other than that ,, your only solution is just buy a new clutch style unit , or Auburn , true- trac

 

[Beechwood45789]

To OP, you do need to replace the differential. If you have a cone style, which I presume would be in the 489 case, I understand they are complicated to rebuild, machine work involved. That's a big advantage of the Dana clutch style which are very simple. There are several options and the prices seem to vary widely.

there are NO replacement parts available on this planet for the cone style 8-3/4 suregrip -- someone on here may have a a torn up sure grip that the spider gears are ok and maybe be willing to sell them - other than that ,, your only solution is just buy a new clutch style unit , or Auburn , true- trac

Looks like the plymouth is getting a new sure grip. On Dr Diffs website it says he no longer sells Eatons due to inconsistent quality issues, he offers his Sure trac as an alternative. Anybody have any input on them? The regular clutch type unit is out of stock on his website.

 

[WhiteOnGreen]

Hi, have installed a Suretrack from Dr.Diff. Very happy, no noises and smooth drive.
Dr Diff recommends 85w140 gear lube oil but I have noticed it is too thick. I have pending change it to 80w90

Looks like the plymouth is getting a new sure grip. On Dr Diffs website it says he no longer sells Eatons due to inconsistent quality issues, he offers his Sure trac as an alternative. Anybody have any input on them? The regular clutch type unit is out of stock on his website.

 

[33 IMP]

I do not mean to insult, but....
Are you sure those teeth came from your centersection? Have you taken it apart?
You describe no problems with your cone style other than a leak. I wonder if those teeth were from a previous open rear.
Just wondering. If they are from your cone, yep, its time for a new sure grip.

 

[anthony69runner]

Mancini racing sells power lock diffs

 

[chtampa]

Mine is the Borg Warner

View attachment 1112325

You have the good one and it is worth fixing I managed to find an NOS clutch pack when I did mine. As said above, you should take it apart and see if it has an issue. Tip, use the axles to align the clutches when assembling.

 

[33 IMP]

You have the good one and it is worth fixing I managed to find an NOS clutch pack when I did mine. As said above, you should take it apart and see if it has an issue. Tip, use the axles to align the clutches when assembling.

No, he says he has the borg warner- the cone style. See post#7
The Dana style is the clutch type.

 

[Beechwood45789]

I do not mean to insult, but....
Are you sure those teeth came from your centersection? Have you taken it apart?
You describe no problems with your cone style other than a leak. I wonder if those teeth were from a previous open rear.
Just wondering. If they are from your cone, yep, its time for a new sure grip.

Thats what I was hoping for when I found the chunks but check that out. Luckily I think I found a new 3.91 dana style sure grip third member and will get a new sure grip unit for my 3.55 set eventually.

 

[beanhead]

If switching from a cone to a clutch-style unit be sure you get the proper carrier bearings. Not a big deal but they are a different size I.D.

FWIW I broke spiders in two 'Power-Lok" clutch diffs in my 742. They are made by Auburn and are a very common replacement setup.
My TrueTrac has been beat on like a hen-eatin' hound and it's still quiet and smooth in the turns, and locks right up and plants both tires when called to do so..