Dana 27A Broken Spider Gears

I was changing the fluid in my Dana 27A (for the first time since I bought it), and found broken teeth in the bottom. the teeth matched up with one each for three of the four gears. I don't see any other damage or wear on the other gears in the differential. Is there anything else that I need to look for as far as damage or wear? Also, are the spider gears sized for the gear ratio or are they all one size?
I will be posting a WTB in the classifieds.
Thank you all for your help,
Hugh

 

They are the same within a group. Spline count varies, so make sure that's the same. IMO its time to get a D30. If you're busting spiders you've reached the limit of a D27. I went through 2 sets before I wised up.

 

I HAVE A BOX OF d27 BUSTED SPIDERS. went d30 and learned how to drive (no hopping or turning under load or backing up under load) and have not broke since..check the case incase a tooth was bound and forced its way out ,I think they crack off and just fall out though.

 

lockrite locker

 

do they make a lockrite for a open 27 case?
I have had fantastic luck with lockrites.

 

Yes. For the 25 and 27.


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Or a power lock, if you can find one.

 

Thanks for all the replies. I will be looking for a locker when funds allow, it looks like the best way to go.

 

I dont think Dana 27 is a weak component on the ECJ-5, even when using it off-road. If you broke 2 sets it has something to do with the way you drive the Jeep or some extreme loads on the front end.

Ziv

 

It is true that every set of side/spider gears I went through in my Dana 25 were directly relatable to inadequate throttle to brain ratio, but the thing is once I switched to a Powr Lok I didn’t take it any easier and I don’t have problems with it breaking.

 

Not going to agree with that. I blew the front spiders out of my 68 just backing it up to turn it around. Steep yes, but no rocks, bouncing, or even wheel spin and bammmm. The spiders in either a 25 or 27 are pretty wimpy and can self destruct under what I would consider a normal loading. A Powr Loc or Lockrite will cure that problem but then the shafts become the weak links.

 

IMO The D27 is too weak for the torque of the Dauntless as evidenced by the change to the D30 in all subsequent years of the CJ5 (Pete was built in '70). I am easy on equipment and have never broke anything except for the spiders in the D27 Pete originally had.

 

I am still running my D27 with a power lock and 33" tires. I would not go any bigger on the tires. If mine greandes I have a line on a D30, but the cost to get the D30 completed (disc brakes, locker, etc...) and installed currenlty out weighs the working D27.

 

Even with the cost of regearing, I beat the cost of a locker for the D27. Of course I swapped over the hubs from the 27 to the 30 (they are Chevy brake converted) so just the cost of the bearing set, R&P, and axle for me. I did throw in an Aussie locker which put it over the top. But just doing the swap is not that expensive.

 

I looked into the D30 when I found it. New gear set and a locker made it too expensive since mine works fine now. Fortunately I found a power lock on flea bay a few years back for $200.

 

mine exploded while climbing a hill with too much skinny pedal and wheel hop and BANG!