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Odd D30 Detroit issue?

Kejtar

Kejtar

PostMaster General
NAXJA Member
Location
Westminster, SoCal
OK, it's the second time it's done it to me: all the bolts (that hold the two halves together) walked out. Wtf? I'm tempted to tack weld the suckers in place.

Anyways, what could be causing that? Had all new bolts in it about a month and a half ago, wheeled in Moab for a week and drove back. Had red locktite on them too.
 
Threads not clean and dry,improper torque(including method),ring-gear runout,bad housing,etc..
What axle are we talking about?
 
Hmm per Eaton tech support it's not a common problem but the most common cause of this problem is not enough preload. According to eaton for a D30 it should have 6 thousands of preload.
 
also a aftermarket cover helps. The 30 housing really likes to flex with the gears we are running no matter the the preload. causing the issue you are having. I just tack welded the arb back together as a last ditch effort to keep it going. so far 2 rides on it and it is staying together. usaully i need to pull cover after a ride to tighten the bolts again. dana 30+35's+locker are a bad mix but untill i can upgrade i will keep applying bandages to the wound.

hasta
 
Here's something interesting: I've dissasembled it today and found out that the smal piece that has the bolts go through is about 1/16" bigger in the diameter on the holes. This means that with the rotational force applied to the case (potentially there is some) things will loosen up. I wonder if the original bolts (long gone) had a sholder to them. Does anyone remember what they look like? Anyone has a d30 detroit laying on the floor someplace they could pull one bolt out of and take a picture for me?
 
You could drill and dowel the case,had the same problem with some 30K horsepower motors about 20 years ago.You should of seen the 60K's!
 
RCP Phx said:
You could drill and dowel the case,had the same problem with some 30K horsepower motors about 20 years ago.You should of seen the 60K's!
Click to expand...
I'm actually thinking about picking up some shouldered bolts.
 
had the same issue ended up being a defect in the threads (cut larger than the bolt). chased them with a tap and a hair larger bolt and the issue went away. I have since fixed 2 others for people this way. my next detroit will get the treatment before install.
 
Gerr said:
had the same issue ended up being a defect in the threads (cut larger than the bolt). chased them with a tap and a hair larger bolt and the issue went away. I have since fixed 2 others for people this way. my next detroit will get the treatment before install.
Click to expand...
Here's the deal though: It lasted a looooong time before I started having this problem. My bad that I didn't pay attention though to what the original bolts looked like a month ago.
 
Kejtar said:
Here's the deal though: It lasted a looooong time before I started having this problem. My bad that I didn't pay attention though to what the original bolts looked like a month ago.
Click to expand...
so did mine then once it was a problem it didn't matter how well i tightened them or how much loc-tite I used on them there was not enough of the threads engaging the bolt to stay torqued properly once they were damaged. Thats how I realized the threads were off size because the bolt would screw down and tighten up like normal but they loosened with less torque than I had applied to tighten (verified by torque wrench) I ended up finding a wire size bolt chart at rainbow bolt and ordering the right tap and bolts from them
 
Gerr said:
so did mine then once it was a problem it didn't matter how well i tightened them or how much loc-tite I used on them there was not enough of the threads engaging the bolt to stay torqued properly once they were damaged. Thats how I realized the threads were off size because the bolt would screw down and tighten up like normal but they loosened with less torque than I had applied to tighten (verified by torque wrench) I ended up finding a wire size bolt chart at rainbow bolt and ordering the right tap and bolts from them
Click to expand...
Hmmm... and I just put the sob together (holding it with three bolts only though for now). I'll have to decide what to do about this now. Damn....
 
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