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Stupid U Bolt Question


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I have the Dana 35 rear end that I'm doing SOA on and I bought 3 inch wide U-bolts these are a quarter inch bigger than normal.... Will these still work? Advice appreciated as always!

No, they won't work.

 

The Dana 35 has a tube diameter of 2-5/8". The Dana 44 has a tube diameter of 2-3/4".

 

The Chrysler 8.25 used 3" tubes. You need u-bolts with a throat dimension of not more than 2-3/4".

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I have the Dana 35 rear end that I'm doing SOA on and I bought 3 inch wide U-bolts these are a quarter inch bigger than normal.... Will these still work? Advice appreciated as always!

No, they won't work.

 

The Dana 35 has a tube diameter of 2-5/8". The Dana 44 has a tube diameter of 2-3/4".

 

The Chrysler 8.25 used 3" tubes. You need u-bolts with a throat dimension of not more than 2-3/4".

 

I can't have a 1/2 inch of space?

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I have the Dana 35 rear end that I'm doing SOA on and I bought 3 inch wide U-bolts these are a quarter inch bigger than normal.... Will these still work? Advice appreciated as always!

No, they won't work.

 

The Dana 35 has a tube diameter of 2-5/8". The Dana 44 has a tube diameter of 2-3/4".

 

The Chrysler 8.25 used 3" tubes. You need u-bolts with a throat dimension of not more than 2-3/4".

 

I can't have a 1/2 inch of space?

 

No.

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I have the Dana 35 rear end that I'm doing SOA on and I bought 3 inch wide U-bolts these are a quarter inch bigger than normal.... Will these still work? Advice appreciated as always!

No, they won't work.

 

The Dana 35 has a tube diameter of 2-5/8". The Dana 44 has a tube diameter of 2-3/4".

 

The Chrysler 8.25 used 3" tubes. You need u-bolts with a throat dimension of not more than 2-3/4".

 

I can't have a 1/2 inch of space?

 

Sounds like a good way to break your rear end.

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I have the Dana 35 rear end that I'm doing SOA on and I bought 3 inch wide U-bolts these are a quarter inch bigger than normal.... Will these still work? Advice appreciated as always!

No, they won't work.The Dana 35 has a tube diameter of 2-5/8". The Dana 44 has a tube diameter of 2-3/4".The Chrysler 8.25 used 3" tubes. You need u-bolts with a throat dimension of not more than 2-3/4".

Just to clarify: most all Dana 44's have a 3" tube. The MJ version is unusually small.

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The correct U bolt may have a contact patch of say 2" as the arch of the bolt wraps around the tube.

 

A larger bolt may have a contact patch of 1/4" and will eventually allow the axle tube to move.

 

You are not going to force a 9/16 bolt to conform to the tube........just ain't gonna happen.

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You are not going to force a 9/16 bolt to conform to the tube........just ain't gonna happen.

The actual bolt diameter is also a consideration, above and beyond the throat opening. The factory u-bolts are metric -- 12mm for the XJ and 14mm for the MJ. Just about any replacement you can find will be an SAE size, so you want to get a decent match. A lot of the u-bolts I've seen in the parts chain stores are 7/16", which is even smaller than a 12mm.

 

For the MJ, 14mm is .5512 inches in diameter. 9/16" is .5625 inches, so it's larger than stock. It's a good choice if you can find them, but 1/2" is much more widely available. Personally, I would not hesitate to use new, good quality 1/2" u-bolts under an MJ, even knowing they are slightly smaller than what the factory used. (But slightly over-sized for an XJ -- since I have both, I just standardized.)

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A shop local to me custom makes u bolts while I wait. They come with thick washers and double height nuts and are cheaper than the packaged ones from the parts store. I used to use 9/16" on everything, but with the 1 ton axles I decided to go 5/8".

 

Anyway, if you can find a shop in your area that does suspension work, it might be worth a shot.

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I never thought about it till now but when I swapped to a 4 :10 rear end I ordered new ones from Crown. They were smaller than the original bolts. I'm guessing now after reading this that they were XJ bolts. Does anyone think that will be an issue? I'm guessing probably not since they've been on there for several years now. Just made me wonder about it.

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I think a new, high quality 1/2" u-bolt is probably at least as good as a rusty, 25-year-old 14mm u-bolt. As I wrote, I've standardized on 1/2" u-bolts and I'm not even a little bit concerned. Remember, the XJ was available with a heavy-duty tow package and was rated for the same towing capacity as the MJ. I think towing a heavy trailer probably puts more stress on axle u-bolts than anything else we could possibly do.

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