Tightening rear U bolt question

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Feb 1, 2017 | 01:28 PM

hoss73ford

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Tightening rear U bolt question

I just put a later rear end under my '66 F250. (1970 w/ 3.54 ratio, good gears, heavy duty brakes & positraction, boy did I luck out !) Any way how many foot pounds do any of you suggest I tighten the nuts to. The U bolts are new as I don't mess with re-using 50+ year old originals on something like this. The bed is off so I have easy access.

Feb 1, 2017 | 01:51 PM

'65Ford

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Which U bolts are you talking about? I can think of two sets involved in your swap...the pinion flange for the drive shaft/u-joint and the axle bolts that hold down the leaf springs. Good idea to replace both. I've never been able to get my torque wrench onto nuts for the pinion flange so I do those by feel. The axle bolts that hold the springs down I believe were around 140-150 lb ft for 9/16inch grade 8 bolts, drive a ways, and do them again.

I'll check my 1970 Truck manual tonight.

Feb 1, 2017 | 02:36 PM

hoss73ford

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The axle to the leaf springs was what I meant

Feb 1, 2017 | 02:42 PM

ATS Junior

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From: Souderton

Do you know now what size rod the Ubolt is? 9/16" 5/8"?

Feb 1, 2017 | 04:02 PM

hoss73ford

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They are 9/16

Feb 1, 2017 | 04:50 PM

'65Ford

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Checked my 1970 shop manual for axle to leaf u bolts. 2wd F250 says 100-120 lb ft for 9/16 12 bolts. 4wd F250 says 150-190 lb ft

BTW, use hardened flat washers...not split ring lock washers.