Brought to you in part by:

.

Shop Eastwood for your Auto Restoration Needs!


  Mustangsandmore Forums
  '64 1/2 to '73 -- The Classic Mustang
  U bolts: bigger is better?

Post New Topic  Post A Reply
profile | register | preferences | faq | search

UBBFriend: Email This Page to Someone! next newest topic | next oldest topic
Author Topic:   U bolts: bigger is better?
Fastback68
Gearhead

Posts: 1348
From: Sucat, Paranaque, Philippines
Registered: Jul 99

posted 11-04-2002 11:49 PM     Click Here to See the Profile for Fastback68   Click Here to Email Fastback68     Edit/Delete Message   Reply w/Quote
I've been looking at my standard 7/16 U-bolts on the rear axle. Why are they so MEAN in terms of length? I've got another set of 1/2-inch U-bolts that are the right spread and provide a clear two inches of thread beneath the axle mounting plates. I don't know where they came from, but they've got to be better, right? There's no possible downside to using giant U-bolts, provided they fit, is there?
I had the 7/16 bolts at 65 lbs. feet (as per Alex's advice in another thread), and thought I would torque the half-inchers to about the same, maybe 70.
Thanks!
Simon

IP: Logged

Calcat
Journeyman

Posts: 75
From: Los Angeles, CA
Registered: Feb 2002

posted 11-05-2002 02:04 AM     Click Here to See the Profile for Calcat   Click Here to Email Calcat     Edit/Delete Message   Reply w/Quote
Yes, this is one of those rare times where bigger is better. But aware you will probably have to drill out your plate a bit to accept the 1/2". You are right, torque should be about the same.

IP: Logged

TomP
Gearhead

Posts: 4637
From: Delta BC Canada
Registered: Dec 99

posted 11-05-2002 06:43 PM     Click Here to See the Profile for TomP   Click Here to Email TomP     Edit/Delete Message   Reply w/Quote
I definately don't agree ... bigger is stronger, but not better!!

The large U-Bolts won't stretch to make tension and they'll lose their clamping on the spring plates... this will have the rear end walking back and forth, bending the spring perches and wearing grooves in the housing.

Unless you plan on tightening these things every few days of driving (lock nuts won't do it) i'd use no bigger than the 7/16" -bolts they come with. Those are fine enough for anything running 11's or carrying 1500lbs of cargo.

IP: Logged

Fastback68
Gearhead

Posts: 1348
From: Sucat, Paranaque, Philippines
Registered: Jul 99

posted 11-05-2002 11:20 PM     Click Here to See the Profile for Fastback68   Click Here to Email Fastback68     Edit/Delete Message   Reply w/Quote
Thanks guys! Calcat, Tom sounds pretty convincing, wouldn't you agree?

IP: Logged

Fastymz
Moderator

Posts: 9095
From: Reno Nv USA MEM#1240
Registered: Apr 2001

posted 11-06-2002 12:38 AM     Click Here to See the Profile for Fastymz   Click Here to Email Fastymz     Edit/Delete Message   Reply w/Quote
Tom really knows his stuff,Not saying Calcat dosen't.

SCOOP

------------------
oddly obsessed with big scoops on little Mustangs

2.26 60'S
14.9 @ 90.86MPH

65 coupe,351w,C4,Big Boss 429 hood scoop,8"3.40 TracLoc,Cragar SS,Black Suede.

https://mustangsandmore.com/ubb/Fastymz.html

IP: Logged

Calcat
Journeyman

Posts: 75
From: Los Angeles, CA
Registered: Feb 2002

posted 11-06-2002 02:17 AM     Click Here to See the Profile for Calcat   Click Here to Email Calcat     Edit/Delete Message   Reply w/Quote
I guess Tom and I can agree to disagree on this one. 75% of the torque to yield rating on a 1/2" bolt is 75ft/lbs. This will put the 1/2" u bolts in tension. That's only 10lbs over what Simon has the 7/16 torqued to right now (Btw - 60 is more than needed for 7/16).
I assumed the application justified using the stronger u bolts and this is not an uncommon upgrade on rear ends.

IP: Logged

All times are ET (US)

next newest topic | next oldest topic

Administrative Options: Close Topic | Archive/Move | Delete Topic
Post New Topic  Post A Reply
Hop to:

Contact Us | Mustangsandmore Front Page

Copyright 2003, Steve LaRiviere. All Rights Reserved.


Ultimate Bulletin Board 5.47d

Amazon Honor System Click Here to Pay Learn More

[The M&M Gearhead Gear Store]

[Build a free Mustangsandmore.ws Home Page!]

[About M&M][Acronyms][Calendar][Chat][Classifieds] [Links] [Members' Pics] [M&M Mug Shots] [Tech] [ Mustangsandmore.com Bookstore] [Advertise on Mustangsandmore.com] [Mustangsandmore.com T-Shirts]