Slant Six Forum :: U-bolt sizes

I know going form 7 1/4 to 8 1/4 in an a-body requires new mounting pads and u-bolts

Well, you won't have to buy U-bolts and shock plates.

Quote:

Well, you won't have to buy U-bolts and shock plates.

Sure you will after you fight them and they still bust off; save yourself the hassle, use the "blue wrench", sawzall, cutoff wheel, etc to remove the old U bolts, and buy new ones! you can still use your current shock plates though.

I did the same to get my U-bolts off after 30+years, and my impact wrench didn't help at all - the U-bolt just twists and absorbs the shock. A deep socket and a big 3/4" drive ratchet did the trick - you need lots of torque over a big angle to get those nuts off.

Many times, the U-bolt sometimes just breaks, leaving you to fight the other side.

Author:	Reed [ Tue Feb 17, 2009 11:12 am ]
Post subject:	U-bolt sizes
I am going to be swapping the 7 1/4 rear axle out of my 84 Fifth Ave and replacing it with a 1969 8 3/4 out of a Belvedere. Dippy.org says I can re-use the existing rear axle hardware, but are the axle tubes the same diameter on a 8 3/4 as on a 7 1/4? Something tells me they aren't, but I might be wrong. Can I re-use the 7 1/4 mounting plates and u-bolts or will I need to fabricate/purchase M-body 8 1/4 u-bolts and mounting plates?

Author:	NewSlanter [ Tue Feb 17, 2009 11:30 am ]
Post subject:
Someone please correct me if I'm wrong, but when I switched from a 7Â¼ to an 8Â¼ I had to get larger U-bolts and different shock mount plates as the axle tubes on my 7Â¼ were 2Â½" dia. and the tubes on the 8Â¼ were 3". Was told the axle tubes were the same between the 8Â¼ and the 8Â¾. Hope this helps, Nat

Author:	Reed [ Tue Feb 17, 2009 11:32 am ]
Post subject:
It does. My research indicated that the 7 1/4 axle used in 1984 in my 5th Ave has 3 inch tubes that drop down to 2 1/2 when they enter the carrier. I know going form 7 1/4 to 8 1/4 in an a-body requires new mounting pads and u-bolts, but that might not be neccessary on an M-body. That is what I am trying to confirm. Thanks.

Author:	Joshie225 [ Tue Feb 17, 2009 12:42 pm ]
Post subject:
Reed, If your 7 1/4 has 3" axle tubes they will taper down to 2 1/2" at the center section. Look at the center section to see if the tubes taper down or not and you'll know the tube size.

Author:	Reed [ Tue Feb 17, 2009 12:50 pm ]
Post subject:
Yes the rear axle tubes taper on my 7 1/4. So I guess I have 3 inch tubes and the 8 3/4 rear will drop right in?

Slant Six Forum https://slantsix.org/forum/

U-bolt sizes https://slantsix.org/forum/viewtopic.php?t=33825	Page 1 of 1

Author:	Joshie225 [ Tue Feb 17, 2009 1:37 pm ]
Post subject:
Well, you won't have to buy U-bolts and shock plates.

Author:	Eric W [ Tue Feb 17, 2009 4:05 pm ]
Post subject:
Quote:

Author:	DusterIdiot [ Tue Feb 17, 2009 6:20 pm ]
Post subject:	You just need...
Quote: I know going form 7 1/4 to 8 1/4 in an a-body requires new mounting pads and u-bolts That swap just requires new U-bolts for the fatter axle tubes, and the bigger shock plates from the 8 1/4" or 8 3/4" axle... the pads on the axle itself are already correct to put into place. -D.Idiot

Author:	Reed [ Tue Feb 17, 2009 6:52 pm ]
Post subject:
Sorry, when I was referring to pads, I meant shock mounting plates. My bad.

Author:	volaredon [ Wed Feb 18, 2009 6:26 am ]
Post subject:
Quote: Well, you won't have to buy U-bolts and shock plates. Sure you will after you fight them and they still bust off; save yourself the hassle, use the "blue wrench", sawzall, cutoff wheel, etc to remove the old U bolts, and buy new ones! you can still use your current shock plates though.

Author:	Reed [ Wed Feb 18, 2009 8:14 am ]
Post subject:
Quote: Quote: Well, you won't have to buy U-bolts and shock plates. Sure you will after you fight them and they still bust off; save yourself the hassle, use the "blue wrench", sawzall, cutoff wheel, etc to remove the old U bolts, and buy new ones! you can still use your current shock plates though. I will probably have to do that, but I am going to at least try to get the nuts off my current u-bolts. Some pentrating lubricant, taking a wire wheel on a drill motor to the threads, and using an impact wrench ought to give me a fighting chance to get the nuts off without breaking the bolts.

Author:	KBB_of_TMC [ Fri Feb 20, 2009 9:57 am ]
Post subject:
I did the same to get my U-bolts off after 30+years, and my impact wrench didn't help at all - the U-bolt just twists and absorbs the shock. A deep socket and a big 3/4" drive ratchet did the trick - you need lots of torque over a big angle to get those nuts off. Many times, the U-bolt sometimes just breaks, leaving you to fight the other side.

Author:	Reed [ Fri Feb 20, 2009 11:14 am ]
Post subject:
Quote: I did the same to get my U-bolts off after 30+years, and my impact wrench didn't help at all - the U-bolt just twists and absorbs the shock. A deep socket and a big 3/4" drive ratchet did the trick - you need lots of torque over a big angle to get those nuts off. Many times, the U-bolt sometimes just breaks, leaving you to fight the other side. I gots lots of torque. I am 6'4. 300 pounds, and I lift weights regularly. Plus, I have a four foot cheater bar. So long as the bolts don't break, I should be okay. I plan on using a wire wheel on a drill motor to clean the threads then spray everything with Knock 'Er Loose (a penetrating lubricant). Hopefully that will get the job done.

Page 1 of 1	All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited https://www.phpbb.com/