Rear block swap

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Feb 19, 2019 | 07:59 AM

rickkk

Thread Starter

Cross-Country

Joined: Jan 2004

Posts: 82

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From: Ga,Buena Vista

Rear block swap

Hi all, I have a 2004 f-350 LWB Crew cab Lariat. I swapped out the rear 4" blocks for 2" ones I now have take off shutter & vibration around 45 mph. Have had the u joints replaced twice and shafts balanced to no avail. Been told to shorten up the carrier bearing bracket or to maybe use one from a 2010 f-250. Does anyone have any thoughts on which way to go? Thanks in advance.

Feb 19, 2019 | 08:03 AM

Sir Kayakalot

More Turbo

Joined: Apr 2016

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Were the blocks you removed tapered? Did you replace with a flat block? You might have changed your pinion angle. Would definitely cause vibration

Feb 19, 2019 | 09:05 AM

Mike189677

Fleet Mechanic

Joined: Jan 2012

Posts: 1,841

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Quote:

Originally Posted by Sir Kayakalot

Were the blocks you removed tapered? Did you replace with a flat block? You might have changed your pinion angle. Would definitely cause vibration

if anything it would be the other way around the blocks for the 2 piece driveshaft trucks are flat from the factory, but you may be on to something here.