Weird problem

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Oct 22, 2018 | 02:05 PM

‘66 F100 Pearl

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Weird problem

after i replaced the diff gasket and reinstalled the axles and drive shaft and filled the diff. I drove to the gas station and had no issues. Driving home about a 1/4mi from the gas station I got a weird vibration. Like a lobing feeling. When I had the truck rolling in nuetral no issues but when I was in gear that’s when I had the issue.

any ideas?

Oct 22, 2018 | 02:14 PM

Daugust32

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Need more info. Long bed or short bed? When you removed the diff, did you remove the pinion?

Oct 22, 2018 | 07:39 PM

‘66 F100 Pearl

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Quote:

Originally Posted by Daugust32

Need more info. Long bed or short bed? When you removed the diff, did you remove the pinion?

long bed. I pulled axles, and driveshaft. Pulled the diff out as a single piece. Replaced gasket. Put it back together.

I may have put the drive shaft on 180° rotated off. Or the U joint went bad.

Or or maybe I just have the shaft off a spline connecting to the other one. More likely the cause

Oct 22, 2018 | 08:07 PM

john jamieson

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From: tucson

Check the carrier bearing as well

Oct 22, 2018 | 08:07 PM

skidoorulz

Fleet Mechanic

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From: Billings Montana

If you slid the drive shaft off the slip joint the is a good possibility your u joints are out of line.

Oct 22, 2018 | 08:17 PM

‘66 F100 Pearl

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Quote:

Originally Posted by skidoorulz

If you slid the drive shaft off the slip joint the is a good possibility your u joints are out of line.

thats what I’m thinking since I didn’t know I didn’t have to pull the back half of the driveshaft off completely. Just off the diff

any tricks to get it aligned back right?

Oct 23, 2018 | 04:19 AM

User 71024

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In all honesty I don't remember ever caring how the 2 shafts went together. And I always store them separately. I'm guessing I've always lined up the joints, but I'm willing to bet the 2 shafts are balanced separately so that may not matter, I'd be more inclined to think it was a u-joint or the carrier. Just my 2 cents.

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Oct 23, 2018 | 10:12 AM

Daugust32

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Drive shaft MUST be in phase... meaning the ears on the spline should be aligned with the ears at the transmission input. The below picture is not mine.

Oct 23, 2018 | 10:33 AM

#10

TA455HO

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From: Seattle

Good diagram there Daugust32. Here's a picture of an NOS Ford coupling shaft (miniature drive shaft) showing the same orientation.

Chad

Oct 23, 2018 | 01:44 PM

#11

jpk_ks

Cross-Country

Joined: Jun 2014

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I would check the phasing per the diagram. If that's in alignment check the carrier bearing to ensure it didn't end up out of alignment. I've been told that you should loosen the bolts on the carrier bearing mount until you get it all back together and then tighten it all up once everything is reconnected. That worked for me, but I've only done it once so I'm not an expert.

Oct 23, 2018 | 02:51 PM

#12

‘66 F100 Pearl

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Yeah, I looked at it and realized that the couplings weren’t in that phase. Fixed it. And problem gone. Should have marked it and paid more attention putting it back on...

thanks guys!