shaking! what is it?

[theredmeadow]

So I think I finally found the problem to my truck vibration. It'll start vibrating around 45 subtly but then when I start getting over 55 it gets REALLY bad. I've checked my torque converter/flywheel and it's fine. I started shaking the driveshaft and this is what I found.

WHat do you guys think? What do I need to replace?

Here's a video link
http://youtu.be/sKIlJWftoeQ

[geezer#99]

Pinion bearing.

[jjzepplin]

Rear-end rebuild. So what gears have you always wanted? Now's the time.

[theredmeadow]

does it need to be a rebuild? can't I just replace the pinion bearing?

[Elliot949]

sound like it needs balanced

[geezer#99]

Originally Posted by theredmeadow

does it need to be a rebuild? can't I just replace the pinion bearing?

Maybe!
Depends on other damage. Might be pinion is damaged and needs replaced.

[theredmeadow]

could the pinion bearing be the cause of my vibrations at higher speeds?

[geezer#99]

Yes it could.

[theredmeadow]

how difficult is it to replace the pinion bearing and seal?

[geezer#99]

Not hard to do if you've done one before.
I'd take it to a pro.
With that much play you might need to replace everything in the rearend.
Pinion, the bearing, the bearing race, the seal, maybe the ring gear too.
The pinion moving that much could have chewed on the ring gear too.
You'll need someone look in there for you.
Find a pro or swap out the whole rearend.

[theredmeadow]

or could it be the yoke?

[imjeff]

The yoke attaches to the pinion gear with a seal and crush sleave between them. The adjustment is made with shims, but the crush sleave is crushed each time. This is the most critical adjustment in your rear end and involves some specialized tools and methods to make sure the gears mesh correctly. I would definitely go to a rear end shop,

Jeff

[geezer#99]

Yoke is attached to the pinion. Pull the driveshaft off and see how much it moves.

[theredmeadow]

so I bought a used functional used differential. is it easy to replace the axles because this one was a 5 lug and I want to use the 6 lug.

[9teen69]

Swapping axles is easy. Go buy a magnet for the c-clips and also replace the axle seals while you are there. AZ rents the seal puller to make it that much easier. Not sure if there is a tutorial here but search Youtube or Google..otherwise know as Skynet.

[9teen69]

Also a good time to make sure all your wheel studs are in good shape.

[theredmeadow]

Originally Posted by 9teen69

Also a good time to make sure all your wheel studs are in good shape.

actually one of my wheel stud is broke so I guess I can replace it now!

[theredmeadow]

are the 70 c10 auto a C-clip style axle?

[frank69]

The 70 diff should be a c-clip axle, be sure to check axle length, depends when diff was built, some 5bolt and 6 bolt axles are different lengths

[theredmeadow]

actually i haven't bought the differential yet. i said i was interested in buying from a craigslist seller. he said it's a 373 gear ratio. i was looking around and from what I'm seeing the 373 is for a manual? I've got an automatic so I'm assuming this won't work for my truck?

[theredmeadow]

I've got a 1970 c10 with 350 5.7L engine automatic

[jjzepplin]

Well what have you got for a drive train? Engine - transmission - Daily driver or highway cruiser?

[theredmeadow]

this is a daily driver that does get onto roads that are 65MPH

[jjzepplin]

What kind of trans? And what tire size makes a difference too.

[theredmeadow]

I'm assuming it's the stock trans and could that be a th350? I have 15 inch rims with 235/75/15 tires