Help me identify a vibration

[1987 GMC Jimmy]

That makes more sense. It’d be interesting to hear what your results are when you put it all together.

 

[da_raabi]

Whelp. That's right over my head. I'm decent with electricity and circuitry, but I think its a bit much for what I'm dealing with here.

On another note, I suddenly started getting a loud CRACK noise from the driver's front wheel well after sitting for a bit. Haven't dug into it yet, but the couple times its happened I didn't feel it, just heard it. Definitely the driver's front.

I have not done anything to that area in a long time so I'm a little worried something broke.

Tends to happen after I back up then start moving forward again. Last time it did it like 4 times in a row just cruising down my street. I quickly took it home and parked it.

I'm wondering if these things are related?

 

[DoubleDingo]

It's possible they are related.

 

[Snoots]

Cracked frame behind the steering gear box?
Slipping of the axle under the spring perch?

 

[DoubleDingo]

The guy on stovebolt reported back....this is copied from his report back of the results....so it may be the pinion bearing going out on yours, definitely worth a check...

"I finished putting the rear end back together in my '62 C10. With the third member rebuild, new U-Joints, and switching from 3.90:1 to 3.38:1 gears, it drives like a completely different truck.

That pinion bearing must have been going out for a long time. The vibrations are gone, the whine is gone and the engine doesn't sound like it's screaming at speed any more."

 

[da_raabi]

The guy on stovebolt reported back....this is copied from his report back of the results....so it may be the pinion bearing going out on yours, definitely worth a check...

"I finished putting the rear end back together in my '62 C10. With the third member rebuild, new U-Joints, and switching from 3.90:1 to 3.38:1 gears, it drives like a completely different truck.

That pinion bearing must have been going out for a long time. The vibrations are gone, the whine is gone and the engine doesn't sound like it's screaming at speed any more."

Interesting. Do you happen to have a link for that? I'd like to read more on the process of elimination he went through etc.

 

[yevgenievich]

Interesting. Do you happen to have a link for that? I'd like to read more on the process of elimination he went through etc.

Currently top post in driveline section. Appears to just found the slack in the pinion
https://www.stovebolt.com/ubbthread...p-in-a-1962-55t-differential.html#Post1259053

 

[DoubleDingo]

@yevgenievich thanks. Edit...I didn't check the link you posted, I thought it was the "What have you done to your bolt today" thread.

I sent him a PM asking for additional info. Will let you know if he responds.

 

[DoubleDingo]

He replied. Of course yours doesn't have the removable third member, the pinion bearings may be the culprit. I removed the link from this response because it was the same one Viktor posted earlier.

 

[rpcraft]

It's surprising but the pinion bearing can take forever to actually get bad to a point where you have a failure. I'd pull the driveshaft off and take a moment to use your hand to see if it has play in it. also if you see any gear oil leaking off the diff that is an indicator as well. A pinion bearing can be replaced pretty easily so long as the mating surface on the pinion has not been scarred. A good shop can probably get it done for a few hours and the parts themselves are less than 100 bucks (probably less than 50 bucks if you bring them to them).

 

[Billy]

Mine was a motor mount and my transmission mount.

 

[pinch1020]

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[da_raabi]

Figured out the issue with the "cracking" sound up front. Turns out something WAS cracking, just not quite what I thought. See anything odd here?

You must be registered for see images attach

Looks like somebody with little hands decided to play a trick on Daddy while the truck was getting its driveshaft fixed...

Dang kids.

 

[rt66paul]

I hate it when that happens.

 

[idahovette]

Just trying to help!!!