Vibs at 50+

Jeff B

Jeff B

Thanos was right
Joined
Dec 23, 2006
Location
Lincolnton N.C.
Just went to 4.10 gears. Had some vibs before but now come on at lower speeds. Thought it was the read drive shaft. So I installed a new one from Oliver's. Great service by the way! However it's still there.. I pull the rear drive shaft & run on front wheel drive & quiet as a mouse..

Give me some ideas guys.. I am going nutz here..
 
This is my rear pinion angle.
20150820_171043.jpg
 
I would say bent wheele bad tire or wheele barings but makes no sence that it dose not happen when shaft is out
 
the tires have about 6k on them. I am going to have them balanced again tomorrow. I just had the shafts out and inspected the bearings. that all looks good.
 
Well that's all the easy stuff lol the way I found mine was put the truck up on 4 jack stands and watch it wile a buddy drove it inside or maybe a go pro
 
If we could hear the sound it would definitely help.
 
I'll be pissed if I have these new tires balanced and it's cured...
 
Questions:
- Is is more pronounced under power or coasting, or doesn't matter?
- Is that pinion angle set up to run straight under power since the springs always twist a little bit (unless you have a traction bar). Typically you would set the pinion pointing down just a degree or two at most.
- Springs worn out?
- Are you sure you have a good pattern on those gears and that the pinion bearings are tightened to spec?
- Do all the u-joints swivel freely?
- Greased the splines for the slip member?
- Can you have Oliver's re-check that shaft for balance?
 
shawn said:
Bad output shaft bearings in the tcase.
Click to expand...

This is what I was told in a pm also.. I think this is the direction I am headed. Rebuild kit is 60$ on ebay.
 
OnlyOneDR said:
Questions:
- Is is more pronounced under power or coasting, or doesn't matter?
- Is that pinion angle set up to run straight under power since the springs always twist a little bit (unless you have a traction bar). Typically you would set the pinion pointing down just a degree or two at most.
- Springs worn out?
- Are you sure you have a good pattern on those gears and that the pinion bearings are tightened to spec?
- Do all the u-joints swivel freely?
- Greased the splines for the slip member?
- Can you have Oliver's re-check that shaft for balance?
Click to expand...

Power or coasting no matter

Gears are good

Pinion is good

Driveshaft is good
 
If removing the rear driveshaft takes the vibe away, it has to be from the t case back. It can't be the tires based on that fact.
I'd verify:
No up and down/ in or out play in rear output (spec is 0.005" end play IIRC)
No play in rear pinon yoke indicating worn pinion bearings
Good luck!
 
I will check that at lunch. Thanks
 
If it was there before the gear swap just at a different speed, you can nearly eliminate everything in the rear axle.
Tires/Wheels/even shafts would be constant and increasing at speed.

I'd point towards the Tcase output bearing as well.
 
Jody Treadway said:
No up and down/ in or out play in rear output (spec is 0.005" end play IIRC)
Click to expand...
10 thou. end play on the rear out put shaft, no side to side play. I pulled the rear drive shaft again just to be sure & there was no vibrations at 60mph. Normally comes on at 50mph. Think it could be internal in the tcase or only under load?
 
So you were running 60 mph in 4wd?
Damn son.
 
Jeff B said:
10 thou. end play on the rear out put shaft, no side to side play. I pulled the rear drive shaft again just to be sure & there was no vibrations at 60mph. Normally comes on at 50mph. Think it could be internal in the tcase or only under load?
Click to expand...

10 thou endplay seems fine IMO. There's nothing in the case that could cause the vibe unless the mainshaft (output shaft) is bent.
Is there any way that the tranny crossmember is installed backwards? The holes line up but the t case will be offset about 1.5" and that will cause vies. BTDT.
 
Jody Treadway said:
10 thou endplay seems fine IMO. There's nothing in the case that could cause the vibe unless the mainshaft (output shaft) is bent.
Is there any way that the tranny crossmember is installed backwards? The holes line up but the t case will be offset about 1.5" and that will cause vies. BTDT.
Click to expand...

I checked for being in line, looks pretty straight from the rear pinion.

I didn't check the fact of the sye with he dial indicator. I will after work.

I did put the rear drive shaft back in, vibration is harder when in the throttle and less when coasting.
 
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