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T-case front output shaft play?

9K views 15 replies 4 participants last post by  Stox225 
#1 ·
So anywhere between 60-70mph, I have an intermittent vibration. It's not REALLY in the steering wheel. When it's at its worst, it feels like it is, but a light shake i don't feel it in the wheel.

I checked all my u joints. All of them. Everywhere. No play. But, when I grabbed the front drive shaft, I could move it up and down a concerning amount. Haven't really examined it yet. Haven't had much time, but there's nothing leaking anywhere.

Wheel bearings were replaced about 2k ago. My sweet "y" steering linkage set up needs a new TRE at the pitman arm, but I convinced the wife I need the "t" upgrade, so tax money's got that coming in the mail on Thursday ;).

What do yas stink? Could that TRE be the culprit?


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#2 ·
Nobody? [emoji53]


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#3 ·
The drive shaft is disconnected from the front wheels and doesn't spin in 2hi. So no it's not your driveshaft/tcase

Everything that spins needs to be balanced or it will shake. Wheels, drums, drive shafts. A bad wheel bearing and a broken or worn u joint with a broken cup can shake too. Normally a vibration is from a u joint or a bad tire.

If you can feel it in the steering it means it's coming from the front end. If the cab of the truck shakes it could be the rear. If you feel it the wheel and your wheel bearings and u joints are good it could be a bad tire coming out of round or balance. Try rotating your tires and see what happens
 
#4 ·
I rotated the tires about .... 2k ago? I've only had this issue for about a thousand or so miles. Got about 12k on them and haven't balanced them since. Maybe it's time for a check.


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#5 ·
I guess I'm not understanding this perfectly. Here's my thought process:

Only one part of the front axle should be disconnected from the ring and pinion/front driveshaft in 2hi; passenger side because of the acutator. There are no hubs to lock/unlock, so the driver side is always engaged with the ring and pinion ... so the driver side tire would spin the front driveshaft, wouldn't it????
 
#6 · (Edited)
That is true, but with the passenger side axle free-spinning, and the open front diff, you get this.



EDIT: this was back with a stock transfercase, so none of my shenanigans have any effect.
 
#7 ·
So why doesn't is spin from a dead stop?

I don't fully understand open differentials and limited slip and all that crap. Gunna have to do some reading on that subject. I'm assuming we have an open front?
 
#8 ·
All trucks have open front diffs, for good reason too, locked front diffs are scary and dont like to steer.

This video will teach you everything about differentials



In layman's terms, the tire with the least traction (resistance) spins. SO the unhooked end (CAD end) be connected to the drive shaft so it will never spin
 
#9 ·
So it shouldn't spin, but it does slightly. But not fast enough to cause a bad enough vibration. Good video lol. Minus the first 2 minutes ha. So the ring gear is attached to the CAD end?

This has been a VERY educational morning so far haha
 
#10 ·
No, both tires spin until one slips, then the slipping tire will spin more. ring placement means nothing.
Does not matter if it left or right. If you have one tire on Ice and the other on a asphalt, the tire on ice will spin all day long .


The ring gear doe not turn, Only the spider gears
 
#11 ·
Due to fluid coupling, the front driveshaft will spin a little especially at higher speeds. The easy way to rule it out as the cause of vibration is to either remove it. Or use a small chunk of weaker string and tie it to the cross member or frame to prevent it from spinning. Just make sure that the string/zip-tie is by far the weakest link.

I may have to strap the camera down there again to see how fast it spins at 70 mph.
 
#12 ·
So if there was no CAD, would the drive shaft spin??? I need like hands on in order to completely get this lol. Sorry for wasting yalls time!
 
#13 ·
That is correct. The front drive shaft would spin at the same speed as the rear shaft it there was no CAD, later 01's and 02's didn't have a CAD so the front driveshaft would spin at full speed. I guess dodge got tired of all the CAD failures, ha!

I have wasted much time on these forums, but it's only when I enter a pointless argument, so it is not this day!
 
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#14 ·
Ha, well I appreciate it! Okay. I think I finally have it all figured out now lol. It all makes sense.

I'm ruling out the front drive shaft only because it happens immediately upon hitting 60 mph. It doesn't take a minutes to cause the shake, so it's something that is rotating at 60 mph with the rest of my truck. Not catching up to speed.

Thank you all for your patience! I will let you know what I figure out. I'll be doing the steering linkage either this weekend or the next, so that will rule that out. I'll have to drive it down the road to get an alignment so I'll know if that was the cause. I will also have the tires balanced at that point as well. After that will be a rotation.
 
#15 ·
No cad would cause it to spin. You can drop the front drive line to confirm it is not the problem. Just drive it with out it to check. Do you have free rebalancing, use it.
 
#16 ·
Turns out I had crappy ball joints on my passenger side. Seems to have fixed the issue. Next step is rebalance. I'll probably do that on the next tire rotation in 3k.
 
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