How screwed am I?

LCL-Dead

LCL-Dead

It broke.. ..again
Original poster
Supporting Member
Joined
Mar 21, 2017
Messages
188
Location
Havelock, NC
Hey guys, long time no see.

So I was accelerating onto a highway the other day and got this huge vibration throughout the entire Jeep.
Limped it over to a repair shop and they said they wouldn't touch it because of the lift kit but that they think a u-joint(s) had finally kicked the bucket.
So I limp it home at 30mph to avoid it vibrating and when I get home and get underneath it.. Well, this is what I found.

00AG8rQ.jpg


There's a lot of play in the circled area, but no play in the u-joints (front or rear shaft). Is this driveshaft fubar? Dust boot is missing because of an accident years ago that left the front of the shaft rubbing the exhaust, as you can see from the dents in the exhaust pipe where severe compression of the front suspension pushed the knuckles into it. And yes, one of my trans cooler lines has a slow leak up near the front of the oil pan.
 
mrblaine said:
I think you dodged a bullet and the Double Cardan joint is fubar. Don't drive it until you know or you'll be looking for a new t-case if it is.
Click to expand...

This a shop fix or something I can do in the home garage (minus the press for the u-joint, so socket drive out)?
 
If you have to drive your Jeep, either remove the front driveshaft or unbolt it from the front axle and suspend it safely up and out of the way. As Blaine said a bad front driveshaft CV can seize and cause the tcase to literally explode.
 
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LCL-Dead said:
This a shop fix or something I can do in the home garage (minus the press for the u-joint, so socket drive out)?
Click to expand...

The double cardan can be rebuilt, it is more tedious than a novice would generally like to deal with and given that the other end isn't as good as it could be, I'd check it by pulling it first and then go for a drive. If the vibes are gone, you know at least one end of the drive shaft needs fixed. If both ends are bad, just order a new one.
 
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Jerry Bransford said:
If you have to drive your Jeep, either remove the front driveshaft or unbolt it from the front axle and suspend it safely up and out of the way. As Blaine said a bad front driveshaft CV can seize and cause the tcase to literally explode.
Click to expand...

Yeah, I need it as its my DD. Work hasn't been too keen on the whole telework bit since Covid regulations for the fed got relaxed. Gonna head outside and start pulling it off to see if it stops vibrating.

Do I need to worry about t-case fluid with the shaft completely disconnected?
 
LCL-Dead said:
Yeah, I need it as its my DD. Work hasn't been too keen on the whole telework bit since Covid regulations for the fed got relaxed. Gonna head outside and start pulling it off to see if it stops vibrating.

Do I need to worry about t-case fluid with the shaft completely disconnected?
Click to expand...

Pull the pinion end and very securely fasten it right above the lower control arm mount bolt. Then test drive it.
 
Since we know the slip and stub(spline) end is bad, my recommendation is check the double cardan end and if there are any questions order a new shaft. With current costs of driveshaft components the cost to repair the slip and stub is well over 50% of the cost of a new shaft.

Just as a note also your lower control arm on the passenger side is installed upside down.
 
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Blackjack said:
Since we know the slip and stub(spline) end is bad, my recommendation is check the double cardan end and if there are any questions order a new shaft. With current costs of driveshaft components the cost to repair the slip and stub is well over 50% of the cost of a new shaft.

Just as a note also your lower control arm on the passenger side is installed upside down.
Click to expand...

Yeah, the shop did that when I took it in to have the mount on the axle repaired and I haven't bothered to correct it yet. Needless to say I've never gone back to them. Since I'm not wheeling it right now due to its myriad issues, just using it as a DD, it hasn't been my top prio.

That being said, disconnected the front and took it for a spin. Vibration still present. Took a much closer look at the rear ujoints with a pry bar and light and the axle side ujoint is definitely bad. How I missed the boots being eaten up is beyond me.

FBCLrVd.jpg


I'll also be pricing new drive shafts tonight for the front. About to head to autozone and see if I can get a breaker bar, torque bar and a clamp press for the ujoints on the rear axle. Those I can swap on my own but I can't break the damn bolts on the t-case side of the shaft for the life of me and don't have anything suitable to use as a breaker in the garage.
 
LCL-Dead said:
Yeah, the shop did that when I took it in to have the mount on the axle repaired and I haven't bothered to correct it yet. Needless to say I've never gone back to them. Since I'm not wheeling it right now due to its myriad issues, just using it as a DD, it hasn't been my top prio.

That being said, disconnected the front and took it for a spin. Vibration still present. Took a much closer look at the rear ujoints with a pry bar and light and the axle side ujoint is definitely bad. How I missed the boots being eaten up is beyond me.

View attachment 405080

I'll also be pricing new drive shafts tonight for the front. About to head to autozone and see if I can get a breaker bar, torque bar and a clamp press for the ujoints on the rear axle. Those I can swap on my own but I can't break the damn bolts on the t-case side of the shaft for the life of me and don't have anything suitable to use as a breaker in the garage.
Click to expand...

Do not now nor ever use a press to install u-joints. Use the hammer method only.
 
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mrblaine said:
Do not now nor ever use a press to install u-joints. Use the hammer method only.
Click to expand...

Explain? Everything I've looked up has a basic C-Clamp style press being used to push the ujoints into place with their caps inside of the assembly.
 
LCL-Dead said:
Explain? Everything I've looked up has a basic C-Clamp style press being used to push the ujoints into place with their caps inside of the assembly.
Click to expand...

Ball joint clamps and the like are good for one thing and that is ruining yokes.

mrblaine said:
Do not now nor ever use a press to install u-joints. Use the hammer method only.
Click to expand...

Maybe it is time for me to show how professionals replace ujoints and how that method can be replicated replicated at home.
 
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Blackjack said:
Ball joint clamps and the like are good for one thing and that is ruining yokes.



Maybe it is time for me to show how professionals replace ujoints and how that method can be replicated replicated at home.
Click to expand...

You’d think a press would make it easier. It’s the opposite.
 
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LCL-Dead said:
Explain? Everything I've looked up has a basic C-Clamp style press being used to push the ujoints into place with their caps inside of the assembly.
Click to expand...

The caps are very hard, they have reasonably sharp edges. The yokes are not nearly as hard. With a press, you can easily bind one up when an edge hangs and then it just mashes the two yokes towards each other and ruins them. With the hammer method, that never happens or if it has, no one has ever admitted it.
 
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