2024 rubicon x vibration after gears

[JT1]

I have seen a high angle Rzeppa from Teraflex for the JK, but they don't show compatibility with the JT. I had an OEM shaft here, but got tired of tripping over it and scrapped........Would be nice to have it for comparison about now?

Hard for a manufacturer to develop something like that when the "gold standard" is to toss the "POS" OE shaft and swap a 1350?

Yeah, all the replacement CVs are basically factory. Rumor has it you can bolt a JK front shaft and flange on a JL or JT, but I don't have one laying around to confirm.

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[JT Nate]

Yeah, I have a replacement CV joint for the stock shaft sitting in the garage. If I get 40k out of each joint, and don't have to buy a new shaft, leaves me more money for other things that would improve it's performance.

I still think the 1310 aftermarket shafts are probably the smart answer. They tolerate misalignment a little better than the 1350s do.

I wish I knew that about the 1310. They don’t list the negatives on the product description . I’m learning for sure. First jeep

 

[CrazyCooter]

I wish I knew that about the 1310. They don’t list the negatives on the product description . I’m learning for sure. First jeep

That's the hard thing about learning....It's sometimes expensive!

 

[JT Nate]

Funny how people "think" 1350 is an upgrade and go for it.........Its a wider cross so the shaft speed oscillates more when the angles aren't perfect. Then you deleted the FAD? I can see a 1350 for the rear shaft , but I feel 1310 front is more appropriate for a vehicle that isn't getting beat.

You can literally be all over the place on tiny joints that are in say a Suzuki Samurai, but jump up to the Yota drivelines and have all kinds of issues.

I will never "upgrade" my front driveline since I'm happy with the 11"+ of travel the OEM shaft supports.

I didn’t

Funny how people "think" 1350 is an upgrade and go for it.........Its a wider cross so the shaft speed oscillates more when the angles aren't perfect. Then you deleted the FAD? I can see a 1350 for the rear shaft , but I feel 1310 front is more appropriate for a vehicle that isn't getting beat.

You can literally be all over the place on tiny joints that are in say a Suzuki Samurai, but jump up to the Yota drivelines and have all kinds of issues.

I will never "upgrade" my front driveline since I'm happy with the 11"+ of travel the OEM shaft supports.

I didn’t delete the FAD. 2024 and up don’t come with a FAD. They have a block off plate. I would love a fad since it already has the weaker split axle.

 

[CrazyCooter]

I didn’t delete the FAD. 2024 and up don’t come with a FAD. They have a block off plate. I would love a fad since it already has the weaker split axle.

Now you taught me something........I didn't know the FAD was gone. All of the JL/JT's I have re-geared here in the shop have been 2018-2023.

That creates a stronger case for leaving the OEM shaft if the travel/strength isn't needed or maybe do a 1310 for the travel?

I personally prefer caster in the 3.5-4° range, so my setup could tolerate more.

 

[JT Nate]

Now you taught me something........I didn't know the FAD was gone. All of the JL/JT's I have re-geared here in the shop have been 2018-2023.

That creates a stronger case for leaving the OEM shaft if the travel/strength isn't needed or maybe do a 1310 for the travel?

I personally prefer caster in the 3.5-4° range, so my setup could tolerate more.

That’s good to hear. I’m on the fence… it’s small vibration at 60 felt through the floor. Not sure if 5 degree caster will take it out or if I should shoot for 4 degrees for the better pinion angle. How much of a difference is there in the steering between a caster of 5 and 4?

 

[JT1]

That’s good to hear. I’m on the fence… it’s small vibration at 60 felt through the floor. Not sure if 5 degree caster will take it out or if I should shoot for 4 degrees for the better pinion angle. How much of a difference is there in the steering between a caster of 5 and 4?

Honestly, it's a stacking of variables. I went from 6.5* back up to about 5.5* and really didn't notice any change in the way it steered.
If you are over the knuckle steering with 2.5T tierod and draglink, it may be more noticeable.

 

[Wheelin98TJ]

I wish I knew that about the 1310. They don’t list the negatives on the product description . I’m learning for sure. First jeep

You may already know this, a 1310 has more travel than a 1350.

 

[JT Nate]

The fix is in!!! Guys at CPW (central parts warehouse) in IL. We’re on the same page with setting the caster at 5. After all set and done the pinion angle went from 11.6 degrees (caster of 6.6) to 9 degrees with a caster of 5. Did a full alignment and had me take it out on the highway. The vibration is gone! He said if It comes back we can always take it down to 4. I feel that won’t be necessary. Also the steering feels great. I can not feel a difference. So hopefully this helps for anyone running a similar setup!

 

[CrazyCooter]

The fix is in!!! Guys at CPW (central parts warehouse) in IL. We’re on the same page with setting the caster at 5. After all set and done the pinion angle went from 11.6 degrees (caster of 6.6) to 9 degrees with a caster of 5. Did a full alignment and had me take it out on the highway. The vibration is gone! He said if It comes back we can always take it down to 4. I feel that won’t be necessary. Also the steering feels great. I can not feel a difference. So hopefully this helps for anyone running a similar setup!

But....but....but.....you cant run caster low (in spec)......you will die in a violent fiery crash if you don't have at least 6°!!!!???

All your driveline angle numbers are just confusing......What you are looking for is a 0° operating angle (or as close as possible) on that front joint. Also keep in mind that the vibration may come and go with loads changing or as the springs settle in.

Congrats on that victory!

 

[ShadowsPapa]

If your Caster is only 4.5 its probably too low . 5.5-6.0 is where most end up.
Do you have adjustable lower control arms ?

That doesn't cause vibration - tire balance or driveshaft - with that many changes, the lift, the driveshaft swap. How many have we seen here with vibrations after a driveshaft swap?
Several for sure.

 

[ShadowsPapa]

What you are looking for it a 0° operating angle (or as close as possible) on that front joint.

I didn't see what shaft he has, which joints it has where, but............Don't run a single cardan joint at 0. they don't live long there. You can easily go up to 3 or 3.5, but 0 will shorten the lift as the needle bearings won't move. They'll get pounded in place.
A true CV won't or shouldn't matter.

 

[Stan H]

That doesn't cause vibration - tire balance or driveshaft - with that many changes, the lift, the driveshaft swap. How many have we seen here with vibrations after a driveshaft swap?
Several for sure.

I was just thinking of pinion angle

 

[CrazyCooter]

I didn't see what shaft he has, which joints it has where, but............Don't run a single cardan joint at 0. they don't live long there. You can easily go up to 3 or 3.5, but 0 will shorten the lift as the needle bearings won't move. They'll get pounded in place.
A true CV won't or shouldn't matter.

Same thing for a 3 joint double cardan shaft.....a 0° constant operating angle isn't good, but the pinion angle and position is changing constantly with load/height so it's getting lube. 3° is a lot and will create a horrible vibration especially with the larger joints and heavier shafts. In this case the OP only made a 1.2° change and the vib is gone? Imagine what 3° would feel like??!!

I'm sure you understand that the two joints in the cardan cancel each other out, but that lone joint at the slip end will cause a vibration when it's off either way of 0° and that what this post is about.

Just a fat guy riding passenger in my YJ throws my front pinion angle off enough to note a slight vibration change.

 

[ShadowsPapa]

but that lone joint at the slip end will cause a vibration when it's off either way of 0° and that what this post is about.

A single joint can go up to about 3, depending on RPM.
(Wood's told Dan that a while back)

We always started out with some angle because under load the pinion wants to climb the ring gear, changing the pinion angle.

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