Knocking After 2.5" Lift Install

[02TJ]

Greetings All,

A few buddies and I installed a 2.5" lift on my 2002, I-6, 5-Speed, 77k miles. Afterwords I noticed a horrible knocking sounds comming from what sounds like the transfer case or U-Joints. Issue happens when accelerating from stop or reverse.

Knock will stop after 5 - 10 mph or if I come off the clutch slowly and baby the throttle.

Any advice??

 

[TurboTJ]

Did you lower the transfer case? If you have a TJ with a slip yoke you’ll need to.

 

[02TJ]

No. Lower with spacers? How much do I have to go down?

 

[TurboTJ]

No. Lower with spacers? How much do I have to go down?

3/4 inch maybe?

 

[Chris]

No. Lower with spacers? How much do I have to go down?

It varies from vehicle-to-vehicle. 3/4" may work, but you may need 1" or more.

 

[02TJ]

Ordering a 1" drop. Report to follow later in the week.

 

[MountaineerTom]

You can just get some longer bolts and a bunch of washers and stack them as needed until the vibes go away. You might not need 1 inch worth.

 

[02TJ]

Now that's a plan! Hitting the Depot after work.

 

[Halfstock]

I did the longer bolts and washers on my '98. 2.5 inch OME spring lift gave similar issues as yours.

Washers measured .100" each, started with a stack of 10 washers to equal an inch. (60 total washers)

After installation the vibes immediately went away, but I gained squalling from the front of the transfer case!

Back to the shop, I removed 2 washers from each stack, drove it again,reduced squall, no vibes.

Back to the shop, removed two more washers per bolt, drove it a third time. No squall, no vibes. For my purposes the sweet spot is .600" drop.

Glad I did the washers as opposed to the 1" drop kit! YMMV, good luck!

 

[MountaineerTom]

Now that's a plan! Hitting the Depot after work.

Get grade 8 hardware And use anti-seize on the bolts. Reduce torque 15-20% with anti-seize.

 

[TurboTJ]

I did the longer bolts and washers on my '98. 2.5 inch OME spring lift gave similar issues as yours.

Washers measured .100" each, started with a stack of 10 washers to equal an inch. (60 total washers)

After installation the vibes immediately went away, but I gained squalling from the front of the transfer case!

Back to the shop, I removed 2 washers from each stack, drove it again,reduced squall, no vibes.

Back to the shop, removed two more washers per bolt, drove it a third time. No squall, no vibes. For my purposes the sweet spot is .600" drop.

Glad I did the washers as opposed to the 1" drop kit! YMMV, good luck!

By squalling do you mean it was making a lot of noise? Maybe the slightly greater angle of the front driveshaft DC was identifying a bad bearing in it? If so that should be taken care of.

 

[Halfstock]

Actually I'm not at all sure what all the squalling was about. I pulled the front drive line and checked the DC and u-joint to see if they were bound up, had play, or otherwise suspect. Ended up giving a clean bill of health to both.

While I was at it, I felt the front output shaft for binding, play, again anything unusual. Nothing I could discern.

I'm a bit baffled.

 

[TurboTJ]

Actually I'm not at all sure what all the squalling was about. I pulled the front drive line and checked the DC and u-joint to see if they were bound up, had play, or otherwise suspect. Ended up giving a clean bill of health to both.

While I was at it, I felt the front output shaft for binding, play, again anything unusual. Nothing I could discern.

I'm a bit baffled.

I’ll bet the bearings in the DC centering yoke are going bad.

 

[Halfstock]

I’ll bet the bearings in the DC centering yoke are going bad.

I've never delved into the DC joint that far. You may well be right on your observation, it's OEM with 133k miles on the clock.

Any specialty tools required on the overhaul of a DC joint?

 

[Halfstock]

Get grade 8 hardware And use anti-seize on the bolts. Reduce torque 15-20% with anti-seize.

X2 on the anti-seize!

 

[TurboTJ]

I've never delved into the DC joint that far. You may well be right on your observation, it's OEM with 133k miles on the clock.

Any specialty tools required on the overhaul of a DC joint?

Just something to press the bearings in and out.

 

[Halfstock]

Just something to press the bearings in and out.

I've got that! Hmmm..

More quality time with my tools, and jeep!

 

[Goatman]

What does 'squalling' sound like? I've never heard that word before when not in reference to a bad storm.
Seriously. Not a dig.

 

[Halfstock]

What does 'squalling' sound like? I've never heard that word before when not in reference to a bad storm.
Seriously. Not a dig.

It was a rhythmic squeal which increased rhythmic pulse and auditory intensity as rolling speed increased. It was also present irrespective of 2wd/4wd, under power, or coasting.

Does that help?