First gear vibrations

[Rob Simmons]

I have a 2000 Wrangler Sport. Just installed a 2 inch suspension lift, and transfer case drop. I also just rebuilt the transmission (it really needed it.)

I am now getting shaking (vibrations) as i release the clutch when going into first gear. (slow speeds).. There are no vibrations anytime else.
I am unsure if this is a transmission issue or a lift issue. Shouldn't the transfer case drop have eliminated any drive shaft issue?

Installing a SYE is expensive and I want to make sure it is needed. Would this be a symptom?

 

[John Scoggins]

Make sure the mounts as tight as well as everything else, if so then you might have some clutch hop if it only happens when releasing the clutch in 1st (how is it in reverse). Did you install a new clutch? If so did you re-surface the flywheel and install a new pilot bushing/bearing (which ever it had)? I know you said you rebuilt the tranny but bad shaft bearings will do that also.
If you reused the old clutch/flywheel did you match mark the pressure plate and flywheel so that it could be reinstalled in the same locations with respect to each other?

 

[mots]

In addition to double-checking everything as mentioned, how far did you drop the t-case? Those definitely are the symptoms of needing the t-case drop in the first place (as you likely know). Perhaps you didn't drop down far enough to correct the pinion angle? Just a thought. After my 2" BDS lift (that yielded closer to 2.5" on my light Jeep) it had rear driveline shimmy on take off only, just as you describe. After dropping the t-case ~1", vibes on takeoff went away.

 

[Rob Simmons]

Make sure the mounts as tight as well as everything else, if so then you might have some clutch hop if it only happens when releasing the clutch in 1st (how is it in reverse). Did you install a new clutch? If so did you re-surface the flywheel and install a new pilot bushing/bearing (which ever it had)? I know you said you rebuilt the tranny but bad shaft bearings will do that also.
If you reused the old clutch/flywheel did you match mark the pressure plate and flywheel so that it could be reinstalled in the same locations with respect to each other?

You asked an interesting question so i went out and tested it. Yes, it occurs in reverse as well!..
I did not do the transmission myself, I had the shop do it. They also installed a new clutch. Makes me now wonder if I need to make a return visit to them. By "bad shaft bearings" do you mean the rear drive shaft? Wouldn't that be evident in any gear,? or just first as well?

 

[Rob Simmons]

In addition to double-checking everything as mentioned, how far did you drop the t-case? Those definitely are the symptoms of needing the t-case drop in the first place (as you likely know). Perhaps you didn't drop down far enough to correct the pinion angle? Just a thought. After my 2" BDS lift (that yielded closer to 2.5" on my light Jeep) it did rear driveline shimmy on take off only, just as you describe. After dropping the t-case ~1", vibes on takeoff went away.

The drop spacers came with the lift. They are 1 inch. I would think that i should not have a shimmy with that drop. Weird.

 

[Jerry Bransford]

Some TJs develop a bit of a vibration with even just a 2" suspension lift. The first lift I installed was a 2" and it caused drivetrain vibrations which I cured by dropping the tcase about 5/8" with washers stacked around all six tcase bolts.

Your 2000 TJ should still be using the longer 1/2x13 bolts to hold the tcase skidplate. They are long enough that you can drop the tcase that amount by just stacking washers around the bolts between the frame and skidplate. To get a 5/8" drop you need probably 3/4" of washers at each bolt since the first washer sits in a shallow depression.

 

[Rob Simmons]

Some TJs develop a bit of a vibration with even just a 2" suspension lift. The first lift I installed was a 2" and it caused drivetrain vibrations which I cured by dropping the tcase about 5/8" with washers stacked around all six tcase bolts.

I have it dropped about an inch.. Still vibrating. Which makes me wonder if it is something else.

 

[Jerry Bransford]

I have it dropped about an inch.. Still vibrating. Which makes me wonder if it is something else.

With a 1" drop it's definitely something else.

Though on second thought I'm wondering if that 1" drop might be a bit too much for a 2" suspension lift. Too much of an angle change in either direction can cause vibrations.

 

[bromel]

I hope your shop didn't resurface the flywheel. The TJ fly should not be resurfaced as it's concave. Not sure if that can cause harsh vibrations, but might be worth checking with the shop.

 

[Jerry Bransford]

I hope your shop didn't resurface the flywheel. The TJ fly should not be resurfaced as it's concave.

It's actually convex (dome shaped) but you are correct it should not be resurfaced.

 

[John Scoggins]

By "bad shaft bearings"

I was talking about input shaft bearings, a bad input shaft bearing can cause clutch chatter during engagement.

TJ fly should not be resurfaced as it's concave. Not sure if that can cause harsh vibrations, but might be worth checking with the shop.

Sure Enough, the shop manual says

Flywheel machining is not recommended. The fly-
wheel clutch surface is machined to a unique contour
and machining will negate this feature. Minor fly-
wheel scoring can be cleaned up by hand with 180
grit emery or with surface grinding equipment.
Remove only enough material to reduce scoring
(approximately 0.001 - 0.003 in.). Heavy stock
removal is not recommended. Replace the flywheel
if scoring is severe and deeper than 0.076 mm (0.003
in.). Excessive stock removal can result in flywheel
cracking or warpage after installation; it can also
weaken the flywheel and interfere with proper clutch
release.

So defiantly check with the shop that did the work, I would bring it back to them and show them what it is doing.

 

[Rosco1216]

My TJ is doing this as well. I’m new to the forum and new to the Jeep community. It’s a 97 TJ. Has 3” bds suspension lift and 3” body lift. Vibration is only in first gear and reverse sometimes. Has not had any thing rebuilt but I’m not sure about how much the transfer case was dropped. The vibration is much greater on a hill or incline. Also, If I’m starting on a flat or down hill and very easy on the clutch and gas, there really isn’t any vibration at all.

 

[Brett Proctor]

I have been having the same issue. I bought a 2006 jeep and immediately added a 2.5" lift without dropping the t-case. Since I never drove it before the lift I can't say that the vibration wasn't there before.
But it does the exact same thing you are describing. Heavy vibrations on takeoff and in reverse. No vibrations at all after moving.
I had come to the conclusion that it was the clutch so I had that replaced by a shop. They said the flywheel looked fine.
I've changed axels in the process as well (not specifically because of this), and I've swapped t-cases, but the vibration remains.
I'm going to try the t-case drop and see if this fixes it.
It is really annoying.

 

[TurboTJ]

My lift in the rear is about 1.5 inch and I have a 1 inch lifted TC skid plate. With that 2.5 inch total it vibrated badly in first and reverse even though it is a Rubicon (no slip yoke). A DC driveshaft solved that problem. You are going to have to drop your skid plate at least an inch, probably more if you have a slip yoke. Preferably you should get an SYE and DC driveshaft although that is obviously a whole lot more money.

 

[97JadeTJ]

My 2.5" suspension lift left me with a slight driveline vibration on takeoff only... I moved up to
33x12.50x15 tires and now my takeoffs are so slow I don't notice the vibrations..

 

[Dyl]

Your 2000 TJ should still be using the longer 1/2x13 bolts to hold the tcase skidplate. They are long enough that you can drop the tcase that amount by just stacking washers around the bolts between the frame and skidplate.

Is it still the case for 1997 TJ as well? That is I could drop it 5/8" by using washers?

Reason being I have noticed this same vibration when I'm taking off that goes away soon after. I have 2inch lift with 31inch tyres and everything else stock.

 

[97JadeTJ]

Is it still the case for 1997 TJ as well? That is I could drop it 5/8" by using washers?

Reason being I have noticed this same vibration when I'm taking off that goes away soon after. I have 2inch lift with 31inch tyres and everything else stock.

Yes

 

[Jerry Bransford]

Is it still the case for 1997 TJ as well? That is I could drop it 5/8" by using washers?

Reason being I have noticed this same vibration when I'm taking off that goes away soon after. I have 2inch lift with 31inch tyres and everything else stock.

Yes that works well for a 97 TJ.

 

[BonnieMcMurray]

I have a 2000 Wrangler Sport. Just installed a 2 inch suspension lift, and transfer case drop. I also just rebuilt the transmission (it really needed it.)

I am now getting shaking (vibrations) as i release the clutch when going into first gear. (slow speeds).. There are no vibrations anytime else.
I am unsure if this is a transmission issue or a lift issue. Shouldn't the transfer case drop have eliminated any drive shaft issue?

Installing a SYE is expensive and I want to make sure it is needed. Would this be a symptom?

I've got an '06 Rubicon and was having a slight vibration on acceleration and just figured it was a Jeep. Had new adjustable lower control arms installed and he set the correct pinion angle for the rear diff and it completely went away. Now accelerates from a stop very smooth.

 

[Jerry Bransford]

I've got an '06 Rubicon and was having a slight vibration on acceleration and just figured it was a Jeep. Had new adjustable lower control arms installed and he set the correct pinion angle for the rear diff and it completely went away. Now accelerates from a stop very smooth.

Glad that took care of your particular issue but you got lucky there. Adjusting the pinion angle is seldom the correct answer for most vibrations caused simply by additional suspension lift height.