Reducing Lift from 4" to 3" Death Wobble Questions

[KDenn]

Hi everyone,

First time posting here. I've had a TJ for a few years but it's not heavily modified. I just bought a 2017 JKU with 40k miles that has a 4" lift and 35" tires a few months ago. I got bad death wobble for the first time a few weeks ago, and after following Planmans inspection tips, I replaced the track bar with a Terraflex HD adjustable one, as well as the drag link with a Synergy HD adjustable link, and the AEV geometry correction brackets. I did this an got an alignment done and all seemed well. We just came back from a weekend road trip on it and during the road trip I got death wobble again (not quite as bad) when hitting a bump going highway speeds, but ever since it has had a slight wobble or shimmy when hitting bumps that is making me nervous to drive it. There isn't much else I can find that is obviously wrong so I am looking at replacing the entire tie rod and/or the ball joints, and possibly all of the front control arm bushings. But now as I read about fixing it, it seems like a lot of the blame can be laid the previous owner putting on a lift over 3" without all of the corresponding upgrades being made. The track bar, drag link, and control arms were all stock. After the trip I've realized it's hard to handle at 60+ mph and I'm getting some bump steer, so now I'm going down the rabbit hole thinking now I need to do the drag link flip and maybe look at adjustable upper control arms at the least.

Anyway, my question is: can I just replace my 4" lift coils with 2.5-3" lift coils, and solve some of my problems? I was looking at AEV's 2.5" lift which I saw people say is actually closer to 3". I found a place that sells just the coils for less than half the price of the entire kit. I think it looks a little too tall for the tire size anyway, and I'd prefer it to be a little lower. I figured out it has a 4" lift by measuring the coil springs and comparing to stock height. It's got some Falcon shocks on it, not sure which ones, but as far as I can tell nothing else was upgraded with the lift besides what I've done personally. Or would it be best to get the whole AEV (or similar) lift kit with the rear track bar and all of that? I'd rather not do this as I'm already about $800 in to trying to fix it and it's still happening. I haven't touched the rear end. Unfortunately, the Jeep will mostly be a daily driver. I do live in the Four Corners area so we go camping in the summers and I go to the Alpine Loop in Colorado to run trails up there every summer, but it's not hard wheeling. Regardless of the lift question I will most likely still put a new heavy duty tie rod on it.

Any feedback or advice is appreciated.

TLDR: My jeep has a 4" lift + 35" tires and I'm having death wobble and slowly replacing parts to try and fix it, but also having bump steer and it doesn't handle as well as I'd like. I'd prefer how the jeep looked with a 3" lift and it seems like it would reduce strain on the front end as well as fix some of the handling issues. Can I just change out the coils from 4" to 2.5" or 3" springs?

 

[BLACKJKU]

Does the Jeep have adjustable control arms?

 

[KDenn]

No, no adjustable control arms. Just the geometry correction brackets. From the alignment sheet I just got the caster is at 3.9* passenger and 4.1* driver. I finally got someone to help me check the ball joints using the pry under the tire method and there is some up/down play in my ball joints, so that's good to know.

While I had it lifted, oil leaked out of the driver side drive shaft, not a fun day

 

[terdogjk]

Whats the condition of your tires? Cupping or wear?

I'd do the ball joints BEFORE the lift.

 

[JeepJeezy]

No, no adjustable control arms. Just the geometry correction brackets. From the alignment sheet I just got the caster is at 3.9* passenger and 4.1* driver. I finally got someone to help me check the ball joints using the pry under the tire method and there is some up/down play in my ball joints, so that's good to know.

While I had it lifted, oil leaked out of the driver side drive shaft, not a fun day

Replace them ball joints!

 

[CD_02TJ-17JK]

No, no adjustable control arms. Just the geometry correction brackets. From the alignment sheet I just got the caster is at 3.9* passenger and 4.1* driver. I finally got someone to help me check the ball joints using the pry under the tire method and there is some up/down play in my ball joints, so that's good to know.

While I had it lifted, oil leaked out of the driver side drive shaft, not a fun day

Hi KDenn,

I’m inclined to agree with BLACKJKU about the adjustable control arms. Before I would reduce the height of your lift, I would throw on a set of adjustable control arms up front, an full adjustable track bar (not a relocation bracket), replace ball joints on anything you aren’t upgrading and see how it rides.

You shouldn’t have any issues with a 4” lift pending it’s comprehensive - coils, shocks, adjustable track bar, control arms, extended brake lines, extended or adjustable sway bar end links (make sure your swaybar is parallel with the ground when parked). Also, on my TJ I needed to drop the transfer case about an inch to get the driveline angles closer to factory. Not sure if this would impact the death wobble but I would imagine it could since you're manipulating factory geometry.

Also, do you know anything about the wheels for your 35s? Curious if prior owner threw on spacers or if they actually paid attention to correct wheel offset/backspacing.

Speaking from experience with this.. definitely not the most mechanically experienced on the forum, so take it with grain of salt. Plus, if you run 35s and you lower to a 2.5” lift you will rub under full articulation with a disconnected swaybar. Not sure of your fender situation, but if you do lower the lift I’d either run fender delete or flat fenders.

Good luck!

 

[Greyfoxvt]

I just purchased the RC driveshaft for my lifted 3.5" RC lift with relocation brackets. Now I am also adding a complete set of RC Adjustable Control Arms, so I am hoping this all works together well. I cannot find an answer as to whether I need to remove the relocation brackets when adding the new Control Arms, or just adjust for the stock and keep them in place.

Called both Rough Country (RC), and ExtremeTerrain (where I bought the gear), and neither could answer the question. Do any of you know? It would seem that the whole reason for Adjustable arms is so you don't need the relocation brackets, but I'm not sure. I am also looking for the measurements for the arms lengths for my configuration. My ride is a 2013 Jeep Wrangler Sport (2-Door) with RC 3.5" lift, with 35's

 

[vaffanculo]

Hi everyone,

First time posting here. I've had a TJ for a few years but it's not heavily modified. I just bought a 2017 JKU with 40k miles that has a 4" lift and 35" tires a few months ago. I got bad death wobble for the first time a few weeks ago, and after following Planmans inspection tips, I replaced the track bar with a Terraflex HD adjustable one, as well as the drag link with a Synergy HD adjustable link, and the AEV geometry correction brackets. I did this an got an alignment done and all seemed well. We just came back from a weekend road trip on it and during the road trip I got death wobble again (not quite as bad) when hitting a bump going highway speeds, but ever since it has had a slight wobble or shimmy when hitting bumps that is making me nervous to drive it. There isn't much else I can find that is obviously wrong so I am looking at replacing the entire tie rod and/or the ball joints, and possibly all of the front control arm bushings. But now as I read about fixing it, it seems like a lot of the blame can be laid the previous owner putting on a lift over 3" without all of the corresponding upgrades being made. The track bar, drag link, and control arms were all stock. After the trip I've realized it's hard to handle at 60+ mph and I'm getting some bump steer, so now I'm going down the rabbit hole thinking now I need to do the drag link flip and maybe look at adjustable upper control arms at the least.

Anyway, my question is: can I just replace my 4" lift coils with 2.5-3" lift coils, and solve some of my problems? I was looking at AEV's 2.5" lift which I saw people say is actually closer to 3". I found a place that sells just the coils for less than half the price of the entire kit. I think it looks a little too tall for the tire size anyway, and I'd prefer it to be a little lower. I figured out it has a 4" lift by measuring the coil springs and comparing to stock height. It's got some Falcon shocks on it, not sure which ones, but as far as I can tell nothing else was upgraded with the lift besides what I've done personally. Or would it be best to get the whole AEV (or similar) lift kit with the rear track bar and all of that? I'd rather not do this as I'm already about $800 in to trying to fix it and it's still happening. I haven't touched the rear end. Unfortunately, the Jeep will mostly be a daily driver. I do live in the Four Corners area so we go camping in the summers and I go to the Alpine Loop in Colorado to run trails up there every summer, but it's not hard wheeling. Regardless of the lift question I will most likely still put a new heavy duty tie rod on it.

Any feedback or advice is appreciated.

TLDR: My jeep has a 4" lift + 35" tires and I'm having death wobble and slowly replacing parts to try and fix it, but also having bump steer and it doesn't handle as well as I'd like. I'd prefer how the jeep looked with a 3" lift and it seems like it would reduce strain on the front end as well as fix some of the handling issues. Can I just change out the coils from 4" to 2.5" or 3" springs?

Hey Grey before you go doing all that work try reducing the air pressure in the tires to 30lbs .this way the tires will absorb the shock of the road along with the shock absorbers and springs ..good luck

 

[vaffanculo]

Hi everyone,

First time posting here. I've had a TJ for a few years but it's not heavily modified. I just bought a 2017 JKU with 40k miles that has a 4" lift and 35" tires a few months ago. I got bad death wobble for the first time a few weeks ago, and after following Planmans inspection tips, I replaced the track bar with a Terraflex HD adjustable one, as well as the drag link with a Synergy HD adjustable link, and the AEV geometry correction brackets. I did this an got an alignment done and all seemed well. We just came back from a weekend road trip on it and during the road trip I got death wobble again (not quite as bad) when hitting a bump going highway speeds, but ever since it has had a slight wobble or shimmy when hitting bumps that is making me nervous to drive it. There isn't much else I can find that is obviously wrong so I am looking at replacing the entire tie rod and/or the ball joints, and possibly all of the front control arm bushings. But now as I read about fixing it, it seems like a lot of the blame can be laid the previous owner putting on a lift over 3" without all of the corresponding upgrades being made. The track bar, drag link, and control arms were all stock. After the trip I've realized it's hard to handle at 60+ mph and I'm getting some bump steer, so now I'm going down the rabbit hole thinking now I need to do the drag link flip and maybe look at adjustable upper control arms at the least.

Anyway, my question is: can I just replace my 4" lift coils with 2.5-3" lift coils, and solve some of my problems? I was looking at AEV's 2.5" lift which I saw people say is actually closer to 3". I found a place that sells just the coils for less than half the price of the entire kit. I think it looks a little too tall for the tire size anyway, and I'd prefer it to be a little lower. I figured out it has a 4" lift by measuring the coil springs and comparing to stock height. It's got some Falcon shocks on it, not sure which ones, but as far as I can tell nothing else was upgraded with the lift besides what I've done personally. Or would it be best to get the whole AEV (or similar) lift kit with the rear track bar and all of that? I'd rather not do this as I'm already about $800 in to trying to fix it and it's still happening. I haven't touched the rear end. Unfortunately, the Jeep will mostly be a daily driver. I do live in the Four Corners area so we go camping in the summers and I go to the Alpine Loop in Colorado to run trails up there every summer, but it's not hard wheeling. Regardless of the lift question I will most likely still put a new heavy duty tie rod on it.

Any feedback or advice is appreciated.

TLDR: My jeep has a 4" lift + 35" tires and I'm having death wobble and slowly replacing parts to try and fix it, but also having bump steer and it doesn't handle as well as I'd like. I'd prefer how the jeep looked with a 3" lift and it seems like it would reduce strain on the front end as well as fix some of the handling issues. Can I just change out the coils from 4" to 2.5" or 3" springs?

Also meant too mention you can heat the springs up an lower them too a desired height and see if that works since you are already willing to buy new ones it's worth a try ..just make sure you heat them up at the exact area in all four springs

 

[vaffanculo]

Also meant too mention you can heat the springs up an lower them too a desired height and see if that works since you are already willing to buy new ones it's worth a try ..just make sure you heat them up at the exact area in all four springs

You seem flabbergasted 101 proof...this is how they lower vehicles ....check out motortrend

 

[Dirty Dog]

Also meant too mention you can heat the springs up an lower them too a desired height and see if that works since you are already willing to buy new ones it's worth a try ..just make sure you heat them up at the exact area in all four springs

Please don't do this. It is done, true, but it is the absolute worst of the several ways of lowering ride height.

 

[vaffanculo]

Please don't do this. It is done, true, but it is the absolute worst of the several ways of lowering ride height.

True most of the time it's done on cars and mini pickups with the factory springs and its like driving a forklift truck but Grey's jeep already has a 4 inch aftermarket lift with huge springs so heating the springs to drop it 1.5 inches will still leave him with plenty of spring left too absorb the bounce of the road

 

[Dirty Dog]

True most of the time it's done on cars and mini pickups with the factory springs and its like driving a forklift truck but Grey's jeep already has a 4 inch aftermarket lift with huge springs so heating the springs to drop it 1.5 inches will still leave him with plenty of spring left too absorb the bounce of the road

Except it will change the spring rate and weaken the steel.

 

[1o1Proof]

You seem flabbergasted 101 proof...this is how they lower vehicles ....check out motortrend

Yea, people have done this…that doesn’t make it right.

 

[vaffanculo]

Except it will change the spring rate and weaken the steel.

Very good D.D. ..i enjoy people who question an action....your my new bud on here 🛠but as long as you keep the heating temperature at 600 degrees or less no weaking of the steel will occur you just let it drop too the desired height slowly...another option is cutting the coil since they are not that difficult too remove

 

[Dirty Dog]

Very good D.D. ..i enjoy people who question an action....your my new bud on here 🛠but as long as you keep the heating temperature at 600 degrees or less no weaking of the steel will occur you just let it drop too the desired height slowly...another option is cutting the coil since they are not that difficult too remove

Both methods will work. Neither is a good option. Both methods will absolutely reduce the strength of the spring and change the spring rate, affecting ride and handling.
Buy springs of the right height. That's the proper solution.

 

[vaffanculo]

Both methods will work. Neither is a good option. Both methods will absolutely reduce the strength of the spring and change the spring rate, affecting ride and handling.
Buy springs of the right height. That's the proper solution.

I agree ....

 

[tJKrider]

Very good D.D. ..i enjoy people who question an action....your my new bud on here 🛠but as long as you keep the heating temperature at 600 degrees or less no weaking of the steel will occur you just let it drop too the desired height slowly...another option is cutting the coil since they are not that difficult too remove

Depends on the metallurgical composition of the steel and how rapidly it's allowed to cool. For instance if someone "helps" cool it quicker so it can be handled that could spell trouble... Also goes without saying that someone would have to have a mechanism to accurately monitor temperature throughout the coil which I can already assume won't happen.

For a vehicle with potentially large articulation this is just a terrible idea. Maybe for some street only vehicle that only uses a small portion of the spring travel. Even then it would just be safer and more straightforward to buy the correct spring.

I'll argue that someone with the knowledge to correctly heat and stress relieve the spring can also perform a simple spring swap.

 

[Snowbird Tom]

Just a comment from the peanut gallery - have the tires looked at for bent belts, delamination and balance.