Need everyone's help assessing what I have

rubigold

rubigold

TJ Enthusiast
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Mar 22, 2019
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109
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Connecticut
Hey Jeep fam. So I picked up a rubicon. This is my first jeep, so bare with me during the learning process. It supposedly has a 4in Rancho lift, but the person I bought I from wasnt the one who installed it. I noticed that the skid below the tranny/transfer case is lowered by a "spacer." What's the purpose of this? Is this to prevent the installation of a slip yoke eliminator? I'd prefer to lift it the correct way, so any advice is appreciated! Lowering the skid seems like a cheap way of lifting to get more clearance for tires.


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Plenty you can learn on here! First off, congrats on the Rubi, and a rare Inca Gold color. The Rubi wont need a slip yoke eliminator, so thats one plus. Skids are usually lowered when you have transferase vibes after a lift. 4 inches on a TJ usually involves getting a new rear driveshaft, or lowering the TC.

There is a post on the forum about how to determine the amount of lift based on coil spring length, that would get you in the ballpark of what size lift you have.

Best way to correct that, if you wanted to, would be ordering up a new driveshaft in the correct length for a 4 in lift. Tom Woods Driveshafts are pretty popular on here, and I'm running their rear driveshaft on mine.
 
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Okay so you have a rubi, that means you’re already on a good path given you don’t need a SYE. You only need a CV driveshaft and adjustable rear arms to correct the pinion angle. This tilts the yoke toward the transfer case and mean vibrations will be significantly reduced. The spacer was put there most likely to take away highway vibes at 50 mph+.
 
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You need adjustable upper and lower control arms. If it were me I would go with either “Currie” or “Savvy” brands. The reason behind those two brands is that they use johnny joints which are arguably the best joints you can get.

Having these adjustable arms will allow you to adjust your rear axle pinion yoke up to match the angle of your transfer case output yoke. Doing so will reduce the chances of driveline vibrations. It also allows you to remove the 1 inch lowering kit.

You may need a new rear driveshaft. The front will likely be fine.

Check your bumpstops and your brake lines before doing any crazy off roading.

Also just FYI the front factory springs are 12 inches long. The rear factory springs are 8 inches long. When measuring yours, anything over 12 in the front and 8 in the rear is equivalent to how many inches of lift you have on your Rubi.

So if you have a 4 inch lift, your front springs will measure 16 inches from the top of the spring to the bottom of the spring. Your rear springs will measure 12 inches from the top of the spring to the bottom of the spring.

Racho is known to make some of the best bolt on shocks for our TJ wranglers. The Rancho RS5000x. They also make some cheaper adjustable control arms. Not sure if they use johnny joints or not.

Also if it has a dropped pitman arm, look into replacing it.
 
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First thing I would do, after you determine the lift height, is take off the transfer skid spacers, reinstall the skid, then take a test drive to see if there are any untoward vibrations. A lot of lift kits come with spacers and the buyers install those without questioning whether they are needed or not.

If you do encounter driveline vibrations, then I would explore other methods of taking care of that vs. the skid spacers.
 
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Good advice in this thread. I'd just like to put it all in one post. Nice Inca Gold Rubi. I'd love one if you ever want to sell out! In this order...

1) Find out how much lift you really have by measuring each spring and any aftermarket spacer (but not including the stock coil spring isolator at the top). As @Fouledplugs mentioned, stock in front is 12" and rear is 8". Any amount over that is the amount of lift you have. Front and rear may not be the same, so measure them all.
2) If 3" or less, you could do a 1" motor mount lift and probably solve your vibes. However, unless you are planning to do a tummy tuck later, the better solution would be to get a Tom Wood driveshaft. You don't need the SYE because you have a Rubi and they already have a Fixed Yoke
3) If you go with a Tom Wood (or Adams) driveshaft, then you will need rear control arms so you can rotate your pinion to face directly at the output yoke of your Transfer Case.

That, at least, will give you some options for solving the driveline vibrations and removing the TCase drop.
 
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JeepZilla380 said:
Plenty you can learn on here! First off, congrats on the Rubi, and a rare Inca Gold color. The Rubi wont need a slip yoke eliminator, so thats one plus. Skids are usually lowered when you have transferase vibes after a lift. 4 inches on a TJ usually involves getting a new rear driveshaft, or lowering the TC.

There is a post on the forum about how to determine the amount of lift based on coil spring length, that would get you in the ballpark of what size lift you have.

Best way to correct that, if you wanted to, would be ordering up a new driveshaft in the correct length for a 4 in lift. Tom Woods Driveshafts are pretty popular on here, and I'm running their rear driveshaft on mine.
Click to expand...

cliffish said:
post some pics of the underside showing drive shafts, steering, shocks etc...that way we can a better look at what is going on.
Click to expand...

Fouledplugs said:
You need adjustable upper and lower control arms. If it were me I would go with either “Currie” or “Savvy” brands. The reason behind those two brands is that they use johnny joints which are arguably the best joints you can get.

Having these adjustable arms will allow you to adjust your rear axle pinion yoke up to match the angle of your transfer case output yoke. Doing so will reduce the chances of driveline vibrations. It also allows you to remove the 1 inch lowering kit.

You may need a new rear driveshaft. The front will likely be fine.

Check your bumpstops and your brake lines before doing any crazy off roading.

Also just FYI the front factory springs are 12 inches long. The rear factory springs are 8 inches long. When measuring yours, anything over 12 in the front and 8 in the rear is equivalent to how many inches of lift you have on your Rubi.

So if you have a 4 inch lift, your front springs will measure 16 inches from the top of the spring to the bottom of the spring. Your rear springs will measure 12 inches from the top of the spring to the bottom of the spring.

Racho is known to make some of the best bolt on shocks for our TJ wranglers. The Rancho RS5000x. They also make some cheaper adjustable control arms. Not sure if they use johnny joints or not.

Also if it has a dropped pitman arm, look into replacing it.
Click to expand...

JMT said:
Good advice in this thread. I'd just like to put it all in one post. Nice Inca Gold Rubi. I'd love one if you ever want to sell out! In this order...

1) Find out how much lift you really have by measuring each spring and any aftermarket spacer (but not including the stock coil spring isolator at the top). As @Fouledplugs mentioned, stock in front is 12" and rear is 8". Any amount over that is the amount of lift you have. Front and rear may not be the same, so measure them all.
2) If 3" or less, you could do a 1" motor mount lift and probably solve your vibes. However, unless you are planning to do a tummy tuck later, the better solution would be to get a Tom Wood driveshaft. You don't need the SYE because you have a Rubi and they already have a Fixed Yoke
3) If you go with a Tom Wood (or Adams) driveshaft, then you will need rear control arms so you can rotate your pinion to face directly at the output yoke of your Transfer Case.

That, at least, will give you some options for solving the driveline vibrations and removing the TCase drop.
Click to expand...


Wow guys great info. I appreciate it all. I'll snap some pics of the underside soon and post them up. This is not my daily driver, and will be used at least once per month for some decent wheeling. probably not any heavy rock crawling, but definitely some decent crawls with what 31-33in tires can handle. So when I measure the springs, this is done while the weight of the jeep is compressing them, yes?
 
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You have fixed front lower control arms with urethane bushings. Those style of arms don't provide much flex and have a tendency to rip arm brackets off. Looks like they re-drilled the track bar hole at the axle end to re-center the axle, so it's probably the stock tb. Also not a good way of doing it. An adjustable tb would be a better solution. To get rid of the skid drop you'll need minimum rear upper adjustable arms and a double cardan rear drive shaft to adjust the pinion angle for vibe free operation. I also don't see any bump stop extensions, but it looks like you have fixed sway bar end links, so your articulation will be limited, which why probably why your tires aren't hitting the fenders.
That's what I can see so far.
 
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