Rough Country 7594 vs Daystar KJ09100BK: TJ Coil Spring Spacers

Published 10 September 2026

These two parts are close to identical in concept. Each is a pair of black spacers that slip onto the TJ's upper coil mount, above the spring. Neither one changes the spring, the shock or any link.

The differences are in what each maker tells you. Daystar publishes a two-page install sheet and approves the rear axle. Rough Country publishes a tire chart and a front-only scope, and nothing else.

At a glance

What each part is, and the problem it solves

Many stock TJs sit nose-down. TeraFlex's own instruction sheet says it plainly: "The rear of many TJs sits higher than the front." That downhill stance is the factory rake.

A coil spring spacer sits between the frame's upper coil mount and the top of the spring. The spring is unchanged, so it pushes the frame up by the spacer's thickness. Put a pair on the front only and the nose comes up while the tail stays put.

Rough Country 7594 is built for exactly that front-only job. Rough Country calls it a "Precision 1.75-Inch Front Lift" that "Levels the stance." Quadratec's listing says the same thing in plainer words: it "will make the front and rear sit at the same height."

Daystar KJ09100BK does the same job, and one more. Daystar lists it as "Front/Rear," so a second pair can go on the rear axle. Daystar files it under its "Budget Boost" line.

Fitment, side by side

Neither maker publishes a "will not fit" note for any TJ trim. Rough Country's only note is "Always read all product page details for more important fitment information." Daystar's page lists no exclusions.

One oddity on Daystar's sheet is worth knowing. Printed beside its XJ front figure is the line "NOT BE USED WITH A LIFT OR ALTERED SUSPENSION." The sheet does not say whether that applies to a TJ.

Distributors blur the Daystar fitment. ExtremeTerrain lists it as front only, and one smaller shop lists only 1997-1998 TJs. Daystar's own page, and its sheet with rear steps, are the ones to trust.

Specs and construction

Daystar makes a specific material claim. "Progressive" polyurethane is its term for a spacer that also acts as an isolator, damping vibration between the spring and frame.

Rough Country says only "Built from durable materials." Its distributors disagree on what that material is, so this page does not guess. The photo shows a molded black ring with a raised inner collar and one flat side.

What's in the box

Rough Country 7594: two spacers. Rough Country confirmed "a pair of 2 spacers" in its product Q&A. No hardware is listed, and Quadratec says they "simply slip onto the front upper spring mounts."

Daystar KJ09100BK: two spacers, sold as a pair. The sheet calls for no new hardware and no extra parts.

One warning if you shop RC by distributor. ExtremeTerrain's 7594 page links an install guide and a box list that belong to a different part, Rough Country's XJ shackle relocation kit. The 7594 box holds spacers only.

Install compared

The job is the same for both. You support the axle, disconnect what holds it up, lower it until the coil comes out, slip the spacer onto the upper mount, and reverse. Neither part needs drilling, cutting or welding.

Daystar documents every step. On the front, its sheet has you disconnect the lower sway bar end links, the lower shock mounts, the tie rod ends and the track bar at the axle. It also warns: "Watch the brake lines for overextending."

On a TJ the Daystar sheet adds one step. You remove the bump stop mounting cup, then reinstall it after the spacer. It ends with "Torque all bolts to factory specs and recheck after 500 miles."

Rough Country publishes no install sheet for 7594. Its product data has no instructions attached, and no archived version of the page ever linked one. Its only install figure is "1-3 hours," which RC's 2013 page described as the average for "a professional shop or mechanic."

One Amazon owner described the RC install in his own words. "Disconnect the swaybars & shocks first," he wrote, and "I used spring compressors on the front." That is an owner report, not a Rough Country instruction.

What it changes on the Jeep, and what else you'll need

At 1.75 in., neither maker calls for a track bar, shock extensions or longer sway bar links. Both say the stock parts stay. That does not mean nothing moves.

Raising the front moves the axle away from the frame by the spacer's height. The track bar then sits at a steeper angle and pulls the axle slightly sideways. What a lift actually breaks explains why that matters more as the lift grows.

Bump stops are the quiet difference between spacer-only parts and kits. Neither of these parts extends the bump stop. Zone's same-height kit adds them, as the Zone comparison shows.

Plan on a front alignment to re-center the steering wheel. Neither Rough Country nor Daystar requires one in writing, but Zone's instructions for the same 1.75 in. height do.

Tires are where RC is clearer. Rough Country tested 30x9.50R15 on the factory 15 in. wheel and lists 245/65R17, 245/70R17 and 245/60R18 sizes too. Daystar publishes no tire guidance for this part.

Warranty and support

Daystar: its product page says "Limited Lifetime Warranty." Daystar's site has no separate warranty page with the full terms, so exclusions are not published there.

Rough Country: Quadratec and Amazon both list 7594 with a "Limited Lifetime Warranty." RC's archived warranty page gives "Hard Suspension Components" a lifetime replacement warranty and "Bushings, Ball Joints, Etc" one year. It does not say which bucket a spacer falls in.

RC's page also excludes "Any and all cost assumed during removal or installation." It adds a 90-day return window. If a spacer fails, expect a replacement part, not a refund of your labor.

Owner reports

These are owner reports, not specs. We could not reach a TJ forum thread on either part, so the reports come from retailer reviews and videos.

• RC 7594, overall: 4.5 of 5 stars from 75 ratings on Amazon.
• RC 7594, compression (owner report): "The flat on the one side has already started giving in to the spring after only a short time." (Audrey, Amazon, 3 stars, 2024-05-31.)
• RC 7594, not quite level (owner report): on an RC 4 in. lift, "There's still a slight rake, but it's definitely better than before... I would recommend 2 inch spacers." (Cole, Amazon, 3 stars, 2024-03-02.)
• RC 7594, bigger tires (owner report): "These fit both front and rear, and give very comfortable clearance for 31s." (J. Gardner, Amazon, 5 stars, 2026-01-16.) Rough Country itself says 30x9.5 is the limit.
• Daystar KJ09100BK: 4.7 stars from 3 reviews on ExtremeTerrain, with no review text shown. An owner's 57-second clip, "Jeep TJ 1997-2006 Spacer Kit Daystar", shows the part on a TJ.
• Cheap spacers in general (owner report): a TJ owner who fitted unbranded $12 polyurethane spacers wrote, "After a few months of use they did not hold up very well." (Muddy Beards 4X4, 2019.) Neither brand here is that part.

Who should buy which

Buy the Daystar KJ09100BK if you can get it. It costs less at Daystar's listed price than RC's MAP, and it comes with real instructions. It also works on either axle, so a second pair can lift the rear later.

Buy the Rough Country 7594 if Daystar is still on backorder and all you want is a level front. It is the same basic part, and RC gives you a clear tire limit to plan around. Budget for a shop or a good manual, because RC gives you no steps.

Buy neither if you want 31s or an even lift. Two front spacers will not make room for bigger tires at the rear. Look at a four-spacer kit with bump stops, or at the other lift types.

FAQ

Does Rough Country 7594 lift the rear of a TJ?

No. Rough Country sells 7594 as a front pair and calls it a front lift. Quadratec's listing says using these spacers on the rear is not recommended. Daystar says its KJ09100BK fits front or rear.

What is the biggest tire either spacer clears?

Rough Country says 30x9.5 is the largest it recommends with 7594, and it declined 31x10.5 in its own Q&A. Daystar does not publish a tire size for KJ09100BK.

Do I keep the factory rubber isolator?

For a 1.75 in. lift, Daystar's sheet says to leave the factory isolator in and add the spacer. Removing the isolator gives about 1 in. of lift instead. Rough Country publishes no install steps for 7594.

Can I stack two pairs for more lift?

Daystar's sheet describes a 2.75 in. setup: remove the factory isolators and put two 1.75 in. spacers on one side. Rough Country publishes nothing on stacking 7594.

Sources

1. Rough Country 7594 product page (Wayback capture, 13 May 2026)
2. Rough Country 7594 product page (Wayback capture, 2013)
3. Rough Country warranty page (Wayback capture, October 2025)
4. Daystar KJ09100BK product page
5. Daystar KJ09100/KJ09103/KJ09107 coil spring spacer instructions, sheet P10438-03
6. TeraFlex 999117 TJ Budget Boost instructions (rake note)
7. Zone Offroad J2200 TJ 1-3/4 in. coil spacer lift instructions (alignment note)
8. Quadratec: Rough Country 7594 listing
9. Quadratec: Daystar 1-3/4 in. coil spring spacers listing
10. ExtremeTerrain: Daystar KJ09100BK listing
11. ExtremeTerrain: Rough Country 7594 listing