ARB Old Man Emu BP-51 Complete Suspension Lift Kit For 2nd Gen Toyota Tundra – Detailed Installation Guide & Initial Impressions + Review
I’ve been building the ultimate Tundra hunting truck. In the process, I’ve added all kinds of accessories; bumpers, lights, a winch, and a Decked system.
As I added accessories, my total vehicle weight really started climbing. One day I took a step back and noticed the saggy rear end of my truck, and it hit me; I had violated one of my rules. I should have started with the suspension.
A Dirt Bike Analogy
I’ve been riding dirt bikes since I was a kid, and the first thing I do when I get a new bike is to tune the suspension. A dirt bike ships from the factory with settings that don’t match my size or riding style. A brand new bike is set up for a 165 lb. rider and thus is under-sprung and needs stiffer front and rear springs to account for the extra padding I’ve built up over the years.
Once the springs are right, I begin to adjust compression and rebound damping to suit my terrain and riding style. If I do some jumps and/or big drops, I will increase the compression damping. If I’m headed to the desert, I’ll reduce the compression damping and play with the rebound damping to try and keep the rubber on the ground through all the small hits.
Factory Suspension Shortcomings
It occurred to me that my truck was exactly the same as my latest KTM dirt bike. Toyota designed the 2nd Gen Tundra with very general use in mind. They want it to be good on the road and in the dirt, just okay. Most of the factory suspension’s performance is geared toward on-road handling without a trailer. The saggy rear end made me realize that I had added all these accessories to my truck – just like I have added a few pounds to my body. I needed stiffer springs and needed the ability to adjust compression and rebound damping.
So, I set out to look for the proper suspension setup for my truck. I wanted to improve upon the factory ride both on and off-road, and I wanted to be able to adjust compression and rebound damping as well. I wanted better stability when towing.
In short, I was looking for a unicorn. So many aftermarket suspension kits have purely focused on the lift and sacrificed everything else. I’ve been building out my truck methodically, and there is a purpose for every part I’ve added. In my search, I found my perfect match in the Old Man Emu BP-51 suspension kit engineered by ARB.
With the kit selected, it was time to get started. I was able to get the BP-51 headed my way from Mudify. They make ordering the correct system quick and easy for your rig. Each BP-51 kit is vehicle specific, so ordering the right parts is key. Mudify makes this process as simple as possible.
Find It Online
- Old Man Emu BP-51 For 2nd Gen Tundra: Check Price
BP-51 Kit Overview
The Old Man Emu BP-51 kit has independent compression and rebound damping, preload compression adjustment on the front coil overs, and the ability to add a leaf to the rear spring pack.
Most shocks on the market use velocity-sensitive damping (damping refers to restraining vibratory motion). This means that the fast the piston moves, the more damping is created in return. The BP-51s also have this feature, but they can also generate damping based on the piston position within the shock’s body with the bypass system.
This bypass system gives shock fluid a secondary way to move from one chamber to another around the actual piston. This is in addition to the fluid that flows through the piston. Simply put, this creates a suspension system that gives an improved ride on the road and a more controlled ride over the terrains we find off-road.
The end result is a system that can give you comfort on and off-road – even with a fully built truck.
- (1) ARB Old Man Emu Front Coil Over RH (BP5190010R)
- (1) ARB Old Man Emu Front Coil Over LH (BP5190010L)
- (1) ARB Fit Kit Front (VM80010034)
- (1 ARB Old Man Emu Shock Rear RH (BP5160020R)
- (1) ARB Old Man Emu BP-51 Shock Absorber Rear LH (BP5160020L)
- (1) ARB Fit Kit Rear (VM80010035)
- (2) ARB Old Man Emu Rear Coil Spring (CS055R)
- (1) Rear Leaf Spring Shackle (OMEGS22)
- (2) ARB Leaf Spring Bushing Kit (OMESB106)
- (1) ARB Old Man Emu Rear Fitting Kit (FK32)
- (4) ARB Old Man Emu Leaf Spring U-Bolt (OMEU53B)
I also added the Old Man Emu Extra Leaf for Dakar Leaf Springs D28XL (07-21 Tundra), which requires a new extended center leaf pin.
I wanted to ensure I had ample time to install this kit and do it justice!
It arrived in excellent condition; interestingly, the leaf springs shipped as is – no box. They are so heavy that I’m not sure there is a box tough enough to handle them. They were wrapped in plastic and in great shape upon delivery. I live in Wyoming, and the installation was around March, which has unpredictable weather.
My truck barely fits in my garage before the lift, so I wanted to avoid completing the lift and then having to take it off to get the truck out of the garage. I have a good friend in town with an awesome open bay shop. Jennings Racing to the rescue. With a weekend set aside, space to work, and the kit in hand, it was time to get busy!
- Socket set
- Box wrenches
- Spring compression tool (if running an aftermarket steel bumper or winch)
- Brass hammer
- Pry fork/ball joint separator
- Jack stand (2)
- High lift floor jack
Step 1. Adjust Preload On Front Coilovers
According to Old Man Emu, I needed to adjust the preload on the front coilovers to compensate for my Tundra’s CBI front bumper and Rough Country Winch. I was looking for 25mm / 1″ of preload. The BP-51 coilovers came set at 0.39″, which is probably the most commonly used setup.
If you have never used a Macpherson strut spring compression tool before, grab a friend and do it before opening a beer. Basically, the fingers on each side of the compression tool grab one of the coils, then compress the tool as you would expect.
You don’t realize that it takes a lot of force to compress the spring far enough to turn the compression nut an additional 0.5″. Notice the bend in the threaded rod above. Make sure you have the fingers of the tool securely on the spring and that you lube the threaded rods with an anti-seize compound to reduce friction as much as possible and alternate compression side to side so that you don’t compress one side too much more than the other as you go.
Step 2. Remove Wheel & Old Coilovers
- Remove the 12mm brake line bolt and 14mm sway bar link bolt.
- Remove the UCA cotter pin and 22mm nut.
Tip: The UCA bolt is a taper fit bolt, so it fits very tight. After removing the nut, knock the arm with a brass hammer to “convince” it to let go.
- Remove the 19mm lower shock bolt and nut.
Tip: Use a punch or a u-joint fork to get the lower shock bolt off.
- Remove the four (4) 14mm upper shock bolts.
- Disconnect the tie rod using the pry fork and 24mm socket.
Tip: At this point, the shock is free, but it can be a little tricky to get the old one out of place. The lower control arm has some flex built into it. Use your foot to push down on the LCA and free the shock assembly. Disconnecting the sway bar is helpful here.
Step 3. Install New BP-51 Coilovers
Since the preload has been set already, this is basically Step 2 in reverse.
Put the new coilover into place. Line up the four studs on the top of the shock assembly (the lower portion will come next). Thread the upper four nuts onto the studs. Now using your foot to push down on the LCA, align the lower shock mount and put the 19mm bolt through. This will take a little creative force to balance the pressure on your foot while pushing the bolt through the LCA and lowering the shock mount hole.
- Tighten the upper shock bolts to 33 ft/lbs.
- Tighten the lower shock bolt to 144 ft/lbs.
Next is the remote reservoir mounting. The reservoir mounting bracket uses the same mount as the front sway bar. Remove the bolts, slide the reservoir mounting bracket in place, and then replace the bolts.
Next is possibly the most challenging part of the entire operation. Slide the sleeve that holds the remote reservoir in place over the reservoir, and then slide the two bolts into the sleeve, ensuring they are in the center. Now place the sleeve onto the mounting bracket. Use one hand to hold the assembly in place and the other hand to thread the 10mm nuts onto the mounting bolts.
Tip: A ratcheting box wrench with a flexible head comes in handy to tighten the reservoir sleeve in place.
Next: Reattach the outer tie rod to the LCA using the castle nut.
- Torque to 51 ft/lbs. and replace the cotter pin.
Next is the UCA. Align the taper bolt with the arm and reinstall the castle nut.
- Torque the UCA nut to 77 ft/lbs. and reinstall the cotter pin.
- Torque the tie rod bolt to 50 ft/lbs.
Tip: Use a ratchet strap or floor jack to bring the upper and lower A-arms towards each other.
Lastly, use the supplied wrench from OME to adjust compression and rebound, then mount the wheel again. You may need to make final adjustments after testing your suspension on the road/trail.
Step 4. Rear Add-A-Leaf (Optional)
Before removing any factory parts, I think preparing the new leaf pack is a good idea. Since I have a Decked System, a fully kitted-out Leitner Forged ACS rack system, a CBI steel rear bumper with swing arms, and frequently haul trailers, I wanted to have the extra carrying capacity of the add-a-leaf.
The factory suspension was very “saggy” and was one of the main reasons I wanted to upgrade the suspension to begin with.
This step requires two (2) C-clamps and a socket wrench. First, clamp the OME spring pack with the C-clamps, then remove the nut from the centering pin. Then remove the two retaining brackets on each end of the leaf pack while taking care not to let the individual leafs get separated.
Slide the add-a-leaf into the pack in size order. You want the overall pack to maintain the largest to smallest orientation. Align the holes for the centering pin and use the new longer pin to accommodate the thickness of the added leaf.
Use the C-clamps to compress the leaf pack again, install the centering pin and nut, and torque to 15 ft/lbs. Finally, reinstall the leaf pack retaining brackets.
While you are working on the leaf pack, if you are using the OME greaseable shackle, go ahead and remove the bushing by using a large socket and a brass hammer to hit out the factory-installed bushing. Replace with the yellow PU bushings.
Step 5. Remove Factory Rear Suspension
First, lift the back of your truck as high as possible and put the truck on jack stands. The higher the better! You will want as much room to move around under the truck as possible, plus you will need to drop the rear axle by the rear differential. Make sure to chock the front wheels as well.
With the rear end on jack stands, remove both wheels. It’s a good idea to put the wheels under the frame in case of an accidental shift; they will prevent the truck from hitting the ground. Disconnect the brake line support brackets. There is one behind each wheel and also one on top of the rear diff pumpkin. Leave these disconnected until you are finished installing all the BP-51 parts.
Now, support the axle from the rear differential pumpkin with a floor jack – just barely kiss the differential; you just want to support it. Next, remove the two nuts from the bottom side of the U-bolts that hold the factory leaf pack to the axle. You will reuse the plate, but not the U-bolts. Next, remove the lower nut and bolt holding the lower rear shock in place.
After the lower shock bolt is removed, you can carefully lower the jack that is supporting the rear diff. You don’t want to go too far, just another inch or so. This will make clearance to remove the rear shock. Now you can remove the upper shock nut and remove the OEM shock assembly.
Now, slowly lower the rear axle to remove the pressure from the rear leaf springs. Once the axle starts to move away from the leaf pack, stop lowering the jack because you don’t want to put too much pressure on the brake lines and abs sensor wires.
With the axle lowered, remove the factory leaf pack by removing the nuts and bolts from the rear shackles and the front mounting bolt.
Tip: Use a breaker bar for the front leaf pack bolt.
Altogether remove the rear shackles, which will be replaced by new OME components.
Step 6. Install BP-51 Rear Components
Check out the difference in size between the factory leaf pack and the OME pack! OEM is on top, and Old Man Emu is on the bottom.
Now that the old components are out of the way, the installation of the new components is basically the reverse of the removal. The difference is in the rear shackle if you use the OME greaseable shackle.
Rear Torque Specs:
- Leaf spring: 77 ft/lbs.
- U-bolt: 74 ft/lbs.
- Shock upper: 21 ft/lbs.
- Shock lower: 66 ft/lbs.
Install the debris shield on the BP-51 rear shock by taking the two yellow plastic clips and placing them around the bottom portion of the shock. Then slide the debris shield over the plastic holders.
Start by holding the new BP-51 shock in place and threading it on the top nut. Only the nut and flat washer go on top of the shock mount.
Note that the rear shocks are side specific. The front-facing debris deflector is different for the driver’s side, which is mounted on the front of the rear axle, and the passenger’s, which is mounted on the back side of the rear axle.
Make sure to keep the order of the rubber grommets on top of the shock assembly. Don’t install the lower shock bolt yet.
Now, maneuver the rear spring pack into place, ensuring that the arrow on the spring is facing forward. Get a helper; the leaf pack is heavy.
Install the forward bolt first and torque it to 77 ft/lbs. Next, install the shackle making sure that the bends on each side of the shackle match and are opposing. Finally, install the top bolt and nuts with washers provided by OME. Make sure that the greaseable end of the bolt faces the outside and tighten each side evenly so that the same amount of threads showing past the bolt are even.
Now install the lower shackle bolt and nuts and tighten to 77 ft/lbs. You may need to raise or lower the rear diff slightly to align the shackle with the leaf. Install the grease nipple with an 8mm socket.
With the leaf pack bolted into place, it’s now time to install the U-bolts. The bottom side of the leaf pack has a centering bolt. This bolt centers the leaves together and positions the axle fore/aft on the spring. If the axle hole and spring centering stud do not line up perfectly, you can use a ratchet strap to move the axle into place. Place the new OME U-bolts over the spring pack and through the original lower axle bracket. Install the new washer and buts provided by OME. Tighten the U-bolt evenly in an X-pattern and torque to 74 ft/lbs.
Now install the lower shock bolt, washer, and nut and torque to 66 ft/lbs. Once again, you may need to raise or lower the differential to align the holes.
Install the rear reservoir bracket with the supplied bolts and 10mm nuts, and then attach the remote reservoir with the same technique as the front reservoirs.
Adjust the compression and rebound damping to your liking. Per the chart above (beginning of post), OME recommends setting 4-8 on compression and 6-10 for the rebound for my truck. I found their recommended settings to be quite good.
Tip: Place a Philips screwdriver in the hole on the top side of the shock assembly to give yourself leverage when adjusting the compression and rebound collars.
Please note: ARB recommends that you notch the frame where the reservoir exits the shock body (by the beginning of the line/fitting). With regular driving, there shouldn’t be any issues, but with harder off-road use, there is potential for contact which could ultimately result in damage that would cause fluid to leak.
Reattach the brake line support bracket under the leaf-pack using the factory 12mm bolt and torque to 22 ft/lbs.
Duplicate for the other side.
Step 7. Install Brake Line Riser
On the top side of the rear differential is the brake line yoke. Use the OME-supplied riser and bolt to increase the height to compensate for the lift.
Final Step: Get an alignment.
I took my truck to my local Toyota dealer for an alignment. The truck only needed slight adjustments to bring it back to spec.
But how does it ride? That’s the most important question, right? Simply put, it’s amazing. The stock suspension was very soft, with lots of sway and body roll in turns. It also tended to pogo, meaning it would bounce too far or too hard back in its return stroke and bounce around before settling back to a normal state. The Old Man Emu BP-51 kit is dead steady.
It eats big hits with ease, and little bumps are almost undetectable. Cornering is also substantially better. Heavy washboard roads feel like gravel roads. It’s very stable at speed. I’d like to congratulate the Old Man Emu engineering team for delivering such an amazing product!
I live in Sheridan, WY, and spend a lot of time in the Big Horn Mountains. My first trip up our main access road to National Forrest with the Old Man Emu BP-51 kit was eye-opening. The ride up felt like going from a go-kart to a decked-out high-performance side by side.
Towing a trailer is much better now compared to the factory suspension. I pulled an 18′ enclosed trailer full of motorcycles to Moab, UT. The rear of my truck no longer looked like a scrawny kid trying to bench press 350 lbs. Before, hooking up the empty trailer would substantially weigh down the rear. The add-a-leaf was a good decision for me.
I am very happy to report that I gained 2″ of lift in the front and 5″ in the rear. I was initially in a bit of disbelief. This was a 3″ lift kit. The factory Toyota TRD Pro suspension is a 2″ front lift with zero lift in the rear.
Factoring in the weight I have added to the rig and the visible sagging in the rear before the Old Man Emu BP-51 kit, it makes sense that I gained 2″ in the front and a full 5″ in the rear. I was sagging a whole 2″ in the rear prior. The truck’s stance is much better now; the rear looks aggressive but not too tall. The BP-51 components look fantastic and I could not be happier with the results.
The only downside is that now with the 5″ of lift in the rear, I will need bigger tires. Old Man Emu’s BP-51 kit really is impressive; the bypass valve technology truly works. From high-speed dirt road blasting to slow rock crawling, the truck feels more confident, faster, and smoother simultaneously. I only wish I had added the kit sooner! I’ll report back with a long-term review, but the first month has been amazing with no issues! Looking forward to diving deeper into the kit and dialing in the compression and rebound adjustments.