- Joined
- Mar 10, 2005
35 spline chromo shafts, sticky tires, 32 spline output shafts, beadlocks... motor mounts? Some may ask "Why are motor mounts in the same sentence as those other, much-needed items that we all need for successful offroad adventures?" Ask that of anyone who has had a weekend wheeling trip (or ECORS race) cut short because of a busted bellhousing or misguided fan blade in the radiator.
Stock type motor mounts are pretty good at what they are designed to do: control vibration and movement. You see, an engine has external rotational forces that must be controlled. Those forces can cause vibrations and broken parts if not controlled. So what does that have to do with us offroaders? Well, we put our rigs through a bit more than the engineers that designed your vehicles' motor mounts ever dreamed of.
Let me speak about my work experience with OEM motor mounts. I work at a Jeep dealer by day. In my 12+ years there, I have replaced quite a few motor mounts due to wear. They will typically wear to a point of causing an idle vibration. That is when Mr. or Ms. Customer notices a problem. Usually the OEM mounts last well beyond 100,000 miles or more without issue. Now take those OEM mounts on a 4.0 equipped weekend offroad warrior and see how long they last.
This is where my need for better mounts comes in. I have been replacing the motor mounts, especially the passenger side one, in my MJ about every 2-3 months. Now that I think about it, I have an ECORS race about every 2-3 months...Hmm? No big deal, right? Takes 30 minutes to replace one and about $20. That's true, but what about when that broken motor mount causes the fan to get frisky with the radiator? Or when the alternator on your XJ starts to use the passenger frame rail as a path to ground until a small fire is generated? Or when you've spent a ton of money on a race rig that is sitting out the last 9 laps of a race due to a busted mount and other collateral damage? Enter Brown Dog Offroad.
Brown Dog Offroad is the leader in super high performance motor mounts and brackets for your Jeep. Sure, some other companies make some great OEM type replacement mounts. But then you are still stuck with three 3/8" x 1.25" bolts on each side holding your engine to your frame. That's just not enough.
I contacted Tim at Brown Dog Offroad to see what he could do to keep my MJ going strong at each ECORS race. About a week later I had a box full of goodies ready to install on my MJ.
Tool list:
Here\'s what was in the box. 2 mounts, 2 block brackets and well labeled packets with hardware. Also included in awesome, easy to understand instructions with pictures.
Here\'s the driver side MM bracket. The factory piece bolts to the block with three 3/8\" bolts. You can see that this one utilizes seven bolts. This speads the load out much more effectively. The passenger side is similar aside from different mounting holes.
Well, I hope you wanted a quality, beefy motor mount, cause you got one. I spec\'d mine with poly bushings. You can choose between poly, rubber or ultra flex rubber.
OK, let's remove the old motor mounts. Grab your shop manual or just follow my lead. Unhook the negative battery cable. Then place a floor jack under the oil pan with a block of wood between the jack plate and pan. Lightly support the oil pan until it just barely begins to lift. Go ahead and loosen the tranny mount hardware, but don't remove it. Loosen the motor mount through-bolts. These will be 18mm on each side. Loosen the 15mm nuts and bolts that bolt the motor mount to the frame. Continue to lift the engine by the oil pan until the motor mount is loose from the frame. Go ahead and remove the through bolts and finally remove the mounts.
Go ahead and remove the MM brackets that bolt to the block now. These will require a 9/16 socket to remove. Each side of the engine will have a bracket. They are secured with three 3/8" bolts on each side. Unbolt and remove from the Jeep.
I removed my 1 race old, 35 mile old, beat to death OEM replacement mounts. Here is what they looked like. Never again.
Now, as per the instructions you will install the driver\'s side BDO MM bracket first. The instructions indicate where each bolt goes and it\'s torque spec too. This will be a great time to chase the threads in the block if have a chaser. You\'ll need a 3/8\'\' course and 5/16\'\' course thread chaser for this. I didn\'t need to, but if you have mud and grime in your block, you may. This is where you see the awesomeness of the BDO kit. What used to be held with 3 bolts, now uses 7 bolts. Torque each one to spec and move on to the passenger\'s side.
This pic shows the difference in the OEM driver side bracket and the BDO bracket
Passenger side. Which one would you place more faith in?
Repeat the BDO MM bracket install on the passenger's side. Torque the hardware to spec.
Now go ahead and drop the BDO motor mounts into the brackets and install the provides through bolts. Next you will lower the floor jack until the BDO motor mounts rest on the frame rails. Go ahead and torque the MM to frame bolts and the MM through bolts to spec. Be careful not to overtighten the provided hardware.
There you have it. Unbreakable motor mounts and a permanent solution to broken bolts in your block. The install should take about 2-3 hours.
I'm gonna put them to the test this season in ECORS. My MJ sports a very healthy 4.7 stroker with 108:1 gearing in double low.
Dirty Dog Racing and Brown Dog Offroad coming to a trail near you in 2011.
Jody Treadway
Tech Dude
Stock type motor mounts are pretty good at what they are designed to do: control vibration and movement. You see, an engine has external rotational forces that must be controlled. Those forces can cause vibrations and broken parts if not controlled. So what does that have to do with us offroaders? Well, we put our rigs through a bit more than the engineers that designed your vehicles' motor mounts ever dreamed of.
Let me speak about my work experience with OEM motor mounts. I work at a Jeep dealer by day. In my 12+ years there, I have replaced quite a few motor mounts due to wear. They will typically wear to a point of causing an idle vibration. That is when Mr. or Ms. Customer notices a problem. Usually the OEM mounts last well beyond 100,000 miles or more without issue. Now take those OEM mounts on a 4.0 equipped weekend offroad warrior and see how long they last.
This is where my need for better mounts comes in. I have been replacing the motor mounts, especially the passenger side one, in my MJ about every 2-3 months. Now that I think about it, I have an ECORS race about every 2-3 months...Hmm? No big deal, right? Takes 30 minutes to replace one and about $20. That's true, but what about when that broken motor mount causes the fan to get frisky with the radiator? Or when the alternator on your XJ starts to use the passenger frame rail as a path to ground until a small fire is generated? Or when you've spent a ton of money on a race rig that is sitting out the last 9 laps of a race due to a busted mount and other collateral damage? Enter Brown Dog Offroad.Brown Dog Offroad is the leader in super high performance motor mounts and brackets for your Jeep. Sure, some other companies make some great OEM type replacement mounts. But then you are still stuck with three 3/8" x 1.25" bolts on each side holding your engine to your frame. That's just not enough.
I contacted Tim at Brown Dog Offroad to see what he could do to keep my MJ going strong at each ECORS race. About a week later I had a box full of goodies ready to install on my MJ.
Tool list:
- floor jack
- small piece of 2x4 wood
- basic hand tools
- thread chasers in the 3/8" course and 5/16" course flavor(maybe)
Here\'s what was in the box. 2 mounts, 2 block brackets and well labeled packets with hardware. Also included in awesome, easy to understand instructions with pictures.
Here\'s the driver side MM bracket. The factory piece bolts to the block with three 3/8\" bolts. You can see that this one utilizes seven bolts. This speads the load out much more effectively. The passenger side is similar aside from different mounting holes.
Well, I hope you wanted a quality, beefy motor mount, cause you got one. I spec\'d mine with poly bushings. You can choose between poly, rubber or ultra flex rubber.
OK, let's remove the old motor mounts. Grab your shop manual or just follow my lead. Unhook the negative battery cable. Then place a floor jack under the oil pan with a block of wood between the jack plate and pan. Lightly support the oil pan until it just barely begins to lift. Go ahead and loosen the tranny mount hardware, but don't remove it. Loosen the motor mount through-bolts. These will be 18mm on each side. Loosen the 15mm nuts and bolts that bolt the motor mount to the frame. Continue to lift the engine by the oil pan until the motor mount is loose from the frame. Go ahead and remove the through bolts and finally remove the mounts.
Go ahead and remove the MM brackets that bolt to the block now. These will require a 9/16 socket to remove. Each side of the engine will have a bracket. They are secured with three 3/8" bolts on each side. Unbolt and remove from the Jeep.
I removed my 1 race old, 35 mile old, beat to death OEM replacement mounts. Here is what they looked like. Never again.
Now, as per the instructions you will install the driver\'s side BDO MM bracket first. The instructions indicate where each bolt goes and it\'s torque spec too. This will be a great time to chase the threads in the block if have a chaser. You\'ll need a 3/8\'\' course and 5/16\'\' course thread chaser for this. I didn\'t need to, but if you have mud and grime in your block, you may. This is where you see the awesomeness of the BDO kit. What used to be held with 3 bolts, now uses 7 bolts. Torque each one to spec and move on to the passenger\'s side.
This pic shows the difference in the OEM driver side bracket and the BDO bracket
Passenger side. Which one would you place more faith in?
Repeat the BDO MM bracket install on the passenger's side. Torque the hardware to spec.
Now go ahead and drop the BDO motor mounts into the brackets and install the provides through bolts. Next you will lower the floor jack until the BDO motor mounts rest on the frame rails. Go ahead and torque the MM to frame bolts and the MM through bolts to spec. Be careful not to overtighten the provided hardware.
There you have it. Unbreakable motor mounts and a permanent solution to broken bolts in your block. The install should take about 2-3 hours.
I'm gonna put them to the test this season in ECORS. My MJ sports a very healthy 4.7 stroker with 108:1 gearing in double low.
Dirty Dog Racing and Brown Dog Offroad coming to a trail near you in 2011.
Jody Treadway
Tech Dude