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Woodpecker Trail near Florence, Arizona

Frequently Asked Questions.
The basics.
Why Brown Dog motor mounts?
What is the bushing material like?
Do your motor mounts have the stud on the inboard side?
Do you make engine brackets (plates) that work with aftermarket headers?
Where are Brown Dog products tested?
 
Vibration and motor mounts.
Is it true high performance motor mounts transmit more engine vibration? 
May I experience more noticeable vibration when these are properly installed?
Any other pointers for reducing vibration when upgrading?
 
A few words about MMLs. 
Does a body lift (BL) require motor mount lifts (MML)?
How can a MML correct Drive Line Angle issues?
How much lift is needed to get rid of driveline vibration?
Do I need the rare 2" MML?


The basics.
 
Why Brown Dog motor mounts?
One reason: They are engineered to take the abuse of extreme driving. If a weld doesn't hold -- and every joint is double-welded -- we'll replace them for no charge.
If you happen to break the plate steel, we congratulate you for doing something no one else has done. We also want action photos, because it must have been amazing! Then call us so we can get another one on it's way. See our life-time warranty for details.
 
Any other reasons to buy Brown Dog products?
  • Made in USA. Not just final assembly, either. All the bushings are made here. Everything is engineered, cut, cleaned, welded, baked, assembled and packaged in the USA. And we're proud of it.
  • $6.00 Shipping. All products. Any USA state, territory, or APO/FPO/DPO (military) address. (Hawaii and Alaska, we learned early in life you're part of the USA. Thus, you get $6.00 shipping, too!) No handling fee. Ever.
  • Grade 8 (10.9 metric) hardware included, no extra charge.
  • More steel and double-welded when feasible.
  • Straight forward installation. Everything bolts on or in. No grinding. Modification is very, very rare. (We'd say never, but we haven't seen every vehicle made by Jeep that's still running.)
  • Choice of rubber or polyurethane bushings.
  • Extended hours and weekend technical assistance.
  • Backed by life-time warranty.
What is the bushing material like?
We now offer a choice. Select Ultra-Flex Rubber motor mounts and motor mount lifts to better absorb some drive-line vibration. Select Classic Polyurethane to give your rig a sportier feel.  To learn more about the difference between our Ultra-Flex Rubber and Classic Polyurethane bushings, click here.
 
Do your motor mounts have a stud on the inboard side like the originals?
Yes, there is a built-in Grade 10.9 (metric equivalent to Grade 8) hardness stud; these motor mounts bolt-in just like the originals. 
 
Do you make engine brackets (plates) that work with aftermarket headers?
Yes, every Brown Dog driver side engine bracket is compatible with after-market headers. Simply order the correct engine bracket for your vehicle year and engine.
 
Where are Brown Dog products tested?
Some of the toughest trails Arizona can dish out. (Yeah, we know about Utah, but we can't stand the cold.) We also periodically apply the
20-Ton Press Test just to test motor mount's integrity. So if you're on the trails in Arizona,
watch for the Yellow 1991 Wrangler YJ. The Brown Dog is getting on in years, so he doesn't go wheeling much anymore.  You'll most likely see us around Florence, AZ.
 
 

Vibration and motor mounts. 
Is it true high performance motor mounts transmit more engine vibration? 
Stock mounts were totally designed for vibration dampening. In fact, some OE parts catalogs list the part name as vibration dampeners or isolators. Any time you go to more steel and less absorbitive material, you can expect some vibration to be transmitted; this is especially true in uni-body vehicles like the Jeep Cherokee XJ (the body is your frame). Generally, the 2.5L (4-cylinder) engine is more likely to transmit vibration than the 4.0L (6-cylinder) engines, which transmit little if any.
 
May I experience more noticeable vibration from Brown Dog motor mounts when properly installed?
Brown Dog high performance motor mounts (MM) and motor mount lifts (MML) for Jeep are designed differently than others; we believe less engine vibration is transmitted by our mounts than by other performance motor mounts. In addition to design differences, following Brown Dog installation instructions (including torque and tightening instructions) is very important to minimizing vibration. 
 
Any other pointers for reducing vibration?
First, double-check to be sure torque and other tightening instructions were carefully followed when installing Brown Dog high performance Jeep motor mounts (MM) or motor mount lifts (MML).
 
Second, be sure your transmission mount is in good condition and properly installed. In testing, we found worn out transmission mounts may not be obvious with older stock mounts. However, installation of high performance mounts accentuates the vibration caused by worn-out transmission mounts. We have found drive line vibration caused by a worn or broken transmission mount mistaken for engine vibration when installing new motor mounts. We have demonstrated this in our own tests.

Third, check for a faulty harmonic balancer. This problem can be masked by the original stock mounts. The harmonic balancer on Jeep engines is the front pully on the crankshaft that has the timing mark on it. Go here to read a good explanation of a harmonic balancer: http://en.wikipedia.org/wiki/Harmonic_balancer
 
Fourth, and often major vibration culprit which must be evaluated, is improper driveshaft alignment and pinion angle. If you have installed a suspension lift on your Wrangler, you might consider our 1" or 2" motor mount lifts as a part of your driveshaft/driveline angle solution. Here are a couple excellent articles about this issue:
        1. http://www.4x4wire.com/tech/pinion angle/,
 
Another important thing you can do to eliminate vibration is to install a slip yoke eliminator (SYE). We recommend the Advance Adapter SYE.
 

A few words about Motor Mount Lifts. 

Myth: Body Lifts (BL) require Motor Mount Lifts (MML).

Some people say that a motor mount lift must be used with a body lift; that is a myth.  Motor mount lifts (MML) and body lifts (BL) are not related except that a BL would eliminate the need to re-locate the radiator or fan shroud (also see 2” MML below).  A body lift, on its own, is not a valid reason for a MML.  MMLs can be installed on some Cherokees provided you have checked for adequate space between the bell housing and floor pan, and the engine assembly and the hood.  Usually, the upper radiator hose is the highest point on the engine assembly.

 

Using Motor Mount Lifts to correct Drive Line Angle issues.

Under normal circumstances, motor mount lifts have only one purpose: to help correct driveline angle issues that are causing vibrations and/or u-joint binding.  In fact, installing a MML on a vehicle with no vibration problems, may cause vibration.  Therefore, it's not really possible to calculate which (if any) MML is needed, simply by knowing how much lift is installed on a given vehicle.  The links above do an excellent job of describing the elements of drive line angle. 


How much lift is needed to get rid of driveline vibration?

As stated before, it's nearly impossible to determine if a vehicle is best with a stock-height motor mount or a 1" or 2" MML based on the amount of your suspension lift and/or body lift alone.  
 
Most vehicles that have as much as 4.5” of suspension lift would probably use a stock height or 1” MML (depending on the remainder of the configuration).  A 2” MML has no place in most vehicles.
 
Remember, no MML will correct vibrations caused by a bent shaft, worn u-joints,  or other failed part.  A MML will correct drive line alignment problems. If this is the cause of your vibes, then a MML can be the solution.

 

Do I need the rare 2" MML?

Some abnormal circumstances in which 2" MMLs may be useful include extreme suspension lift, custom frames, custom engine installations, or bodies that require a particular engine position due to an out-of-the-ordinary configuration.  Most typical lifts (up to about six inches) and other common modifications of stock vehicles do not fall in this category.  If you are considering installing a 2" MML,
  • Please check for enough clearance between the bell housing and floor pan.
  • Also check for enough clearance between the valve cover and the hood; this can be done by putting a ball of modeling clay on the highest part of the valve cover and closing the hood (measure the resulting ball). 
  • Remember, you're moving the entire engine assembly 2" upward at the radiator fan.

Still not sure which product is best for you?
Give us a call, 866-401-3877. We want to be sure you get the correct motor mount for your vehicle.