I original found this article on 4x4xplor.com and decided to post it here so TJ owners might be able to find it easier. I take no credit for this article, just sharing it with other TJ owners!
If you've just lifted your Jeep 3" or more, you will most likely experience vibrations coming from your driveline. The cheap way to fix this is problem is to add a transfer case drop and the best way to fix it is to install a Slip Yoke Eliminator & CV driveshaft. However, there is a solution somewhere in between the two and that is to install a 1" motor mount lift.
A motor mount lift (also know as an MML) will help to straighten out your driveline the way a transfer case drop would except you don't have to sacrifice any clearance under your Jeep.... you know, the same clearance you just paid a bundle lift higher. Anyway, a high quality MML like M.O.R.E.(Mountain Off Road Enterprises) makes will set you back about $120 and you will need to install a 1" body lift if you don't already have one (approx. $70), but it's still cheaper than an SYE/CV. I decided to get M.O.R.E.'s Bombproof motor mounts because they are made torsion rubber bushings. Unlike polyurethane bushings (like most other manufacturers use), torsion rubber is very durable but still behaves like traditional rubber (i.e. no engine vibes).
For those out there who think installing an MML is a good idea when doing a body lift, all I can say is this. If you don't have any vibes, you don't need an MML and it certainly isn't a better solution then relocating your fan shroud. Trust me, I have done both. Relocate fan shroud = 10 minutes and it's a piece of cake install. MML install = 2 hours of moderate to hard work. You do the math.
What You Will Need
Installation
BEFORE YOU START:
It is important that you have a 1" body lift already installed on your Jeep before you install a 1" motor mount lift.
1. Park your Jeep on a level surface, put it into gear, engage the parking brake and chock your rear tires for good measure. If you live in a rust region, hose the underside of your Jeep good and then spray the bolts you will be removing with some PB Blaster.
2. Open your hood, pop off the hood lamp and turn it upside down so that it doesn't stay on draining your battery while you do this install.
3. Remove your radiator overflow bottle and disconnect the hose from the radiator cap. This bottle is snapped into place by a round button tab about half way down the bottle and you may need to push on it a bit while pulling to get it free.
4. Remove the bolts holding your radiator fan shroud to the radiator and just let it hang on the fan.
5. Remove the four nuts attaching your transmission mount to your skidplate.
6. Now, place a floor jack underneath the front edge of your bell housing and then jack it up just a bit applying a slight amount of pressure. You can also jack from underneath your oilpan but make sure to use a block of wood in between to help distribute the load.
7. Loosen, but DO NOT REMOVE the thru-bolt, the bracket bolt on top and the bracket stud nut on the bottom of your passenger side motor mount. A long ratchet extension will make this job a lot easier.
8. Now, if you have AC like me, start on the driverside motor mount by removing the bracket bolt on top and the bracket stud nut underneath. Then, remove the three bolts securing the bracket to your engine block (see pic to the right). If you don't have AC, all you need to do is remove the thru-bolt.
9. Jack up your engine a little higher now and then pull the entire motor mount and engine bracket out from under your Jeep.
10. With everything out from under your Jeep, remove the thru-bolt and then swap in your new M.O.R.E. motor mount. Re-attach the thru-bolt and tighten but do not torque it down at this time (See pic to the right).
11. Climb back under your Jeep, slip your driverside motor mount on top of your frame bracket with the stud coming through (slowly jack engine up higher if required). Make sure to loosely attach the bracket bolt on top and bracket stud nut underneath so you can maneuver the whole thing around.
12. Now, re-attach the engine bracket back onto the block using the three bolts you had removed earlier and then tighten them to the appropriate torque specs.
13. The passenger side motor mount is a heck of a lot easier to deal with. Simply remove the thru-bolt, the top bracket bolt, the bracket stud nut underneath and then swap in your new M.O.R.E. motor mount.
14. Re-attach the top bracket bolt, bracket stud nut and then slip in the thru-bolt. You will most likely need to jack up your engine higher to do this. A pry bar to help shift things around and/or a friend to man the jack really make this part of the job easier.
15. Lower your engine and then go around tightening all the bolts you worked on down to their appropriate torque specs:
17. Fasten your transmission mount back onto your skidplate using the four nuts you removed earlier. Torque these down to 40-45 ft. lbs.
18. Pop your hood light back on and close your hood
That should do the trick. This job took me about 3 hours to install but only because I had to remove an oilpan skidplate before I could begin. Also, taking pictures and talking notes eat up some time too. Please let me know if you have any questions.
This is pic of what you will get. Really heavy duty stuff!
Pop your hood light off and turn it upside down to prevent it from staying on.
Remove your radiator overflow bottle.
Unbolt your fan shroud and let it hang.
Remove the four nuts attaching your transmission mount to your transfer case skidplate.
Loosen but DO NOT REMOVE the motor mount bolts. A long ratchet extension really comes in handy.
Here you can see th driverside OEM motor mount and the new M.O.R.E. mount on the engine bracket.
Here is what the ne M.O.R.E. motor mount looks like installed from underneath the driverside of the Jeep.
The passenger side mount is a piece of cake to work on. Here you can see me removing the throug bolt.
Finishing things up. Once again, a long ratchet extension really makes working on these bolts a lot easier.
Make sure your fan blade rotates freely and does not make contact with the shroud.
As you can see here your transmission will shift a bit after the install.
If you've just lifted your Jeep 3" or more, you will most likely experience vibrations coming from your driveline. The cheap way to fix this is problem is to add a transfer case drop and the best way to fix it is to install a Slip Yoke Eliminator & CV driveshaft. However, there is a solution somewhere in between the two and that is to install a 1" motor mount lift.
A motor mount lift (also know as an MML) will help to straighten out your driveline the way a transfer case drop would except you don't have to sacrifice any clearance under your Jeep.... you know, the same clearance you just paid a bundle lift higher. Anyway, a high quality MML like M.O.R.E.(Mountain Off Road Enterprises) makes will set you back about $120 and you will need to install a 1" body lift if you don't already have one (approx. $70), but it's still cheaper than an SYE/CV. I decided to get M.O.R.E.'s Bombproof motor mounts because they are made torsion rubber bushings. Unlike polyurethane bushings (like most other manufacturers use), torsion rubber is very durable but still behaves like traditional rubber (i.e. no engine vibes).
For those out there who think installing an MML is a good idea when doing a body lift, all I can say is this. If you don't have any vibes, you don't need an MML and it certainly isn't a better solution then relocating your fan shroud. Trust me, I have done both. Relocate fan shroud = 10 minutes and it's a piece of cake install. MML install = 2 hours of moderate to hard work. You do the math.
What You Will Need
- M.O.R.E. 1" Motor Mounts - Part # JM600L
- Sockets/Wrenches: 7/16", 13mm, 15mm, 18mm
- Ratchet
- Torque Wrench
- Ratchet Extension (12" or longer)
- Floor Jack or OEM Bottle Jack is Ok
- Wheel Chocks
- Pry Bar
- Block of Wood
- PB Blaster
Installation
BEFORE YOU START:
It is important that you have a 1" body lift already installed on your Jeep before you install a 1" motor mount lift.
1. Park your Jeep on a level surface, put it into gear, engage the parking brake and chock your rear tires for good measure. If you live in a rust region, hose the underside of your Jeep good and then spray the bolts you will be removing with some PB Blaster.
2. Open your hood, pop off the hood lamp and turn it upside down so that it doesn't stay on draining your battery while you do this install.
3. Remove your radiator overflow bottle and disconnect the hose from the radiator cap. This bottle is snapped into place by a round button tab about half way down the bottle and you may need to push on it a bit while pulling to get it free.
4. Remove the bolts holding your radiator fan shroud to the radiator and just let it hang on the fan.
5. Remove the four nuts attaching your transmission mount to your skidplate.
6. Now, place a floor jack underneath the front edge of your bell housing and then jack it up just a bit applying a slight amount of pressure. You can also jack from underneath your oilpan but make sure to use a block of wood in between to help distribute the load.
7. Loosen, but DO NOT REMOVE the thru-bolt, the bracket bolt on top and the bracket stud nut on the bottom of your passenger side motor mount. A long ratchet extension will make this job a lot easier.
8. Now, if you have AC like me, start on the driverside motor mount by removing the bracket bolt on top and the bracket stud nut underneath. Then, remove the three bolts securing the bracket to your engine block (see pic to the right). If you don't have AC, all you need to do is remove the thru-bolt.
9. Jack up your engine a little higher now and then pull the entire motor mount and engine bracket out from under your Jeep.
10. With everything out from under your Jeep, remove the thru-bolt and then swap in your new M.O.R.E. motor mount. Re-attach the thru-bolt and tighten but do not torque it down at this time (See pic to the right).
11. Climb back under your Jeep, slip your driverside motor mount on top of your frame bracket with the stud coming through (slowly jack engine up higher if required). Make sure to loosely attach the bracket bolt on top and bracket stud nut underneath so you can maneuver the whole thing around.
12. Now, re-attach the engine bracket back onto the block using the three bolts you had removed earlier and then tighten them to the appropriate torque specs.
13. The passenger side motor mount is a heck of a lot easier to deal with. Simply remove the thru-bolt, the top bracket bolt, the bracket stud nut underneath and then swap in your new M.O.R.E. motor mount.
14. Re-attach the top bracket bolt, bracket stud nut and then slip in the thru-bolt. You will most likely need to jack up your engine higher to do this. A pry bar to help shift things around and/or a friend to man the jack really make this part of the job easier.
15. Lower your engine and then go around tightening all the bolts you worked on down to their appropriate torque specs:
- Thru-Bolts = 48 ft. lb.
- Bracket Bolts = 40 ft. lb.
- Bracket Stud Nuts = 30 ft. lb.
17. Fasten your transmission mount back onto your skidplate using the four nuts you removed earlier. Torque these down to 40-45 ft. lbs.
18. Pop your hood light back on and close your hood
That should do the trick. This job took me about 3 hours to install but only because I had to remove an oilpan skidplate before I could begin. Also, taking pictures and talking notes eat up some time too. Please let me know if you have any questions.
This is pic of what you will get. Really heavy duty stuff!
Pop your hood light off and turn it upside down to prevent it from staying on.
Remove your radiator overflow bottle.
Unbolt your fan shroud and let it hang.
Remove the four nuts attaching your transmission mount to your transfer case skidplate.
Loosen but DO NOT REMOVE the motor mount bolts. A long ratchet extension really comes in handy.
Here you can see th driverside OEM motor mount and the new M.O.R.E. mount on the engine bracket.
Here is what the ne M.O.R.E. motor mount looks like installed from underneath the driverside of the Jeep.
The passenger side mount is a piece of cake to work on. Here you can see me removing the throug bolt.
Finishing things up. Once again, a long ratchet extension really makes working on these bolts a lot easier.
Make sure your fan blade rotates freely and does not make contact with the shroud.
As you can see here your transmission will shift a bit after the install.