Motor Mount Write Up


Since I haven’t seen a very good DETAILED write up on how to do polyurethane motor mounts I thought I might guide you through hell. I mean… the install

First of all I suggest you do motor mounts at the same time you do headers, believe me when I say you will be sorry if you don’t!

That being said lets get started.

You will need:

- 15mm socket (short & deep)
- 13mm socket (short & deep)
- 18mm socket (short or deep)
- Various extensions
- A pivoting U-joint elbow helps A LOT!!
- A 13 mm boxed end wrench
- A few pieces of wood
- A Bigass pry bar (we needed it, you may not)
- A drill with extra batteries (preferably a corded one with some ***** but its up to you)
- A vice (once again we used it, you may not need it)
- Jack (two is safer but we only used one)
- two Jackstands
- A lot of time and patience, it took an estimated 20-25 hours not including breaks to do mine…. But I am slow.


1. Start by getting the car nice and high in the air and support it on jack stands. The higher the better.

2. DISCONNECT THE BATTERY - NO SERIOUSLY DO IT

3. Remove your air lid and mass air flow sensor so you don’t break something when you’re moving the motor around

4. Now you want to either use the same jack to jack up the motor on the oil pan or use another jack if you have it. Put some wood between the head of the jack and the oil pan. Jack it up just a bit to let the motor sit on the jack. Too high and you will start to lift the car by the motor. You don’t want that.

5. The alternator and A/C compressor will need to be moved forwards and out of the way. Don’t do this yet, read on…

6. So you can start by just taking the belts OFF otherwise you end up with a tangled mess.

7. THIS IS AN IMPORTANT STEP! There is a small red wire that feeds into a 4 pin weatherpak connector on the top of the alternator. It is very easy to miss and moving the alternator very far without disconnecting it first WILL rip it clean out of the connector and you’re alternator won’t work! (trust me!!)

8. Now go ahead and take off the 3 – 15mm bolts that connect the alternator and alternator bracket, and move the alternator forward. If you decided not to disconnect the battery you will probably find out why it is important right about now. (lol I did :-p) Also note that the middle bolt is a different length than the other two.

9. Now move to the passenger side and unbolt I believe it is 2-15mm bolts from the bottom side and like 3 or 4 - 15mm bolts from the top side and move the bracket and compressor as far forward as possible. Try to rest it on the sway bar works the best.

10. Now if you have headers or manifolds on the car still I strongly recommend that you at least disconnect the driver’s side header/manifold from the head to allow for more room to work. Remove it completely if its not too much hassle. The passenger’s side is no big deal really.

11. Now you can probably see the motor mounts pretty well and see how they work. 4 -13 mm bolts attach the clamshell holding the mounts to the motor those slide inside the pedestals and a big 18mm bolt slides through the mount and the pedestal to connect them.

12. You want to go ahead and get that 18mm bolt out. Once you get the nut off the one end you may have trouble getting the bolt out. This might require you to jack the motor up a bit or let it down a bit to get it out.

13. Once you have the 18 mm bolts out the motor is no longer connected to the car! You can jack the motor up pretty high. But be careful of the power steering hose coming off the reservoir. It is not very long and I managed to pop it off from jacking up the motor too high and made a big F’ing mess. So go ahead and jack it up nice n high. Other write ups said the intake manifold hit the cowl. But I had about 1 ½” of clearance there.

14. Ok now the fun part! Now you have to get the clamshells off the motor. Honestly I couldn’t get a damned socket on any but one bolt. I loosened them almost completely with a boxed end wrench (which took forever). Try spraying them with some penetrating oil to help break them loose a little easier since that was the hardest part for me. Also for some reason the drivers side bolts have another stupid thread on top of them that prevents you from getting a short socket on them which would really make everything a lot easier.

15. Now 600 hours later you got the clamshell loose from the motor. Pivot it around a little bit to get it out.

16. Once you have both sides out go ahead and drill out the 5 rivets.

17. Once you have the clamshell cracked open you can get the old mounts out fairly easily and put the new ones in. Make sure you follow the directions for the new mounts about their orientation because it DOES MATTER. We had to put the clamshell and the new poly mounts in a vice together to get them to fit because damn it was a tight fit!!

18. Bolt the clamshells back together and use some locktite if the mounts didn’t come with those goofy nylon threaded nuts.

19. Now bolt the mounts back onto the motor and make sure the tab is facing the top side of the motor. Facing UP!

20. Now here comes the tricky part. Lower the motor back down and line up the holes for the mounts and the pedestal. We had A LOT of trouble with this but I could see you could just get lucky. I recommend trying to line BOTH sides up before putting the 18mm bolts back in. This is where our prybar came into play. We had to pry the motor left and right and up and down a bit to line everything up.

21. Now you have your motor reconnected to the car you can go ahead and lower it and put that jack back under the K-Member for safety

22. Now go ahead and the A/C compressor and bracket back and the alternator and bracket back. Put your belts back on. Don’t forget to reconnect the battery and plug in that little bastard alternator wire. Reconnect the headers/manifolds if you disconnected them and anything else you may have decided you needed to remove.

23. Fire it up , watch your engine not rock all over the damned place anymore and relax.

Let me know if there is anything thats inaccurate or I maybe left out. Hope this helps someone!

 

Excellent- i still just wanna wing it and weld my block to the k-member lol

 

heh good luck welding aluminum to just about any other metal :-p.

But if I had to do it all over again and the price was the same, I'd probably do solids

 

Nice write-up. Do you notice a difference inside the cabin?

 

Yea I feel the motor alot more just cruising now and it moves around alot less when you go WOT. But I have read that alot of the vibrations I am feeling in the cabin while driving are just due to the fact that the mounts need to break in a little bit.

 

I love my ratchet wrenches.

 

did they stop your y pipe from banging?

 

It depends on how much your y-pipe moves in relation to its position in the floor board. It surely reduces the ability of the engine to tweak the y-pipe thus making it less likely to hit the floorboard. Some people get complete alleviation of their y-pipe banging, some don't, just depends on the relationship of the pipe to the area it comes in contact with.

 

Great job, very informative, sticky material.

 

I did a poly torque arm brushing and a trans mount and all banging under the car went away...

 

No it didn't but after readjusting my Mufflex Y hangar it doesnt bang anymore. It just moved way too much before for the hangar to be effective. Now that the pipe moves much less the hangar can do its job properly.

 

The Prothane Poly's Cured my ills. I did it as an afterthought because I did not know that underbangin was more common than most people expect. It should be freakin mandatory to intall these puppies or solid mounts(depending on your preference) when droppin headers + Y just to avoid the the damn headache of havin to do them after all your stuff is mounted . No freakin room to move. Great post dude. Much needed!

 

Who makes solid mounts? I have ran them in the past on a few cars and do not find them to be to hard to live with.

 

Spohn makes some http://www.ls1speed.com/catagory.cfm...%20/%20Chassis

Speed PN SP992

 

good to hear it's not banging anymore, now you can enjoy driving your car without the annoying banging.

 

Wow! $145 for solid mounts really makes me miss the $25 small & big block solid mounts ($5 to $10 at swap meets).
Thanks for the link but I am going to have to wait on that one.

 

Yea the price is what deterred me too, the poly mounts being as hard as they are I can't see solid mounts being much worse. I was going to do solid mounts but I'm not gunna pay almost 3 times as much as I would for poly's

 

Now we need to talk jrp into adding it to his FAQ's

 

Sweet I would be honored

 

Bring this TTT......

How far off were the holes in the motor mounts from the ones in the K-member pedestal?