Tips on motor mounts?

[Incommando]

'91 4.0 auto. Anything that I need to watch for when I tear into it? Thanks

[ARareBreed]

Break the bolts loose first, support the engine by separating the weight evenly (wood plank on the oil pan), remove the mounts.

[johnj92131]

Do you have one of these engine support bars from Harbor Freight or something like it?

 

http://www.harborfreight.com/1000-lb-capacity-engine-support-bar-96524.html

 

Should be easier than trying to hold the engine up from below.

[SBpunk]

Go with factory replacements if you can find them. I used brown dog awhile back and they were insanely stiff. I could feel every vibration in my jeep. Swapped to MOPAR and everything went back to normal. Driver side is easy if I remember correctly. Passenger side... not so much. Still on a scale from 1 to 10 its only about a 4. Just make sure you use locktite on the bolts.

[Incommando]

I was planning on using an engine hoist

[johnj92131]

I was planning on using an engine hoist

Good.

[gogmorgo]

Fun fact, quick tip, whatever you want to call it, the nuts off the motor mount through bolts (the long horizontal ones) match the head studs, and work great for bolting on a chain to hoist the engine.

[Skorpyo]

The oil filter adapter will have to come off to get the passenger side mount bolt out. Get a spare o-ring for that while you're at it. I just installed brown dogs in mine, but this is my first experience with them so we'll see if they're to my liking.

 

Good luck!

[gogmorgo]

^^^This wasn't an issue for me :dunno:

[Skorpyo]

Hmmm, Might be a renix vs non renix issue, just a heads up.

 

 

Sent from my iPhone using Tapatalk

[DirtyComanche]

Even on a Renix you shouldn't need to pull the oil filter adapter off, but if the bolt has never been flipped around and shortened you will have to pull the filter...

[MeanLemons]

Hmmm, Might be a renix vs non renix issue, just a heads up.

 

 

Sent from my iPhone using Tapatalk

i recently pulled the motor out of my 91 mj. The passenger side mount bolt couldn't come out due to hitting the oil filter adapter, so I just unbolted the bottom two nuts of the mount. Definitely not a renix thing

[Incommando]

Thanks for the tips.

[Jeep Driver]

On the subject of engine mounts-

 

I had already gone through 2 sets of aftermarket mounts, so, I decided to order Brown Dog mounts. Once installed, the vibration was intolerable. I also had another problem to resolve, I needed to lower the engine to gain room for the CAI (carb hat).

 

Some time ago there as a guy looking for mounts for a '98 XJ, Euro-diesel IIRC, the mount inserts were similar to those pictured below, that gave me the idea of looking around. 

 

NAPA has a counter book with about 100 different mount inserts, I chose the off-set mounts, this allowed me lower the engine about 7/8". 

 

If you have the ability to make your own, I highly recommend it. I now have virtually no engine torque-roll movement and the vibes are no more than you would expect with any late model car or truck. 

 

 

 

 

 

 

 

 

 

 

And yeah, on the 2.5, the oil filter has to come off to get the bolt out.

[Incommando]

Really nice work

[Dzimm]

Just curious what brown dog mounts people are hating. Is it the rubber mounts or the Poly mounts? I've never heard a bad thing about them until reading this thread. The brown dog website states the Poly ones cause more vibes and that's why I opted for the rubber ones. I have yet to try them out. I'm just hoping they aren't bad.

 

Edit: also their website says that if you over tighten the bushing it will cause vibes too.

[Jeep Driver]

Just curious what brown dog mounts people are hating. Is it the rubber mounts or the Poly mounts? I've never heard a bad thing about them until reading this thread. The brown dog website states the Poly ones cause more vibes and that's why I opted for the rubber ones. I have yet to try them out. I'm just hoping they aren't bad.

 

Edit: also their website says that if you over tighten the bushing it will cause vibes too.

 

 

I had the poly. It was not necessarily the physical vibration, that I could have lived with, it was the reverberation of every part of the truck, the sound was horrific.

[88whitemanche]

Nice mounts!

Those bushings look like the late model 97+ Xj 2.5 bushings

Stupid clean engine bay as usual by the way...

[cerial]

Ask around for part outs. I know a few people that part out jeeps and managed to snag a pair of newish mounts and new bolts for $40.

 

Get a long extension for removing the drivers side mount bolt and exhaust bolts from under the jeep.

Impact sockets and an impact will make this job tons easier.

If you have a floor jack you can remove the transmission cross member(after setting one side of driveshafts on the floor) and drop it down a few inches which will let you move the engine slightly higher for more room.

 

Take a rag to the engine block/frame while the mounts are off.

Buy new hardware and clean your threads.

Great time to replace your oil pan gasket if it is leaking.

[big66440]

Just curious what brown dog mounts people are hating. Is it the rubber mounts or the Poly mounts? I've never heard a bad thing about them until reading this thread. The brown dog website states the Poly ones cause more vibes and that's why I opted for the rubber ones. I have yet to try them out. I'm just hoping they aren't bad.

 

Edit: also their website says that if you over tighten the bushing it will cause vibes too.

I've been running my Brown dogs (rubber mounts) for about a year and a half, you will feel/hear  more of a "humming"  at idle because of the stiffer rubber. I don't mind it so much since it reminds me of my old muscle cars :D ,It's a personal preference thing.

[Dzimm]

 

Just curious what brown dog mounts people are hating. Is it the rubber mounts or the Poly mounts? I've never heard a bad thing about them until reading this thread. The brown dog website states the Poly ones cause more vibes and that's why I opted for the rubber ones. I have yet to try them out. I'm just hoping they aren't bad.

 

Edit: also their website says that if you over tighten the bushing it will cause vibes too.

I've been running my Brown dogs (rubber mounts) for about a year and a half, you will feel/hear more of a "humming" at idle because of the stiffer rubber. I don't mind it so much since it reminds me of my old muscle cars :D ,It's a personal preference thing.

OK that's good to hear. All you hear from people who don't like them are that it shakes so much you bounce around in the seat and parts fall off as you go down the road. I figured it wasn't too bad.

 

Sent from my HTC6525LVW using Tapatalk

[gogmorgo]

That's also the difference between poly mounts and rubber.

[big66440]

 

 

Just curious what brown dog mounts people are hating. Is it the rubber mounts or the Poly mounts? I've never heard a bad thing about them until reading this thread. The brown dog website states the Poly ones cause more vibes and that's why I opted for the rubber ones. I have yet to try them out. I'm just hoping they aren't bad.

 

Edit: also their website says that if you over tighten the bushing it will cause vibes too.

I've been running my Brown dogs (rubber mounts) for about a year and a half, you will feel/hear more of a "humming" at idle because of the stiffer rubber. I don't mind it so much since it reminds me of my old muscle cars :D ,It's a personal preference thing.

OK that's good to hear. All you hear from people who don't like them are that it shakes so much you bounce around in the seat and parts fall off as you go down the road. I figured it wasn't too bad.

 

Sent from my HTC6525LVW using Tapatalk

 

The tuning  on your engine has A LOT to do with it.

[cody4359]

I too have brown dog rubber mounts, top notch company with amazing customer service imo. I had a bit of an issue right off the bat with more vibration than I'd like, had to loosen the bolts a smidge and all is well. I have thought about going to oem just to see if there would be a difference

 

Sent from my SM-G900V using Tapatalk

[johnj92131]

That's also the difference between poly mounts and rubber.

 

Poly bushings etc also tend to have a higher durometer reading than natural rubber bushings.  That durometer reating translates to more noise, vibration harshness tranmission.  A lower durometer reading means a softer, more compliant bushing and less noise vibration harshness transmission.

 

But Poly bushing can come  with higher or lower durometer readings, Just like natural rubber can. But Poly bushings tend to be higher in durometer readings than natural rubber in general.

 

Poly bushing have a longer lifespan than natural rubber bushings. 

 

I suspect BrownDog uses very high durometer reading Poly bushings, simply because of the many, many comments about the noise, vibration, and harshness they transmit.