looking at some after market moter mounts, saw rustys 1" raised moter mounts with poly bushings. pros/cons of the 1" raise? lmk all thoughts opinions and experiences. anything else id need? or anything to modify? thanks

 

The 1" raise is suppose to take slack away along with drive angles, also they are a great upgrade if you plan to run the ZJ fan which I am running.

According to online no matter what 1" Motor Mounts brand you run you will feel more vibrations due to that stock motor mounts are made to absorb thus causing cracking/failure.

Iron Man Motor Mounts are the best bolt on motor mounts you can buy besides the Brown Dog 300$ complete set.

http://www.ironman4x4fab.com/Products/MM.html

 

Generally, a raised engine mount is there to account for a body lift - you can't do a body lift in an XJ, since it's a unibody.

There may be uses for a slight engine mount lift (as Post #2 mentioned,) but I've not seen them in person (doesn't mean they don't exist, just means I haven't seen them.)

A MML can be used to help correct drive angles, but bear in mind that there's not a lot of room between the top of the engine and the hood on the XJ. I once had failed engine mounts - I could make the hood itself jump (from the engine hitting it) if I jumped on the gas, because the bushings were gone.

I'd use MMLs as a weapon of last resort on the XJ, if I were trying to correct driveline issues (better to use a proper driveshaft anyhow.)

But, chances are awfully good you don't need the lifted mounts. Go with the standard mounts - and maybe the heavy-duty brackets by Brown Dog...

 

yea im not looking for raised ones particularly.. just odds are im gonna be replacing my engine in the coming weeks so i figured i might as well make some upgrades while its out n the engine mounts were my first thought. just happened to find a good deal on a rustys raised set.

 

As I said, you're probably not going to need them.

OEM replacement using L&S or Anchor will work well for general-purpose stuff, this replaces the elastomer bushings to either side and under the transmission (replace all three, if you replace one. Else, the old mounts will cause the new mount to wear much more quickly...)

A slight upgrade is to use polyurethane mounts, but poly is stiffer than the EPDM that is usually used, and will therefore transmit more vibration. However, fewer chemicals are antagonistic to polyurethane, so it may be an effective trade (most petroleum-based chemicals are antagonistic to EPDM, while they're rather less antagonistic to polyurethane.)

The Brown Dog mounts are more the brackets that are screwed to either side of the engine block, but I believe they're available in a kit that includes the bushings as well.

NB: It's a known issue that the screw holes in the side of the engine block aren't always drilled & tapped deeply enough to accept the entire screw! This is an easy fix - get a handful of 3/8"-16x1" hex head capscrews and a handful of flat washers. While you're down there, replace the screws one at a time with the new parts, and I would suggest installing two flat washers under the screw heads. Use LocTite #242 on assembly, torque to spec. The spec should be on my site in the Tech section. (This won't go amiss even if the holes in your engine are D&T properly, but the screws are fairly likely to lose their heads if not. The washers prevent the tip of the screw from "bottoming out" in the hole, allowing for the screw to be properly preloaded in tension to be useful.)

 

im using brown dog motor mounts

 

The main reason to do a Motor mount lift is to clear steering/diffs/truss ect when fully stuffed. When I fully flex my tie rod was about 1/4"-3/8" form the oil pan with stock mounts. I am sure with some setups and LCG builds it is pretty likely someone would need it....

A motor mount lift may make the read drive-line point a little more down causing less vibs for some. but it also makes the angle of the Cardon joint for the front drive-line a worse angle just like with a transfer case drop.... and makes the Double cardon joint max out sooner with droop... its all a give and take.

I use stinkyfab's motor mount brackets 225$ (+shipping) I mainly got because they are raw And I wanted them to be black not Yellow and I use M.O.R.E. mounts I found for sale for 40$ (shipped) almost any brand of mounts/brackets are going to be good. I would just get the ones you like better, or like the price better

 

<- Another happy Brown Dog customer

These are the options BD offers for your year:
http://browndogindustries.com/cherok...-2000-40l.aspx

Here's BD's mml faq:
http://browndogindustries.com/Jeep-M...unt-Lifts.aspx

If you have any questions regarding their stuff, get in contact with Tim or Karol. They'll help you get the right mounts for your setup.

 

Brown Dog it

 

Interesting Faq's... I didn't know that was there main/only use.

 

Brown dog rubber here.

 

This information surfaced on the internet a few years ago. Since that time I have measured the depth on the thread bosses of every engine I have worked on and have found that it is...not true; they are very consistent and adequate. I believe this started as someone's hypothesis and became an internet fact or legend. No flaming please. It is simply based on my experience. However, it doesn't take much dirt in one of those bosses to cause a depth problem.

Tim

 

Really? Interesting.

Considering I'd seen it on two late RENIX (ChryCo-built, not AMC) and caught it before failure, and have caught no less than six reports from the field where it was reasonably certain that those screws hadn't been out (four of them were from original owners, the other two were from people who'd bought from the original owners,) I'd had no reason to doubt the veracity of the claims.

I usually advise people to stick a leaf gage under the screw heads when changing the mount cushion - if they can touch the screw shank using the thinnest leaf gage, replace the screw and add washers.

Maybe it's not necessary, then - but it's cheap insurance (as long as you use a good quality screw, and not Chinese crap.)