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Unread 04-12-2009, 08:17 PM   #61
CrawlnFool
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1998 XJ Cherokee 
 
Join Date: Apr 2008
Location: Utah
Posts: 53
Man im so glad i found this thread! After reading i went out to check mine and bolts are tight but i found out i need new mounts. The drivers side is shot all the rubber is 100% gone and the passenger side is about 1/2 gone. I have had the jeep about a month and check everything but those

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Unread 04-30-2009, 05:05 PM   #62
OHIOMAN
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1995 XJ Cherokee 
 
Join Date: Dec 2006
Location: Sierra Vista, Arizona
Posts: 186
Well, hate to say it, but I've joined the club. I just got Brown Dog mounts cause mine were gone. While replacing them, I realized I only have one bolt holding the passenger side bracket in. I have to have this fixed by tomorrow, so I'm kind of freaking out. Gonna try some easy outs now. Wish me luck.
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Unread 04-30-2009, 07:19 PM   #63
escapeartist
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Just a word or two about the bolt size. Let me start by saying I have not had the misfortune of others yet, so I do not know what size the bolts are and I am just responding after reading this thread out of concern, after seeing some odd size combinations tossed around.

5/8 bolt head=.625"
16MM bolt head=.629"

3/8" bolt =.375"
10mm bolt =.393"

1/16 (1 divided by 16) = the lead on a 3/8" NC thread of .0625"

1.5MM lead on a 10MM bolt = .059"

Lead is how far the thread advances in one revolution.

Pitch is number of threads per inch. American standard. 3/8-16

Metric fasteners are called out in lead. 10X1.5MM

so you see they are very close. I have worked as a machinist for longer than I care to admit in a repair shop and I have NEVER ran across a mass produced fastener with a standard thread and metric head or vice versa.

The point is be careful that you have the right bolt thread combination otherwise you will create a world of grief for yourself down the road.
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Unread 04-30-2009, 07:31 PM   #64
mattathayde
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Quote:
Originally Posted by escapeartist View Post
Just a word or two about the bolt size. Let me start by saying I have not had the misfortune of others yet, so I do not know what size the bolts are and I am just responding after reading this thread out of concern, after seeing some odd size combinations tossed around.

5/8 bolt head=.625"
16MM bolt head=.629"

3/8" bolt =.375"
10mm bolt =.393"

1/16 (1 divided by 16) = the lead on a 3/8" NC thread of .0625"

1.5MM lead on a 10MM bolt = .059"

Lead is how far the thread advances in one revolution.

Pitch is number of threads per inch. American standard. 3/8-16

Metric fasteners are called out in lead. 10X1.5MM

so you see they are very close. I have worked as a machinist for longer than I care to admit in a repair shop and I have NEVER ran across a mass produced fastener with a standard thread and metric head or vice versa.

The point is be careful that you have the right bolt thread combination otherwise you will create a world of grief for yourself down the road.
if it fits there nothing to worry about, and if it takes more effort to make it fit that just means it will stay in better



but in all seriousness that is a very good point to make sure people are aware of, i know the stupid mistakes even intelligent people make with sizing like this and studying metals (its supposed to be more jewelry but i like the very technical stuff) i am blown away by how little some of my fellow class mates and upper class men know of technical metal stuff

-matt
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Unread 04-30-2009, 07:38 PM   #65
escapeartist
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Quote:
Originally Posted by mattathayde View Post
if it fits there nothing to worry about, and if it takes more effort to make it fit that just means it will stay in better -matt
um.... No
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Unread 04-30-2009, 07:57 PM   #66
brand0nlp
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my motor mount broke about 2 weeks ago, on the passengers side, while i was driving at 60 mph, well my distributor stopped my motor from falling any further, all i had to do was replace the bolts its was about a 3 hour job, between drilling them out, and going into town and getting new ones along with new rubber mounts,
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Unread 05-01-2009, 11:26 AM   #67
limited
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To the guys wondering about how to replace the bolts without an engine hoist; Take a jack and center it under the oil pan and use it to take the weight off the mounts. Be sure to use a piece of wood in between the jack and pan.
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Unread 05-01-2009, 08:55 PM   #68
94HOCHEROKEE
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I TQ'd my 14mm engine mount/block bolts, and they were all where they were supposed to be. Is the torx bit bolt go into the block???
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Unread 05-01-2009, 11:23 PM   #69
nightgrown
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i had my passenger side bolts shear and cracked 2 of the bosses completely off i ended up buying the block brackets and just bolting up 5 out of the 7 bolts.. worked out great

http://www.mountainoffroad.com/Catal.../XJmounts.html
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Unread 05-02-2009, 11:29 AM   #70
94HOCHEROKEE
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Quote:
Originally Posted by nightgrown View Post
i had my passenger side bolts shear and cracked 2 of the bosses completely off i ended up buying the block brackets and just bolting up 5 out of the 7 bolts.. worked out great

http://www.mountainoffroad.com/Catal.../XJmounts.html
What are the bosses???? The tops??
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Unread 05-03-2009, 02:43 AM   #71
nightgrown
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Quote:
Originally Posted by 94HOCHEROKEE View Post
What are the bosses???? The tops??
the parts that stick out of the block you screw the bolt into
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Unread 05-03-2009, 08:58 AM   #72
BrunoS
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nearing 10k miles on my original forum post about the sheared bolts and repair. The welded plate/boss/single bolt has fully held under all conditions, no cracks in the weld repair yet.

on any casting, a raised area that is threaded or has attachment points on it, is usually called a "boss". These are pretty strong and sheared bolts are usually retained in the "boss". a really bad shear can crack or break the boss, but the break most of the time will be external only. bosses can be welded, but usually many shops will make a support "girdle" to spread the stress load to more areas.

i've looked at the "bomb" proof motor mounts, the seem a very good solution that will bolt in and get rid of the headaches of trying to drill and tap the 3 passenger side bolts, as in my case.

There seems to be only 2 solutions: check you bolts now, and repair BEFORE you shear the mount off, like many of us poor souls, and if it's broken and you are reading this thread, then drill/tap, weld, or buy the bomb-proof motor mount and have it installed.
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Unread 05-03-2009, 02:57 PM   #73
kzjim
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Been there done that.. every second of the repair ordeal sucked... ordering a set of more mounts soon...
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Unread 05-04-2009, 12:33 PM   #74
94HOCHEROKEE
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I went to tq my 3rd bolt which is a torx, on my passenger side mount wen I realized the bold is brokek about half way in!!! The head came right out. the other 2 bolts I just tq'd, Do I replace those also??? Whats the best way to drill/tap the one pass. side bolt lifting or dropping engine?? I don't have a hoist so any ideas/walkthrough for this ??? Hellllp!!! any input appreciated!!!!
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Unread 05-05-2009, 07:14 PM   #75
brand0nlp
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i let my motor down just undid the motor mount, used a block of wood and a jack under the oil pan and carefully dropped it oto the steering arms. but kept the jack just snug underneath it so it wouldnt put to much weight on the steering components.
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