WARNING: All 4.0 owners check your motor mount/block Bolts!!!! - Page 2 - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Cherokee & Comanche Forums > XJ Cherokee Technical Forum > WARNING: All 4.0 owners check your motor mount/block Bolts!!!!

Rough Country Deals at JeepHut.comShocktober is here! Get new shocks for your Jeep!!!!KOR Labor Week Sale and Giveaway

Reply
Unread 09-25-2008, 10:43 PM   #16
xjpro
Registered User
2001 XJ Cherokee 
 
Join Date: Feb 2007
Location: Miami, FL.
Posts: 259
If all bolts are ok, is it a good idea to replace all of them with grade 8 ones?????

__________________
xjpro
01 xj limited
ZJ rear disc brakes with working parking brake
Electric fan conversion with spal fan controller
xjpro is offline   Reply With Quote
Unread 09-26-2008, 03:17 AM   #17
blackcar87
Registered User
1994 XJ Cherokee 
 
Join Date: Sep 2008
Location: Montgomery, AL
Posts: 155
been there also, ran over a railroad track pretty hard motor mount bolts broke. I did not know one of the bolts had already came out and was gone.
The other 2 broke off in the block. I drilled out the bolts and used an ease out to get them out. Also had to use alot of heat from a torch. Not a good day.
blackcar87 is offline   Reply With Quote
Unread 09-26-2008, 06:46 AM   #18
96upcountry
Registered User
1996 XJ Cherokee 
 
Join Date: Sep 2008
Location: New Paltz, NY
Posts: 192
Where is a good place to get new mounts and bolts? Also what brand are those ez outs pictured?
96upcountry is offline   Reply With Quote
Unread 09-26-2008, 09:27 AM   #19
johnsoninc86
Registered User
1998 XJ Cherokee 
 
Join Date: Nov 2004
Location: Bloomington, IN
Posts: 512
Yes, I would like to know a little bit more about this as well. I have 220k on my motor and have never touched the motor mounts or bolts holding them in. Do you guys just go to the hardware store and get grade 8 stuff or is this a part that comes with aftermarket motor mounts? This is the first time I have heard about this problem, and I have been on this forum for awhile now.
__________________
98 XJ Sport
07 JKU Sahara
johnsoninc86 is offline   Reply With Quote
Unread 09-26-2008, 10:01 AM   #20
jeeptown
Registered User
1998 XJ Cherokee 
 
Join Date: Jan 2008
Location: canton mi
Posts: 189
Iv'e never heard of this either. I'm at 180k. Could these bolts been from a bad batch or something? The bolts that break could they have been from engines that have been removed b4 and maybe over torqued when reinstalled or might not have been tightened enough.
jeeptown is offline   Reply With Quote
Unread 09-26-2008, 11:59 AM   #21
skullver
Tarpitz
1991 XJ Cherokee 
 
Join Date: Jan 2007
Location: Ventura, Carp, La Conchita, CA
Posts: 967
I remember reading somewhere that there was a problem with some of the fasteners being too long so they would not properly torque, I think Collins Brothers jeeps released this information from their personal findings/fixes but I can't seem to find the article now.

As for Grade 8 I would not do it, grade 5 should be fine IF they are properly torqued, you don't want to pull the threads out of the block nor as somebody else stated, if it does fail, good luck getting it out.
__________________
Blah blah blah blah.

my Jeepspeed build thread:
http://www.jeepforum.com/forum/f37/dez-racer-xj-build-367176/
skullver is offline   Reply With Quote
Unread 09-26-2008, 08:13 PM   #22
mramos
Registered User
2009 JK Wrangler 
 
Join Date: Sep 2006
Location: milwaukee wi
Posts: 149
hey that happen to me i have a 95 xj
mramos is offline   Reply With Quote
Unread 09-26-2008, 08:36 PM   #23
2drx4
Registered User
1990 XJ Cherokee 
 
Join Date: Jun 2008
Location: North
Posts: 320
I've never had one fail. Or witnessed it in person.

MORE sells upgraded mounts.

http://www.mountainoffroad.com/Catal.../XJmounts.html

Anyways, I'd recommend using them over the stock ones, as they definatly wouldn't fail. Steep price though. However, if the failures are THE BOLT and only the bolt (I would assume damage to the bosses to be as a result of the bolt failing), simply swapping in Gr8 hardware is probably the easiest acceptable solution. With about a 30% increase in strength, the fatique life of the fastener would be much longer... And I mean MUCH longer. I'd have to do some reading to remember how the relationship works exactly, but I'd expect no less than a 10X increase in life. And about the worry of pulling the threads out... I'd assume they're UNC (coarse) threads. I believe you only need about a 5 or 6 thread engagement in aluminum (2024 T3) before the strength of the threads is higher than that of the bolt. Given we're dealing with cast iron, I'd not worry.

The stock brackets are kinda hokey though.
2drx4 is offline   Reply With Quote
Unread 09-26-2008, 09:38 PM   #24
jonnyblaze
Registered User
2000 XJ Cherokee 
 
Join Date: Sep 2008
Location: RI
Posts: 70
saw it happen to my buddies xj. 94 i believe. anyway i told him to buy me an engine hoist and a case of beer and i would do it for him instead he sold it for $200. Dumb@$$. I would have given him more than that
jonnyblaze is offline   Reply With Quote
Unread 09-26-2008, 10:26 PM   #25
rod_serengeti
Registered User
1995 XJ Cherokee 
 
Join Date: Sep 2008
Location: Star Meadow, MT
Posts: 11
The factory bolts are 16mm heads on 3/8-16 NC threads. This seems like a rather small bolt me, even if there are three of them. Also, I don't particularly like the cantilever design of the bracket attached to the engine. There is a lot of leverage applied to those bolts. They stretch (the grade 5's) get loose, and then begin to fatigue from the flexing of the mount.


Ace Hardware, standard grade 8, 3/8-16 NC.
__________________
1995 Cherokee Sport, 4.0HO Auto, ARB front bumper, LightForce Offroad lights. Quarter-Million mile club member (I drove them all)
rod_serengeti is offline   Reply With Quote
Unread 09-29-2008, 06:48 PM   #26
CraigAllen
Registered User
1996 XJ Cherokee 
 
Join Date: Oct 2004
Location: Klamath Falls OR
Posts: 755
Thanks for the warning! I retorqued mine today. One of the right side bolts was indeed loose... all the others were tight.

181,923 miles.
__________________
96XJ Sport 4.0 Auto CommandTrac, Chrys. 8.25, 1-3/4" BB, WARN HS9500 winch, WARN Body Armor front & rear bumpers, tire carrier, rock sliders and transfer case skid plate. 30x9.5 BFG Mud-Terrain T/A's. As of March 10, 2011, there are 205K miles on the clock and she's still good and strong!
CraigAllen is offline   Reply With Quote
Unread 09-29-2008, 08:02 PM   #27
bwilliam
Registered User
1998 XJ Cherokee 
 
Join Date: Aug 2007
Location: Pennsylvania
Posts: 78
Happened to my 95 xj 5 speed i had too about 3 years ago right around 200,000mi..lost the radiator because i just ran it home like it was..shifter and tranny were sitting way down and to the right..couldnt put it in reverse because was hitting on the console. This seems to be a really frequent thing with the 95 models??? Have a 98 now with 102,000 and not a single mount problem.
bwilliam is offline   Reply With Quote
Unread 09-29-2008, 08:20 PM   #28
k_h
Registered User
1991 XJ Cherokee 
 
Join Date: Jul 2008
Location: oahu
Posts: 9
i'm waiting for my brown dog motor mounts... should be here this week..
k_h is offline   Reply With Quote
Unread 09-29-2008, 08:21 PM   #29
CherokeeErik
Registered User
2000 XJ Cherokee 
 
Join Date: May 2008
Location: Mpls
Posts: 90
those easy outs pictured are snap on, i have them, they are nice, but once you get the bolt out its hard to get the bolt of the easy out..
If the stock bolts are 3/8 coarse, why and how could they have a metric head??? Ive never heard of such a thing??
CherokeeErik is offline   Reply With Quote
Unread 09-29-2008, 09:24 PM   #30
davet1960
Registered User
1997 XJ Cherokee 
 
Join Date: Oct 2003
Location: Los Lunas NM
Posts: 159
my 97 is equiped with brown dog mounts and grade 8 bolts
davet1960 is offline   Reply With Quote
Reply
Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.