NAXJA Forums -::- North American XJ Association  

Go Back   NAXJA Forums -::- North American XJ Association > NAXJA Unibody Jeep Technical Forums > Jeep Cherokee XJ (1984 - 2001) > OEM Tech Discussion
HOME Member FAQ Sponsor Info Rules Bylaws E-Mail

OEM Tech Discussion Forum for OEM (Original Equipment) or stock XJs and MJs.

Reply
 
Thread Tools Display Modes
  #1  
Old May 27th, 2017, 16:16
fursphere fursphere is offline
NAXJA Forum User
 
Join Date: Mar 2016
Location: Sacramento, CA
Posts: 7
'93 4.0 Flywheel to Crankshaft Torque - Stripped

Need some help please.

I was prepping my freshly rebuilt 4.0 to to reinstall in the XJ today. Installing the flyhweel onto the crankshaft.

Looked up torque specs - Haynes manual I have and everything I could find online said 105 ft/lbs. Sounded right to me, so I started started slowing tightening things up.

One of the bolts totally stripped (threads in the crank stripped). I chased the threads with a tap and tried again - didn't even get to 75 ft /lbs.

so.. at this point I've got an extremely expensive paperweight.

Can it be fixed?
And is that torque spec correct? I started digging around and found the flexplate (automatic) torque specs were like 55 ft/lbs? Is it really 55?

I found a PDF of the '93 FSM - and its a complicated mess to try and understand what its saying.

Any help is appreciated, but that this point i'm about to lose my mind.
Reply With Quote
  #2  
Old May 27th, 2017, 16:20
ljobbins ljobbins is offline
NAXJA Forum User
 
Join Date: Mar 2016
Location: SD County
Posts: 151
Re: '93 4.0 Flywheel to Crankshaft Torque - Stripped

I dont see any reason why an engine machine shop cant fill in the hole, tap and rebalance if neccessary.
Reply With Quote
  #3  
Old May 27th, 2017, 16:36
RCP Phx RCP Phx is offline
NAXJA Forum User
 
Join Date: Mar 2003
Location: Phoenix,Az
Posts: 10,698
Re: '93 4.0 Flywheel to Crankshaft Torque - Stripped

That's the correct torque, so maybe look into Heli-coils! There must have been something wrong with the existing threads?
My ARP flex plate bolts torque to 100 ft/lbs.
A rebuilt exchange crankshaft would be the simplest.

Last edited by RCP Phx; May 27th, 2017 at 16:42.
Reply With Quote
  #4  
Old May 27th, 2017, 16:38
fursphere fursphere is offline
NAXJA Forum User
 
Join Date: Mar 2016
Location: Sacramento, CA
Posts: 7
Re: '93 4.0 Flywheel to Crankshaft Torque - Stripped

Can helicoils take 105 ft/lbs of torque?

I had to helicoil the heads on my silverado when the machine shop screwed up the intake manifold bolts - and they're only like 18 ft/lbs, and they BARELY held after that.

I can't imaging putting 100+ on a heli coil.
Reply With Quote
  #5  
Old May 27th, 2017, 18:17
Jeep Driver Jeep Driver is offline
NAXJA Forum User
 
Join Date: Jun 2016
Location: Parrottsville
Posts: 637
Re: '93 4.0 Flywheel to Crankshaft Torque - Stripped

you might find this interesting http://www.hotrod.com/articles/how-t...shaft-threads/


In your case, I'd replace the crank.
Reply With Quote
  #6  
Old May 27th, 2017, 19:54
fursphere fursphere is offline
NAXJA Forum User
 
Join Date: Mar 2016
Location: Sacramento, CA
Posts: 7
Re: '93 4.0 Flywheel to Crankshaft Torque - Stripped

Replacing the crank, directly after a full rebuild, it a damn expensive way to fix the problem. But its on the table.

I'm going to take it back to my machinist and see if he can fix it. And probably have him install the flywheel too - so if it strips out again (or another one of the damn bolts strips) its already there.

Thoughts of stripping everything good of my XJ and transferring the parts to my LJ are ringing loud in my head though...
Reply With Quote
  #7  
Old May 27th, 2017, 22:04
RCP Phx RCP Phx is offline
NAXJA Forum User
 
Join Date: Mar 2003
Location: Phoenix,Az
Posts: 10,698
Re: '93 4.0 Flywheel to Crankshaft Torque - Stripped

You can get a crank w/ bearings for 200$ and all you need to do is pull the pan!
Reply With Quote
  #8  
Old May 30th, 2017, 13:15
RCP Phx RCP Phx is offline
NAXJA Forum User
 
Join Date: Mar 2003
Location: Phoenix,Az
Posts: 10,698
Re: '93 4.0 Flywheel to Crankshaft Torque - Stripped

One last minute thought, make sure the bolt threads are long enough! Someone may have used flex plate bolts.
Reply With Quote
  #9  
Old May 30th, 2017, 13:29
fursphere fursphere is offline
NAXJA Forum User
 
Join Date: Mar 2016
Location: Sacramento, CA
Posts: 7
Re: '93 4.0 Flywheel to Crankshaft Torque - Stripped

Pretty sure they're the right bolts. I'm going to order a new set anyway.

Engine is going back to the shop tomorrow morning - machinist thinks he can fix it. I'll install the flywheel there in case it strips again.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
88 XJ Flywheel Torque Spec? RAVC1 OEM Tech Discussion 14 April 5th, 2011 23:11
Crankshaft key YosemiteJeeper OEM Tech Discussion 2 October 28th, 2010 22:35
Pinion Nut Torque vs Bearing Preload Torque??? Zeke23 OEM Tech Discussion 3 July 28th, 2008 14:47
need torque spec 86 cherokee flywheel carnuck OEM Tech Discussion 3 June 1st, 2005 09:49


All times are GMT -7. The time now is 16:48.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
NAXJA and NAXJA logo's Copyright NAXJA. All content/images Copyright NAXJA 1999-2014