head bolt issue
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Construction and other equipment
Forum Description: everything else with orange (or yellow) paint
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=22673
Printed Date: 18 Jul 2025 at 8:19pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: head bolt issue
Posted By: giz's hd-6ep
Subject: head bolt issue
Date Posted: 21 Dec 2010 at 5:44pm
|
we have a loader with a diesel engine it blew a head gskt bolt loosend up .put new head gskt retorqued head and same thing happened ,the bolt actually backed right out, same hole different bolt.we checked the threads and all was well ,and the bolt torqued down with no problem, anyone ever hear of such a thing?
|
Replies:
Posted By: Jeff Z. NY
Date Posted: 21 Dec 2010 at 6:00pm
Sounds like the threads in the hole are strecthed out.
The bolt threads are probably strecthed also.
I would look into Time-Serts and new bolts.
http://www.timesert.com/
|
Posted By: Coke-in-MN
Date Posted: 21 Dec 2010 at 10:23pm
bolts may be streached and not good for holding torque. Cummings engines says replacethe bolts every time head is off. check also if threads in block are bad or if bolts are bottoming out and not to torque to hold but false reading from bad threads.
Some bolts call for a sealant to be used on threads also like white lead or teflon sealing compound to prevent leakage or galling.
-------------
Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something.
"Challenges are what make life interesting; overcoming them is what makes life meaningful."
|
Posted By: CTuckerNWIL
Date Posted: 21 Dec 2010 at 10:37pm
Clean the threads out in the block with something like brake clean after chasing threads with a tap. Throw the bolts away and get studs to replace them. Clean the studs with brake clean and put a couple drops of 680 Loctite on each stud and bottom them in the hole, not torquing them, just turn till you feel like you ran out of thread. Put head back on and torque nuts to specs.
-------------
http://www.ae-ta.com" rel="nofollow - http://www.ae-ta.com
Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF
|
Posted By: dadsdozerhd5b
Date Posted: 22 Dec 2010 at 4:45am
if you tried a different bolt with same result, sounds like the issue is in the block, chase the threads with a tap and clean out as in previous posts and try new bolts. also, be sure there is plenty of clearance in the hole that it goes through int he head. run the bolt down without the head and make sure it is not too long. some heads use differnet length bolts depending on their position in the head. what type of engine is it?
-------------
HD5B, HD5G, (2) FARMALL A's, CUB. DO IT RIGHT THE FIRST TIME, IGNORE THE LAUGHTER. FLANNEL IS ALWAYS IN STYLE.
|
Posted By: giz's hd-6ep
Date Posted: 22 Dec 2010 at 7:11pm
|
thanks guys, sounds like its problem with threads and or bolts will pass on info, thanks for replying helps to get a different point of view sometimes .
|
Posted By: DMiller
Date Posted: 26 Dec 2010 at 4:49pm
Head bolt holes need to be clean and dry to start with, put 90 wt gear oil on the threads of the bolts just prior to inserting them and under the head as the bolt tightens up to the washer or to the head surface and then torque them in stages of thirds of final value.
If it is a Detroit engine with bolts someone screwed up, Detroits' were studded blocks not bolted. With studs the threads are done the same as bolts as far as lube the threads but the stud is torqued into the block first then the nuts torqued to hold the head; all with lube on them.
We used to use a lube called International Compound #2 from Detroit Diesel for bolt lube; I have not been able to find any for years, called it peanut butter due to color and consistency.
|
|