G head bolts
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=151037
Printed Date: 24 Aug 2025 at 6:51am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: G head bolts
Posted By: JohnCO
Subject: G head bolts
Date Posted: 05 Jun 2018 at 11:40am
|
I am replacing some broken head bolts on a G and am wondering what grade should be used. I'm thinking gd 5 but an existing one is an 8. There sure are a lot of bolts for such a little head! TIA, John I think this is my post 7777, should be lucky, right? ------------- "If at first you don't succeed, get a bigger hammer" Allis Express participant |
Replies:
Posted By: JohnCO
Date Posted: 05 Jun 2018 at 11:41am
|
Nope, guess the last post was the lucky one, don't remember which one it was... ------------- "If at first you don't succeed, get a bigger hammer" Allis Express participant |
Posted By: Leon n/c AR.
Date Posted: 05 Jun 2018 at 11:48am
| I believe head bolts are normally a grade 8 bolt. I would want grade 8 myself. Leon |
Posted By: Allis dave
Date Posted: 05 Jun 2018 at 1:52pm
|
I think the WD and WD45 head bolt were only grade 5. I might be wrong. The right way to do it would be to replace all of them, so they'll stretch the same. Probably not a big deal though with a gas.
|
Posted By: SteveM C/IL
Date Posted: 05 Jun 2018 at 11:18pm
| I think the bolts in my 45 have no markings but I'd buy G8 if i was buying. |
Posted By: Richardmo
Date Posted: 06 Jun 2018 at 5:39am
|
I used Grade 8 on my G's when rebuilding them. |
Posted By: Gerald J.
Date Posted: 06 Jun 2018 at 10:47am
|
The Continental owner's manual I have in my library doesn't mention head bolts or studs. Pictures look like studs with nuts. The Allis G Owners manual: http://geraldj.networkiowa.com/Trees/Allis%20Chalmers%20G%20Owners%20Manual%20%28TM-4A%290001.pdf" rel="nofollow - http://geraldj.networkiowa.com/Trees/Allis%20Chalmers%20G%20Owners%20Manual%20(TM-4A)0001.pdf shows an assortment of short cap screws, long cap screws, and studs. The Allis G shop manual: http://geraldj.networkiowa.com/Trees/Allis-Chalmers-G-B-C-CA-Service.pdf" rel="nofollow - http://geraldj.networkiowa.com/Trees/Allis-Chalmers-G-B-C-CA-Service.pdf shows only studs and has the diagram for the order of tightening them to 55 ft pds torque. The fasteners may have changed over the lifetime of that engine. Grade 5 isn't as strong as grade 8 but is less brittle so grade 5 handles shock and impacts better than grade 8. I doubt the threads in the cast iron block are as strong as grade 8. Grade 5 is a lot better for most applications than grade 2. Gerald J. |
Posted By: JohnCO
Date Posted: 07 Jun 2018 at 12:59am
|
Thanks for your thoughts, Gerald. I'm sure this engine has been apart before so who knows how long the bolts were in. I think studs are a much better idea as the nuts are much less likely to seize and break the stud then a bolt right next to the exhaust manifold. It's got 20 bolts/ studs in that little head! ------------- "If at first you don't succeed, get a bigger hammer" Allis Express participant |
Posted By: solidground
Date Posted: 07 Feb 2020 at 3:19pm
|
Hey all, I've got a related question re the G head bolts. In taking the head off, one of the bolts - a corner bolt - sheared (just about flush at the block, if it matters). I tried drilling a pilot hole and using a bolt extractor, but the extractor snapped. Now I've got no chance of drilling it out. So how terrible would it be to put everything back together with that bolt missing? I know it's wrong, but like "no chance of working at all" wrong, or "might start to leak eventually" wrong? I've been having a lot of problems with this tractor (hence the engine work!), and am at my wits end. I know one answer is to bring the block to a machine shop and see if they can fix it, but I was hoping to get it rebuilt this weekend. Any thoughts? Thanks so much for any insight-
|
Posted By: Sugarmaker
Date Posted: 07 Feb 2020 at 7:00pm
|
Solid ground, You might get more response to start your own thread, Darn "easy-outs" never seem to work for me either. You wont like it but the right thing to do is get the remaining stud out. Not sure that the head will ever seal right without that stud in place?? Experts will be along shortly. If you could heat it and weld on a washer then a nut you might get it out? You might need to get the easy out broken part out first?? The machine shop may be the best safest way to go. Not quick, not cheap, but right! Regards, Chris ------------- D17 1958 (NFE), WD45 1954 (NFE), WD 1952 (NFE), WD 1950 (WFE), Allis F-40 forklift, Allis CA, Allis D14, Ford Jubilee, Many IH Cub Cadets, 32 Ford Dump, 65 Comet. |
Posted By: K-Mo
Date Posted: 08 Feb 2020 at 5:37am
|
I used bolts from ZORO-- https://www.zoro.com/Grade" rel="nofollow - https://www.zoro.com/Grade 8
G9050867 2-1/4" G1409301 2-1/2" Can't guarantee suitability. Just saying that's what I used. K-Mo
|
Posted By: Dusty MI
Date Posted: 08 Feb 2020 at 8:46am
------------- 917 H, '48 G, '65 D-10 series III "Allis Express" |
solidground wrote:
