880 Implematic cracked block and head issues

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Brend880
Posts: 9
Joined: Sat Dec 19, 2020 11:14 am
Location: Tyrone

880 Implematic cracked block and head issues

Post by Brend880 » Wed Jan 06, 2021 7:59 pm

Hi All,

just joined DBTC and looking for some advice. I own an implematic 880/C/352905 think it is 1961 or 1962 with the Ad4 40T engine. Had issues with water in the sump and low compression in cylinder 2 so took head off and found what I believe to be incorrect head gasket fitted and worn liners. Extracted liners and found a hairline crack in the bottom of the block between cylinders 2 & 3 where the liner o rings sit. The crack is on both sides and top and bottom, I have attached photographs.

Is it possible to weld the crack? has anyone had any luck with epoxy weld such as JB weld or block sealer added to the coolant?

The head gasket is stamped C902040 and from what I can find out appears to be for a 990. it covers 2 water ports and 2 oil ports preventing circulation between head and block, the gasket has blistered in these locations. I also have an additional water port in the head with no corresponding port in the block (different head fitted at some time??) - I assume there would still be adequate cooling even with this hole blocked.

Does anyone know the head gasket OEM for the AD4 40T engine? I've had a look at some part sites including David Brown Parts Limited and cant find anything that looks the correct fit.

Also doesnt appear to be many AD4 40T engine parts available generally, were these a rare engine?

download/file.php?mode=view&id=9160
download/file.php?mode=view&id=9161


thanks

philedge
Posts: 488
Joined: Sun Dec 03, 2006 11:27 am
Location: Chester UK

Re: 880 Implematic cracked block and head issues

Post by philedge » Wed Jan 06, 2021 8:19 pm

If its OEM part numbers youre after, theres a parts manual here https://sites.google.com/site/deerebrow ... ts-manuals
'66 880 Selectamatic rat.

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db2d
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Location: Monmouthshire

Re: 880 Implematic cracked block and head issues

Post by db2d » Wed Jan 06, 2021 9:28 pm

The AD4 40T is a one of the most popular DB engines. The head gasket is the same for all 3 5/8 inch bore Diesel engines up to the 990.
WWW.DAVIDBROWNPARTS.COM Have these in stock along with all the other parts required for an engine refurbishment — contact them
In my opinion welding is not an option.
Can you please provide a picture ( The link you provided does not work )

Brend880
Posts: 9
Joined: Sat Dec 19, 2020 11:14 am
Location: Tyrone

Re: 880 Implematic cracked block and head issues

Post by Brend880 » Wed Jan 06, 2021 10:01 pm

thanks for the replies guys.

I have tried to attach the photos again
Attachments
880 cracked head 1.jpg
880 cracked head 1.jpg (83.23 KiB) Viewed 631 times
880 cracked head 2.jpg
880 cracked head 2.jpg (77.54 KiB) Viewed 631 times

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cobbadog
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Location: beautiful Coopernook NSW. near Taree. NSW. Australia

Re: 880 Implematic cracked block and head issues

Post by cobbadog » Thu Jan 07, 2021 2:38 am

Time to source another block. Welding will hold for a very short time, JB Weld is good stuff but this is way above what it can do successfully. So your now on the look out for another block which you should be able to source online or at a breaker yard.
Is is possible that the gasket was put on either up side down or back to front because it sounds as if this is what caused the problem. I had a grey fergy that had no oil pressure on the rockers and this was because the head gasket was incorrectly installed.

Gard
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Location: Fairfax Vermont USA

Re: 880 Implematic cracked block and head issues

Post by Gard » Sat Jan 09, 2021 11:41 pm

What a bummer to find a crack like that after disassembling everything. Good luck in finding another block. Thanks for sharing the photo.

Brend880
Posts: 9
Joined: Sat Dec 19, 2020 11:14 am
Location: Tyrone

Re: 880 Implematic cracked block and head issues

Post by Brend880 » Sat Jan 23, 2021 9:02 pm

Well I’m still looking for a block, hard to come by in Ireland. If anyone knows where I might get one please let me know.

Would also appreciate some advice on a potential clutch issue . Is the thrust bearing support snout which sits over the driveshaft supposed to be the same diameter over its length? Mine has 2 steps in it but I can’t believe it would have worn that much? I have attached a photograph
Attachments
B2E7A22D-3D2B-4111-961E-7DBB5652288D.jpeg
B2E7A22D-3D2B-4111-961E-7DBB5652288D.jpeg (105.33 KiB) Viewed 506 times

tomryall
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Location: canada

Re: 880 Implematic cracked block and head issues

Post by tomryall » Sat Jan 23, 2021 10:07 pm

That shaft looks good to me , if it was worn it would be easily seen as it would be out of true round.

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db2d
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Re: 880 Implematic cracked block and head issues

Post by db2d » Sat Jan 23, 2021 10:39 pm

Nothing wrong with it

Brend880
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Location: Tyrone

Re: 880 Implematic cracked block and head issues

Post by Brend880 » Sat Jan 23, 2021 10:53 pm

Thanks guys. So the snout steps down in diameter twice before the end nearest the splines on the shaft, that’s as it should be?

Brend880
Posts: 9
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Location: Tyrone

Re: 880 Implematic cracked block and head issues

Post by Brend880 » Mon Jan 25, 2021 8:45 am

Sorry just to be clear it’s not the main shaft I’m concerned about it is the snout that fits over the main shaft that the throw out bearing sits on. It looks fine next the gearbox but the other end after the key is much narrower as if it’s worn. I came across a picture of a 990 snout (picture attached) and it is uniform across its entire length. Compare this to the previous picture. I assume the 880 would be the same? Apologies if I’m not explaining myself too well
Attachments
B8D63CA5-14A5-4387-84F0-8BF438ACFB2C.jpeg
B8D63CA5-14A5-4387-84F0-8BF438ACFB2C.jpeg (108.82 KiB) Viewed 460 times

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db2d
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Re: 880 Implematic cracked block and head issues

Post by db2d » Mon Jan 25, 2021 10:00 am

It looks as if the thrust bearing carrier has been spinning on the support snout and the key has worn a groove. Is there any indication of a key, what is the inside of the bearing carrier like?
Going from memory I think all live drive Implematics have the same snout and bearing carrier

Brend880
Posts: 9
Joined: Sat Dec 19, 2020 11:14 am
Location: Tyrone

Re: 880 Implematic cracked block and head issues

Post by Brend880 » Mon Jan 25, 2021 12:53 pm

The "good" part of the snout measures 57.3mm diameter as does the inside diameter of the thrust bearing carrier. However the snout at the end nearest the flywheel only measures 52.6mm so must be worn. The carrier looks fine. The key sits on the snout not the carrier so I dont think this could have caused the wear. I can also see evidence of the snout key worn at the end of the key nearest the flywheel. Having looked at the parts diagram i also noticed that the thrust bearing carrier spring clips are missing. I'm thinking with the spring clips missing there is nothing to return the bearing carrier back to its resting position , it's possibly come down the key too far at some stage and eventually come off the key, sat at the end of the snout and rotated on the snout (though I'm surprised the carrier hasnt worn as well, maybe the end of the key broke off inside the carrier and caused the wear?).

I'll have to try and source a snout and the spring clips somewhere.

the joys of working on a 60 year old tractor, the more you look at things the more you find!

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db2d
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Re: 880 Implematic cracked block and head issues

Post by db2d » Mon Jan 25, 2021 5:48 pm

The figure of eight is the easiest bit. Try WWW.DAVIDBROWNPARTS.COM

Brend880
Posts: 9
Joined: Sat Dec 19, 2020 11:14 am
Location: Tyrone

Re: 880 Implematic cracked block and head issues

Post by Brend880 » Sat Feb 20, 2021 7:52 pm

Removed the old snout, shaft etc today and noticed there was no felt washer. looking at some of the posts on the site and the parts diagram there should be a felt washer where the shaft meets the muff coupling? I dont quite see what it would do though as its not going to stop oil coming out between the shaft splines. Funny thing was there were no oil leaks from the gearbox in to the clutch housing but I obviously want to put it back right now I have it dismantled.

My question is should there be a felt washer and if so where exactly does it sit?

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