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Onan CCK Rebuilding FAQ


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  #1  
Old 01-05-2009, 10:14:22 PM
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Default Onan CCK Rebuilding FAQ

The following info applies to many Onan gensets with the two cylinder opposed twin air-cooled engines.

The Two Piece steel backed main bearing part number 101-0804 can be used front or rear on all CCK, CCKA, CCKB, B series, BF, BFA, BGD etc. N series, NH, NHC, NHD, NHE etc. and also the P series, P216, P218, P220 & P224 Onan twins. Onan used this exact bearing originally from the factory for the front and rear but the parts book will call for a 101-0805 one piece bearing for the front.

Two problems with the aluminum non-steel backed 101-0805 one piece main bearing: The cost is nearly double that of the two piece steel backed main bearing and it has known issues with fit/shrinkage.

In certain cases the 101-0805 one piece bearing will "shrink" when pressed into the block and the result is little or no clearance. The 101-0804 two piece bearing is steel backed and I have never seen or heard of any clearance/fit issues ever.

Part number 101-0804 is a direct replacement for or supersedes the following part numbers found in many Onan parts books.

101-K420, 101-0420, 101-0450, 101-0432 & the 101-0805

For undersize just add -10, -20 or -30 to the part number for .010", .020" & .030" when rebuiding your genset.
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  #2  
Old 01-21-2009, 02:32:21 AM
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Default CCK CCKA CCKB Intake Valve Guide Seals

When rebuilding or overhauling your CCK series genset this is the time to update to intake valve guides with the provision for use of intake seals. This was an option not found on most CCK series engines but it is very easy to do the upgrade for improved oil control on that old genset.

If your old guides do not look like the one pictured with the raised area to install seals on then get the following parts.

Two Onan intake guides part# 110-1827 and two Onan intake valve stem seals part# 110-3604. As of the date of this post these parts are readily available from Onan.
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  #3  
Old 06-08-2009, 12:23:10 AM
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Default Piston Ring Part Numbers & Sizes 10KW or less

The following info is for piston rings as found on Onan gensets 10KW or less with 3 1/4" & 3 9/16" bores.

CCK, CCKA, CCKB, JB & JC. 3 1/4" bore.

Part # 113-0332 is the current number as of the date of this post.
The above number supersedes the following #'s.
113-0152
113-0153
113-0107
113-0089

Add a -10, -20 or -30 for oversizes.

For the popular "N" Series engines: N52M, NH, NHA, NHB, NHC, NHD, NHE, NHP, the T260G & P224G with 3 9/16" bore it gets a little more interesting.

The only accurate way to determine the correct rings for these engines is to measure your old compression ring thickness. Onan changed the ring and piston design several times over the production life of these motors and going by the book may or may not get you the correct part. Spec number unknown, original pistons changed etc.

Part # 113-0296 has compression rings that are .078" or 5/64
The above number supersedes 113-0203

Part # 113-0311 has compression rings that are .058" or 1/16

Part # 113-0312 has compression rings that are .093" or 3/32
The above number supersedes the following numbers:
113A165
113-0165
113-0166
113-0202


For "B" or "P" series with 3 1/4" bore: BG, B43, B48, P216, P218, P220 etc. there are two possible ring sets.

Part # 113-0310 has compression rings that are .058" or 1/16

Part # 113-0314 has compression rings that are .078" or 5/64


TJ
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Old 08-16-2009, 08:51:07 PM
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Default How to remove crank timing gear and crank.

How do you remove that crankshaft timing gear on an Onan two cylinder opposed twin engine? CCK, CCKA, CCKB, B, P & N series.

No room behind it to give the gear puller arms a place to grip and until that gear is off the crank is not coming out!

Time for a "special tool". I made this adapter years ago and never got around to making it perfect.....if it works don't fix it! This was a chunk of steel I made to bolt on to the gear face via the two 10X32 threaded holes already tapped in the gear. Use allen style 10X32 as they typically are grade 8. Cheap or low grade screws will break! 20 years on these and they are in perfect shape.

Grind a small notch on the back side for clearance of the gear woodruff key. You can see where it sticks out slightly in the second pic. Put the flywheel bolt back in all the way for the puller bolt to bear against. The gear is a press fit and on VERY tight.
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Last edited by OnanParts; 08-16-2009 at 09:28:46 PM.
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Old 08-16-2009, 08:53:18 PM
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Default Remove timing gear and crank.

Adapter bolted on to gear. Just tighten the bolts until they are snug. Puller setup and ready to go and then gear almost halfway off. I did this one by hand with a plastic mallet handle wedged into the puller arms to keep the block from trying to roll and get away! The tougher ones require Mr. Impact!
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Last edited by OnanParts; 08-16-2009 at 09:29:35 PM.
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Old 08-16-2009, 08:55:28 PM
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Default Remove timing gear and crank.

OK, Mr. crank timing gear is now separated from the crank and we can now remove the crank from the block.
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Last edited by OnanParts; 08-16-2009 at 09:30:07 PM.
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Old 08-16-2009, 09:14:53 PM
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Default Remove timing gear and crank.

Rear bearing plate bolts removed. Do NOT pry this plate off with a screwdriver! Doing so will in most cases damage the gasket sealing surface! Put that screwdriver down! NOW! OK, grab a plastic or rawhide mallet or a block of wood and "gently" tap on the flywheel end of the crank. Keyword is "gently". You just want to get the rear bearing plate to separate from the block not launch it across the garage floor!

Tap tap, ok it's free now but still with the block. Push the crank back in and hold it in while carefully pulling the bearing plate out and off.
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Last edited by OnanParts; 08-16-2009 at 09:30:37 PM.
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Old 08-16-2009, 09:17:04 PM
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Default Remove timing gear and crank.

Line up the crank with the area pictured on the block that is relieved for just this purpose and very carefully and slowly remove the crank. Slow and easy so you don't ding or damage the journal surfaces.
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Last edited by OnanParts; 08-16-2009 at 09:30:58 PM.
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Old 08-17-2009, 02:30:31 AM
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Default Valve guide replacement Onan opposed twins

Onan valve guides hold up really well but at some point they will need to be replaced.

For those of you that are going to replace them here are the part numbers, specs and how to remove and replace.

B series: B43E, B43G, B43M, B48G, B48M etc.

Intake guide: Part # 110-3161. Takes intake seal 110-3604
Exhaust guide: Part # 110-1935 This # supersedes 110-1807

P series: P216G, P218G & P220G.

Intake guide: Part # 110-3526. Takes intake seal 509-0289
Exhaust guide: Part # 110-3527

B & P series Intake valve clearance (stem to guide) 0.0010-0.0025

B series exhaust valve clearance (stem to guide) 0.0025-0.0040

P series exhaust clearance (stem to guide) 0.0020-0.0035

See previous post for CCK numbers. Stem to guide clearance is the same as a B series.

First part is removing the old guides.

Tools required: Hammer and a stepped punch that will fit down the guide bore.
No stepped punch in the toolbox? No problem. Use a long bolt with a nut threaded at least an inch up with a small washer as a shoulder and drive the guides into the valve box. Lifters need to be removed before attempting this!
You should be able to see the guide around your punch/homemade driver. You don't want to scar up the guide bore here!

Put a small rag in the valve box to catch the guide and prevent damage to the lifter bore. A couple of good whacks to get the guide moving and then easy tap tap tap until it falls into the valve box.

Intake guides have the raised shoulder for the stem seal and the intake valve/guide is always at the rear end of the block. Exhaust valve/guide always at the flywheel end of block. Intakes valves are larger than the exhaust.

First pic is of my home made copy of the factory stepped seat guide tool with some 1/4" all thread and washers. Use a lock nut at one end with correct size washers built up for intake or exhaust seat for the do it yourself super cheap tool. Don't go oversize because you want the washer to rest on the seat shoulder not the block. Seats and guides are at an angle compared to the head gasket surface and you want the guide to be pulled in nice and easy.

Small washer with oversize nut and regular nut for the guide or valve box end. Second pic is of the all washer cheap tool. Washers work fine if you pay attention to the next part. Put some clean engine oil on the outside of the new guide before installing.

When you are turning the locknut/all thread go easy and keep it centered so you don't mess up the inside of the new guide with the all thread. You may or may not have to put a wrench on the nut inside the valve box.

Some CCK/CCKA/CCKB series intake guides use a thin rubber gasket, new part # 110-3136. Old # 110-0068.

Third pic ready to start pulling the guide in.
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Old 08-17-2009, 02:33:31 AM
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Default CCK Rebuilding FAQ

First pic of guide halfway in and second pic it's all the way in and done! You will feel when the guide bottoms out, it's not a lug nut so stop turning the wrench at this point.
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