Page 1 of 2

broken crankshaft 184 lowboy

Posted: Fri Jun 22, 2012 8:47 pm
by dalebaklund
The flywheel started shaking violently , pulled engine , dropped pan and crankshaft was broken between rear main bearing and first rod journal. 184 ser. # 2000115u047164* , engine #251341 R8 , L3 , 62B 1 . Was being used for mowing at the time it broke. Does anyone think the PTO belt set up is causing cranks to break ? It seems like the belt pressure pulling to the side could put excessive pressure on the crank. Any suggestions Please. The crank in engine is marked M .010 - R .010 , I'am thinking it means the crank has been ground down .010. I haven't pulled the crank out yet to measure it. I have purchased a different crank, and it measures 1.6235 main , 1.4986 rod journals. I think is factory size. I want look at the bearings in the engine for wear to see if I should have the new crank ground down .010 or buy new factory size bearings . Any suggestions Please . What is the proper clearance on main & rod bearings per side / or total , (.003 total ?)

Re: broken crankshaft 184 lowboy

Posted: Sat Jun 23, 2012 5:05 am
by twotone
Dale the proper bearing clearance is 2-3 thousanths total. I don't what is causing your cranks to break.

also welcome to the forum!


Tom

Re: broken crankshaft 184 lowboy

Posted: Sat Jun 23, 2012 6:55 am
by Eugene
dalebaklund wrote:I have purchased a different crank, and it measures 1.6235 main , 1.4986 rod journals. I think is factory size. I want look at the bearings in the engine for wear to see if I should have the new crank ground down .010 or buy new factory size bearings.
Buy bearings to fit the new crankshaft. Do not try to reuse the old bearings.

Do a thorough job of measuring the new crankshaft. Measurements will tell you if you need to have the crankshaft ground or polished and the bearing size to purchase.

Don't know what caused the crankshaft to break. The pto set up is not a likely cause. Examination of the crankshaft and other engine parts after disassembly will probably reveal the cause.

Just me. Since you are going to have to almost fully disassemble the engine to remove the crankshaft - I would refresh or rebuild the entire engine.

You need a specialized puller to remove the crankshaft front pulley. Examples of the pully puller are available on this site. Do not use the typical 3 jawed puller - it will break the pulley.

Re: broken crankshaft 184 lowboy

Posted: Sat Jun 23, 2012 7:16 pm
by dalebaklund
Thanks for welcoming me to your forum :D Thanks for the input its much appreciated :D One more question about the year of my cub lowboy 184 , can someone tell me the year by the ser. # I listed on my first posting , & what does the engine # mean ?

Thanks Dale

Re: broken crankshaft 184 lowboy

Posted: Sat Jun 23, 2012 7:22 pm
by Rudi
Dale:

Your 184 going by the Serial # 047164, is a 1974 and you can see that by clicking this link Cub FAQ's #1 on ATIS. I don't have a lot of information on the Numbered Series Cubs, but I do have some - Cub-184 Lo-Boy. Suggest you follow the links below as there is all kinds of resources available to our members.

Image to Farmallcub.com :big smile: Forum Family. And you have come to the right place for all things Cub related. If you click on the Site Rules, Regulations, & Important Information, it will point you to :arrow: the Welcome Wagon wherein you will find links to many useful sites and topics. One of which is the Cub Manual Server. Enjoy!.

Re: broken crankshaft 184 lowboy

Posted: Mon Jun 25, 2012 8:48 pm
by dalebaklund
HI :D I found in FAQ on Farmall Cubs , The international 184 Low-Boy , red in color , was made in the years 1977-1980 , the sel # 047164 would make it a 1978 . Can anyone confirm this ? Thank :D I also learned that spect's for the Cub crankshaft are 1.623 to 1.624 dia. main , 1.498 to 1.499 dia. rod . These spect's. put the crank I purchased right in the middle , not bad for a used crank . :{_}:

Re: broken crankshaft 184 lowboy

Posted: Mon Jun 25, 2012 9:47 pm
by Jim Becker
Yes, your serial number is from 1978.

From the numbers you read on the engine, "251341 R8 , L3 , 62B 1" we have:
251341 R8 --- part number of the engine block, doesn't tell us much at this point.
L3 --- meant something to someone at the time, no real significance.
62B --- probably looks like *6.2.B* date code, June 2, 1978, agrees with the serial number. This is the date the block was cast in the foundry. The tractor was built at some later date.
1 --- meant something to someone at the time, no real significance.

The above codes were CAST into the engine block. The actual engine number is STAMPED into the block. It is in a flat area above the part number, mostly blocked behind the carburetor.

Re: broken crankshaft 184 lowboy

Posted: Tue Jun 26, 2012 9:00 am
by outdoors4evr
DaleBaklund,
I just went through this on my 184 last fall. Might want to check the pistons (make sure they are the dome topped aluminum)
Here's a link to the thread and what I found on mine. Your issue may be different, but severe investigation is required.
viewtopic.php?f=31&t=65141&p=533192&hilit=crankshaft#p533192

Re: broken crankshaft 184 lowboy

Posted: Tue Jun 26, 2012 6:44 pm
by dalebaklund
I found rod bearing sets for $7.00 / per rod in std -.002 ,-.010 , -.020 , -.030 , but no main bearings .(at NAPA auto)
:help: I was thinking of washing down the gaskets still stuck to the pan & front engine plate with alcohol or other solvent and using RTV to seal them . Any suggestions ?
My 184 cub has the large tapered front fan , alternator pulley , of which I haven't been able to locate a puller . Looks like I'll have to build one , I like the one using a hyd. jack .
My flywheel has ball bearing in it , do I really need pilot bushing in the crankshaft , what would bushing do in the drive sys ?

Re: broken crankshaft 184 lowboy

Posted: Wed Jun 27, 2012 1:05 pm
by outdoors4evr
Get the gaskets. They don't cost much from NAPA, though you will have some leftovers in the kit. The one for the cub works well. I ordered my main bearings from TM (link @ bottom of page).

Regarding the front pulley, I didn't have a puller. Since my crankshaft was trashed, I removed the front cover and crankshaft from engine and took it to the vise. Clamped the crank in the vise, removed the bolt from the pulley and drove the front timing gear off the crank with a hammer and a chisel. This pushed the cover and the front pulley off the end of the crank.
Be sure to change that front crank seal in the cover.

Re: broken crankshaft 184 lowboy

Posted: Sat Jun 30, 2012 4:49 pm
by dalebaklund
I was expecting a tug-of-war getting the front pulley off , so I made a very strong puller , started pulling and it came off effortlessly :D
Still looking for someone that has tried RTV on their gaskets ?

Dale

Re: broken crankshaft 184 lowboy

Posted: Sun Jul 01, 2012 5:11 am
by outdoors4evr
I used RTV on my oil pan because I didn't want to use a more permanent (harder to remove) gasket sealer. It's leaking of course.
I should have just sealed it with a gasket & sealant like indian head.

Re: broken crankshaft 184 lowboy

Posted: Sun Jul 01, 2012 6:57 am
by River Lizard
Try Loctite 598 it should hold up for the application

Re: broken crankshaft 184 lowboy

Posted: Tue Jul 03, 2012 7:25 pm
by dalebaklund
Just a little info. I've found about Rod & Main Crankshaft Bearings .
NAPA has rod bearings for $7.00 per set .
O'Reilly's Auto has rod b $9.50 a set,& mains for $32.75 a (3) set .
Carquest Auto has rod b (r11) $17.94 a set ,(r3) $14.12 a set , main b $60.00 a (3) set.
Case IH rod b $13.96 a set , main b (2) $47.92 , Main center b $71.82 ea .
(rod set is for 1 rod)
If someone has this info. I would like to know the torque settings for the rod cap bolts & main bearing cap bolts ?

Thanks For Everyones Help & Happy Wrenching :)

Re: broken crankshaft 184 lowboy

Posted: Thu Jul 05, 2012 8:55 pm
by dalebaklund
I was looking through Rudi's Farmall Cubs I & T -50 Condensed Shop Manual , I found the torque for rods = 16 ft lbs , mains =55 ft lbs , Flywheel bolts 45 to 50 ft lbs . That should take care of the assembly bolt torquing .

Learning more every day , Dale :) Click on page 2 for a picture of my 184 , Thanks :D