case 1680 - The Combine Forum
Register Home Forum Active Topics Gallery Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools
Old 07-23-2011, 03:33 PM   #1 (permalink)
Member
 
Join Date: Nov 2009
Posts: 74
Default case 1680


have had recurring problem of broken top sieve, have replaced all bushings and centered properly, all related bearings have been replaced.
Now the sieve is broken again and shoe side rail has snapped, has anyone else had this problem?
mbcat is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 07-23-2011, 04:13 PM   #2 (permalink)
Senior Member
 
Join Date: Jun 2007
Location: Leeds, north dakota
Posts: 1,987
Default

You need to pull bottom part below sieve assy, bet its broke or twisted, should use tool to alighn, bushings assembled correctly, washers in between shaker arms? replace sieves with plastic ones from Westward is on manufacturer, alot littler, easier on shoe, long shoe? got questions fire away, Scott.
scott is offline   Reply With Quote Quick reply to this message
Old 07-23-2011, 08:16 PM   #3 (permalink)
Senior Member
 
doorknob's Avatar
 
Join Date: Jun 2006
Location: Hillsboro Oregon
Posts: 2,346
Default

Did the bushing and bearing replacement include the cams and cross shaft?

There is a hex shaft that drives the conveyor augers and connects both sides of the shaker. On each side there is a cam that runs inside those large ball bearings. On the left side, the cam will wear where it is fit to the shaft. Once this wear gets a bit slack, the two sides of the shaker will not be in time anymore.

One other thing, when you remove the chaffer, does it come out really difficult or just slide out? It should be a bit tight to get out. You near have to use a crow bar to get it started. If it just pulls out even once the hangers are lowered, it may be loose on the front side. There are lock nuts on those bolts and very little adjustment will go a long ways.

Here's a picture of the cam location even though you likely already know.


Here's a link to a write up I did on agtalk about how I choose to rebuild the shaker. It also explains the alignment tool use.
Viewing a thread - CIH combine shaker system R&R. (with some pictures)

Here's something else I did to help hold the chaffer a bit better.
Viewing a thread - CIH combine chaffer mount. Your ideas? Mine with pics.

This thread, a few replies down, has pictures of my chaffer fix after I got tired of them beaking.
Viewing a thread - 2388 broken chaffers?
Attached Images
File Type: jpg IM001936.JPG (218.5 KB, 175 views)
doorknob is offline   Reply With Quote Quick reply to this message
Old 07-24-2011, 08:16 AM   #4 (permalink)
Member
 
thn43's Avatar
 
Join Date: Jul 2010
Location: Chatham, MS Mississippi Delta
Posts: 99
Default

I had this problem on a 1688, the hex cross shaft was twisted throwing it out of time, also I put in a slow down kit, a pulley change slowed down the sieve. I had no more problems after that. If you have a long sieve 1680 I would think the slow down kit would help alot.
thn43 is offline   Reply With Quote Quick reply to this message
Old 07-24-2011, 11:04 AM   #5 (permalink)
Member
 
Join Date: Nov 2009
Posts: 74
Default

Thanks for the replys everyone, i pulled the bottom sieve assembly and it looks ok,not twisted or broken.im going to replace the hex cross shaft and hub cams on both sides and new bushings.where would i get the alighning tool to square it all up? The slow down kit sounds good as the shaker shoe seems to run too fast.Read the whole thread on the shaker system doorknob and found it excellent,just what i needed thanks. any ideas why the bushing support plate on the pitman arm would break,both sides have broken before and welded before i owned it. Its a long shoe scott and the spacer washers were in place.are the plastic sieves adjustable or the same as an airfoil?
mbcat is offline   Reply With Quote Quick reply to this message
Old 07-24-2011, 12:13 PM   #6 (permalink)
Senior Member
 
doorknob's Avatar
 
Join Date: Jun 2006
Location: Hillsboro Oregon
Posts: 2,346
Default

Your dealer should have the alignment tool, and maybe will let you borrow it if you do business with them, or maybe would rent it to you.

The slow down kit was a remedy for a speed up kit the 2188s had. Possibly the last 1688 had them to, but your 1680 should be the same speed as the slow kit, or as it should be stated, the same speed as normal.

The plates would break because someone either did not tighten the bolts well enough, or they used the stock bolts that are called for in the book. I looked at the bolt length and position in the arm, and really did not like it. So,....I use USA made grade 8 bolts that the shoulder goes all the way through both the cast part and the plate. The threads stick out a bit further and a cut off wheel should be used to cut them off, but the issue that I see is when you have a bolt in that position with the shoulder in part of it and threads in the other half, it is a problem looking for a place to happen.

There is a needle bearing setup on the pivot pins of the pitman arm. Those pins and bearings are replaceable and relubricable. 2-3 pumps each morning should suffice, no matter what the book says about them being 50 or 100 hour zerks. IMO.

When you replace the hex shaft, there is a 3rd bearing in the center of the shaft. That bearing holder has slotted holes. When you install the new bearing, leave the bolts loose until you have the shaft installed. Then tighten the bolts, holding the bearing in a neutral position. When the combine leaves the line, it has not had a load on the superstructure yet. Once a few heavy loads are hauled around and a few bumps hit, the superstructure will "settle" or shift slightly to it's life long places. Usually this shift places a bind on that bearing, which contributes some to the early failure of the shaft and cams.
doorknob is offline   Reply With Quote Quick reply to this message
Old 07-25-2011, 11:05 PM   #7 (permalink)
Member
 
thn43's Avatar
 
Join Date: Jul 2010
Location: Chatham, MS Mississippi Delta
Posts: 99
Default

The slow down kit was the best money we spent on the 2 1688's we had, The bushings lasted alot longer and the screens never broke again. The pulley on the 1680 must already be the bigger one according to doorknob.
thn43 is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply


Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the The Combine Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 04:56 AM.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0