TRACTOR PARTS Allis Chalmers Case & David Brown Farmall & International Ferguson Ford & New Holland John Deere Massey Ferguson Massey Harris Minneapolis Moline Oliver & Cockshutt Kubota / Yanmar

TRACTOR MANUALS

Allis Chalmers	Case	Farmall IH	Ford 8N,9N,2N	Ford
Ferguson	John Deere	Massey Ferguson	Minn. Moline	Oliver

Farmall & IHC Tractors Discussion Forum

300U Tachometer Problems

Welcome Guest, Log in or Register

Author

Kerwin

07-28-2006 18:52:05

Report to Moderator

The tach on my 300U has stopped working correctly. It had been running fine since installing new cable a couple of years ago. Now, once the engine is running it spins around a couple of times and sticks at 0 rpm. Almost like it is spinning too far.

Can these tachs be rebuilt? Or who would sell a replacement for a 300 Utility. I believe they are different than the 300 Farmall. Thanks for the help.

[Log in to Reply] [No Email]

Rumplestiltskin

07-31-2006 09:09:59

Report to Moderator

Re: 300U Tachometer Problems in reply to Kerwin, 07-28-2006 18:52:05

Kerwin:

Check eBay. There is a guy in the Grand Rapids, MI area who sells new reproduction tachs. They usually seem to go for about $60. I think I saw a couple on there last week.

I don't have my parts manual handy, but I seem to remember there were two different tachs available for the 300 Utility. You may want to double-check to make sure you get the right replacement.

As for myself, I have a "tach-less" 300 Utility. I was planning on buying a rebuilt tach, but judging from the postings I've read recently it sounds like the drive gears may be hard to come by. I may end up going electronic -- the old "originality vs. practicality" tradeoff.

Mark W. in MI

[Log in to Reply] [No Email]

Janicholson

07-29-2006 09:00:06

Report to Moderator

Re: 300U Tachometer Problems in reply to Kerwin, 07-28-2006 18:52:05

When the bearings in the tach head get dry or loose, they act that way. It is possible to unbend the bezel and take it apart (I grind a pair of pliers to make a sharp edged hook shape lip to assist the unbending) Or take it to a pedometer shop (big city thing) or buy a new one. If stock is not an issue, Sun makes electronic tachs that fit the hole well.
JimN

[Log in to Reply] [No Email]

Kerwin

07-29-2006 12:32:28

Report to Moderator

Re: 300U Tachometer Problems in reply to Janicholson, 07-29-2006 09:00:06

When I first got the tach working again I had the bezel off to put new glass in, so I should be able to get it apart again.

Once the tach is apart, what should I be looking for/fixing? Thanks.

[Log in to Reply] [No Email]

Janicholson

07-29-2006 15:49:35

Report to Moderator

Re: 300U Tachometer Problems in reply to Kerwin, 07-29-2006 12:32:28

There is a cup shaped rotor made from aluminum in the middle of the guts of the beast. This cup is driven around and around by the tach shaft. there is a bearing controlling the location (accurately) of this cup. The cup is a eddy current driver. The needle is connected to a hair spring just behind the face plate. Under this hair spring there is a magnet that sits inside the cup. This magnet is located by a small bearing in the inside cf the cup. This, and the cup bearing need a light synthetic lube Found at good hardware stores, and other places, ___not 3-n-1 or other plain petroleum oil___ . Lube sparingly and put it back together.
The magnet sets up a field in the cup. This field is intercepted by the cup. when the cup turns, the field moves in the cup setting up what are called eddy currents in the metal of the cup. These currents oppose the magnetism in the magnet, causing the magnet to be dragged in the direction of the cup's rotation. The faster the rotation, the more current, and the greater the drag on the magnet. This rotation on the magnet is opposed by the hair spring, and the opposition is what causes the needle to point to the correct rpm. I hope this helps, JimN

[Log in to Reply] [No Email]

biggerred

07-29-2006 10:44:08

Report to Moderator

Re: 300U Tachometer Problems in reply to Janicholson, 07-29-2006 09:00:06

I just recently hooked up with an outfit to sell brand new reproduction tachs for those tractors. (55.00 plus shipping) In fact I put one in my 300U and it really looks great to see a shinny new tach in that gaping hole. I still need the plastic drive gear in the dist drive though.

[Log in to Reply] [No Email]

[Options] [Printer Friendly] [Posting Help] [Return to Forum] [Log in to Reply]

TRACTOR PARTS	TRACTOR MANUALS

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

Home | Forums

Copyright © 1997-2023 Yesterday's Tractor Co.
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters

Website Accessibility Policy