Re: Hi-Lo Gear Arrangement on 8N

Posted by Nolan on March 05, 2003 at 17:38:15 from (63.64.219.158):

In Reply to: Hi-Lo Gear Arrangement on 8N posted by BA on March 05, 2003 at 12:55:31:

You most likely have a Sherman. There are other auxiliary transmissions that had a lever on the left side, but they are very rare.

The Sherman came in three flavors. Overdrive, underdrive, and combination. The overdrive and underdrive units are two speed, with the combination being a three speed.

They can be identified by the shifter lever arm. The two speed units of either overdrive or underdrive have a straight lever arm. The combination units have a dogleg shaped lever arm.

The overdrive and underdrive units had a straight forward and back shift pattern. Back was direct, forward engaged the auxiliary gears giving either the overdrive or underdrive effect.

The combination unit has the same forward and back shifting motion that is for overdrive and direct. Underdrive is engaged by going mid way through the motion to neutral, pulling the lever straight out away from the bell housing about an inch, and then shoving it forward.

It is not at all uncommon to find a combination unit that hasn't had underdrive engaged in decades because it was forgotten about by a previous owner and none of the subsequent owners knew it was there. That was the case with my Sherman equipped Ford 8N.

Do understand that the Sherman is in front of the main transmission, and affects ground speed and pto rpm identically. You don't actually gain a 12 speed gearbox.

The sherman was designed to allow the engine to run at higher rpms in underdrive mode for the correct pto rpm, thereby giving an effective 30% power increase. Overdrive mode was for transportation in road gear. It does allow the engine to operate the pto at near idle, which can save gas when very lightly loaded.

Follow Ups:

• Re: Re: Hi-Lo Gear Arrangement on 8N BA 19:46:23 03/05/03 (0)

Post A Followup Name: E-Mail: Subject: Re: Re: Hi-Lo Gear Arrangement on 8N Comments: Optional Link URL: Link Title: Optional Image URL: Email Notification: If you check this box, email will be sent to you whenever someone replies to this message. Your email address must be entered above to receive notification. This notification will be cancelled automatically after 2 weeks.

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 ]