Doug Nash Corporation was able to produce a Muncie 4 speed case, around late 1960’s to early 1970’s, it was called the Doug Nash Muncie 4 speed case, along with it is a gear set.  The best thing about it, is that it is heavy and made up of nodular iron, on the other hand its reverse idler boss would break under load, which became a big problem to them, because their counterpart which is a factory GM alloy case, never encounter such problems.  That was the start of their downfall, because instead of solving the problem, they ignore it that makes it grow even worse.  Another problem that Doug Nash has faced, and again was not able to succeed, which in the end makes him packed up his bag and leave was during the year 1986, when the Corvette Overdrives that they designed where defective and to add more the street 5speeds were breaking.

It was a company named Eaton Corp., which designed the gear set that Doug Nash was selling; it was based on a 12 lug “pro-shift” design. The gear set were 9310 nickel gears that uses a special 2nd, 3rd, counter gear and an input shaft.  During those days, T104 speed was produced accompanied by a 9310 nickel gears, that makes the Nash set used a 1st gear that has a special spacer, to complete the set the remaining Eaton made pro- shift gears were added.

Everything has its flaws, and so does the set, its pro-shift gear lugs were machined into the gear and so it can’t be removed.  Because of this, you have to go to Nash and returned the gears, whenever the lugs wore out, so that Nash would be able to get the old lugs ground off and a new lug ring be welded on, which was a bad idea because services at Nash was horrible.  Finally and thankfully Liberty’s High Performance Products allowed people to send in Nash gears, and they will be the one to reprocess them.

 

MUNCIE Four 4 Speed TRANSMISSION Service Repair Manual is available now.

This is the same Muncie Transmission used on all the GM cars of the 60's & 70's era including Corvette, Camaro & Firebird very informative and illustrated with easy to follow directions. All the information you need to show you how to completely rebuild this Muncie transmission by yourself. The manual is available in two versions: For the printed version please click here For the downloadable e-manual version click here