Chevelle updates

[VintageMusclecar]

I was going to post a new thread detailing the repairs after the catastrophic driveshaft failure, but that would've made 3 Chevelle threads...which is at least one too many.

So without further ado, here's the new trans for the car:













I had several options on the table to consider after the untimely demise of my Muncie.

1) Jerico 4 speed or 5 speed. (5 speed is based on the Nash/Richmond style trans)

2) GForce 101A 4 speed or (5 speed also a Nash/Richmond style tra... Street 5 speed.

5) Legend LGT700 5 speed.

Several important considerations had to be made (aside from cost, none of which were what could be considered &quot;affordable&quot; Minimal floor pan mods (those done by the driveshaft during it's hasty egress notwithstanding [img]<<GRAEMLIN_URL>>/rolleyes.gif[/img] ) , strength, gear ratios, and availability.

I was first interested in the new Richmond 5 speed as it's now rated for 600 lb.ft where the street boxes are only good to 450 lb.ft. Unfortunately, the Richmond won't even be available until July at the earliest, so I had to scratch that off the list.

The Liberty, GForce and Jerico 4 speeds were eliminated for various reasons, mainly lack of a speedometer provision and shifter fitment issues.

The GForce 5 speed was eliminated due to lack of 5th gear OD along with cost.

The Jerico 5 speed was eliminated due to cost and fitment issues.

The Liberty 5 speed was eliminated due to cost and fitment issues as well.

That pretty much narrowed my choice down to the Legend box. For those who aren't familiar with it, this is the same box that Keisler was selling before they went belly-up. Thankfully the parent company who was actually manufacturing the trans' and components stepped up to continue production.

As luck would have it, Jody Haag (Jody's Transmissions over on the Chevelle forum) just happened to know of the whereabouts of an &quot;exact fit&quot; box for my Chevelle sitting patiently on a retailers shelf. A few phone calls later the trans was ordered and on it's way here.

The Legend box addresses 3 of my needs in near-perfect manner:

1) .069 5th gear overdrive. This effectively reduces the current 4.56 gears down to an effective 3.14 ratio, which means rpm @ 60 mph goes down from ~3300 with the Muncie to 2260. [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img] Once the 3.73 rear end goes in, that 60 mph figure will drop down to a lumbering 1850 rpm--the highway equivalent of a 2.57 gear.

Road trip anyone? [img]<<GRAEMLIN_URL>>/cool.gif[/img]

2) As mentioned before, the primary issue which led up to the failure was the OEM 60&quot; long driveshaft. Thankfully, the Legend is roughly 3 1/2&quot; longer than the Muncie, which shaves the driveshaft down to 56 1/2&quot;. (ALSO, with the trans yoke moved back, that <span style="font-style: italic">should</span> allow the use of a 4&quot; diameter driveshaft!) In addition to this, the new Mark Williams billet CM pinion yoke is 1&quot; taller than the OEM yoke which cuts the figure down to ~55 1/2&quot;. That makes a <span style="font-style: italic">significant</span> difference in the critical speed issue with the driveshaft.

Check out the MW chart to see the difference:



3) The Legend box is not only rated for 700 lb.ft, it is also rated to shift up to 7500 rpm, which is impressive for a fully synchronized transmission.

A few changes are necessary to accommodate the new trans--a swap from a 10 spline clutch disc to a 26 spline, the crossmember will need to be re-located slightly, and the speedometer cable will require a little creative re-routing as the hookup is on the drivers side of the new trans as opposed to the passenger side on the Muncie. However, the shifter is in the exact same spot as the Muncie was, which means no shifter hole surgery will be necessary. It even accepts the previously installed Hurst shifter arm.

I hope to get on the install tomorrow. Once it's in I can measure for the new driveshaft and get it ordered.

I'll report back with pics &amp; more info as things progress.