[DeTomaso] 1972 Pantera shift linkage

[MikeLDrew at aol.com]

Hi guys,

I'm coming into this a bit late; I was stuck in Iraq with no e-mail access. 
  Now I'm in Spain, going to Afghanistan tonight.   Whoopee!

Anyway, there are several things to look at when the shifter doesn't work 
properly.   One of the most easily overlooked things is the trunnion bearing, 
the shift rod support that's mounted to the chassis on the left side of the 
engine.   I had shifting issues with my car which turned out to be caused 
by this sucker coming loose; fore-aft movement of the shift rod wasn't being 
properly transmitted to the gearbox due to unwanted side-to-side movement of 
the trunnion.   Raising/lowering it can also impact shift performance.

While really gross adjustments of the side-to-side and fore-aft positioning 
of the lever can be accomplished by 'clocking' any part of the shift 
linkage U-joints on the splined shafts, it is really unnecessary most of the time. 
  Adjustment is supposed to be accomplished by means of the adjustable 
turnbuckle.   This is located ahead of the trunnion bearing, and consists of a 
tube with standard threads on one end and reverse threads on the other (the 
reverse thread end is easy to spot, both by looking at the threads, and also 
by virtue of the fact that the nut has small notches in it to indicate it's 
a reverse thread nut).

If you loosen BOTH locknuts, you can then turn this turnbuckle one way, and 
the total length of the shift rod assembly will shorten (drawing the shift 
lever towards the rear); turning it the other way will cause the lever to 
move forward.   Now, for side-to-side adjustment, you tighten the forward 
locknut only.   Turning the turnbuckle now moves the shift lever side-to-side 
(as well as shortening or lengthening the total length of the system, although 
the adjustment is miniscule because you're only turning the thing a 
fraction of a turn).

When I was in France for the International Meeting a few years ago (2008 I 
think), Alain Guerin was having a hell of a time with his linkage.   He had 
been working on it alone for two or three hours and couldn't get it set up 
properly.   It's admittedly much easier with two people (one to hold the 
shift lever), and working together we got it sorted in under five minutes.

The first step is to ensure that the shift lever is centered in the 
fore-aft plane.   Put the gearbox in neutral, and turn the turnbuckle as required 
to get it centered up.   Then tighten the forward locknut, and pull the lever 
into 3rd gear.   Tightening the locknut puts torque on the system, so if 
you have the lever centered perfectly in the gate when tightening, when you 
let go it may be deflected slightly to one side.   Trial and error will enable 
you to find the right place to hold it, so that it's properly centered when 
you're done.

I've also done this job working alone with good results; I simply wedged 
wooden shims in between the shift lever and the fingers of the gate while 
tightening the locknuts.

Also, at the risk of stating the obvious, make sure that all the U-joint 
pinch bolts are super-tight.   I had a problem once where I couldn't get any 
of the 'forward' gears (reverse, 2nd, 4th) because a pinch bolt had come 
loose; moving the lever forward of the neutral position didn't move anything 
past the loose U-joint as it slid forward on the splined shaft, but pulling it 
to the rear caused it to bind up so I could get those gears.

Good luck!

Mike