1969 521 Tranny issue

[agt]

Not sure what to make of this. Maybe it's something completely obvious, but before I start to sort it out, figured it's best to ask the experts.

 

The engine in my 1969 521 runs strong, all through first gear, all through second, but when I shift into third, I get about half a second of rev, and then it just dies out altogether.

 

No power. It's as if I shifted back into neutral.

 

I can bypass 3rd and go right into 4th from 2nd gear without a problem. But if I try for 3rd, nothing going.

 

Any ideas? Please??

 

Thanks in advance.

[Jayden71]

Is this a late 69 with an L engine/tranny or J series??

 

Could be going past 3rd into a "false" gear?? I have had a tranny do this before. Throw the shifter too far and it feels like its in gear but its really not.

 

Is the shifter real sloppy??

[datzenmike]

'69 would be an L521 with J motor.

 

Can you hold a steady speed (light throttle) in 3rd? Can you drive in 3rd at all??? or does it just rev up and go nowhere???

 

Or does this only happen after accelerating through 1st and 2nd?

 

 

Things to try:

 

Idle the engine and look at the fuel level mark on the sight glass on the front of the carb. Is it near the horizontal line? If not the float level may be set too low.

 

 

Next time it quits, as fast as possible turn off the engine and get the clutch in. Then pull over safely. What we are trying to do is see what the carb looks like while this is happening: so engine off and clutch in as soon as possible. I suspect the carb has gone dry, so if the motor keeps turning the fuel pump will refill it and this won't tell us anything. If this is the case and you find the fuel level low (or empty) replace the fuel filter. They are cheap, about #3 so maybe just change it anyway.

[MicroMachinery]

I had this issue with mine and it didn't make sense.. until I discovered how my dual point distributor worked. I would be driving and shift into 3rd, and the truck would fall on it's face. I couldn't figure it out, it was like truck decided to lose power in 3rd.

To check if you have this, pull your distributor cap and look to see if there are 2 sets of points. If it does, the 2nd set of points retards your timing in 3rd gear and at cruising speed in 4th(Crazy, I know). If your 2nd set of points is way out of adjustment, that would explain why your truck doesn't run worth a darn. At best, it makes it doggy at partial throttle in 3rd. Worst case, it would run like crap, if at all in 3rd.

 

IF your truck has a dual point system, there is a 3rd gear switch on your transmission that acts as a trigger for the 2nd set of points in your distributor cap when you shift into 3rd gear. Find and disconnect this switch, along with the 2nd set of points.

 

All I had to do was disconnect the 2nd set of points from the dizzy, or you can just disconnect the switch. Set the timing for the first set, and that's what your truck will run at. 3rd gear will be smooth all the way through. The difference is like night and day. Try that; it sounds to me like that's what could possibly be what's going on.

[agt]

Amazing. That was it. Bizarre, but thanks so much!!

[MicroMachinery]

You betcha ;)

[Juniper11]

This just happened to me too. The oddity of the problem points me to electrical so I will try this ASAP. Glad to find this!  However- Does disconnecting the second set of points have any negative effects?

 

datzenmike in another thread "72' 521 question about 3rd gear clicking sound.." you were saying the second set effects the performance and emissions.... 

[datzenmike]

If the second set are on the timing will be retarded slightly. This will back off the performance slightly but clean up the emissions.

 

You can simply disconnect the second set to disable them.