Trannsmission Problem

[warren va]

What could be causing my transmission on my 28 tudor to jump out of high gear occasionally while driving.
Warren

[boomerusmc]

Warren,

Any recent transmission work or replacement? There was a recent thread on a similar issue:

http://www.fordbarn.com/forum/showth...ight=jump+gear

[Joe K]

Very likely a bad pilot bearing in the flywheel. Causes the input shaft of the tranny to "wallow" and walks the output shaft out of engagement.

Also adjustment of the clutch. If the throwout bearing "rides" on the fingers of the clutch throwout arms, the vibration can cause the same effect. You need that 1" of free play at the pedal before it touches.

A vibrating u-joint can have the same wallow effect from the other direction - but this one you're likely to feel. (or hear.)

Joe K

[Bob/Kansas City]

Originally Posted by Joe K

Very likely a bad pilot bearing in the flywheel. Causes the input shaft of the tranny to "wallow" and walks the output shaft out of engagement.

Joe K

It could also be the nose of the main drive gear shaft itself (input shaft) that has worn and become loose in the pilot bearing. The dimension of the nose should be .668" and if worn more than about .002" will need to be built up or replaced. Another area to look at before pulling the trans is wear in the shift tower - worn forks, plungers, shift rails etc can cause trans to walk out of gear. It's much simpler to inspect and repair the tower if necessary than to pull engine and trans or rear end and trans...

[Tom Wesenberg]

Has the flywheel cover been dialed in?

The top 2 ears need shims, usually about the same thickness as the gasket.

[BILL WILLIAMSON]

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I'd first try replacing the shafts, detent plungers & spring, in the shift tower.
Bill W.

[larrys40]

Warren,
I agree with all the guys above. There are things that are easiest to do/check first which suggest. In short when in high gear the 2nd and high gear is directly engages to the main drive input shaft. which is always spinning . When alignment issue from wear and tear/flywheel housing shims missing, etc, it can cause the alignment of that to torque slightly which can cause the gear to walk off engagement while under power.

Bill mentioned the shift tower. I would definitely look at that first and look for wear. The shift ball ends get worn as well. Spring and plungers get weak... That's the easy one. check for shims between the upper ears ( where the accelerator linkage bolts) and make sure there's thin shims between the block and the ears of the flywheel housing. The shims account for the gasket difference on the back of the black to flywheel housing when it's assembled. If not used it puts undo stress and pressure on the housing and they will crack and cause issues. It is hard to see but with good light and inspection you usually can see. You may need to unbolt the accelerator linkage to take Look from the engine/firewall on the drivers side and you may need an inspection mirror slightly from the inside (floorboard removed) on passenger.

if in then remove transmission to proceed with checking the input shaft and bearings as they have noted

Keep us posted. It is nice to know what the outcomes are.
Larry Shepard

[JohnLaVoy]

The shift tower is an easy fix and is very likely the problem. There were some repro plungers that were incorrect and add to the problem. The ones from Brattons, Snyders etc. are correct now.

[warren va]

Thanks to all for your replies. Will start with the shifting tower and work my way down from there.

Thanks again

Warren