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Discussion Starter #1
n process of 3 year frame off resto on a 77 bronco. I have a pan fill C4 transmission assembled from a busted C4 that came with truck, and "working when removed" 2wd pan fill from van or pickup. finally at point where truck is assembled enough to test tranny and it will not shift into 3rd gear. Engages in reversed fine. When in D, engages 1st, does not up shift, coasts when let off gas. 2 position will start in 1st gear and upshift to 2nd, 1 engages 1sst gear.

I have scoured the internet trying to find solution, to cut down on some common issues and suggested fixes here is what I know.
-transmission fluid level is where it needs to be
-linkage is fine, valve body is seated where needs to be, as is kick down lever.
-kickdown (cable on my build) is fine , not hung up,
-all new seals, clutches, steels, thrust bearings, endplay in spec
-pin is in modulator, modulator is seated fine, modulator opens completely at around 20inHg,
-manifold vacuum is low at 12inHg, measured at hose where it attaches to modulator (still need to tune holley carb)
-putting shorter pin in modulator to account for missing vacuum (8inHg) does not change shifting issue
-switching valve body to a another "sold to me as working VB" results in the same issues, when I pulled apart the original VB I had transition valve and spring revered, not sure that is the issue though.
-clutches, servos, bands all engage as they should when air tested.
-governor does not flutter when air tested
-the governor in there now is from a "working when removed" tranny, I did not go through it though. Rest of tranny looked fine, just old fluid, nothing in there led me to believe it had any issues.

I'm 3 years and ~$30K in. just want to drive this thing. Please, any help is appreciate. I'm at the point that next step is to send it to a local rebuilder.
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"No upshift" issues are usually the governor.

I'd start there.

You say you didn't go thru the governor... well...

my experience is that Ford governors can be finicky/sticky.

Just look at the damn thing a little sideways and they stick.
 

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Discussion Starter #3
That’s the next step I guess. I have to pull the transfer case. But that should be easier than the whole transmission.
Anything specific in governor I should be looking for when I pull it apart.
 

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Re: Help with rebuild, won’t shift to 3rd

That’s the next step I guess. I have to pull the transfer case. But that should be easier than the whole transmission.
Anything specific in governor I should be looking for when I pull it apart.
Well... sticky valves, obviously.
The trouble is... sometimes when you just touch the thing the valves become free and that makes you wonder WTH...

With the governor removed from the support, but before taking it apart, check the primary valve.

The primary valve is the one with the really light spring and the inside snap ring and a small washer.
The assembly goes... valve first, then spring, then washer, then snap ring.
Sometimes the washer gets cocked and blocks the valve from moving.

Make sure the washer is seated correctly flat against the snap ring.

If the washer is ok, then you can push the valve from the inside and it should stroke freely.

Next the secondary valve you can "pick" the valve with a small screw driver to make sure it's free.

If it all seem ok, you're not done yet...
It could still be sticky, even though it seems free right now.

Take both valves out and wash everything with clean solvent.
Pay attention to the order/assembly sequence and lay the parts out on a clean surface with respect to where they go.

Now this is gonna sound kinda redneck way to fix something... but here goes...

Put the primary valve in the housing but no other parts.
Holding your finger over the open end where the valve goes in, shake it back and forth.
The valve should rattle freely back and forth in the bore.

Now the redneck part...

Holding the gov level with the flat machined surface down and the primary valve in the bore, and your thumb over the open end to prevent the valve from flying out...
Smack the flat machined surface of the governor housing against a flat work bench or other flat solid surface.

You don't have to kill it... just a good fast smack. Make sure to keep it level and flat to the bench.
Imagine that you are using the flat of your hand to smack a bug on a table.

Substitute the governor for your hand... and there you go.

Do this with both valves separately, several times each and also shake the housing with the valve in the bore to make it rattle like before.

The tech behind this...

The aluminum housing gets microscopic burrs in the valve bore that cause the valve to stick.

By smacking it on the bench you are using the valve itself to flatten those burrs in the aluminum, and establish a smooth bore.

You can also turn it over and smack the other side so it flattens the burrs on the "other side" of the bore.

This all sounds crazy but trust me, it works.

You can skip all this, and get a fancy high tech brush hone to polish the bores if you feel like spending some money.

Google search "Superior Bench Buddy" brush hone. Pro tranny guys use them to fix problem valve bores.

After all this... and you are SURE the valves are free, put it all back together,
and be careful to NOT over torque the bolts holding the governor housing to the support.

Making the bolts too tight will warp the housing and cause... you guessed it... sticky valves.

There could be other issues causing your "no shift" problem, but the governor is usually the main culprit.

Good Luck!

 

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Discussion Starter #6
Ok, ordered by bench buddy kit, will pull governor and VB, next week. go through everything and keep my fingers crossed.
 

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Discussion Starter #7
Pulled the transfer case today, as I did this the output shaft came out a few inches. Ultimately I was able to pull it all the way out......that sucks. The C clip in front of reverse ring gear should prevent that. So I removed transmission and that c clip was in place, I didn’t forget it. It must not have seated, I hope. It was the smaller of the 2 C clips, and the one behind governor was in place and seated.

I think with C clip not in place on the output shaft it was able to move back and the groves in governor distributor became misaligned with holes in housing. Regardless went through entire transmission again. Everything looks good. No visible damage on anything from that clip not seating.

I purchased the superior bench buddy set And polished all the bores in valve body and governor. I used 600 grit on the valves in a drill, cleaned with mineral spirits and compressed air. Valve and governor went back together with every thing sliding in their bores without the least bit of resistance.
Tomorrow will put transmission back in. If is still doesn’t shift into third, then I give up. I’ll just never drive faster than 35mph
 

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Discussion Starter #9
Gregaust, I have seen that. Thanks though. None of the C clips I have conform to those measurements. They were all smaller by a few mm. I measured 4 from 2 different transmissions. Regardless transmission is back in and running well. I really appreciate help from this forum.
 
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