Transmission / Overdrive: Bad 1-2 shift in a FOM

[Warren Webb]

Took the 62 Champ with Flightomatic out the past couple of days and was startled with a real bad shudder when the 1-2 shift occurred. As soon as it warmed up after a 1/2 mile or so, things were fine. Any ideas what might be the cause? 2-3 shift went fine at all times.

[thunderations]

Check the fluid level first. Sounds like the seals are leaking a little when cold and once warmed up and everything expands a little are sealing better.

[jackb]

Think of refreshening the tranny. Maybe you get away with only soft parts.

[(S)]

I'd assume this is one that does run around on occasion, so start with fluid check and then onto torn eng/trans mounts. Throttle pressure adjustment controls all of this, unless there is an internal leak like stated above......... worn or broken mounts also sent many of these to the shop when nothing was wrong.

[Stude Shoo-wop!]

I had a similar issue with my GT Hawk (wouldn't shift smoothly from 3-2). I found that new motor mounts and a bolstering of the undercarriage did the trick rather well.

[Rosstude]

Warren,
Assuming this is the green/gray truck you got from my buddy Dave, I have some info.
It needs seals, most likely in one of the clutch packs.
We had that trans on my bench when the 259 went in, and we cleaned the control body assembly, seals in the 2 servos, and the external seals. We did not go too deep, as it was working fine.
It worked fine for a few months, then started the slipping thing you describe.
Since then, its been living on occasional Trans-X treatments. This worked well for many months of daily driving.
It has the vacuum modulator, no throttle linkage. The adjustment on that modulator is sensitive, a 1/8 turn makes a difference, too much and it slams into 1st, too little and it the shift points are delayed and slow to engage. (however, the mounts were replaced, and we welded in cab supports)
On Dave's list was overhauling the trans, and changing the differential gear ratio/carrier.

[Steve Winzar]

Hi Warren- check my blog on 'refreshing' a Flightomatic and have a go at it perhaps. PM me if you would like to leave me some feedback or queries.

http://studebakerflightomatic.blogspot.com.au/

Steve

[Ron Dame]

Thanks for that link Steve, I'm almost ready for the first drive after recommisioning my Avanti after an 18 year slumber in poor storage. Most of the rubbere is shot, so I won't be surprised if my trans doesn't need a refreshing.

[jackb]

I'm starting to wonder if its not a bad idea to find one of the last tranny shops that "can" really work on these..... I know the parts are readily available (mostly), but in a couple of years the likelihood of a decent, experienced tranny person gets very muddy. I'd get it to a good shop and let them go though it. Don't skimp, you may not have another crack at it. Around here, there is only 1 guy who can work on the FOM's..... and he's not motivated to open one up unless he's slooooow.

[GrumpyOne]

The best stuff that you can put in that tranny is Lube-Guard available at most transmission parts supply depots. $10-$12 and if that doesn't improve things, you'll need to go into the tranny itself...

[RadioRoy]

What models of flight-O-matic had vacuum modulators?

[GrumpyOne]

What models of flight-O-matic had vacuum modulators?

Truck transmissions...

[RadioRoy]

If the diaphragm in the vacuum modulator is leaking, it will suck fluid from the transmission, there will be hard shifts, and smoke from the tail pipe.

[Ron Dame]

The best stuff that you can put in that tranny is Lube-Guard available at most transmission parts supply depots. $10-$12 and if that doesn't improve things, you'll need to go into the tranny itself...

A lot of the LubeGard seems to exclude Ford and Type F. I've emailed them (yesterday evening) to find out which product works with a BW8 and Type F. But maybe someone already knows?

[Warren Webb]

If the diaphragm in the vacuum modulator is leaking, it will suck fluid from the transmission, there will be hard shifts, and smoke from the tail pipe.

No smoke and as soon as it warms up it shifts fine. Took it out yesterday for a run to the auto parts store. Between starting it up & driving to the gate to open it, then pulling forward to close the gate, it ran great with no issues at all. Will see how it goes later today when I take it to church.