AOD will only manual shift

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lukep6470
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AOD will only manual shift

Post by lukep6470 »

Hi,

First some background.

This B&M AOD has been in my 67 for about 5 years now and has over 25000Kms on it so it is far from a new build.

Two days ago it would only drive in reverse and first. I figured it had a stuck valve and could be low on fluid so I let it cool down overnight, put 1L of fluid in it and took if for a drive and it was shifting normally again.

This morning I reversed out of the garage and when I selected drive it stalled. Every time I started it it would go into revers OK but would stall when I put it in drive.

I worked out that if I put it in low it would be OK. Now I have to select low, which turns out to be second get it up to speed, select 2nd (Which is 3rd on the old shifter) and it goes straight into 3rd. When I select drive it immediately goes into OD no matter what speed I am doing.

So now I have a full manual AOD that takes off in 2nd!!! Reverse works fine.

I am guessing a clip or something has come astray in the VB?
Nuts
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Re: AOD will only manual shift

Post by Nuts »

That is very unusual. Before you pull the vb check that all is ok with thg he tv cable.
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lukep6470
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Re: AOD will only manual shift

Post by lukep6470 »

TV cable looks OK.
Nuts
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Re: AOD will only manual shift

Post by Nuts »

Sounds like what you indicated. Something has gone astray in the vb. Inspect the pan thoroughly for little bits..
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hybrid
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Re: AOD will only manual shift

Post by hybrid »

Very weird. Sounds like your direct clutch is engaging as soon as you put it in drive, which means no slip in the converter.
lukep6470
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Re: AOD will only manual shift

Post by lukep6470 »

That is exactly what is happening. What ever gear you select it goes into it instantly. People pay a fortune for a mod like that ?

I found a troubleshooting guide here and it describes the initial fault with it only selecting first as being a possible loose TV lever:

https://www.becontrols.com/ourfaqs/aodt ... hoot_1.htm

I really hope that's what it is. It was 38 in the shade at my place on Sunday so there was no way I was going to work on my car. I will take a look Thursday morning.
lukep6470
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Re: AOD will only manual shift

Post by lukep6470 »

I dropped the pan and everything looks OK. The TV and shifter linkages are connected properly internally. There was a lot of clutch material in the pan which might be expected considering the miles on the transmission. I replaced the filter and it is still going straight into whatever gear you select.

I suspect this is probably a (stall when going into drive) type of fault as it may not occur to other people to try selecting 1st.

Oh well the car will most likely be off to Bob Grant in the new year.
Nuts
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Re: AOD will only manual shift

Post by Nuts »

"A lot of Clutch Material" does not sound good. Checked my AOD after 20K and it was clean..
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lukep6470
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Re: AOD will only manual shift

Post by lukep6470 »

Hmm looks like Bob Grant is still on Hols :-(

Can anyone recommend a Transmission repair guy in Brisbane inner west/north side?
lukep6470
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Re: AOD will only manual shift

Post by lukep6470 »

So I just spoke to Bob Grant Automatics. From what I described they think the governor has jammed and the box is stuck in 3rd. Also the clutch material in the pan may be the cause so it is possible a gearbox out job as a clutch may have shredded.
lukep6470
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Re: AOD will only manual shift

Post by lukep6470 »

OK so it's fixed :-)

In the end the fault was a broken valve near the TV circuit, they've never seen that before. It is apparently shifting like new.
hybrid
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Re: AOD will only manual shift

Post by hybrid »

lukep6470 wrote:OK so it's fixed :-)

In the end the fault was a broken valve near the TV circuit, they've never seen that before. It is apparently shifting like new.
Yeah that is really bizarre. Surely it was cracked in the past or something during assembly.
Nuts
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Re: AOD will only manual shift

Post by Nuts »

Good result!
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