Hi Folks,

Esme, (my '85 VDP) had to be towed home in the wee hours of last night. It's a strange transmission failure, unlike anything that's happened to me before. Also haven't been able to find similar on this forum, so here goes:

For a few months now she has occasionally refused to go into gear after being parked. I used to think it was just into reverse, but it's also into drive. Usually after waiting a few minutes she'll finally engage and then drives fine. It seemed like being parked on a slope nose down was particularly bad. When refusing to go in gear she would make a loud whining noise, almost siren like. A couple weird things about that; when putting the car back into neutral the whining would not go away all at once but just winds down and stops. AND, weirdest of all, if I put the car in park after it's whining in reverse in makes a brief ratcheting sound as if I put her in park while rolling. Last night we were just driving down the road at moderate speeds when she made a big Pop sound (more felt than heard really) and she was no longer in gear and wouldn't go anywhere. We sat there for quite a while hoping she would get over it, but no dice. Finally we called a tow truck. Before the truck came the police did and offered to push us into the nearby gas station to clear the road. As they were pushing (I started the engine to make steering easier) she dropped back into gear. Stupidly I thought it would run now that it was in gear. We waved goodbye, canceled the tow and started off again. Made it less than a mile when it conked out again. This time we gave up and got towed home.

So to me the weird parts of this, compared to other non-jag transmission failures I've had in the past, is 1) it's intermittent. 2) when it does work it seems fine, no slipping under load, etc. 3) the weird whining that turns into a ratcheting sound when put into park.

I haven't tried to get under her today but the tranny fluid is not low (never has been) and is clean and pink (not burnt). I should also mention that the parking pawl has been useless for a long time, don't know if that is connected.

Any thoughts? Anybody want to buy a pretty but derelict VDP cheap?

Thanks,

-mB

 

Mike:

Not great at auto boxes, but, here goes:

1. Big clue. The lack of the P function. it is a pawl that hooks to the pump or flex plate. They can bust. A chunk of metal bouncing around in the cavity between the transmission and engine can make noises and even a mess.

2. I've a vague recollection that this BW has a sprag clutch. They can get touchy before complete failure... Our 71 AMC Hornet AKa rambler used a similar BW. It did something like that, and the trans shop replaced the trans and advised of the sprag failure.

3. The front pump is affixed to the transmission by a "dog clutch". those can fail.

4. the pump is affixzed to the flex plate by bolts. gone???? Long shot.

5. The shift cable has parted. Engagement of any gear is spasmodic.

5. should be checked. The replacement fiddly, but doable.

If not, 1-4 mean, pull it out, replacement probable...

A friendly local transmiision ship may be willing to talk with you. Beware, there are sharks there....

Carl .

 

I agree with Carl. See a tranny specialist.

But, I must say, what you've described doesn't sound good. I hope I'm wrong but I see a trans overhaul or replacement in your future

Cheers
DD

 

Update:

Well she's be sitting around for about ten days now. During most of that time the transmission seemed to work fine, though I only moved her a few feet back and forth. This just made it harder to diagnose of course. But yesterday I caught her in the act, so to speak, and was able to take some video you you can see and hear what I'm talking about.

If you listen to the first video you'll see what I mean by the ratcheting noise as one puts it into park. This tells me power is getting as far as whatever the parking pawl engages, but not to the output shaft. The second video shows that it works the other way around too, the drive shaft can turn free of the parking pawl (yes I said the parking pawl didn't work, but I meant that it wouldn't hold on a hill, not that the wheels turn effortlessly when in park.)

It would help if I knew for certain what part the parking pawl clicks into. I haven't been able to find that out for certain but I think it's the ring gear, which is supposed to be locked to the output shaft. (The best illustrations I can find of the innards of a BW66 are here: https://procarmanuals.com/pdf-online...service-group/ )

If I'm correct then the ring gear and the output shaft are only making intermittent contact. I see that they are held together by a snap ring, and if that snap ring snapped... Just a theory so far. Not a very helpful one, because it looks like if that is correct it'd be a case of "Parts: 99 cents, Labor: $3,000" because I think the only way to get to those parts is to remove and dismantle the transmission. But I want to at least know what went wrong before she gets towed off to the junk yard. Call it closure.

If anyone can confirm that the ring gear is what the parking pawl contacts I'd appreciate it. And if anyone has any bright ideas. I'll probably do a little more diagnostic work this weekend, but it looks grim.

:_(

-mB