Some parts from the old 722.6 gearbox

[meri_gadi]

there are pics of the damaged box. the box was damaged beyond repair. £1650 for a new box supplied and fitted by http://www.stephensengineering.co.uk/. they had a new gearbox in stock.

here are the pics. can anyone tell me what parts are they?

 

[meri_gadi]

couple more pics

 

[Hibbo]

What kind of life has your car had? (Mileage, typical usage, SH etc). Blimey!

 

[meri_gadi]

125k. R reg. full service hist but oil hadnt been changed. mixed usage.

what parts are they? thy got big chunks missing out the parts.

 

[eric242340]

In all my years on MB ive never seen one so badly damaged, and no wonder you had to replace it. What, on earth, could have caused so much damage. I dont believe its because the oil hasent been changed

 

[eric242340]

Are you sure this box was not re-built before you got the car? Hve seen damaged boxes due to mistakes in the re-build but not as bad as this one. The only other thing I thought, upon seeing this, was no oil. But you said they took four litres out. I will check the filling capacity again. Could you E Mail/ PM me with your VIN no. Im totally shocked with this one.

 

[television]

4 liters is correct to come out as the box holds 7.5 from new, this list is up in the engine section.

It only takes on tooth to shear or break and when the bits have gone round a few times in the other gears thats the result. It did not just all go at once, just one bit,thats all it takes.

Malcolm

 

[eric242340]

4 liters is correct to come out as the box holds 7.5 from new, this list is up in the engine section.

It only takes on tooth to shear or break and when the bits have gone round a few times in the other gears thats the result. It did not just all go at once, just one bit,thats all it takes.

Malcolm

Yes i agree, but what caused that one bit to break off? And the damage is horendous The simple, knock on effect, of one piece breaking should not be that bad.

 

[television]

Yes i agree, but what caused that one bit to break off? And the damage is horendous The simple, knock on effect, of one piece breaking should not be that bad.

One broken tooth and 2 tons of car x say 50mph and that damage is normal.

Same as a crown wheel losing a tooth.

Malcolm

 

[eric242340]

One broken tooth and 2 tons of car x say 50mph and that damage is normal.

Same as a crown wheel losing a tooth.

Malcolm

Hi Malcom, Im inclined to agree. But the components in the thumbnails are from almost all parts of the transmission. Normally the damage is localized. This is the first one ive seen like this. I would love to know what could cause so much damage to the whole transmission. Wont sleep tonight thinking about this one.

 

[television]

Hi Malcom, Im inclined to agree. But the components in the thumbnails are from almost all parts of the transmission. Normally the damage is localized. This is the first one ive seen like this. I would love to know what could cause so much damage to the whole transmission. Wont sleep tonight thinking about this one.

Stop making a mountain out of a mole hill, the speed of one broken tooth could land anywhere creating havoc, and it did like a giant mincing machine.

Malcolm

 

[eric242340]

As a further thought to my last post, I did have one similar to this. But not as much damage. However in this case the owner admitted to putting the car in park whilst still moving forward. And I add, the damage was not this bad. And Im not saying the owner of this car did anything wrong.

 

[panason1c]

As a further thought to my last post, I did have one similar to this. But not as much damage. However in this case the owner admitted to putting the car in park whilst still moving forward. And I add, the damage was not this bad. And Im not saying the owner of this car did anything wrong.

I was under the impression that, though absolutely NOT recommended!, selecting 'Park' whilst the car is moving was not detrimental because the mechanism was (cleverly) designed in a way that the trans-lock would only engage once the vehicle was actually stationary.....true?

I wish to add that i am not brave enough (or rather, stupid enough) to personally test this belief.

 

[television]

I was under the impression that, though absolutely NOT recommended!, selecting 'Park' whilst the car is moving was not detrimental because the mechanism was (cleverly) designed in a way that the trans-lock would only engage once the vehicle was actually stationary.....true?

I wish to add that i am not brave enough (or rather, stupid enough) to personally test this belief.

You are correct in what you say panasonic there is a safety valve and the car will make a few clicks,just before it stops.

It can be seen as argumentative if it is only me correcting the post.

Malcolm

 

[Hibbo]

Does this also apply to the older hydraulic boxes like mine? I always grimace if I drop it into P a bit too soon!

I think MB should test the safety valve as part of every service - 60mph down hill should do it

 

[television]

Does this also apply to the older hydraulic boxes like mine? I always grimace if I drop it into P a bit too soon!

I think MB should test the safety valve as part of every service - 60mph down hill should do it

This has been the case Hibbo since the early Borg Warmer gearboxes that I can rec cal from the 50's. It could not be any other way.


Malcolm

 

[Hibbo]

That's reassuring! I don't think I'll be testing it though!

I'd always just assumed that parking pawl would bounce on the teeth until you'd slowed down enough for it to latch, then BANG! Goodbye gearbox.

I really must learn more (ie something) about the innards of these boxes - amazing feats of engineering.

 

[television]

That's reassuring! I don't think I'll be testing it though!

I'd always just assumed that parking pawl would bounce on the teeth until you'd slowed down enough for it to latch, then BANG! Goodbye gearbox.
.

When I roll down my steep drive with the engine off, and then select P, it goes click click click and the car stops with a jolt as the pawl finally drops in. Just the way you say.
http://www.detali.ru/cat/oem_mb2.as...M=717.433&CT=GA&cat=08R&SID=27&SGR=090&SGN=06

Malcolm

 

[Ultymate]

The pictures at the start of this thread show most of the damage as being in the main epicyclic cluster one tooth failure there will instantly take out several gears as for parking pawls they can take out a box if a cars transported on a transporter with "P" selected, just the bouncing of the car is enough to smash the parking mechanism. The AA's recovery fleet drivers are under strict instruction not to transport "any" autos in park period. Personally I doubt you'll ever know what caused this catastrophic failure SHoneT does sometimes happen

 

[eric242340]

I could not resist this one, took my laptop to work today and showed these pictures to the chief mechanic. He came to us from the main dealers one year ago and had worked in the dealers for 16 years. When he saw the pics his eyes nearly popped. Thus started a heated debate with all his section and it lasted nearly all afternoon (on and off). I know him quite well and I bet tonight he will be calling his mates in the dealers to discuss this. Maybe I can get some common sense answer out of them, because Ive no idea. Incidently, what speed where you travelling at when this happened? Dont mean to drag this thread out, and im sure your pretty biffed about this box, but its an interesting subject. Thanks Eric.