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Transmission Rebuild, 6.9

Started by TJ 450, 03 January 2009, 07:56 AM

TJ 450

After much anticipation, PB and I removed and stripped down the transmission from my 6.9. Many thanks for the extreme amount of assistance. 8)
It was no easy task and it was discovered that the engine really has to be removed for this. In any case the transmission is now almost completely disassembled and all has been revealed.
The roller bearing between the front and rear shafts has failed, thus both drive shafts are seriously worn at the bearing's journal. The spigot is slightly worn.
Otherwise it is good and the bands have plenty of lining left on them. One even has the part number still visible on the lining.
The issue is that these failed parts are likely to be extremely expensive or NLA, but we'll see.






Tim
1976 450SEL 6.9 1432
1969 300SEL 6.3 1394
2003 ML500

WGB

This really is a labour of love.

Was there any shrapnel in the works?

Bill

TJ 450

Fortunately there wasn't any large amounts of shrapnel, just some very fine metal particles in the bottom of the pan. I think the rest of the transmission has been saved just in time, providing the failed parts can be replaced.

Tim
1976 450SEL 6.9 1432
1969 300SEL 6.3 1394
2003 ML500

s class

What were the symptoms that made you decide to open the transmission?


[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

TJ 450

There was a lot of noise in first gear under load, which sounded like a bad bearing. It could also have been the centre support, but I think this was the culprit.
Both the front pump and output seals were also leaking. certainly the rear seal could have been replaced in-situ, but I doubt the transmission would have lasted much longer in its current state.

Tim
1976 450SEL 6.9 1432
1969 300SEL 6.3 1394
2003 ML500

WGB

Do you need any technical information.

I have been thinking about adding the Transmission manual to my collection of documents and quite happy to buy it and give you access to it if it would be helpful.

If you want to buy it yourself it can be found at http://www.schiffeuropean.com/

Having purchsed the Engine manual from them the quality of the photos was crap but the knowledge was priceless.

Bill

Big_Richard

wow, what a nightmarish job it is removing a 6.9 auto with the engine installed. I would certainly never recommend doing this, it is MUCH easier to remove the engine and transmission as a  complete asssembly, just as it was installed in the factory. That is one HUGE bell housing that only has a couple centremeters clearance in the transmission tunnel. To remove it with the engine installed requires unbolting the flywheel & torque converter and dropping it straight down. There is simply not enough room to leave the torque converter installed. without unboting the engine and shifting it forwards. The engine will be comming out to reinstall the transmission as there is just no way of reinstalling the lot without causing dammage in a driveway situation.

PS - so glad there was no builders crack visible in that picture of me sitting in an M100.

WGB

Quote from: Patrick Bateman on 03 January 2009, 07:51 PM

PS - so glad there was no builders crack visible in that picture of me sitting in an M100.

Close run thing though PB - saved by a voluminous T-shirt :o

Big_Richard

Quote from: WGB on 04 January 2009, 01:42 AM
Quote from: Patrick Bateman on 03 January 2009, 07:51 PM

PS - so glad there was no builders crack visible in that picture of me sitting in an M100.

Close run thing though PB - saved by a voluminous T-shirt :o

haha, yep, very close call, im well known for that problem, thats why i have to ware shirts 3 sizes too big to prevent it  :P

WGB

Anyway - couldn't help myself - anything so I don't have to visualise your builder's crevice PB. :o

I have been wanting that transmission manual for a couple of years so have purchased one via paypal today.

Should be here over next week or ten days and will make sure it is available to any interested "True believers" if required.

Seems to cover 722.001 to 722.006 (W3A 040 to W3B 050) which covers all 116 and 107 V8's 3.5 up tp 6.9.

Bill

koan

I think what you guy's have done is what the manual says, unbolt the convertor from the drive plate and pull the transmission away.

If you need any info from the transmission manual before WGB get his I can email scans or fax a few pages -  not the complete manual, there's a lot in it.

koan
Boogity, Boogity, Boogity, Amen!

TJ 450

Thanks Bill. That manual would be an excellent help.
Perhaps, if there is any info on removing the stator shaft (spigot) and the rest of the front pump from the bell housing in the manual, that could be worthwhile emailing, Koan. Many thanks. 8)

I have got to soaking the main casing and output housing in petrol today. Every other component is stored safely in bags and boxes.

Tim
1976 450SEL 6.9 1432
1969 300SEL 6.3 1394
2003 ML500

koan

Quote from: TJ 450 on 04 January 2009, 09:56 AM

Perhaps, if there is any info on removing the stator shaft (spigot) and the rest of the front pump from the bell housing in the manual, that could be worthwhile emailing,


Scanned a few pages covering that job, 5.3 Meg total, PM me a "real" email address and you will have them.

Recently there was mention of what's different about the 6.9 box, have scanned that page for you also.

The case is 10mm longer!

koan


Boogity, Boogity, Boogity, Amen!

s class

You are correct.  The torque converter must be unbolted from the flywheel and then removed with the transmission.  Doing it the other way around will damage the input radial seal, and possibly the torque converter neck too.  Damaging the seal on removal isn't such an issue, but you don't want that to happen as you reassemble. 


[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

TJ 450

#14
The last part to remove is the Stator Shaft from the Bellhousing. I haven't had any luck yet, but is it just a matter of belting it out from the rear of the bellhousing?

Here are some pics of the arrangement. The shaft is worn enough that it definitely requires replacement. I'm not sure what to do with the TC at this stage.

BTW, all required parts are available at considerable expense, from the dealer. I'm now in the process of investigating whether the bands are available or not.






...Tim
1976 450SEL 6.9 1432
1969 300SEL 6.3 1394
2003 ML500