722.300 Transmission Manuel

[sean sherry]

Ok Geoff,no problems here. But I would like to point out that I have found that there is a distinct gap between experience and an understanding. E.g., Not having a lot of experience of Mercedes Automatics ,I inquired from two experienced Mercedes Specialists about sorting the 3-4 flare in my newly aquired
280 SL 107. both said strip and reseal the Box. I knew from an "understanding" of Automatics in general that correct vacumn and modulator pressure is usually the cause of flares between upshifts. Sorting 2 speed Fords in the early sixties taught me that , ....the hard way. That's why a lot of parts are changed unnecessarly, even today by most Dealerships.
My apologies if this sound like preaching, can't help myself. My wife always says it is an Irishman's privalage to talk until he is understood. Sean

 

[Styria]

Hi Sean, it's only when one finds out about certain facts that a surprise is expressed. There's no way that I was trying to belittle you, or doubt you. I have been involved with all matters pertaining to Rover Cars, and to a lesser extent Mercedes, for the last fifty years, and I recall quite vividly as long ago as thirty years, that DG boxes required total skill and knowledge by a rebuilder. So when someone like yourself comes along virtually from the clouds, or the back of 'never never', and tells you what you have posted, that comes as a complete surprise.

I used to do business with ATP at North Parramatta many years ago, and of course they have been out of business for quite a while. I am sure you would have heard of them. Even in those days, say at least ten years ago, they maintained that it was becoming increasingly difficult to obtain rebuilding kits for the DG boxes. Invariably, one was referred to the guy at Guildford that I mentioned in my previous post, but whose nama I cannot remember. I am sure that you would have known of him. So that's the story, and the nitty gritty of explaining myself to you.

When I bought GB about seventeen years ago, the box was flaring from second to top gear. I could, of course, stop the flaring by manually engaging second gear, and then shift, again manually, into top once I had attained my desired and 'safe to engage' speed. I did have the modulator valve adjusted to eliminate the flaring, but this adjustment only led to harsh intermediate gear changes. When eventually the box was pulled out and dismantled, all clutch lip seals were as hard as rock. It was a wonder that the box even worked in the first place. At the time when I bought GB, the quote to overhaul the box was $3500.00 - and that's seventeen years ago. In reality, there really is nothing all that special or peculiar to the 722.001/2/3/4 range, nor terribly expensive unless you have to buy 'hard' parts. I would be interested in your opinions if you would like to add to the thread. Regards Styria

 

[abl567]

Small world, I used to print the T shirts for ATP about 15 years ago

 

[motec 6.9]

Hi Sean i will agree about Ford-O-Matics having owned a 66 Galaxie fitted with a 390 FE, XP Falcon 200 pursuit & XR Falcon 289 . But if you have anything to add i am all ears. Geoff

 

[BenzBoy]

Dare I say it? Real Men drive manuals...yeah, but try to buy one new...
Regards,
Brian

 

[sean sherry]

Small world Styria, I was a one third owner of ATP, togather with Fred & Unince Pendlebury. I was responsible for all purchases and a frequent visitor to the USA and Europe as part of the Job. Yes if the seals are hard , over heating and old age, then it's major o/h time. Usual symptons of that are slow engagement and long up shifts when cold. Improve when hot. With the DGs common problem a long slow engagement to top going up hill means a new convertor clutch plate.This was mostly in heavy weight Jaguars with high reving engines. All the American transmissions were designed for low reving high torque engines. That's why the V12 Jaguars with Turbine 400s burnt out on the UK Motorways. 6000 revs on acceleration was not what they were designed for! Before convertor shops appeared we cut DG convertors open changed the clutch plate and welded them up by hand. I had a steady hand back then ! I got to know the engineer who designed the DG s , he was retired but gave talks at the Transmission Meetings, I well recall that he said to me that all Transmissions are the same ,they just look different.
Also on Mercedes units, well designed, but don't work properly. That was thirty plus years ago . Of course back then all Transmissions were purely Hydraulic, no fancy electronics or automatic manuals. ........Sean

 

[Styria]

Hi Sean, I know I am digressing a bit, but were the DG boxes known as Detroit Gear and were they used in troop carriers during World War II ? They were Borg Warner boxes, weren't they ? Getting back to the 722.003 boxes as used in 6.9s and probably 450s as well, have you ever come across any perceived weaknesses ? I have had two boxes now where the clutch pack retaining circlips would let go and allow the pack to partially come out of the clutch drum and start destroying other components in box.

It's my understanding that the circlip is situated too close to the edge of the drum and there is not a lot of 'metal' in the recess the circlip fits into. BTW, thanks for understanding (hopefully) the meaning of my remarks when I first replied to you. BTW, in the end, what was the solution to your problem with the box in your 280SL ? I take it that the fix was simple. Regards Styria

N.B. As a matter of interest, have you come across Ross Burgess ? He specialices in the rebuilding of American boxes for hot rod applications.

 

[sean sherry]

Don't know about the DGs used during the war, but I used to get Parts for the old Hydramatics fitted to Bentlys etc from the War Time Stag Hound Weapons Carriers. They had the same manual reverse set up. You are probably on the right track with the weakness in the clutch drums. A spot of weld from a Tig Welder might help sort it.. Also too high a line pressure would aggraviate the weakness. The circlip has a lot to do and was probably ok until the clutch plates were worn and there was too much clearance. so the apply piston had a good run up at the clip. With all the bashing the softer drum would probably be rounded off
letting the clip jump ? ? ?.
I have to admit that I cheated a little with my 280 SL, I knew by the milage that the seals were getting hard, so I first added some Wynns Trans Treatment to soften the seals, particularly the one for 4th gear. This product was used extensively when I worked for Lincon & Buick Dealerships in New York in the sixies. Hard seals was a big problem in the Winter ,as cars got stuck in the snow and the transmissions overheated via the convertor . Owners tried to extract them, continually spinning the wheels from Foreward to Reverse...........

After a couple of weeks the Wynns had done its job on mine. the transmission
then responded to Modulator adjustments. ........Sean

 

[Styria]

Interesting Sean - I have many times wondered how additives would work and what they'd achieve. Here's my answer. Thank you. If a box behaves normally, and works well, is there any advantage or benefit to be gained by supplementing the normal oil with the additive ? I rebuilt my box about ten years ago, and it's working well.

Incidentally, at the time the box was rebuilt, I was advised to re-use the original bands. The notion was that relined bands would slip prematurely and thus the box would have to come out again. This has not happened. I am glad to say. Interested in your opinion. Regards Styria - I had the bands relined.

 

[sean sherry]

Geoff the 2 speed fords were a cheap and nasty Box.......
No centre supprt, held togather by the valve body. They ran too hot under load. A seperate oil cooler helped a lot coupled with reducing the end clearance to a minium. ( keeps the top gear drum in alinement )
The cast iron 3 speed units were robust. but cracked the case where the rear band servo bolts on. Selecting Reverse with too high an idle speed ,especially when cold, probably was the cause.
I'm passing the time in the Virgin Lounge at Heathrow, should be Home on Friday.......to some warmer weather....Sean

 

[Helmet]

Hi Sean, I know I am digressing a bit, but were the DG boxes known as Detroit Gear and were they used in troop carriers during World War II ? They were Borg Warner boxes, weren't they ? Getting back to the 722.003 boxes as used in 6.9s and probably 450s as well, have you ever come across any perceived weaknesses ? I have had two boxes now where the clutch pack retaining circlips would let go and allow the pack to partially come out of the clutch drum and start destroying other components in box.

It's my understanding that the circlip is situated too close to the edge of the drum and there is not a lot of 'metal' in the recess the circlip fits into. BTW, thanks for understanding (hopefully) the meaning of my remarks when I first replied to you. BTW, in the end, what was the solution to your problem with the box in your 280SL ? I take it that the fix was simple. Regards Styria

N.B. As a matter of interest, have you come across Ross Burgess ? He specialices in the rebuilding of American boxes for hot rod applications.

Hi Styria,
The problem is the circlip its self, wave spring steel, prone to fatigue and breakage. I always replace these clips when rebuilding these boxes. Also make sure that the clutch clearance is at its minimum, then if the circlip breaks there is less chance of it falling out. Its another one of those $10.00 dollar parts causing serious damage when the let go.

 

[Styria]

Hi Helmet, you're dead right, of course. The problem is, however, that the circlip lets go PRIOR to the box giving trouble and having to be removed from the car. I just don't know how one can prevent the problem arising in the first place. Also Helmet, as a matter of query, do you have any spare splined front input shafts ? As you would know, the splines can get stripped with consequent complete loss, or retarded acceleration, depending on wear of the splines. I believe that Pendlebury (forgotten his christian name) used to manufacture them when he was situated at Granville. Regards Styria

 

[Oversize]

P.S. DGs are not a complacated Box. They are a simple 2 speed unit with a total lock up convertor clutch for top gear. Parts are generally available from America or England when you know where to look. And also for Dyna Flows, Ultramatics, Hydramatics etc. etc.
( But not for Smith Electrics or Renault Feredex or other weird and wonderful nightmares. dump them and fit a B W 35)

Sean you may be my new best friend!! Dynaflows you say??? Hey I thought you were living in Melbourne?

 

[Helmet]

Hi Helmet, you're dead right, of course. The problem is, however, that the circlip lets go PRIOR to the box giving trouble and having to be removed from the car. I just don't know how one can prevent the problem arising in the first place. Also Helmet, as a matter of query, do you have any spare splined front input shafts ? As you would know, the splines can get stripped with consequent complete loss, or retarded acceleration, depending on wear of the splines. I believe that Pendlebury (forgotten his christian name) used to manufacture them when he was situated at Granville. Regards Styria

I don't have any , but I know where I can get the latter type (with a clirclip).

I always had a theory that people that use the auto to assist braking (changing down), put extra strain on the circlip in question

 

[sean sherry]

No problem with re lined bands Styria, provided that all the oil has been purged from the metal . I used hard relind bands extensively in BW35s .The rear bands for reverse were too soft for the high pressures in Reverse. I imported a box of 1000 from the UK . I had a high volume of Falcon etc., through my Shop in Brisbane. Never had a failure using approx. 10 per week.
The bands in GM cars were a much better quality . Interestly we had to do the reverse with the cast iron BW 8s in the heavy weight Jaguars, fitting a wider soft band from a Rambler, to stop the slip on the 1-2 shift .A larger servo would have increased the clamping force, but then the kick down from 3 to 2 was too harsh.

Interesting about the quality of the Mercedes clutch drum clip. The cost accountant must have designed it !
Sean

 

[sean sherry]

Yes Helmet, Brakes are cheaper than gearboxes

 

[Helmet]

Yes Helmet, Brakes are cheaper than gearboxes

 

[sean sherry]

Just remembered something from yester year. One of the old Torque Flites , either the 50s cast Iron Boxes or the Alloy 727 had a hard steel shim to take up the slack in the cir clip grouve in the clutch drums. Can't remember if they were a selective fit. Also some of the BW 8s and 12s broke the drum at the cir clip on high milage cars. So Mercs are not the only ones. ............ Sean

 

[daantjie]

Hello all
Sorry to tack onto this old thread, but I am desperate for some sage advice
I have posted on other MB forums Re my 6.9 trans woes and have had some good tips, but I am at a stale mate now it appears.
I am experiencing a bad flare in all gears under hard throttle. Soft throttle, level road shift is very soft with no flare, but uphill or hard throttle shifts are crazy flare events.
Engages into drive and reverse nice and quick with no clunk.
Most advise so far points to vacuum modulator, so I replaced it, and cranked IL the pressure. But it has had absolutely no effect.
Now this is after I had the rad recored.
Is there a chance that gunk made its way to the valve body?
Can the modulating valve get stuck "in", do that the thrust pin is not pushing on it?
Any help much appreciated!
Cheers
Daniel

 

[Styria]

I have just re-read this thread, and how excellent is it? Really great information. I should make some attempt to PDF some workshop manual items I have at my disposal. Hmmm.....time, time. Anyway, Daantje, I have replied to you in another thread. Regards Styria