View Full Version : 6.9, on the road

TJ 450
24th August 2009, 10:45 PM
My 6.9 is a road registered vehicle as of last Friday.

It's going very well and all systems are performing extremely well, except for the alternator today and an exhaust leak at the RH manifold joint.
The alternator decided that it no longer wanted to charge the battery, so the result was that I was stranded for a couple of hours.
A quick inspection when I got back revealed that the positive battery terminal was slightly loose and the brushes were all gummed up in the regulator.

A bit of a clean and reassembly solved the problem and I took it out for yet another extended drive. I've now done about 400km in the car and it keeps on getting better.

The only other issue that I've found is a whine that appears to be coming from the differential and a slight rear end clunk when coming to a stop. Both of these observations are apparent on two other 6.9s I have experienced, so it seems it isn't uncommon.

The engine is very tight and there is no smoke during the forced change down to second test, revealing that the valve guides and stem seals are in good condition.

Here's some footage of the test drive tonight:



25th August 2009, 05:44 AM
Love the night-drive effect ;)

Who did the video taping? Was it someone behind you?

The car felt quite smooth (as a 6.9 should)

TJ 450
25th August 2009, 10:05 PM
It seems I rarely film a test drive during the day. ;)

Yes, that was my Brother in the rear seat holding the camera.

The car is remarkably smooth... in just about every way. In comparison, my 450 has a harsh driveshaft vibration, although that will be attended to in due course.


26th August 2009, 04:46 AM
HI TJ450, you now might have to change your Avatar to something that includes the 6.9 ? I am sure being as thorough as you are, you may already have given that some consideration ?

Anyway, back to your car. At the moment, I am unable to watch your video as Optus has slowed down my Internet Access quite dramatically. It is also the reason why I've not uploaded phots onto the website. It would take forever. I sort of have lost track of all the work you have carried out, or the information you have provided on 'Topklasse', so you'll have to forgive me if I mention items that you have already alluded or referred to previously.

You say that it is smoke free (valve stem seals etc.) - I was under the impression that you removed both heads at some stage, or am I wrong in thinking that ? You say somewhere you're just about broke, so should I ask you what the car owes you, or how much you'd accept ? What are exterior and interior like ? Anyway, a "BIG" congratulations is in order in what has been a colossal undertaking. Regards Styria

TJ 450
26th August 2009, 03:08 PM
Indeed I have considered changing my avatar, although I don't have any suitable photos just yet. The 6.9 is in the foreground, though it was some time ago.

I was considering removing the heads, but I decided to leave that as there was no reason to, at that stage.

Regarding the interior/exterior etc., some photos are definitely in order, so that is on the cards. I'll comment on the interior when I post those.

Last time I checked, it was up to $10k (inclusive of purchase price), although that was before rebuilding the transmission and the subsequent work, so I'm sure it's in excess of that now.

Although the car is in good condition bodywise, there are a few dents and it needs a paint job to really lift the appearance.

Thanks for the congratulations! :)


26th August 2009, 08:07 PM
Well, it's interesting, isn't it ? I guess as far as the gearbox work (overhaul) is concerned, you can comfortably add another four grand to your ten. Agree ?..and you still have some body issues (respray) to consider, as well as some interior work - might be minor, or major, but it will cost money - and by the way, I am not criticizing you in any way shape or form. One could refer to my other thread that I have just started - why a 6.9.

It's quite remarkable, Tim. When I bought Gleaming Beauty some 14 years ago, I had a Mercedes specialist check the car over prior to purchase, and one of the items mentioned for attention was 'flaring' of the box from second to top, and I was quoted $3500.00 to rectify the problem - in other words, overhaul the box. That was 14 years ago. It may also be of interest to know that a very well known Mercedes concessionaires charged a customer $8500.00 to recondition a 6.3 box. Whilst that box is fundamentally different in a number of areas, some parts, usually the wearing ones, are indeed shared by both 6.3 and 6.9 boxes.

Getting back to the Auto Box in Gleaming Beauty, I kept on driving for probably about four to five years and, in the end, rebuilt the box myself. All that was worn, in fact, were the clutch lip seals - they were like bakelite. Needless to say, it cost me somewhat less than $3.5k. to rebuild the box.

I hope you'll keep up your interesting anecdotes as far as your 6.9 is concerned. Regards Styria

TJ 450
26th August 2009, 09:36 PM
It certainly does all cost money, although I'm still working within my set budget despite some unforseen work.

If I was to have sent the transmission to a specialist, it would have been much more expensive than the average rebuild.

I was donated a 722.004 transmission to tear down for possible parts substitutes. I ended up using the 722.004 front and intermediate shafts, K2 clutch piston and flange
To compliment this, I used a full set of new bearings, new stator shaft and all new friction discs and seals. I also used the front pump from the 722.004, as the original was worn.

The rebuild in my case was very cost effective, factoring everything in. I know it was a compromise, but I had no choice in the matter as the shafts are NLA.

Despite all this, it works flawlessly. I did encounter some nuisance problems along the way though, such as an incorrectly assembled B2 piston that was bypassing.:o The box also had to be removed for a second time for a revision of the K2 clutch assembly. I was not particularly peturbed by these problems though, as it was all a learning experience and nothing was damaged in the process. I also had an assistant troubleshoot the B2 piston problem as well as assisting me with the first removal and re-installation.

It is also worth mentioning that the 722.004 clutch piston and flange are compatible with the 722.003's extended K2 clutch drum. Despite the manual stating that the hollow shafts are longer to account for the extra length, they are actually identical.

I'm quite certain that my car would not have seen the road again, if I hadn't purchased it. That alone gave me the determination to get it fixed and back on the road.

Regarding the second to top flare on your GB, that's what my 450's unit has been doing since I acquired the car. I have minimised it by increasing the modulator pressure, but that is risky and a band-aid fix at best. I plan to rebuild the box fairly soon, although it hasn't got any worse.

There is some work to be done on the 6.9's interior, though I am mostly happy with it. I acquired a set of MB Tex seats to replace the old ones... front MB Tex and rear original leather. I kept the original leather seat from the rear for obvious reasons.

Anyway, I'll start a separate topic explaining what has been done and what needs to be done with pics, very soon.


27th August 2009, 04:14 AM
We've virtually got two threads running side by side, but I'll still endeavour to keep matters and observations separate. So, this thread remains as is - your trials and tribulations, future tasks and past experiences. That you have decided to illustrate with some pics is greatyly appreciated as I know how long it takes to transfer them to our website.

Without wishing to be personal, you have indicated that you are still within your budget, and it would be interesting to know just how far your budget will stretch to. Would you be concerned to spend, all up, twenty grand realizing full well that the ACTUAL value would be below what you have spent ?

When I had the flaring problem with Gleaming Beauty, I also had the modulator adjusted to compensate for this. Increasing the pressure did eliminate most of the flaring, but it rendered the change from first to second far too harsh. I went back to the 'flaring situation' and compensated for that problem by holding the box back manually until I would attain a comfortable speed to be in top gear. As I said, the flaring was a clutch seal problem.

I am also interested what you did with bands replacement, if any. I had my bands relined locally (they do use US made linings) despite being warned that the linings would not work properly. The Repair Shop that advised me had greater preference for original linings even when they displayed cross cracks. Anyway, I just wanted to have new linings for peace of "my mind", and it has been vindicated as the box has been absolutely trouble free for about nine to ten years. My, (again), where has time gone ? Unbelieveable. Regards Styria

TJ 450
27th August 2009, 02:06 PM
20 grand was the limit I originally set as far as getting the car to the standard I'm after. Much over that and I would have to reach a tighter compromise. In that regard, it's pretty well going as planned.

I intend to keep the car in the long term, so resale value isn't a huge concern, although I will need to keep it contained.

With the bands, I kept the originals. There was minimal wear, in fact the part numbers were still visible and there were no cross cracks. Even the lip seals were still soft in the clutches.

It's a shame all the bearings were chewed out, otherwise it wouldn't have needed a rebuild.

As of now, the car has done an indicated 224,000km and feels remarkably tight, with the exception of the diff whine as mentioned on the M-100 forum... it has that new car feel about it.

Regarding the pressure compensation, the harsh 1-2 shift is what I'm also experiencing on the 450.