Saturday, September 30, 2017

W463: 1996 Puch Worker G350 Turbodiesel: Preventive Maintenance Part Deux

Continuing from the last post:

The last pic I put up was of the valve train. I always make this excuse, but the last thing I want to be doing when dealing with internal engine work is stop to take pictures. It's sort of like building a puzzle, once you get into a steady groove of sorting pieces together, you don't want to break the groove.

Anyway, Mercedes came up with a new motor mount design for these trucks - a completely free floating design as seen on the right.

Just kidding - the mount that was on the truck I can almost guarantee to be original to the truck. They're fairly tedious to replace on turbo 60X trucks as the turbo sits on the stud to the passenger side mount. It's replacement almost requires turbo removal. They were bad.

The height difference is pretty staggering as well. Doesn't help with drive line alignment when the mounts are totally collapsed all around. These are unloaded - imagine how slammed down these were with the weight of the engine sitting on them. Pretty spectacular failure.

All the heads that I have machined get 5 angle valve jobs - I have one machinist I've been using for years and none of his work has failed me yet. I don't expect his work to fail either. Very meticulous.

The rare occasion I snap a pic - this was in between head torque stages. 3rd stage is a 15 minute wait before setting the final 90 degree turn for the head bolts.

Injectors, intake, etc all put back in.

There was quite a bit wrong with the exhaust manifold - most of it stemming from the lack of qualilty control on whoever serviced the truck in a past life. Namely, the booger welded exhaust support that hangs off the rear section of the manifold.

Here I just went after it lightly with a grinding wheel to see if I could start getting outlines of a stud that I know is still in the manifold.

Excellent weld penetration on behalf of whoever did the welding on this..... good grief.

As far as I'm concerned, this section of the manifold is saved and perfectly usable again.

but wait, THERE'S MORE

There happened to be a bolt missing for a bracket that supports the weight of the turbo off the manifold. That bolt also happens to go into the motor mount bracket. Because the manifold is left to it's own devices in supporting the weight of the turbo AND the turbo's exhaust (remember, booger weld) it stresses and will inevitable do this sort of cracking.

This is mid process, I realized I hadn't taken finished result pictures.... I promise my weld's penetrate and aren't ugly. I drilled holes into either end of the crack to prevent it from spreading, then ground into the manifold to create a bevel. Torch the casting to get her nice and toasty, fill with a nice hot weld. She won't be cracking here anytime soon.

Installed manifold with new flex joint combining the now totally saved exhaust manifold.

More assembly

A wild turbo appears

Just going to throw this EGR cross tube back on without cleaning. Self deleting EGR anyone?

Small, but it's still a blockage of airflow

Here's the engine totally assembled. Owner supplied Monark nozzles, which I installed and balanced to 135bar. She runs as good as she looks.

Here's a quick video of it on it's first start up with all the fresh work. No leaks!

Also went after some wiring in the truck - dash lights weren't working, oil pressure gauge wasn't working, overall just a mess of wiring in the cabin.

The above picture is essentially a before shot. Here's where I've got the after shot. Looks considerably less busy, right? We've also got dash lights back.


Found some snipped wiring, some missing wiring, some wiring work that I wish I never saw. 21 years of somebody messing with the truck you're bound to get these sorts of problems.

Also installed King offroad shocks on the front - rears were already installed.

The biggest dilemma I had was deciding where to run the reservoir on the driver side while retaining some form of convenience in changing dampening. These were designed with a G500 (M113) in mind. The driver side was problematic as an OM603 oil pan is extremely deep and front sump. This got in the way of mounting the reservoir to the skid plate like it should've been. So I decided to find the most protected area I could while retaining convenience. The bracket is mounted to the motor mount bolts and is holding the reservoir behind the sump.

This mounting point follows King's install to a G500. It works nicely in this application as there's nothing getting in the way. Both locations seem to offer fairly easy on the fly damper adjustment. I've set all 4 corners to a middle ground in damper settings. It's easy for the end user to adjust to their liking. Very nice quality shocks, but I'm not a fan of the piston rod being in the direct path to road debris. Seems like it would be detrimental to the longevity of the shock with the debris constantly being wiped off by the seal. I'm sure King know's better than I in this regard though. 

All in all this was a pleasure to work on. If all I had to do was rebuild OM603's for a living I'd have a great time. I love these motors.

Thanks again for reading! 


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