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Discussion Starter · #1 ·
Hello all, the past few months I've been slowly resurrecting a 1968 Belgian 404.1 troop carrier. I had purchased it from a friend in non running but complete condition. He had bought and shipped it from a farm auction out west 5-10 years prior so little to knothing about its history was known. It had a box of used parts presumably take offs..and all the manuals in English thank God!

Fast forward 3 months and a lot of work later..over the weekend the Pennsylvania antique vehicle plates arrived and I was confident enough to give it a good 40 minute shake down run. I stuck to a 10 mile radius of home stopping several times to check Temps "by hand" on portals, brakes, diff, engine, Trans etc. Roads were hilly back roads and there was little sustained 6th gear running.

The only temp that I found unusual or worrisome was the transmission. The side plate on the case "driverside" was borderline hot to the touch. I could keep my hand on there but wouldn't want too if it was any hotter. Oddly the new penngrade oil inside looked/smelled pristine and did not feel as hot as the case did.

The other item of concern was the brakes. They weren't stellar. Initially it wanted to pull to the right on hard braking so I assumed it was a frozen front left brake cylinder.. that seemed to get better so it may have freed itself up, however the second time I fully bled the system I was unable to get a solid pedal on the first depress. It will go spongilly about half way down but pump up hard the second application. It's also a bit slow to retract. I suspect the master cylinder may need a rebuild but it does not appear to leak fluid from anywhere.

At this point all systems have fresh fluid (Engine, Trans, diffs, portals, brakes) and rubber brake lines have been replaced.

I'd like a little community input before I run the truck much further given the frightening stuff I've read about there bronze bushed transmissions..likewise prior to ordering a master cylinder rebuild kit has anyone shared those symptoms?

Thanks, Ben
 

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85' U1300L Holset Turbo VA A/C, 66' Propane 404.1 rock mog, 1975 416 Doka, G500, Volvo C303
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My best piece of advice is to replace the slave cylinders and maybe even the rubber brake lines. A 404 that sits for more than a year or two will rust out the slave cylinders and cause major issues. As you seat the old pads again the cylinders may get stuck.
 

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Discussion Starter · #3 ·
Good to know they can go bad that fast. I'll put them on the short list of things to order.

I replaced all the rubber lines except for the front torque tube. It was had been painted over at some point in its previous life and was going to break the hardlines in the process of removing it..so I left that one alone.

Any thoughts on the transmission Temps? I don't know what "normal" is for these trucks.
 

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Discussion Starter · #7 ·
Hey Mic, Landenberg specifically just a few minutes outside of Kennett Square. If your familiar with 404's and want to take it for a spin let me know next time your local.

I still want to get into the head and make sure the valves are correct and figure out a way to verify timing is ballpark too. The marks on the harmonic balancer were missing or rusted off. It's got to be close though because it starts easy, revs out clean, and doesn't appear to ping.
 

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1963 Unimog 404
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The harmonic balancer should be copper. At least mine is. The numbers are stamped into mine. Pretty easy to read once it is cleaned off.

If you haven’t performed a valve clearance adjustment, you should check that. It’s super easy to do as long as nothing is sick or broken.

thinking it’s easy to adjust also. Just loosen the clamping screw and twist the distributor. You can do this while driving too. Remove the doghouse and reach in to the distributor. As you are driving turn each direction until you feel power loss and split the difference. Not exactly fine tuning, but it’s something.

Also, there are some very knowledgeable 404 peeps in your area. I won’t call them out, but they will likely chime in. I’ll let you know the next thing I’m out that way. I’d love to check out your truck.
 

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Discussion Starter · #9 ·
Thanks for the insight Mic. I pulled the valve cover today and will be adjusting valves tomorrow. Gasket was leaking, so I had one waiting to go on. The valve train looks relatively clean, some surface rust/sludge on the cam lobes but most of it wipes off. I did not see any galling.

Do unimogs have auto cam chain tensioners? I cannot find a procedure for this in the manual but I did notice the chain seemed to have a decent amount of play.
 

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Some visual references for the timing chain. It looks like there are three plastic guide / tensioners for the chain. Two No. 84's. and one No. 92.

Then, there is the cog & pivot assembly (195 / 168 / 175 / 179 / 183 / 187 /191 ) that looks like a tensioner to me. I don't have any experience with these engines, but there are many guys on here that do, and hopefully they can help.
Maybe the hole in the red circle is a way to adjust the cog & pivot ?

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Discussion Starter · #12 ·
Good to hear! I appreciate the diagrams they're quite helpful. The chain did seem to go more taught after adjusting the valves. Not that they're related..but bumping that starter a bunch must have made its auto setting self happy.

All but one of the intake valves was tight, and one of the exhaust valves was loose. It's buttoned back up now, and running well. The ground was semi frozen so my 3 year old and I took it for a back yard romp. Fun times dodging trees and dogs.
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