It All Started with the Windshield Seal...
Part 3 - Engine Replacement
After having just replaced the cab after painting and head rebuilding,
discovering that we had to replace the engine (hence remove the cab
for the second time in under six months) was very disheartening.
Here is a shot of our show stopper. We were one week away from our first
camping trip of the season (only one week later than originally
planned) and we were completely stopped.
We researched our engine options pretty carefully. Choosing to fit a
non-Mercedes engine was never really on the list. Diesel was never
on the list (allergies to diesel exhaust fumes). Our first preference
was actually to go with an M130 engine, but we soon discovered that
option to be cost prohibitive. Buying a crated M180 from Scott was
by far the cheapest (and easiest!) option... one glitch... he was out
of stock. His shipment of engines docked during the trucking strike,
offering further delays. Then he got a return from a customer in
Arkansas. The other customer wanted to keep a few bits, but they
were bits we didn't really need anyway... so we said yes!
We asked Ken if he would be willing to let us borrow shop space from him
to do the engine swap procedure. Our shop is only barely big enough
to house the UniMoG, and it isn't big enough to use an engine hoist
in the shop with the truck. Ken's shop is big enough to hold four
UniMoGs! He and his truck were willing to help us get the engine
transplant done in the shortest time possible. Since we had just done
the cab removal & re-installation, we made these checklists to help us to remember
all the details. Feel free to use our lists if you have to do this
job yourself, but do note that there are things that are specific to
our truck and do not apply to other 404's.
Once we had cleared the engine at customs, we towed our truck (with Ken's) over to Ken's and started disassembly while we waited for engine
When the engine arrived, it was discovered to have an old style
"short-reach" head - Scott had made every effort to make sure the
correct engine was being shipped to us, but since it wasn't in his
hands he didn't see that a short-reach head had been installed on a
newer style block. The problem was solved with the long-reach head
had already had rebuilt. The swap also involved swapping the timing
chain as the chain for the newer style head is two links longer.
The first time we took the cab off, three of us lifted it no problem - the
windshield had already been removed. This time we wanted to leave the
windshield on in order to limit the chances of scratches to our new
paint job. We also didn't want to take any extra time to do the
engine swap. We modified Ken's engine hoist with a piece of square
tubing for more lifting length and bolted the top half of the stand
to the deck of his MOG in order to get the height needed to lift the
cab from our truck. Once we had lifted the cab high enough to clear,
we pushed the chassis out from under the cab and back into the shop.
With Ken creeping along in 1st gear we placed the cab in
the other bay of his shop out of the way. We have no pictures of this
operation as we were both "walking" the cab to keep it from swinging
about and becoming unbalanced. Dropping that thing in the alley with
our new windshield glass in place was not part of our plan.
Once we had swapped out the timing chain and head, it was time to remove
our broken block from the chassis (with Ken's engine hoist back in
its normal configuration).
Reassembly of the truck from this point proceeded along at a good pace. The
engine was delivered late on a Friday afternoon & we were able to
start the truck for the first time with the new engine early on
Monday afternoon. Once again we had reached the point of heating up
the engine in order to do the hot torquing procedure which helps seat
the head gasket. The engine ran well despite the fact that the
exhaust was full of coolant from the previously cracked engine
block.... the tailpipe definitely smoked & spluttered for a bit.
Re-torquing the hot head was a nerve wracking procedure, but it went off without
a hitch. (Getting through that procedure without having anything
break definitely called for a beer!) Once we had put together the
last few bits and pieces of the truck we were able to drive it home
that night. Seven months after we had pulled it into the shop to
replace the windshield seal the truck was actually moving under its
own steam again!
Return to Part I