2006 T1N Sprinter: Harmonic balancer replacement

As we were getting ready for our fairly monumental trip to Alaska, in addition to getting everything we needed ready we were also working on our van. There had been a front end noise for a while after replacing the fan and serpentine belt that we wanted to take care of before driving five thousand miles. So I quickly and easily replaced the two idler and single tensioner pulleys. But that didn't fix the noise. K took another look around all the component pulleys, tugging on them to see if any of them made noise. 

Umm, yep. Turns out one of them did. With the serpentine belt and fan already off, it was easy to pull off the thing we discovered was making the rattle.

That's the outer ring of the harmonic balancer, or crankshaft dampener. It was completely separated from the balancer and just clunking around, somewhat dangerously. Basically, the harmonic balancer keeps the engine from shaking loose while it spins at two-thousand-plus-RPMs. This was not good. Our hearts sank, that sort of dreaded feeling in the pit of our stomachs of What now? It was Monday evening. We were set to board the Alaska ferry in Bellingham on Friday. With greasy and nervous hands, I shifted gears and sat down at a computer to do some research into replacing this part.

The job was straightforward enough, but a pretty intimidating repair for just about everyone that shared their experience. Mainly, because the stretch bolt holding the balancer on was cranked to about 250 ft-lbs of torque. Wow. It's also a very specific part and requires some very specific tools. Thankfully, in hindsight, with less than four days to repair our now-stranded van on which our entire Alaskan trip depended there was absolutely zero time to be intimidated. It was go time.

Quickly, after what seemed the necessary research, we came up with Plan A, Plan B, and Plan C. I got on the phone and the internets. They were all a little nuts and would require the grace of God.

PLAN A: Source the OEM parts and necessary tools, overnight ship them all, and somehow get them installed in our driveway before having to leave

PLAN B: Source a non-OEM part from O'Reillys in town and the required Mercedes bolt, washer, and seal from the Mercedes dealer in Bellingham, then bring a bunch of tools with us to change the balancer at a campground in Alaska

PLAN C: Push back our sailing, shorten our vacation and drive up to Alaska in a couple of weeks, then take a later ferry back home

Spoiler: we achieved Plan A. It wasn't without a fair amount of stress, I'm not gonna lie.

Enough of our woes and onto doing the job at hand. After all was said and done, it wasn't terrible. If you're tackling this in your driveway (or a campground, God help you), there are some specific considerations and needs.

1. Bolt: For the 2006 T1N Sprinters, there are two different bolts depending on when they were manufactured. THIS IS CRITICAL! Again, with the fan removed and the radiator loose, I was easily able to take a photo of our bolt so I could make sure to order the correct one. Ours was a "10.9" bolt as marked on the head in the photo below (the other bolt on later 2006 Sprinters are marked "1150"). NOTE: Because of the massive amount of torque used, this bolt is a stretch (or "torque-to-yield") bolt which means it cannot be reused!
   
   Torque spec: 240 ft-lbs PLUS an additional 90-degrees
   
   
   
   
   
2. Flywheel locking tool: This is a very specific tool that, after all that research I did earlier, I was able to find one and verify it would work by a photo (I couldn't order it from Million Mile Sprinter because he only had one slow shipping option) and the Amazon description (It states–"Applications: CDI-C Class 2.0 (03-08), 2.2 (98-04), 2.2 (03-08), 2.2 (07-09), 2.7 (00-06) E-Class 2.0 (02-09), 2.2 (98-03), 2.2 (02-09), 2.7 (98-03), 2.7 (02-09), 3.0 (02-09), 3.2 (98-03), 3.2 (02-09) G-Wagen 2.7 (01-05) M-Class 2.7 (99-05) S-Class 3.2 (99-03) Sprinter 2.7 (99-06)––THIS IS A T1N SPRINTER! V-Class 2.2 (99-03) Viano 2.0 (03-09), 2.2 (03-09) Vito 2.2 (99-03), 2.2 (03-09).") We only had one shot at getting the right tool or we'd be stuck going with Plan C. The tool at the time I'm writing this is amazingly available on Amazon.
3. 27mm shallow socket: A shallow, 6-point socket (vs. a deep socket, which at 27mm is much easier to source) is necessary if you don't want to remove the radiator. Also, a 12-point socket is not suitable for this amount of torque. Just as thankfully as that very-specific flywheel lock, I found one on Amazon.

In addition to the bolt and those two tools, for this job you'll need:

1. Harmonic balancer: I sourced a non-OEM one from O'Reillys which showed up the next day along with the OEM Corteco from Europarts SD. NOTE: There are two different balancers depending on if your van has standard or dual AC compressors
2. Seal: For $12, I opted to replace the seal at the same time. I ordered one from Europarts SD and another from the Mercedes dealer in Bellingham
3. Bolt (see above): Like the seal, I ordered one from Europarts SD and another from the same dealer
4. Washer: Same––one from Europarts and another from the dealer
5. Woodruff key: I ordered one from Europarts but, following the advice I read about how NOT TO REMOVE the key or else the engine timing could be off, I left the original key in place and never used this one. NOTE: The keys, like the bolts, are different for 2002-mid-2006 and late-2006 Sprinters
6. 24" (or longer!) 1/2" (minimum) ratcheting breaker bar (this is the Gearwrench one I have) PLUS a big-ass pipe extension (we used our floor jack's steel pipe handle)
7. 1/2"-drive 250-ft lb (minimum) torque wrench (this is the one I have)

Oh so thankfully, the socket and flywheel lock shipped overnight and 2-day, respectively. Europarts was absolutely awesome and, after talking to a guy on the phone who assured me the order was going out as soon as we hung up, it shipped overnight. That didn't mean we sweated bullets the Thursday before our Friday sailing as we waited for the flywheel tool and parts from Europarts to arrive. An Amazon van pulled up just after 3pm to deliver the tool, and an hour later a FedEx truck pulled up to our front gate. We gave Luke some cold water and snacks and thanked him profusely. 

While we waited, I drove the van up on our ramps. I'd read we would need the extra height off the ground to work with our 24" breaker bar plus added steel pipe extension. The added height would give us more leverage and more room to work. Without ramps, I'd read of folks driving their van up onto a curb or having the front end hang over a ditch. Sometimes it’s all about being creative. K began documenting our ordeal.

STEP 1: Lock the flywheel which is necessary to remove/install the bolt holding the harmonic balancer

The tool worked wonderfully with some figuring-it-out-as-I-went. Worth noting:

• The tool only fits in one way (the little grooved ends face DOWN and the open slotted end is on the passenger side
• Put the key in the ignition and turn to "ON" while you or a helper takes the socket-plus-breaker bar on the balancer bolt and slightly rotates the crankshaft (either direction) to align the teeth on the crankshaft with the teeth on the tool and seat the tool in place
• DO NOT use the bolts you removed from the van to hold the tool!––they're aluminum and do not have the holding strength to keep the tool in place when torquing the balancer bolt to 240 ft-lbs! We found out the hard (and stressful) way when the tool slipped out while beginning to torque the bolt. The bolts that came with the kit are steel and held (oh so thankfully!)

STEP 2: Remove the harmonic balancer

This is the step with which everyone seemed to be concerned and to caution others into reconsidering doing this job. With the flywheel locked and the breaker bar loaded with a 27mm socket and steel pipe extension, I maybe surprised myself by easing off the massive bolt myself. I’m not even a big guy. It's all about leverage and it wasn’t bad. 

STEP 3: Remove/replace the seal

NOTE: Pay attention to how much the existing seal sticks out beyond the front of the engine casing! This is critical. Then, use a flathead screwdriver and pry out the existing seal. It doesn't matter if you destroy it because you have a new one. Fitting the new seal however takes some caution and precision.

• Without a proper bearing tool (which likely wouldn't fit without removing the radiator), I improvised with a short piece of 2-1/2" ABS pipe
• With K and the piece of scrap pipe, I lightly tapped it while K watched from above to seat the seal equally all around its circumference with as much sticking out as the original (I took my time on this step, sweating it a little)

Inside of seal (new seal on left, old on right):

Outside of seal:

STEP 4: Install the new harmonic balancer

NOTE: Pay attention to the location of the woodruff key (see illustrated photo above). The harmonic balancer body is slotted for the key and only fits when the key and slot are aligned. Once the balancer was in place and seated fully onto the crankshaft, I hand-threaded the new "10.9" bolt through the beefy new washer until it was tight. Then set my torque wrench to 240 ft-lbs. With K pushing and me pulling, together we were able to get the wrench to click! Then, it was a matter of getting it another 90-degrees…

(The busted, original harmonic balancer with the separated ring that was causing our front end rattle)

(The new, OEM Corteco harmonic balancer from Europarts SD)

At this point, our buddy Trevor showed up after a day spent paddleboarding. He wanted to be helpful so I handed him the breaker bar to get the bolt that additional 90-degrees. Beforehand, I marked a line on it at 6 o'clock with a Sharpie. As Trevor cranked on the breaker bar-plus-steel tube from our floor jack as a necessary extension, I checked the line. It needed to get to 9 o'clock. Trevor did it!

Holy. Cow. We were done.

I fired up the van… silence! No more front end rattle. We broke out some beers, breathed a monumental sigh of relief, and relaxed for a bit. Our collective relief was palpable. The clock was still ticking and our ferry was still leaving at 6pm the next day, but we were going to enjoy the moment. Eventually, we reattached the radiator, headlights, and grill. K continued to document.

With that, we were done. After some last-minute scrambling to load the van, we rolled out after 11pm. We had a campsite reserved just south of Bellingham, which we'd roll into around 3am. The next day in Bellingham before boarding the ferry, we made two stops: I returned the non-OEM part to O'Reillys and picked up/immediately returned the parts I had ordered and had overnight delivered to the Mercedes dealer. All but the washer. The guy was incredibly friendly, but acknowledged for some reason his system wouldn't allow him to return the washer. We were stuck with it.

"No worries," I told him. "We'll keep it as a souvenir." He smiled. So did I.

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Endnote… During my research and phone calls to track down the parts and tools we'd need for this job, I also called the couple shops in town I knew or thought could work on a Sprinter as a sort of Plan D. Also, could they fit us in over the next three days? I knew it was a long shot. Neither shop thought they could get the parts in time. The reality set in, if only briefly: We were on our own. If we were going to get on our scheduled sailing for Alaska, we had to get this job done ourselves.