Replaced idler sprocket engine in car
#1
Replaced idler sprocket engine in car
I will post a full summary with lessons learned when finished but should have listened to others here and removed engine from the start. Other than unbolting the trans I already did everything else and the engine needs to come up 4-6 inches anyway to clear the oil pump to get the pan out. 2007 cls550.
That is is where I am at now. The metal trans cooler lines that run alongside the oil pan are in the way. I have not decided to do so yet but can I remove one of them at the trans without taking a bath in fluid? Meaning remove bolt and plug back quickly?
Getting one of them out of the way would be a big help in oil pan clearance.
That is is where I am at now. The metal trans cooler lines that run alongside the oil pan are in the way. I have not decided to do so yet but can I remove one of them at the trans without taking a bath in fluid? Meaning remove bolt and plug back quickly?
Getting one of them out of the way would be a big help in oil pan clearance.
#6
Raised engine. Did not need to unbolt cooler lines. Was surprised that the engine cleared the oil pump to pan but needed to come up another inch because it was hitting the trans at the back.
Needed to make a jig to hold a timing guide rail while installing timing cover. The sealant was a pain. Then did the oil pan which was tricky and could have easily scraped off sealant since there is little room. Needed a few dry runs. Then did lower oil pan.
Another tip was to use feeler gauges to ensure the timing cover wouldn’t pinch the head gaskets.
Needed to make a jig to hold a timing guide rail while installing timing cover. The sealant was a pain. Then did the oil pan which was tricky and could have easily scraped off sealant since there is little room. Needed a few dry runs. Then did lower oil pan.
Another tip was to use feeler gauges to ensure the timing cover wouldn’t pinch the head gaskets.
#7
Woo Hoo, cam gears back on which were a little tricky. Harmonic balancer on. Everything torqued to specs. Chain tensioner on and released. Cam covers on and timing perfect.
Getting close to starting it.
Getting close to starting it.
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#8
Today used sealant and permanently installed cam covers. It was easier to install the magnets on the covers at bench first.
Then plugged in cam sensors with new o rings and electrical connections.
Next alternator, a/c unit and power steering pump and reservoir. The bolt behind the pump is a bear to get to and don’t get me going about the c clip on the reservoir. Getting it off was easy. Getting it back on was a pain.
Found that I am missing a gasket on the air pump (there are 3) and my exhaust bolts don’t arrive until Monday so I stopped for the day.
Then plugged in cam sensors with new o rings and electrical connections.
Next alternator, a/c unit and power steering pump and reservoir. The bolt behind the pump is a bear to get to and don’t get me going about the c clip on the reservoir. Getting it off was easy. Getting it back on was a pain.
Found that I am missing a gasket on the air pump (there are 3) and my exhaust bolts don’t arrive until Monday so I stopped for the day.
#9
BTW, getting the bolt torqued through the harmonic balancer (ie crank pulley) is a joke. Even with my home maid jig that perfectly holds the balancer I cannot understand why so much torque is needed.
Torque on crank bolt is 200nm which is 147lbs. Ok no problem.
BUT...then you need to turn an additional 90 degrees. Seriously? Do you know how much force it takes to turn that massive bolt 90 degrees after it already has 150lbs on it?
I marked bolt horizontally with a paint pen and marked the impact socket. Put breaker bar and 4 foot jack handle extension. The pipe was totally stressing and was going to snap any second. I finally said oh well and put towels all over the fenders and goggles on and went at it.
Somehow the thing didn't snap but my life flashed in front of me multiple times. I had to do it multiple times because you can only turn so far from topside with engine in.
Torque on crank bolt is 200nm which is 147lbs. Ok no problem.
BUT...then you need to turn an additional 90 degrees. Seriously? Do you know how much force it takes to turn that massive bolt 90 degrees after it already has 150lbs on it?
I marked bolt horizontally with a paint pen and marked the impact socket. Put breaker bar and 4 foot jack handle extension. The pipe was totally stressing and was going to snap any second. I finally said oh well and put towels all over the fenders and goggles on and went at it.
Somehow the thing didn't snap but my life flashed in front of me multiple times. I had to do it multiple times because you can only turn so far from topside with engine in.
#11
So what size thread is that harmonic balancer bolt? That sounds like excessive torque and could be a misprint for value in the book or where ever you got that number.
If that bolt is equivalent to say a 5/8 - 11 thread and torqued to 212 fl lbs, which is way less than what you had to put on that bolt, the load that it is pressing that balancer on is 20325 pounds.
So 10 tons of clamping pressure plus? And if that crankshaft was made of cast iron like many nowadays are I think that would strip the threads. So I am guessing there is no key to lock the crank and balancer in place? If there is there is no reason for that high of torque, even with a sprocket behind it.
If that bolt is equivalent to say a 5/8 - 11 thread and torqued to 212 fl lbs, which is way less than what you had to put on that bolt, the load that it is pressing that balancer on is 20325 pounds.
So 10 tons of clamping pressure plus? And if that crankshaft was made of cast iron like many nowadays are I think that would strip the threads. So I am guessing there is no key to lock the crank and balancer in place? If there is there is no reason for that high of torque, even with a sprocket behind it.
Last edited by exhaustgases; 07-01-2018 at 09:38 PM.
#12
Oh...I thought the same as you initially so did some searching. The specs are correct and everyone expresses the insane amount of torque required. The initial torque was ok with my 1/2 torque wrench but the additional 90 degrees was crazy. I marked the bolt and balancer to be spot on.
My searches revealed a handful of owners with bolts backing out and the consensus is that they did not fully do the additional 90.
My searches revealed a handful of owners with bolts backing out and the consensus is that they did not fully do the additional 90.
#15
Oil pan gasket separator, socket and extension for crank bolt, e10’s in 1/4 drive and special matco built in swivel, t60, harmonic balancer holder, bolts with heads cutoff for timing cover to slide on, shims so timing cover doesn’t pinch head gaskets.
#16
It will come loose
Oh...I thought the same as you initially so did some searching. The specs are correct and everyone expresses the insane amount of torque required. The initial torque was ok with my 1/2 torque wrench but the additional 90 degrees was crazy. I marked the bolt and balancer to be spot on.
My searches revealed a handful of owners with bolts backing out and the consensus is that they did not fully do the additional 90.
My searches revealed a handful of owners with bolts backing out and the consensus is that they did not fully do the additional 90.
#19
I may attempt this job in the near future. I have a few questions:
1. If you just removed the chain tensioner, could you have left everything in place (cam hardware) and just replaced the idler gear?
2. Why was the oil pan removal necessary? Did it need to come off for the timing cover to come off?
Thanks!
1. If you just removed the chain tensioner, could you have left everything in place (cam hardware) and just replaced the idler gear?
2. Why was the oil pan removal necessary? Did it need to come off for the timing cover to come off?
Thanks!
#20
I may attempt this job in the near future. I have a few questions:
1. If you just removed the chain tensioner, could you have left everything in place (cam hardware) and just replaced the idler gear?
2. Why was the oil pan removal necessary? Did it need to come off for the timing cover to come off?
Thanks!
1. If you just removed the chain tensioner, could you have left everything in place (cam hardware) and just replaced the idler gear?
2. Why was the oil pan removal necessary? Did it need to come off for the timing cover to come off?
Thanks!
2. Yes and I was in denial for awhile. Then I realized the two part oil pan thing and that Mercedes had lower timing cover bolts inside the pan. Must come off and it was possible to do with engine raised up trans still attached but it added like a hundred hours. There is no room down there and the process of sealing the pan with sealant instead of a gasket is a bugger with that little room. Would have been heaven to have had engine out and I was 95% there anyways.
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didimao0072000 (10-19-2019)
#21
1. No. That would be too easy but won’t work. Timing cover top bolts cannot be accessed with cam gears in place.
2. Yes and I was in denial for awhile. Then I realized the two part oil pan thing and that Mercedes had lower timing cover bolts inside the pan. Must come off and it was possible to do with engine raised up trans still attached but it added like a hundred hours. There is no room down there and the process of sealing the pan with sealant instead of a gasket is a bugger with that little room. Would have been heaven to have had engine out and I was 95% there anyways.
2. Yes and I was in denial for awhile. Then I realized the two part oil pan thing and that Mercedes had lower timing cover bolts inside the pan. Must come off and it was possible to do with engine raised up trans still attached but it added like a hundred hours. There is no room down there and the process of sealing the pan with sealant instead of a gasket is a bugger with that little room. Would have been heaven to have had engine out and I was 95% there anyways.
Thank you for the insight. Having just done some preliminary research, I read that some have done it with engine in and some with the engine pulled. It didn't make sense why people were saying pulling the engine is preferable and easier. You explanation certainly cleared things up. Thanks!
#24
Pulling the engine took me 4 hours by myself drinking after work one day. Mine is a 4 matic also and it would be impossible to do it in the car.
Little disclaimer I bought this car knowing this was the issue. When I took it apart I couldn’t believe what I found
when Mercedes said the best or nothing I guess they meant it
Little disclaimer I bought this car knowing this was the issue. When I took it apart I couldn’t believe what I found
when Mercedes said the best or nothing I guess they meant it
#25
Loosening the bolt was a great tip, I just put one of the longer bellhousing bolts into the torque converter to stop it from moving. It did get bent slightly. No 1/2 impact would’ve been able to get it off.