'95 E300 Vacuum Pump Cam Replacement Project

[Doug306]

So, I removed the vacuum pump and it was damaged but the bearings were thankfully still in place. The drive cam was also damaged however, so I am getting ready to replace that as well. I have put together the procedure as best as I can but would like some assistance from someone who has done this before as I do have a few questions. Thanks.


First you have to remove the Timing Chain Tensioner:
http://www.w124-zone.com/downloads/MB%20CD/W124/w124CD1/Program/Engine/605_606/05-7800HA.pdf

Then you remove the IP:
http://www.w124-zone.com/downloads/MB%20CD/W124/w124CD1/Program/Engine/605_606/07.1-8410.pdf

What is the Noise Encapsulation that I am removing the bottom part of?
The Installation Note says to lock the IP after removal. Everything else I've read says to do this before removal. Or is the thinking that it is not needed for removal, and it's easier to install the blocking bolt after removal.


Then you remove the Injection Timing Device:
http://www.w124-zone.com/downloads/MB%20CD/W124/w124CD1/Program/Engine/605_606/07.1-8014.pdf

What's with the Locking Pin, 40/11? Do you need the special tools to remove and install?
What keeps chain tension on the crankshaft if there is no tension on the Camshaft or ITD?
How much does this thing weigh and why is it not possible to remove the ITD without removing the IP anyway?


Then you Service The Injection Timing Device:
http://www.w124-zone.com/downloads/MB%20CD/W124/w124CD1/Program/Engine/605_606/07.1-8050.pdf

Is it a 2 piece sprocket/cam as depicted and bolted together with 40/12? I don't want to buy this part until I see it ($$$) as it was later changed to a one piece from what I understand.

Reassembly: How much can I rotate the sprocket for the IP to line up and not affect the timing? Or do I just choose the nearest spline?
The torque figures are all there but would you recommend using Loctite?


Then you put it all back together and go have a beer.

My car (built in 3/94) has only 165K miles on it and I would highly recommend everyone change out the VP before it damages the cam. Then you won't have to do this procedure at all!

I will be buying the Basket along with the IP Locking Tool and then listing them in the Tool Rental page when I'm done.

Thanks again.

[Doug306]

Well, don't all chime in at once. Has anyone done any aspect of this? I have to do it myself as the only MB dealer doesn't work on cars older than 10 years. There may be one indy who could do it but he has no special tools, would charge me a fortune, and wouldn't do things like clean out the intake ports and IM and probably wouldn't guarantee his work. Thanks again.

[chronometers]

This looks like a lot of difficult work. What damage did the VP cause?

[sixto]

I've never done this in a 606 but I don't understand why the IP has to come off. Is this only to provide enough slack in the chain to remove the timer? After removing the tensioner, I'd roll the cam CW slowly stopping at the slightest resistance, which could be a valve coming in touch with a piston, to see if enough slack builds between the cam and chain to slip off the timer with the IP in place. This isn't just conjecture, it's Sixto conjecture. Attempt at your own PERIL!

Sixto
87 300D

[Doug306]

It IS a lot of work, way more than I ever wanted to do.

I don't know why the IP has to come off either. If it slides out the back and you then slide the timer out the front after after removing the cam sprocket to give you more chain slack - why shouldn't it be able to come out first? Maybe it's a reassembly thing.

The cam itself is scored and would damage a new VP pretty quickly.

I will put up some pics as soon as I figure out how to resize them on a Mac.

[vstech]

I was under the impression the VP ramp is removable from the timing device while installed in the engine... I guess this is not the case...
I've got a 602 I'm parting out, and another member wants the timing cover, so I may pull the timing device and inspect...
I think startek has the fsm for working on 124's and you may have the procedure for the ramp "cam" replacement...

[Doug306]

I've got it disassembled and thought I would comment on my previous questions as the answers are now apparent. It's not a difficult job. Just take lots of pictures and make notes when needed. You will need the basket and IP locking tool.


The Noise Encapsulation thingy that you're supposed to unbolt from the bottom part of the IP - I guess I did it but was not able to identify it at the time.

The IP Locking Tool. I installed this after removing the IP. Aligning it was no problem either, with a rag and a pair of vice grips only as tight as necessary. It needed to be turned just a few degrees to see the ridge inside to engage the locking tool. You're good to go as long as it is installed in the correct position.

TD Pin. I had a bolt that fit this pin. I put a large washer on it and using a cold chisel under the washer, a fulcrum and a few hammer taps was able to get this out no problem. It's about 2" long. No need for a special tool here.

The TD itself was not difficult to remove after the IP was out. I did zip tie the timing chain to the camshaft sprocket in 2 places and used a pair of vice grips on the chain itself to keep tension on the crankshaft sprocket. The only reason I can see why you are supposed to remove the IP before removing the TD is make sure that it doesn't separate during removal by not being able to push it out from the back at the same time. If it separates while inside the crankcase, the springs and counterweights will fall into the abyss because it is held together only by spring tension and slides apart on the bushing.

The IP weighs about 19lbs.

Mine is a one piece cam and sprocket. The dealer price is about $700 and he would let me have it for $500 but I found a source in FL for $300. I'm yet to receive it.

[Doug306]

It's all finished and it was actually a lot of fun.

It wasn't all that difficult. I initially thought the IP timing was going to be a problem but it wasn't. I installed the ITD with what I thought was the same position as the one removed and the IP splines lined up and it just slipped right in. The CC is bolted on with allen bolts which are 6.5 inches in and hard to reach. I had to use vice grips on the wrench to apply the torque needed to remove them. I then bought some allen headed sockets and installation went much smoother. I used Locketite all around. I had some questions about routing of the hard fuel lines but after reviewing the pics I had taken it was clear which way they went. There are plenty of steps to take, just take your time and it will be fine. It's not rocket science.

I also solved the photo problem. I have uploaded many photos with captions onto my Picasa website. Use the link below to view them:

https://picasaweb.google.com/111784438992038385687/1995MBE300InjectionTimingDeviceRR?authkey=Gv1sRgCOXc1OjDi7aBiQE

I really hope this will encourage other people to try, and succeed doing this and other projects and saving a bundle of $$ too.