converting single to dbl chain kit? newbie - PeachParts Mercedes-Benz Forum

lesrrt · #1 11-15-2003, 06:32 PM

Ok! Iam a newbie and have used the search for many time saving info. 1st? Ihave an 82 380 sel w/ a single chain. Remarkably ran great without noise. I decided to tune the motor and change valve cover gaskets too. Noticed the sprokets on the cams are shot. Can you purchase a kit that includes both cam sprokets, idler sproket, and ditrib gear and crank units also. Assuming I also purchase all rails and new tentioner and chain, are the above pieces easy to disassem. via crank, idler, and distrib or do they have to be purchased as indiv. Items via dealer? The auto has 120k, 3.8L 116.963. Will these parts be real exp$ to convert? Iam not a mechanic by trade however, I do all work on my autos. Having worked on many cars, including my c5 corvette, I know a "servicable" car when I see it. These 126's are that! This website seems to be the most benz versatle around. I really do want to keep this car.It was given to me by someone that did not want to spend anymore$. I already put on new rotors/brakes/ shocks, and fixed two window motors. I even got the cruise to work too. So... if any of you veterens can help me, It would be most appreciated! les

stevebfl · #2 11-15-2003, 08:07 PM

You will have to replace all the gears and all the rails. The pieces are all available separately from numerous sources.

This job will stress a DIYer. It is a 25 hour job requiring the removal of the front timing cover and some amount of the pan. I have heard of techs who pull the motor to do the job. Lots of things to go wrong.

#3 11-15-2003, 08:19 PM

I've seen prices In the $2500-3000 range...

gedeonbgjr · #4 11-15-2003, 09:46 PM

You will also have to remove the left head in order to replace the distributor drive gear on a 116.963

gedeonbgjr · #5 11-15-2003, 09:51 PM

You will also have to remove the left head in order to replace the distributor drive gear on a 116.963

ctaylor738 · #6 11-15-2003, 11:05 PM

From a DIYer's perspective, it is a huge job. Especially the first time. Pulling the head requires that the intake manifold come off which requires removing most of the injection plumbing. Getting the exhaust manifold off is no fun.

You will also need several hundred dollars worth of tools, including a slide rail pin puller and extended hex-bit sockets.

With that said, if you take your time, and are careful to follow the instructions, and check and double-check all of the alignments of the crank and cams, it will be a very satisfying repair. You will certainly learn a lot about your M116!

I hate to say it, but unless you are going to keep this car for a long time, you might consider just replacing the chain, cam gears and the upper rails.

lesrrt · #7 11-16-2003, 12:08 AM

HMMM.. With the above said, I think i'll consider. Maybey the easier route would be replace the cam gears/chain/top rails and leave alone the rest. I wonder if a 420 engine would fit if considering A complete engine change. Are these engine blocks identical to the 3.8, and are the 5.0/5.6 parts compatable. Thanks for the heads-up!! les

william rogers · #8 11-16-2003, 12:12 AM

I did a cover off timing chain and rails with out a manual fun but a lot of work get a manual! nice to see all the goodies and learn about a great engine.......
William Rogers........

lesrrt · #9 11-16-2003, 12:22 AM

Coyote ugly for sure!! But I like ugly and a challenge. It is removing the head part that makes me ponder. I have a 126 cd but the engine tech is nill and vauge. Can that distrib shaft be removed so that the gear will fall, or is this one assembly? Thanks for the pic Bill! les

william rogers · #10 11-16-2003, 01:00 AM

Yes the left head would need to come off to change the distributor gear.

My car is an 86 Euro 500SE with a 86 Euro 420 engine and a 722 311 transmission. The 116 420 engine would be a direct bolt in but you would probaby have to use a a 420 ECU ,Steve would know.as my car came with a 117 engine I think that a 500 or 560 would be a straight bolt in but you might need a different tranny. I bought my car sight unseen as a 500 and was P------ off when I found out it had a 420 engine but after almost two years of driving I really like the 420 engine as the car is a Euro model it is geared very high so I'm getting a little over 20MPG with lots of 2 lane Mt. driving............
William Rogers.......

MrCjames · #11 11-17-2003, 11:04 AM

Personally I did numerous chain conversions without removing the Left Cylinder head and I never had a problem installing the distributor drive gear. I do not think the work instructions mention anything about removing the left cylinder head for this repair, to be certain I will review my info.

IMHO-There are many different things that can, and do go wrong. Besides being experienced to address rounded off allen bolts, broken bolts, or even seized bolts you will need to be adequately equipped with special purpose tools. The better quality tools to address this job are mainly German made and they will add up quick. You may want to seriously consider investing in the right repair facility to do this job for you.

lesrrt · #12 11-17-2003, 11:32 AM

Thanks all for all of the support and info. I have started to remove and label everything and am down to the waterpump assem now. Iam hoping that I don't have to remove the heads, however if I have to i'll have them cleaned up w/new guides seals. The auto has only 120k and ran remarkable prior to teardown; no oil consum. or anything. Assuming I have to remove the heads, would it advisable to just leave them be? Also and finally, If I can remove the distri gear off w/o removing the left head, would the head gasket still be ok to refit the t-chain cover; given that extra care is taken when removing assembly. Thanks all! Ill keep you posted!! les

ctaylor738 · #13 11-17-2003, 12:34 PM

The CD is very clear on the need to remove the head on the 116 engine. Hopefully, there is a work-around because the biggest danger in this job is that the head bolts will pull the threads out of the block. The bolts are not perpendicular to the block, so a special jig is needed to re-drill the holes for the inserts.

And you gotta buy a gasket set!