[MBGraham]

Returned to Canada last weekend.
Today my plan is to start my 300D and take it for a short drive. It is blocking access to my 350SL.
So most I will do is have a quick look at SL. Maybe re-attach battery cable.
Then get back to watching Master's on TV! Then work on my taxes.
Still too cold here for SL.

 

[MBGraham]

Bought this steering wheel online with everything needed to install for $235 shipped. Installed yesterday quick and simple.

Very nice, I would love to have one of those.

By the way, do you have some sort of dash cover over existing?

And clock is back in center like early 107s on 380SLs? Didn't know that.

 

[MBGraham]

Here is a link to a steering wheel:
https://www.ebay.com/itm/Mercedes-Benz-R107-Wood-Walnut-Steering-Wheel-350MM-Woodgrain-R-107-SL-1980-1986/163636892071?hash=item261984d1a7:g:QAwAAOSwtLtbpk~P

I did buy a dash cover as there is a few minor cracks starting.

The clock is on in the tach guage. The center is the outside temp guage.

Too bad those wheels are not for the early 107s.

I have a few dash cracks starting too. have thought about a DIY repair or getting a local guy to do the repair. Probably have to paint dash afterwards for it not to show. Not so sure about the plastic dash covers, but that is another option. But yours looks like it is thicker - felt or fabric or ??

Outside temperature gauge? Mostly top down for me, so I "know" when it is too cold to drive

 

[MBGraham]

Only 7000 miles! Wow. Looks like a great acquisition. By the way, back then in 80s were UK cars still using miles?

 

[MBGraham]

Thanks for the info Cavallino Red. I have contacted the Canadian dealer and am waiting to hear back. Of course, Mr. Murphy has to have his say and our dealer is located at almost the other end of the country in Niagara on the Lake, a mere 2,800 miles away.

I am sure you can find someone closer to home. There are leather restoration companies most places. Often furniture related. I did a quick search and this one popped up not too far from you:

https://www.facebook.com/uniquetouchrepair/

 

[MBGraham]

I may be wrong, but I think the normal way to check chain stretch, is to align the passenger side cam marks, then observe how far from TDC the marks on the balancer are. At same time, check the driver side cam marks. Probably a good idea to rotate the engine several times while checking this to be sure the readings are consistent.

 

[MBGraham]

36 teeth = 1 degree?

According to shop manual, 1 tooth on cam sprocket = 18deg at crankshaft.

p5 https://www.tonk.ca/r107CD1/Program/Engine/107/M117_45/05-215.pdf

 

[MBGraham]

I am trying to figure out how they came up with 18 degrees. If the cam sprocket has 36 teeth (10 deg./tooth), the crank must have 18 teeth (20 deg/tooth). If the cam moves 1 tooth (10 deg.) the crank must move 20 degrees (1 tooth). For 18 degrees at the crank per tooth there would have to be 20 teeth on the crank and 40 on the cam.

I agree, it is almost certainly just a mistake. It would be interesting to read what the German engine manual says - could be something lost in translation. Can't imagine MB engineers making mistakes

Jyuma - Your post needs a bit more editing Hope you got over the headache This is what it says:

In your picture the crank appears to be about 2 1/2 degrees after TDC, which means the cam marks s/b 1 1/4 degrees after dead nuts (about 1 tooth) but they appear to be the proverbial x hair before dead nuts.That would indicate to me that the chain is worn (not stretched) a little but I wouldn't call that bad yet. There are 36 teeth on the cam sprocket, therefore each tooth represents 1 degree of cam

rotation.

1.25/10= 1/8th of tooth and as established, each tooth represents 10deg of cam rotation.

 

[MBGraham]

At least we now know how many teeth we have. Good thing at my age.

 

[MBGraham]

Tensioner on my car was the biggest problem. It of course keeps chain tight and that compensates for wear. If it is weak, the chain can slop around and as Jyuma said, that is probably the main cause of failures of the plastic guides. I still have the original metal backed guides and they show little wear. I should have changed sprockets, but haven't got around to it. Maybe this summer!

 

[MBGraham]

There are 3 gears down below that you can't see unless you pull the front cover. I wouldn't worry about them too much unless a problem developed with one or all of them that was far more serious than the possibility of a little wear.
:
:
Replacing the cam sprockets is a matter of some speculation... yes they can wear but how much it effects chain life appears to be a matter of opinion.

It is an interesting question. Why do we focus on the cam sprockets when there are several others that could be equally or more worn? Wouldn't the smaller diameter crankshaft sprocket likely be more worn than the cam sprockets. And if we put a new chain on a mix of new and old sprockets, does that make sense? No doubt changing all the sprockets would be best (but not easy!) But is changing only two and not the others better than not changing any?

It would be interesting to see a comparison of sprocket wear on engines that have had the front cover removed.

On my car, I figured the cam sprocket teeth looked OK, but I had no way of judging that really. Somewhere on this forum, there is (or was) a post that showed affect of wear on
tooth profiles. I may try and find it.

This is not it, but does have an explanation of chain wear. He also says that sprockets are made from harder steel and should last twice as long as a chain. Scared of changing camshaft sprockets

This is the one that I recalled that shows tooth shape when worn (cant say I fully understand the jpg): Timing Chain Slack and Cam Gear Replacement Question

 

[MBGraham]

Wish I could take pictures like that! What sort of camera & lighting did you use?

 

[MBGraham]

Amazingly good phone pictures!! Also great restoration. Well done

 

[MBGraham]

They never should have changed from the old style. I wonder if there are any after market suppliers who sell metal backed chain guides for the later models. I know I'd buy them.

At one time, I recall posts about metal backed guides being available for the M116. From Meyle, I think. OK - found the link: Mahle Aluminum backed Timing Chain Guide - PeachParts Mercedes-Benz Forum

I see Strife said he used them on 380SL. That thread is from 2008!

 

[MBGraham]

Decided to take sl for a run. But, just like the other day, it would not start jiggling coil wire didn't help this time.
No better idea, so I cleaned connections to coil and resistors. Also pulled all ht wires & reinserted. No obvious problems.also cleaned up distr cap contacts

Had another try, and she started right up. Went for a run and she ran perfectly.
Nothing much else to "fix".

Will see how she starts tomorrow.

 

[MBGraham]

Decided to take sl for a run. But, just like the other day, it would not start jiggling coil wire didn't help this time.
No better idea, so I cleaned connections to coil and resistors. Also pulled all ht wires & reinserted. No obvious problems.also cleaned up distr cap contacts

Had another try, and she started right up. Went for a run and she ran perfectly.
Nothing much else to "fix".

Will see how she starts tomorrow.

Had to have car towed home As posted in my other thread about testing fuels pumps, problem turned out to be bad fuel pump relay. Cant believe those relays don't last longer than 48 years

 

[MBGraham]

Not sure just exactly what the 74 has Andy, but there may be a breather valve under the rear of the car. It lets air in to reduce vacuum as fuel leaves and also vent when tank is filled or vapor expands on hot days. While under there, if not already done, check hoses around the fuel pump as well as return line.

 

[MBGraham]

Not sure just exactly what the 74 has Andy, but there may be a breather valve under the rear of the car. It lets air in to reduce vacuum as fuel leaves and also vent when tank is filled or vapor expands on hot days. While under there, if not already done, check hoses around the fuel pump as well as return line.

Andy, I had a look at the engine manual! Looks like on USA 73&74 the vapors, after first passing through the vent valve, are then directed to the engine for burning. Section 47-800.

 

[MBGraham]

Does anyone have any special tricks for keeping the gaskets in place during installation? I am thinking of using RTV to glue them onto the cover before installing them.

I have had similar problem in past on my W123 300D. The gasket seems similar. It has a slot that fits over the edge of the bottom of the valve cover? Just as you get it almost in place, part of it slips off? I have found that if I buy the OE Mercedes gasket for my 300D, it is a snug fit and does not fall off during installation. Aftermarket gaskets do.

Assuming gasket is similar:
Some owners apply just a thin smear of contact cement on the sides at bottom of cover just to hold the gasket in place. Then set cover on a flat surface (table saw in my case) with some weights to make sure gasket is fully inserted while glue adheres. There are products that can be used. If RTV is used, it shouldn't be much. You don't want it oozing out and then getting pieces into your engine. One of the thinner products might be better

Permatex do have a number of products for valve covers that could be used, but they are aimed more at the sealing surface. Because of imperfections in my old 300D, I usually put a very thin smear of a sealant on the sealing face. This to eliminate leaks once you get the gasket installed! I just did a valve adjustment, and no leaks!

Take your choice here. One I have not used but seems interesting for the sealing surface, is Permatex® Ultra Rubber Gasket Sealant & Dressing Item # 85409 . I have used the Ultra gray and black in past.

https://441py33rout1ptjxn2lupv31-wpengine.netdna-ssl.com/wp-content/uploads/2015/12/Permatex_GasketDressingSelector.pdf

 

[MBGraham]

Maybe it's my confirmation bias in full view, but I like the US bumpers. They provide a place to sit and watch the cars go by as you wait for the towtruck.

I was embarrassed to have to call tow truck recently when fuel pump relay failed. I actually called my wife first because she has the CAA membership! (My credit card tow service was next to useless). As it turned out, it was just as well because I then got a ride home. The Tow trucks won't take you with them these days, because of Covid-19. They did tow car to my home and even helped me push it into the garage!