[MBZ] 124 Vacuum Pump install question
Hi group! I'm replacing the original vacuum pump on my 1987 300D turbo, 191K miles to prevent any surprises from the old pump. I have the latest Pierburg # 7.20607 (000-230-3165) and a metal gasket, (601 238 07 80). My Mercedes 124 engine maintenance manual does not include the repair. My question is do I have to coat the metal gasket with a sealer or leave it alone? The gasket appears to have a black plastic coating on it. The Pierburg Service information bulletin # 0025 says to remove the basket ( it's removed) and 3 hex head screws with their washers, install the pump and start the engine with the vacuum line off and fill it with 50 cm3 of oil. Then the vacuum line is immediately connected. There is plenty of room to install the pump without removing the radiator, fan and shroud. The upper radiator hose, power steering pump pulley, serpentine belt and tensioner spring was remove to gain access. I'm ready to tighten up the six screws to compress the pump to the block. The double cam has very little wear. Am I missing anything? Thanks in advance, Ted Lucas '81 300D, 206K miles '87 300D, 191K miles
[MBZ] Black Rubber Floor Mats for a 123
Hi Group! I am looking into purchasing a set of black rubber floor mats for my '81 300D. The set I would like to have is a Mercedes original with the star logo but they are only available for the 124, 300D. I have seen the ads for Husky, WeatherGuard etc. but are generic fit and not custom cut for the 123 body. Can anyone chime in as to the brand, model that looks right? Thanks in advance Ted Lucas 1981 300D, 207K miles 1987 300D, 190K miles
[MBZ] 6 degrees of stretch
Hi gang! I am faced with replacing the timing chain on my '81 300D, 207K miles, now at 6 degrees of stretch. Searching around I found articles and post to replace the chain. My concern, given the various guides, tensioner, rails and chain that are interlinked, what is normally replaced to do a proper chain replacement? Should for example the tensioner be automatically replaced or inspected and reused if good? Should all the rails be changed? Who would have the best prices for the parts? What are the necessary tools? What are the got you? Are there any good diesel chain replacement write-ups? Thanks in advance, Ted Lucas '81 300D, 207K, miles '87 300D, 190K, miles
[MBZ] 6 degrees of stretch reply
Thanks Marshall for the reply. I feel more confident now to just replace the tensioner, chain and link to keep it simple. The two lower rails look to be a lot of work to replace and given they hold the shortest free length of chain, they should hold up the best. The tensioner rail appears to receive the bulk of the wear and I will inspect it and replace if worn. I will contact Rusty for the parts. Ted Lucas '81 300D, 207K, miles '87 300D, 190K, miles
[MBZ] Modulator valve blues re-update
Russ the trans is a 722.118 and does not use the K-1 spring update. I bought the K1 spring but could not use it. Nor does it have the bolden cable. The only control seems to be the gear lever on the trans that is directly connected to the console shift. When I first bought the car in March the trans was doing pretty much the same. When I backed off of the modular valve (c.c.) and with a new vacuum control on the IP the flaring stoped. The oil was changed to Mobil 1 ATF with a new filter. The vacuum switching valves on the valve cover were replaced along with the worn small teflon levers. Found one of the vacuum hoses cracked and repaired it. I now have 14 of vacuum at idle to the modular valve. The latest shift characteristics prior to the new modular valve evolved into a harder shift and some down shifting from fourth to third but could be controlled by easing off of the accelerator. Given the improvements of the previous repair I attempted to further improve the shifting with the new modular valve. Unable to get the new valve to shift, I reinstalled the old modular valve and backed off c.c. numerous times to where the valve is non functional. The trans is shifting with out the vacuum and still slipping on harder acceleration and now slips in fourth and stops when I back off on the accelerator and then holds to top speed. I think in retrospect I may have caused a bit of additional wear on the bands when attempting to use the new modular valve and various adjustments c.c. and c.w.. This was also accompanied by a series of brief run in my neighborhood with slipping experienced in third gear. At this point I have to be gentle with the acceleration through the gears and then seem to hold at higher speeds. I guess I will drive it awhile to see if things improve. This trans may be on its last leg and maybe a rebuilt or pick and pull trans is in my future. I don't know what more I can do the improve the situation. Ted Lucas '81 300D, 207K miles '87 300D, 190K miles
[MBZ] Modulator valve blues
I replaced the trans modulator valve on my '81 300D with a new red one. Trans was shifting so so with the old one and various adjustments but tried to improve on it with a new modular valve. Now the car slips when shifting into second gear and nothing beyond that gear. I tried numerous adjustment such as 2 turns c.w. and c.c. and beyond. I even reversed the pin in the modular valve. As it stands now the pin with the shoulder side is engaged in the valve and the tapered spring end is into the trans. Topped off trans oil and did not disturbed and vacuum line except for the connection at the valve. First and reverse works good. I am now at a loss to try anything else short of reinstalling the old valve. Can anyone knowledgeable chime in with any suggestions?
[MBZ] Modulator valve blues update
I removed the new modulator valve and reinstalled the old one and the trans. shifts with a bit of flair from 2nd to 3rd gear. All others shifts seem OK. I will back off the adjustment 1 more turn c.c. and see if that improves the flair. I studied the operation on the new valve through its full range of adjustment and noticed it would not open at 14 or of vacuum the car is putting out at idle. I adjusted the new valve to open at the 14 vacuum threshold.. Now I understand the operating function of the valve and will have to test the old valve and find its opening vacuum in inches and adjust the new valve to that value. Now I will be in the ball park to fine tune the shift characteristics. That will require removal of the old valve and the loss of another $6.00 quart of Mobil 1 ATF. Just wasted three quarts. I will wait until the next oil change and tinker with the new valve. Anyway that is what I found out for other to build on when faced with the same problem. Thanks Joe for the reply. Ted Lucas '81 300D, 207k miles '87 300D, 190K, miles
[MBZ] What is a good, non turbo, '81 300D center muffler to buy?
Hi gang! My exhaust seems a bit loud and running out of repairs to address, I am inclined to believe the center muffler needs to be retired. A recent post on the an exhaust question suggest the center baffles may be eroded away on my muffler. I checked Rusty's site and there are two center mufflers listed. Bosal for $86. and Eberspaecher for $134.00 (OEM). The rear muffler seem to have been replaced my the PO and appears to be very good. The center muffler has some eroded metal on the new front pipe connections but not leaking and suggest it was an original or replaced many moons ago. Obviously the cheaper muffler looks inviting but I am concerned fitting it may run into problems as opposed to the OEM muffler. Any feedback welcomed. Thank in advance, Ted Lucas '87 300D, 190K miles '81 300D
