What should I lubricate the throttle linkage with?
 

Hi,
I've been having this problem where at cold temps (it's been about 5-18 degrees here in New York) and cold starting, my transmission wouldn't shift gears until about 2500-3000 RPM until warm (my trans. also flares and slips between shifts, although I can prevent it most of the time by coming off the throttle a bit, but this problem is unrelated to outside temperature). I found a thread from December 2003 where someone wrote that lubricating all the throttle linkage (especially everything related to the bowdon cable) cured his seemingly identical problem. So, I think I'm going to do the same thing. What should I lubricate all those parts with? Thanks!

Alex

The Factory Shop Manual specifies AT fluid for the balljoints on your throttle linkage....
But for the life of me I can't imagine a light grease like Chrysler type A white lithium not being just fine... (door hinges etc )
On the cable I would use PBBlaster if you are trying to lub it without taking it out... if taken out I would use the type A grease myself. I used it in motorcycle cables....

Go ahead and flame me, but it works
 

I'll probably get flamed for this, but I use a product caled "Phil Woods Waterproof Grease". It's sold in bike shops and intended to be used in the
drivetrains of bicycles, but it works damn good on throttle linkage too. :)

I use graphite impregnated grease used on Military helicopters....Got a qurt of it at a DRMO sale when I was overseas during the guld war...

I used the white lithium stuff in a tube you can find at any auto parts store. Seemed ok; on the other hand, it hasn't been on there long :confused:

Anyone try MMO?

MMO is probably too thin to stay there very long. I'd go with one of the other suggestions. I've always had good results using a waterproof grease made expressly for winches on sailboats (not wenches, WW....)

Cheers,
Wes

Stay away from anything petroleum-based (like Marvel Mystery Oil), as this will destroy the plastic parts (look closely, there's plastic in there!). I use silicone-based grease designed for lubricating brake parts. Basically anything lithium- or silicone-based should be fine.

Webwench: As a Libertarian, I feel obligated to say: "OMG! Big@$$ kitten :eek: !"

The manual actualy calls for Automatic transmission fluid. ATF

"The manual actualy calls for Automatic transmission fluid. ATF"

I don't believe that.....

THats how I found out.....I read it there...seriously....

I knew a "mechanic" (who turned out to be more of a fly-by-night used car salesman) that used Vaseline to lube the accelerator linkage parts. That actually worked ok I suppose but I won't go any further on that idea~
I have used the white lithium based grease and still have a tube of it where I can grab it if necessary but I have seen it get caked up, it sorta dries out or something. It also attracts dirt and that might be the reason I stopped using it in favor of a spray stuff, I don't have access to it from where I am but I recall it might be teflon spray from CRC or some company. I use that stuff now. I might even use antisieze if I had some next time I am lubing under the hood but that spray is so easy to get up into the joints you don't have to remove all of them to apply it. I still remove the ones atop the engine but its the ones along side the IP, between it and the block, that I try not to remove because its a PITA to put them back on!

Whatever you use, its probably less important to worry about what to use as it is to check the lube frequently, because I saw an accelerator on a 300D that stuck such that the engine was revved up nicely going down the road at nearly full throttle until one kicked the pedal real hard to free the linkage up! It turned out that the car had been detailed and someone probably used steam cleaning or a pressure wand to clean the engione and all the grease from the accelerator linkage was removed in the process. Some of the balls were rusty and the total friction exceeded the pull of the return spring under some conditions. Not a good thing!

Yeah, I know, but I just can't get past the idea of putting petroleum-based lubricant on plastic. They probably recommended ATF instead of axle grease because it is lighter, and therefore easier on rubber and plastic. The greases on the market have improved significantly over the past 20 years, though, and I'm convinced that the linkages will last much longer with a more plastic-friendly lubricant.

Actually its section 415 of the maintenance section on the Factory W116 manual on CD

Calls for Hydraulic oil..............on all the linkages.......not specificly transmission fluid I need to find where I red that.....Need to find my hardcopy manuals...

I also read somewhere that ATF should be used. Maybe it was the Haynes manual. I still won't put ATF on plastic, though :P .

Evidently not all throttle linkages are the same. Mine are all metal, no plastic. '82 300D. Kent Bergsma of ************** recommends ATF in some one his publications.

Remember that the original manuals are 20+ years old... ATF of 20 years ago is not the same stuff as the ATF of today. Your manual also suggests using ATF in the power steering, but you shouldn't use modern ATF in power steering systems, you use power steering fluid.

Now, modern ATF might work for throttle linkages, but since its a different product than the manual is referring to, YMMV.

peace,
sam

I used a water proof dry spray lube called McLube. Seems to work very well, and doesn't collect dirt.

I use axle grease t lubricate the linkage rods. ATF to me is too thin. Using the grease actually quiets the linkage rattle. I clean and repack the linkage rods every other oil change. This way any grit that gets caught in the grease will be removed.
The side discussion about fluid standard of 20+ yrs ago, is something I have brought up before. How can one tell which modern products can be use don something 2 decades old. An example of fluid standard inproving with time is the oil requirements for MB diesels. My' 1983 TD's owner's manual says that 15W-40 is good down to 23F. Yet the owner's manual for the '87 says 15W-40 is good down to 5F. What changed in 4 years?

I used Redline Synthetic CV-grease, but it seems like the plastic areas are causing a good deal of drag. I think I'll try some stuff like spray on teflon for that. Any other ideas? I know I don't want to put any petro based substance on it.

Technology changed, I believe 5*F is about the standard for a 15w40 oil even today.

That's what it's supposed to do.

Are you certain? My '82 300D has plastic clips inside the female ends of the linkages. You have to look closely to see them.

Yes, I'm certain. All metal. no plastic. Mine have a spring steel clip. In fact, I just bought a couple of replacements, no plastic in those either.

No plastic? That sounds like an interesting future upgrade! Where did you buy the replacements?

Wow, thanks for all the responses. I don't know what I'm going to use yet, but you all certainly gave me good ideas. What do I do to get the rods off the ball joints? I wouldn't want to snap or bend anything.

For the last five years I've used whatever grease I happen to have on hand for the throttle linkage (the brass fittings). I've used wheel bearing grease and plain old multi purpose grease. I've never had a problem.

Scott

The only thing I use ATF for is the throttle linkage :D

Fastlane has the them. You can see the spring steel retainer clip in the photo. (I hope we are both talking about the same thing.)

http://catalog.eautopartscatalog.com/mercedesshop/sophio/quote.jsp?clientid=mercedesshop&cookieid=1EH0TL2AI1FJ0SAAGE&baseurl=http://catalog.peachparts.com/&partner=mercedesshop&year=1982&product=C7025-26867&application=000030452

I recently noticed that a couple of the throttle linkages on the valve cover were making contact (where there should not have been contact). Further investigation revealed that the accellerator bushing on the firewall had somewhat disintegrated and was allowing the a rod to move forward. The bushing itself was made of nylon and appeared to be suffering the affects of old age and perhaps prolonged exposure to the heat of the engine compartment. Had this problem progressed it could have had serious implications. Possibly a jammed throttle or a major loss of power due to lost motion in the linkages.

Use a large flat-blade screwdriver. I just stick the blade between the fittings and rotate so that one side of the blade presses against the male part of the fitting and the other side of the blade presses against the female part. It should pop right out without much force. Unless I have to remove the linkages to remove the valve cover, I find that it's less complicated to just do one fitting at a time. To keep the mess to a minimum, I just coat the male end (looks like a little ball) with grease and leave the female end alone. Then I don't have problems with excess grease leaking all over the place.

Tangofox007, that's exactly the part that I was talking about. Thanks for the info...and they're cheap, too!

I disassembled my accelerator linkage and sent it out to have all the components hard coated with a teflon-graphite coating used to reduce friction by the NHRA crowd. Upon reassembly it was greased with Krytox, a lube developed for NASA's space shuttle. :rolleyes: Slicker than snot on a doorknob. But seriously folks, any old oil or light grease will do..... :) RT

And where can one get Krytox (sounds like an exotic material allocated under govt programs to selected military contractors or something!)
Do you have a NASA decal in your window? I got one, Ha!

BTW I think PBBlaster evaporates and doesn't leave behind long term lubrication?

I put some on a door hinge way WAY back when as it was the only thing I had in our old ford picup and it worked good until later that day when it started sqeaking like MAD every time you opened the door. Some aresol lithium spray fixed that.
Just not sure about the use of that on a bowden cable...anyone?

I like either white lithium grease. The CRC spray in the red and black can. Or I put a light coat of Mobil 1 synthetic grease on the ball and snap it back into place. Especially important to relube the linkages after cleaning the engine.

The MB 617.95 engine service manual has this to say about the throttle linkage: "Grease bearing points as well as ball sockets with Molykote Longterm 2." (Page 30.8-310/2)

Actually a friend of mine got some Krytox, a sample, from an industrial lube supplier as he works in a machine shop. Krytox was ridiculously expensive, impervious to temperature, water, all solvents, etc. The rep told him NASA used it for the space shuttle. We tried it for 1/4" cable driveshafts in model boats. They get wet, spin at 18,000 rpm under a 5-6hp load. Worked well but not well enought to justify the cost. It was white and looked like Crisco.... No NASA decal, just a Scaled Composites sticker.....

I actually use Mobil1 grease, its what I have. RT