Accelerator Linkage

[georgem]

Guys, your help please.

I am in the process of replacing all the bearings and ball joints etc in the linkeage system. I have so far installed the new bearings in the cross over shaft and all ball joints and sockets above the engine. I am about to start on the joints at the pivot block on the side of the engine.

I am having problems at the moment with the engine speed returning to idle  as the linkeages are binding just before the stop. I have isolated some of the problem to be the cross over shaft which is a tight fit in its bearings- there is no slop with the new bearings, (which is good)  but it just seems to be too tight. I was wondering if there was  a right and wrong way to install the bearings (they looked identical and symetrical to me), or whether I was supposed to hone them before I  slid them onto the shaft.

Its an annoying problem. 50% of the time, once I let off on the accelerator, the engine will settle down to normal idle at about 800 rpm. Sometimes it settles at about 1200rpm, but if I blip the accelerator, it will drop down to 800. Worryingly, occassionally it will jam at about 2000rpm.

And a secondary question: if I remove the bottom linkeage bracket, will I loose any fluid - is it a special gasket? I do know that it will be a PITA to get at it to remove it!

Thanks

George

[mdsalemi]

George,

Just a wild guess here--but is it possible that the bearings are so tight a fit that the inner race expands ever so slightly when installed, and thus binds?  Or maybe something similar with the outer race?  If you can't get the bearing issue sorted maybe the fix would be slightly stronger spring to overcome the bearing's tightness.

(Check with a Toyota mechanic they know all about this stuff )

[georgem]

Thanks Michael,

Nice comment re Toyota..............

Re the bearings - they are not ball races - perhaps I should have used the term bush because they are solid brass.

Thanks for your interest though.

George

[ja17]

Hello George,

Check and lube the linkage pivot on the engine block. It seldom is lubed and often gets stuck. Check each linkage pivot and shaft by rmoving the linkage rods and moving the parts until you find which is difficult to move. If the "cross over" rod is tight in its bushings, you may need to clean the shaft with som steel wool. Check to make sure  you did not nick or damage the bronze bushings during installation. Touch it up with a fine file if you find a bad spot on them. Lubricate. Graphite solvent is the factory recommended lubricant for linkages although a light oil will also work well. Heavy grease will collect dirt and grit and cause more wear than lighter lubricants in the long run. The worst thing is no lube at all.

[wwheeler]

Joe,

When you talk about graphite solvent for the linkage, are you talking about key cylinder lube in a spray can? I use light oil now, but it can be messy.

[georgem]

Joe,

Thanks for contributing.  I pulled the shaft off and did what I should have done before I assembled it - ran some very fine wet and dry paper around the shaft. I thoroughly oiled the contact surfaces and put it back together - the linkeage now snaps against the stop.

Cheers

[Wes Bender]

George,

Just a wild guess here--but is it possible that the bearings are so tight a fit that the inner race expands ever so slightly when installed, and thus binds?  Or maybe something similar with the outer race?  If you can't get the bearing issue sorted maybe the fix would be slightly stronger spring to overcome the bearing's tightness.

(Check with a Toyota mechanic they know all about this stuff )

You might also check with a Chrysler mechanic.  Seems they're finding gas pedal bushings on the floor mats these days....

[ja17]

Your welcome  George, glad I could help.

Wallace, yes I was reading through some old maintenance literature from MB where they actually suggested using graphite solvent as a linkage lubricant. This makes sense since a dy lube like this will not attract any ditrt and grit.

[georgem]

One problem solved, another emerges....

I now have a great linkeage setup with all ball joint and bearings replaced, so after achieving this I started to reset the idling mixture; playing with the mainfold air and injector pump as per Joes technique. She now idles just under 1000rpm on the tacho - a touch lumpy but with fluctuating rpm; probably only a 100 or so but enough to be noticeable PLUS she won`t idle when cold. Stalls every time until up to uperating temp then she is fine.

For the stalling  I went straight to the WRD ( i regard this as our equivalent of a choke)with a hose to my ear to check for induction around the mini air filter, sure enough when cold there was a strong hissing (my wife had to keep it idling) and when it warmed up, the idling cut out, as I believe it should.  So could I have suggestions on the two problems please:

The fluctuating rpms at idle
Stalling when cold.


Thanks

George

[georgem]

Guys,

Just to correct a typo in my last post............when checking the WRD, when the engine came up to operating temp, the "hissing" cut out, not the idling.

Cheers

[ja17]

Hello George,

First make sure your linkage is set up properly. Check to make sure that the venturi stop screw is correctly set etc. Use the split linkage CO test to determine what if the idle mixture irich or lean when the engine is cold and hot.

Keep us up to date.