Throttle linkage binding against manifold

[twistedtree]

This is on an early 230, #1949 build in late 1963.  The throttle linkage rod that runs from the pivot on the side of the engine block up to the pivot/bracket mounted on top of the intake manifold - the rod is binding against the exhaust manifold.  The car is a "barn find" so history is uncertain.  One thing I noticed when comparing it to a 280 is that the exhaust manifolds are quite different.  From a quick inspection, I'd say the manifold on the early 230 is welded tubes when the 280 is cast iron.  The resulting shapes are quite different, and on the 280 there is a clear space where the link rod passes up through the two manifolds.  On the 230, the opening is much narrower resulting in the binding I'm seeing.

My presumption currently is that I either have the wrong exhaust manifold on the engine, or the wrong linkage bracket(s) on the intake manifold or side of the block.

Does anyone happen to know what changed in this area along the way, or have any insight into what might be amiss?

Thanks,

Peter

[Tomnistuff]

Hi twistedtree,
According to http://www.silverstarrestorations.com/113SL.htm, which has a history of the main changes on the pagoda, the exhaust manifolds were changed from tubing to cast iron in 1965.  Check out the history at the link above.  I didn't check the EPC to verify their statement.
Tom Kizer

[Atazman]

Is it possible that the plate on the side of the block is mounted incorrectly?  My best recollection is that I had this problem and it limited my throttle from going "wide open".

[twistedtree]

Thanks for the history link.  That confirms the manifolds are correct, along with a few other things I was wondering about.

It's certainly possible that the swivel plate on the block is installed incorrectly.  It's also a different design from what I have on my other cars.  All the others I've seen have a cast aluminum cover plate with integral lever post.  Mine has a stamped steel cover plate, then a second bracket with the swivel post mounted on top of the cover plate.  I don't have a good camera with me, but I'll try to snap some pictures with my phone.  On the cast cover/post, it's positioned so the post is directly below the forward bolts for the engine mount.  On mine the bracket/post has the post much further forward, but given the way the manifold works I think that's how it needs to be.  If anything, it needs to be even further forward.

If anyone has pictures or knows how this older arrangement should be assembled correctly, I'd love to hear about it.

Thanks in advance,

Peter

[Tomnistuff]

I can't advise, due to my extreme ignorance and poor memory.  My car is a 1967 230SL with the cast iron manifolds, but it's completely disassembled.  Here's a photo of a Metric Motors 230SL short block.  The orientation of the plate is the same as photos of my old one before Metric and my new one from metric.  Maybe the plate orientation with the lever pivot pin will give you something to compare to.  I've never seen a stamped steel plate but I'll look at the EPC.
Good Luck,
Tom Kizer

[twistedtree]

Thanks!  That's how the cover/pivot plate is oriented on my other cars.  The pivot is in the 7/8 o-clock position.  On my early 230 with the separate cover plate and pivot bracket, the pivot is in the 4/5 o-clock position.

The EPC shows a superseded part that looks like the cast one-piece style.  I don't see any reference to two part numbers.

[Tomnistuff]

It looks to me like the original cover was A180 015 07 05 (Qty unknown) and was changed to A180 015 08 05 (Qty 2).  At engine number 011153, the quantity of A180 015 08 05 was changed to 1 and an additional pivot plate (called a bearing bracket) was added (A127 070 17 24).  I think the original two identical plates are the CAD plated ones and one or more of the attachment bolts were used as a pivot.  Look at the number of bolts and pivots vs the number of holes in the plates.

Later at engine no. 011153, when the manifolds were changed, the front CAD plated plate was eliminated and replaced by the cast aluminum plate with the integral pivot pin mounting boss.  WHO KNOWS which of the bolt holes in the front CAD plated cover plate was originally used for a pivot pin on the early cars with the tubular manifolds?  I'm over my head now and abdicate.

Good luck.

Tom Kizer

[twistedtree]

Pictures are worth a thousand words....

The first shows the cover plate, pivot bracket, and lever arm.  Above you can see the manifold pipes.  The rod runs up between the pair of pipes.  On the side of the left pipe, you can see where the rod has been rubbing.

The next picture shows the bracket and lever on the intake manifold.  I'm beginning to think this part might be the problem.

[Benz Dr.]

I have this exact set up on my car and I had to find all of the correct parts to make it work. It will have a flat steel plate over the front cylinder cover. The small bracket is in a different position than the later version and is mounted on two studs. You can use a long 6 mm screw and fit two nuts on it so that the first one tightens against the cover plate and the second one tightens up against the first nut.
 Once you determine how long the screw has to be, you will have to cut the cap off and then thread the stud into the hole for the cover plate. Thread the wo nuts on and then mount the bracket on top of the second nut using a third nut to hold the braket to the stud.This is important to keep the bracket spaced away from the engine block. MB used a screw that had the hex in the middle and two threaded pieces on each end. If you don't have these two pieces you can make them or I might have some originals around.

 I found that the rod coming up from the bracket on my car was also rubbing against the pipes so I bent it just enough to clear everything.

I'll go out and look at my car to see what quadrant the bracket should be mounted at.

[twistedtree]

Thanks Dan.  What you describe matches the picture I posted (I think).  Maybe my upper bracket is bend somehow.  I'll focus on that next.

[DaveB]

Here's the setup on my car, which works without binding. The attachment points of the bottom bracket differ to yours. This is a manual so not necessarily correct for your auto.

[twistedtree]

DaveB,

That first picture is exactly what I needed.  It's the same set of parts, but clearly assembled differently.  Allegedly this engine was recently rebuilt, but never driven, so it wouldn't be surprising if it were not put back together correctly.  I've already found several other things amiss.

If anyone else can confirm theirs is also assembled like DaveB's then I think this mystery may be solved.  The way his is put together shifts the lower link ball forward compared to mine which would relieve the binding (or at least help).

[DaveB]

This image in the edition B 230sl parts list confirms the bracket attachment points are the 4 and 6 o'clock bolts.
Hope all the internal parts are in spec and assembled correctly!

[Benz Dr.]

The rod that comes from the firewall is also different. I can't remember if it's longer or not but it's not the same part as the one used with cast iron manifolds. I remember I had to change that part before I could make the throttle work properly.
If you have everything assembled but leave that rod off you should be able to tell if it needs to be longer or not.

[twistedtree]

OK, I'll change the mounting of my bracket - it's clearly wrong.

But the next question is the lever on the intake manifold.  The parts diagram and the photos that DaveB posted shows a slip joint lever mechanism, and mine is a solid lever.  I've got an automatic, which might make a difference.  I'm slowly finding my way around the BBB and parts books that come on the CDs, and the EPS catalog.  The one thing I can't find is a parts diagram for the linkages for an automatic, including the mounting for the constant speed solenoid.  That would answer my lingering linkage questions.  Is there a parts diagram that I'm missing?

[Naj ✝︎]

Hi, Peter,

Attached picture of  the linkage on the engine block on a 230 SL (RHD manual with non-cast iron pipes).
Afaik, All 230s have fixed length operating rods, the slip joint in the top rod belongs to later 280 engines.

Hope this helps
Naj

[twistedtree]

Naj,

Sorry, I wasn't clear on the outstanding issue.  I think I've solved the block-mounted pivot question, and have now moved to the pivot directly above it that's mounted to the top of the intake manifold, and which on an automatic also houses the constant speed solenoid.

The attached parts diagram shows a two piece slip joint lever, and this matches the picture that DaveB posted in this thread, and another picture that I happened to find.   However, all appear to be manual transmissions as there is no Constant Speed Solenoid.  My car has a different bracket that also mounts the solenoid, and a single-piece lever with no slip joint as show (just barely) in the attached picture.

So the question is, do automatics also have a slip-joint lever, in which case I've got the wrong parts?  Or do automatics have a single lever in which case I probably have the right parts?  I'll have a clue once I've correctly reassembled the block pivot and see whether the linkage parts have clearance and work properly, but I'd love to get additional confirmation if possible.

Does anyone have a car of this vintage with an automatic?

I'm heading out now to fix the block pivot......

[J. Huber]

Hey Peter. I have a 63 automatic. I will go try and take a picture from the same vantage point as yours. Give me a few..

Ok here is a shot. Big enough? Hope it helps

[twistedtree]

Excellent, that confirms it.  Your manifold lever is one piece just like mine.

I also rearranged the mounting of the lever on the block and now my linkage works with good clearance just like it should.  Many thanks to everyone for all the great help!

Has anyone ever mentioned how awesome this group is?  I'm just saying....

[J. Huber]

Has anyone ever mentioned how awesome this group is?  I'm just saying....

Yes, but we never get tired of hearing it!       Glad you got things worked out!

[twistedtree]

Yes indeed, one problem down, plenty more to go.....