1100 Throttle Plate Shaft Leak-Old Topic-Revived

Junior64

Junior64

Well-known member
Well, I found out where the vacuum leak on my 170 is coming from. The throttle plate shaft is leaking on both sides of my 1100 carb. I pulled the shaft out and there are no bushings in the lower housing that I can replace. I think the housing and shaft are both worn. Is there a way to repair this, or do I need to buy a new/re-manufactured one?
 
They can be fixed though finding a good carb shop now days is tough.
 
Sounds like $$$. It's gotta be cheaper than a Pony carb though. I would like to repair this one since it's got the manual choke. They are hard to find and I am trying to keep the car original. If I can't find any local shop around here to do the work, can you recommend someone to ship it to?
 
Oh yeah, thats that thing that nobody knows how to work on anymore because they cant plug a computer in to it to diagnose the problem it has.
 
Sounds like $$$. It's gotta be cheaper than a Pony carb though. I would like to repair this one since it's got the manual choke. They are hard to find and I am trying to keep the car original. If I can't find any local shop around here to do the work, can you recommend someone to ship it to?
Click to expand...

No reason for it to be all that much money, of course what one person thinks is a lot is not so much to the next. I use to do them for many years is not so much the amount of time. Can't really recommend anyone in this or your area every shop that I knew of has either retired or closed their business for the lack of business. As the EFI cars became more and more the norm for transportation the need for carbs just went away. That’s progress I guess. :shock:
 
Have you tried looking around at some local junkyards and such?? The 1100 is pretty simple to rebuild and the kits are really cheap to buy.
 
I just rebuilt this one, except for the shaft. I found a shop near me and will give them a call on Monday.
 
:unsure: Can`t remember "who dunnit",but appx 2 years ago one of our members had a similiar proplem with his carb.He did exactly what you are talking about in this thread.
His write up was in the "Extreme Tech"section.
Good luck.
Leo
PS:Just found the thread.Hehehehehe.It was titled "some carb mods--application for the hard core tech forum
Author-simon
Date-Fri Aug04,2006.
Forum-Hardcore tech.
See guys and gals,sometimes I am helpful. :eek: :eek:
Leo
 
dagenham":2orhjppm said:
Have you tried looking around at some local junkyards and such?? The 1100 is pretty simple to rebuild and the kits are really cheap to buy.
Click to expand...

Rebuild kit was cheap, but I wasn't able to source a local vendor for a float... restoring mine with POR-15... will let you know in my other active thread...

http://www.fordsix.com/forum/viewtopic.php?f=2&t=63198&start=0

Actually am taking my three carbs (Ford 1100, Ford 1101 and Holley 1904) to a co-worker to have the tolerances checked to see if I should have bushings installed.
 
:unsure: Actually,JF,I did tell you where the thread was.Also one thing that I DID forget.Its on page 5.Was`nt a link as such,but was findable.
Leo
 
I showed my carbs to a co-worker. He's going to try to build up the shafts and then turn them down, rather than inserting bushings... going to try one of the Fords and the Holley. He was concerned about the relative thinness of the bushings compared to his suggestion... makes sense to me. Will see how it goes.
 
sasktrini:
"I showed my carbs to a co-worker. He's going to try to build up the shafts and then turn them down, rather than inserting bushings... going to try one of the Fords and the Holley. He was concerned about the relative thinness of the bushings compared to his suggestion... makes sense to me. Will see how it goes."

I rebushed my Autolite 1100 a few years ago. I have concerns about what your co-worker is suggesting - how is he planning on building up the shaft? If your shaft does not have a noticeable worn ridge that your fingernail catches on, I would strongly suggest bushing trhe carb instead. Note that the shaft is steel and the carb body is aluminum. Typically the carb body will wear much faster than the shaft. I would be concerned about the straightness of the throttle shaft after building it up.

Unfortunately, I did not take any pictures of the 1100 when I rebushed it. That carb was replaced by a Weber 32/36 a couple of years ago and I sold off the 1100 last year to someone on this list. I did take some pics where I did the same type of repair on the choke shaft of the Weber. I would suggest a sintered bronze bearing material -I may have used brass on the choke bushings. The first couple of shots are before pics:
http://i290.photobucket.com/albums/ll27 ... 190012.jpg
http://i290.photobucket.com/albums/ll27 ... 190013.jpg
This one is an after picture. Note: the bushing in this picture is actually a bit thicker in cross section than what I did on the 1100 because the choke shaft bore was so badly worn on the Weber. http://i290.photobucket.com/albums/ll27 ... 190015.jpg

I am not a machinist, I am more if a self tought metal working hack (who is fortunate enough to have some big toys such as a lathe and mill). My proceedure: 1. Using a long drill (that allows me to drill all holes from one side) & drill press, drill hole oversize. 2. Rough turn bushing so that the OD is a light press fit relative to the newly drilled open bushing with the ID about 0.015 undersize to the throttle shaft. 3. Press in the bushings. 4. Ream the bushings to size.

I am cheap an use an adjustable reamer and after every reaming iteration I test fit the shaft until it slips in with out binding. From memory, the throttle shaft is 5/16 dia. and if I needed to do several of these, I would buy a 5/6+ reamer. Notice that the bushing wall thickness is faily small.

On some list, I remember reading a message where someone mentioned that one could buy throttle shaft repair bushings. With that, the only power tool that would be recommended would be a drill press. Try a google search to see if you can buy bushings for your shaft diameter.
 
We discussed that, because I asked for bushings.

1) drill bits leave a triangular hole (I said "wha?") because they only have two cutting edges and there is some wobble caused (even with a drill press)... compared to a reaming bit that has several relatively straight cutting edges. Those bits are pretty pricey, like $30 per. Reaming bit plus drill press = ideal, but you need two bits... one to bore out for the bushing, one to bore out for the shaft.
2) your repair is on the choke plate at the top of the carb, where there's no fuel journals machined anywhere near the shaft bores, so you could use your method there with a significant size difference between your OD and ID measurements. If there are air leaks around the choke plate, it's not as detrimental as a vacuum leak around the throttle shaft below. My friend, in looking at the carbs, thought that only the Holley base had enough meat to bore it out for a bushing, at least as precisely as he can with his tools... he's used to machining larger items... but with the Ford, the bushing thickness would end up being virtually paper thin.
3) I agree, and challenged him with this, that the bores on the 1100 carb would wear because much softer than the machined shaft. Holley has a steel throttle plate base, so it's hard to tell which would wear first... even then, the throttle plate should be the side that wears. Still, because he's not a carb shop, just a guy who turns some projects on his home lathe, he's not equipped to "properly" ream them out without risking the internals of the carb or throttle plate.

His method (going to try it on the junkiest carb, the 1100 that was full of crud) is to build the shaft up with silver solder and use his lathe to bring it down until the fit is snug in the bore... it's easier to remove material than it is to add it on.

Personally, I guess I've seen drill bits make triangular holes when I use a hand drill, but never noticed the phenomenon with a drill press... I don't know how precise it has to be when installing bushings on carbs... I suppose even if it was, it could be sealed up between the bushing and carb. I'm not sure what he's worried about. But I cheaped out and didn't want to call a carb shop... After he tries his method he will probably give me both carbs back and curse me out that he never wants to try anything that small again, and I'll be stuck with a carb shop for the other one. I actually got lucky... my 1101 did not have any noticeable wobble, but the 1100 and 1904 do.
 
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