Stripped throttle body shaft screw!

[@TDC]

Hey guys! I nearly destroyed my 90 throttle body trying to get the 23 year old throttle plate screws off! I ended up drilling them out and making the shaft completely non reusable. I purchased another throttle body from a member. He got one screw out but the other was stripped. When I drilled out my screws in my old throttle body I used a 1/8 drill bit. Then I used an autozone easy out. (Unknown size) What would be the best way to successfully get that screw out? I'm almost sure if I were to get a smaller drill bit and smaller easy out it would come out. Has anyone ever tried this method? What would be the ideal size drill bit and easy out for the throttle plate screw? If not what can I do to get it out! There is not much information on what to do after the screw has been stripped hence the reason I created this thread! Here's a picture of what I'm working with!

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[FIBA M - EC17PSE]

Your going to have to drill it out! Start with a very small drill bit say 3mm or slightly smaller then it might even come out after that,

Another way is put a slit in the head and use a flat head after hitting it to shock it and it might help loosen it up a little

ere all I can think off

 

[DSM1491]

If you can make a deep enough cut in one of the lines on the bolt you can take it out. Get a flat head screwdriver and tap it with a hammer until its deep enough and your good. Or use anything to make it deep enough and use the flat head. Idk if a hammer is a good idea though not sure if the throttle can take that.

 

[@TDC]

Your going to have to drill it out! Start with a very small drill bit say 3mm or slightly smaller then it might even come out after that,

Another way is put a slit in the head and use a flat head after hitting it to shock it and it might help loosen it up a little

ere all I can think off

Thanks for the help! I really appreciate it!

 

[@TDC]

If you can make a deep enough cut in one of the lines on the bolt you can take it out. Get a flat head screwdriver and tap it with a hammer until its deep enough and your good. Or use anything to make it deep enough and use the flat head. Idk if a hammer is a good idea though not sure if the throttle can take that.

Thank you sir! I most likely will try this method before I attempt to drill it out!

 

[toybreaker]

I used to deal with this problem on Weber carbs back in the day.

I learned (the hard way of course, after ruining more than a few throttle shafts) that there's times that it's easier to thread it thru the plate and out the other side.


The factory screws are often staked/expanded on the backside where they protrude thru to keep them from backing out in service.

... this means that even if you do get the screw out, you booger up the threads in the shaft in the proccess. This makes the prospect of losing a screw that much more likely in the future. (and nothing "good" will ever come from injesting that screw )


What worked for me was to drill all the way thru the screw, (with a drill bit up to ~50% of the diameter of the screw)

Then I would go back and drill the head of the screw deep enough I can "snap" the head off. (use the empty hole from the screw you did get out for an idea of what it'll take. I usually just drill it ~close~, and then try to remove the recalcitrant screw. The head usually pops right off flush with the throttle shaft

Then, thread a small sheetmetal screw into the hole you drilled all the way thru, and use it to drive the remains of the throttle plate screw out the backside.

... it'll usually move pretty easily, and start threading the whole shitarree thru the shaft.

Twist it thru enough to get ahold of the nubbin of the original screw that should be sticking out the backside. Vise grips work well for this task.

While holding it from the back, remove your sheetmetal screw from the front, and then finish threading the screw out the back.

... harder to explain than it is to do


Biggest advantage of doing it this way is that the threads are spared, making for a more permanent installation of the new hardware.



If you do decide to stake the screw in place, proceed with caution! Many shafts have been bent/damaged during this proccess.

What works the best for me is to put a screwdriver in a vice tightly, pointy end up.

Place the t-body (uspside down) over the vise, and engage the throttleplate screw into the screwdriver tip.

Now, when you smack the backside of the screw to stake it in place, you won't put any load on the shaft.

Use an automatic center punch to make the intitial divot, or just use a punch carefully, your choice, just give the screw a solid shot.

Since the idea is to expand the screw on the backside to keep it from ever coming back out, a little expansion goes a long way.



Red (high strength) loc-tite also works well, just be sure everything is clean and oil free before applying the product. They sell a cleaner/primer/enhancer that gives a little extra margin of safety/peace of mind



On the high dollar stuff, I usually did both loc-tite and a solid stake job.

... life's too short to sweat something you can do once, and do right

 

[snowborder714]

I've had this happen numerous times and typically will try cutting new slots in what's left for a flat or phillips screwdriver.

If that doesn't work, I'll try and drill the head off and then remove the screw from the opposite side of the shaft with pliers. There should be some sticking out the back that you can grab on to.


If you ever plan on doing this again, get an impact driver (hand tool). Makes removing these and the FIAV screws a piece of cake. I think I've only stripped one or two screws since using this tool, whereas using a drill was over 25% chance of stripping the screw most likely.

 

[@TDC]

I used to deal with this problem on Weber carbs back in the day.

I learned (the hard way of course, after ruining more than a few throttle shafts) that there's times that it's easier to thread it thru the plate and out the other side.


The factory screws are often staked/expanded on the backside where they protrude thru to keep them from backing out in service.

... this means that even if you do get the screw out, you booger up the threads in the shaft in the proccess. This makes the prospect of losing a screw that much more likely in the future. (and nothing "good" will ever come from injesting that screw )


What worked for me was to drill all the way thru the screw, (with a drill bit up to ~50% of the diameter of the screw)

Then I would go back and drill the head of the screw deep enough I can "snap" the head off. (use the empty hole from the screw you did get out for an idea of what it'll take. I usually just drill it ~close~, and then try to remove the recalcitrant screw. The head usually pops right off flush with the throttle shaft

Then, thread a small sheetmetal screw into the hole you drilled all the way thru, and use it to drive the remains of the throttle plate screw out the backside.

... it'll usually move pretty easily, and start threading the whole shitarree thru the shaft.

Twist it thru enough to get ahold of the nubbin of the original screw that should be sticking out the backside. Vise grips work well for this task.

While holding it from the back, remove your sheetmetal screw from the front, and then finish threading the screw out the back.

... harder to explain than it is to do


Biggest advantage of doing it this way is that the threads are spared, making for a more permanent installation of the new hardware.



If you do decide to stake the screw in place, proceed with caution! Many shafts have been bent/damaged during this proccess.

What works the best for me is to put a screwdriver in a vice tightly, pointy end up.

Place the t-body (uspside down) over the vise, and engage the throttleplate screw into the screwdriver tip.

Now, when you smack the backside of the screw to stake it in place, you won't put any load on the shaft.

Use an automatic center punch to make the intitial divot, or just use a punch carefully, your choice, just give the screw a solid shot.

Since the idea is to expand the screw on the backside to keep it from ever coming back out, a little expansion goes a long way.



Red (high strength) loc-tite also works well, just be sure everything is clean and oil free before applying the product. They sell a cleaner/primer/enhancer that gives a little extra margin of safety/peace of mind



On the high dollar stuff, I usually did both loc-tite and a solid stake job.

... life's too short to sweat something you can do once, and do right

Thank you for that!! I really appreciate it! Now when you drill to remove the head from the bolt what size drill bit do you use??? Also is there an exact size sheet metal screw you use? Or do they all just come in one size? This sounds a little safer!

I've had this happen numerous times and typically will try cutting new slots in what's left for a flat or phillips screwdriver.

If that doesn't work, I'll try and drill the head off and then remove the screw from the opposite side of the shaft with pliers. There should be some sticking out the back that you can grab on to.


If you ever plan on doing this again, get an impact driver (hand tool). Makes removing these and the FIAV screws a piece of cake. I think I've only stripped one or two screws since using this tool, whereas using a drill was over 25% chance of stripping the screw most likely.

Thank you for the help! I hope I get this thing out no problem!