How can I get a bolt to spin freely into the threading?
#1
11-08-19, 12:06 PM
How can I get a bolt to spin freely into the threading?
You know how sometimes you'll have a bolt that you crack loose and then it spins freely out of the threading (this is what I want)
and other times you crack a bolt loose but effort is still required to turn it out of the threading? (this is what I have)
My case, specifically, is I'm adjusting the clutch pushrod on a Baker motorcycle transmission.
The instruction, at the transmission end, is to tighten the pushrod until you feel the slightest tension and then back it out a 1/4 turn. (and then tighten the locking nut, put the cover back on etc etc)
Starting from completely out, my pushrod will only spin freely one or two turns max before it encounters a good amount of tension but that tension is not the clutch cable providing the tension (which is the idea here), instead, that tension is from the threading itself being sticky so it's hard to tell when the tension from the clutch cable is.
Any ideas on how to get the threading to be free spinning so that I can tell when the clutch cable is providing tension?
and other times you crack a bolt loose but effort is still required to turn it out of the threading? (this is what I have)
My case, specifically, is I'm adjusting the clutch pushrod on a Baker motorcycle transmission.
The instruction, at the transmission end, is to tighten the pushrod until you feel the slightest tension and then back it out a 1/4 turn. (and then tighten the locking nut, put the cover back on etc etc)
Starting from completely out, my pushrod will only spin freely one or two turns max before it encounters a good amount of tension but that tension is not the clutch cable providing the tension (which is the idea here), instead, that tension is from the threading itself being sticky so it's hard to tell when the tension from the clutch cable is.
Any ideas on how to get the threading to be free spinning so that I can tell when the clutch cable is providing tension?
#2
11-08-19, 01:32 PM
Could be several reasons. Is the threaded rod perfectly clean? No grime or dirt. Has it ever had any thread lock applied to it? Has the nut or rod have any nicks in it? Often the first few threads will be worn away enough to allow a damaged thread to spin freely. Is the rod perfectly straight? That is perhaps the biggest problem. I would try another nut.
#3
11-08-19, 01:38 PM
It's the rod itself that screws into the housing.
Rod looks like it's in good condition, not sure about thread locker.
I'll clean grime and dirt off it.
Any recommendations on how best to get rid of grime and dirt? Metal polish?
Rod looks like it's in good condition, not sure about thread locker.
I'll clean grime and dirt off it.
Any recommendations on how best to get rid of grime and dirt? Metal polish?
#5
11-08-19, 02:42 PM
First
Double check to make sure the bolt is meant to go there.
Do the threads match- e.g. fine-thread vs coarse thread? Thread pitch?
Can You Explain Some Basic Screw and Thread Terms? - MW Industries ASM
Try screwing a chopstick or soda straw into the hole, the markings should let you tell if the threads are coarse/fine.
Now, a small battery terminal cleaner would be my first option to clean out the hole.
Double check to make sure the bolt is meant to go there.
Do the threads match- e.g. fine-thread vs coarse thread? Thread pitch?
Can You Explain Some Basic Screw and Thread Terms? - MW Industries ASM
Try screwing a chopstick or soda straw into the hole, the markings should let you tell if the threads are coarse/fine.
Now, a small battery terminal cleaner would be my first option to clean out the hole.
#7
11-09-19, 06:01 AM
Group Moderator
You can run the part in and out, cleaning the threads off each time you have it out. Keep doing it as long as it's still tight and your'e wiping stuff off the threads.
#8
11-09-19, 07:50 PM
I've used a brass gun barrel cleaning brush chucked in a drill to clean out the threads on many things. Just get one slightly larger than the bolt threads. I regular brass wire bush and some solvent should clean off the bolt threads just fine. Make sure you don't have a burr on the bolt threads. Try running a new regular bolt in the hole in the trans.
#9
11-09-19, 08:15 PM
If you use a wire wheel on a bench grinder to clean the threads, make sure you have gloves on and keep a tight hold on it, or *zing*! (Pushrod gets launched across garage)
#10
11-10-19, 05:49 AM
Re-tap the threads on the rod with a tap and dye
You can run the part in and out, cleaning the threads off each time you have it out. Keep doing it as long as it's still tight and your'e wiping stuff off the threads
When the part was made the die could have been worn thus not properly shaped threads.
Also the thread Tolerance will effect how it fits along with if the part was plated.
When I work on my car projects pretty much every nut and bolt gets a quick chase and a coating of oil, sure makes assembly a lot easier!
