OT Bolt question

[pikewi]

Hey guys. I have an el cheapo riding mower that decided to lose a bolt. It is one of the 4 bolts that go up thru the frame and into the engine to keep it attached to the mower. I replaced the missing bolt with one I had in my collection of bolts, tightened it as much as I dared but it fell out after a few minutes of mowing. Tried another with a lock washer--same thing. OK must be a special bolt. Went to parts book. Says bolt is Hex Wash. Hd. TT-Scr. 3.8-16 x 1.25". Translation please?
Thanks
Pike

 

[Ron-MO]

No idea on translation, but I would either try one of the nylock nuts or lockwasher, AND a strong threadlocker like locktite (I think 680 is a good one). Let the threadlocker set up overnight, and give it another go. Or all the above.

 

[dakota dave]

Translation metric bolt. 3.8MM

 

[bobs old iron]

go to a local mower shop and ask them for a bolt that holds the motor in. don't go crazy trying to figure it out...

 

[Den N Ms]

A Washer head bolt.

 

[Bob]

No. Just a missing "/".

NO such thing as a 3.8 MM bolt, NO common Metric thread is "16".

It's simply a 3/8", 16 threads per inch bolt 1-1/4" long.

 

[Ken(Ark)]

(quoted from post at 11:25:57 08/14/11) No. Just a missing "/".

NO such thing as a 3.8 MM bolt, NO common Metric thread is "16".

It's simply a 3/8", 16 threads per inch bolt 1-1/4" long.

I would second that , 3/8 S.A.E. by 1 1/4" long .

Use blue thread locker to stop it from backing out again - Ken(Ark)

 

[old]

Bolts on ALL the lawn mowers I have worked on and I do a lot of work on them are all ones that have lock nuts on them. Bolts are the common run of the mill stuff for the most part but the nuts are all the lock nut type because of all the vibration. One way around using the lock nut is dab a little silicone gasket stuff on the bolt and then tighten it up and let it sit 30 minutes

 

[willie in mn]

Quick & dirty, no parts book required.
Take out another bolt. Go to local friendly old time hardware store. Find a nut that fits thread size, look on tag on bin to get numbers. In this case 3/8 x 16.
Go to bolt bin, select a 3/8 x 16 that matches length.
If original bolt plus replacement fell out, chances are that they are all a bit loose & worn from vibration. Put in all new bolts, with a dab of your favorite thread locker.

 

[GB in MT.]

(quoted from post at 13:53:53 08/14/11) Quick & dirty, no parts book required.
Take out another bolt. Go to local friendly old time hardware store. Find a nut that fits thread size, look on tag on bin to get numbers. In this case 3/8 x 16.
Go to bolt bin, select a 3/8 x 16 that matches length.
If original bolt plus replacement fell out, chances are that they are all a bit loose & worn from vibration. Put in all new bolts, with a dab of your favorite thread locker.

b:b17ceceb91][i:b17ceceb91]

Dam good answer Willie!!!
Works for me a lot of the time!!!

Gary :wink: "MacNaughtons"[/i:b17ceceb91][/b:b17ceceb91]

 

[Dr. Bert]

With not Loctite on hand or any lock nuts in the bin, I take the bolt to my anvil and with a ball peen hammer damage the threads ( don't over -do it and ruin the bolt) and screw on a conventional nut with a lock washer.

 

[Bob]

NOT to be a wise-donkey, by Loctite is a REALLY handy item to have around the shop.

As another poster said, silicone gasket maker is another GREAT way to keep lightly-loaded, non-critical parts in place.

 

[David Bond]

Seen this happen many times. Just replace with a 3/8 bolt that is longer and use a flat washer, lock washer or lock nut on the engine side. That is the way it was done before the manufacturers went to the self tapping bolt. Experience shows that you probaly will need to replace all the bolts this way. I was a profession small engine mechanic 36 years and have had to convert many back to way it was done before these type of bolts.. Not a big deal....

 

[36 Coupe]

Before the threadlockers came along,Indian Head gasket shellac worked fine.