Is this the right tool? - PeachParts Mercedes-Benz Forum

gmask · #1 11-02-2002, 06:51 PM

Here's what I have found for thread chasers to use on my m130 block. the Bolts are 12mm 1.75 pitch. It says this tool works for any diameter ??

http://buy.snapon.com/catalog/pro_det1.asp?qt=1&P65=yes&Desc=File%2C+Thread+Restorer%2C+Metric+%28Pitches%3A+.75%2C+1%2C+1.25%2C+1.50%2C+1.75%2C+2+and+3+mm% 29&ListPrice=8.85&FORMNAME=2&qty=1&tool=all&Item_id=9693&PartNo=TFM7530B&Price=8.85&SUB_Cat_ID=1316729&SUB_Cat_NAME=Thread++Restorer+Files&Cat_ID=1316656&Cat_NAME=Thread+Restoring&group_id=1149&group_NAME=Thread+Restoring+Files&store=snapon-store&dir=catalog&pix=objects%2F18500%2F18497.JPG&email=true&test=File%2C+Thread+Restorer%2C+Metric+%28Pitches%3A+.75%2C+1%2C+1.25%2C+1.50%2C+1.75%2C+2+and+3+mm% 29%7E8.85%7ETFM7530B%7E9693

leathermang · #2 11-02-2002, 07:11 PM

It works for any diameter because you are only working on one side of the bolt at time... this is " just" a file which has 8 sides cut to the different number of threads per inch.. uhh...millimeter...
What exactly is the problem you are trying to correct ? Are you just trying to clean up bolts before reinstalling them so you will get accurate torque readings ?
This tool, in my opinion, is more for something like where you have some threads exposed to use for guidance... and you have some threads near it which have " issues "

.... I have two of these tools and they have really saved the day when I needed them... but usually if the end of the bolt is good it would be better to run a die over the bunged up portion...
What you do is hold the bolt by its head and place the right size thread section on a good portion of the bolt... then file with some of the good threads on the side and where you start guiding your strokes as you turn the bolt towards you... so the good threads keep you lined up while you file away the banged up portion....
On a vehicle one place which this tool really helps is the sleeved and threaded part of a steering box... if you hit a rock you can't just run that big nut down over messed up threads... but you may can clean them up with a tool like this....So in a way it is more of an emergency tool than a thread restorer.... and it is very slow and not accurate enough for normal reconditioning of bolts... well, that is probably more than you really wanted to know... but it is raining here so I can't be out on the tractor...

gmask · #3 11-02-2002, 07:17 PM

THanks for the info..

It's not for the bolt as I have new bolts but for the nut or in this case the threads inside the engine block. I'm my previous posts about replacing my head gasket everybody has been suggesting that I use a thread chaser but I'm not sure if they meant on the bolts and/or nuts ..In this case it's what I'm screwing into?? Do I need to clean those threads?

gmask · #4 11-02-2002, 07:23 PM

Oops mayb ethis is what I need...

Gee it better be if it's going to cost $122!!!

http://buy.snapon.com/catalog/pro_det1.asp?P65=yes&store=snapon-store&tool=all&PartNo=TR25M&Price=122.15&ListPrice=122.15&Desc=Set%2C+Metric%2C+Thread+Chaser%2C+Internal&qty=1&group_id=1151&Item_id=9708

gmask · #5 11-02-2002, 08:13 PM

OK I think this is it!

http://buy.snapon.com/catalog/pro_det.asp?P65=yes&qt=1&test=Tap%2C+Rethreading%2C+Metric%2C+M12+x+1.75%3B+%242.05%3BTRT55%3B9648&tool=all&INV_ONHAND=&FREIGHT=0&qty=1&Item_id=9648&PartNo=TRT55&Price=+%242.05&ListPrice=+%242.05&FORMNAME=37&Desc=Tap%2C+Rethreading%2C+Metric%2C+M12+x+1.75&SUB_Cat_ID=1316657&SUB_Cat_NAME=Rethreading+Taps+And+Dies&Cat_ID=1316656&Cat_NAME=Thread+Restoring&group_id=1145&group_NAME=Rethreading+Tap+and+Die+Set+Components&store=snapon-store&dir=catalog

Tomguy · #6 11-03-2002, 12:18 PM

That looks like it's too short. I'd go into Sears and look for one. It would look something like

They don't have the exact size on their site (I bet they would in the store) but it's the way to go, I have a Sears set and they are great.

leathermang · #7 11-03-2002, 03:00 PM

Tomguy is exactly correct... and it will be more fun and easier to do the thread chasing.. which I conside a mandatory step just like you mentioned... if you get one of the handles for the tap shown.... it will help you get it going straight in and be much faster,,, and cleaning all the holes is a boring process...

The best trick I have ever seen for getting them clean fast... is to place a plug of wax into the dirty hole.. then put the tap in it and turn it... the wax will capture the bad stuff and squish it out of the hole for you to capture....squish is the very technical term for this sort of stuff....

The handle will also make thread making easier when you want to do that...

Just be sure all the dimentions are correct on your tap with respect to the hole.....Volkswagon engines used to have one size which had two thread pitches... bummer if you did not know about it... pretty much wiped out the strength of the hole if you ran the wrong tap into it....

Billybob · #8 11-03-2002, 03:46 PM

That tap pictured looks like a standard starting tap, tapered at the tip to allow it to "guide" down the hole. Good threading taps will usually come in a set for a certain size (dia. and length) and pitch (threads per inch/MM) and will include three taps (real good sets include a couple of each, because it is not unusual to break a tap and that would delay the job completion if you had to wait to obtain a replacement), a starter tap, a straight tap, and for holes that are not bored through a "bottoming " tap with thread cutting tool face all the way to the tip to allow cutting proper threads to the bottom of the bore. Assortments of taps and dies ala' Sears or the like, will in most cases not include the triple tap system to reduce assortment's overall costs of the

It would seem that for engine block threaded bores you will want a bottoming tap to ensure that the head bolts have the "chased" threades all the way to the bottom of their respective bores. This would be especially important when you think that it is the torque specified clamping force that holds the head in place, and the hardest part is the final torque angle spec. If the bore threads are insufficiently "chased" things will start well but as the fastener gets deeper into the bore the deepest threads are the least conditioned and cleaned and therefore might offer unwanted resistence to the proper torquing of the fastener.

You should be able to get a three tap set for any size for $5 -10 from a precision tool house, ask and you may be able to find a DIN spec tool, as I believe that is the standard that is used in german MB specs.

I have always used commpressed air to clean out threaded holes, but I like the wax idea!!!

A light tapping oil makes life easier and aviods broken tools , especially the small diameter ones because the tools are so hard (in order to cut) they are brittle. You also have to make sure that all the liquid/wax substance is cleaned from the threaded bore because even a small amount can cause a Hydro-Lock condition where the fastener will be prevented from bottoming in the bore because whatever is still down there is both uncompressable and cannot escape (up the threads!?)

I do like the look of those Snap-On thread restorers and I'll probably get a set so as to use them regularly, Thanks, Good Luck

gmask · #9 11-03-2002, 04:28 PM

Quote:

Originally posted by leathermang
The best trick I have ever seen for getting them clean fast... is to place a plug of wax into the dirty hole.. then put the tap in it and turn it... the wax will capture the bad stuff and squish it out of the hole for you to capture....squish is the very technical term for this sort of stuff....

Ok well I have obtained both a tap and the thread chaser from sears.. I didn't really need to the whole set but I guess I can return it even if I actually end uo using it.. gotta love those satisfaction guarentees.

The wax idea is interesting but how do you get any residue out? Do I just hit it with a torch and burn out the remaining wax???

leathermang · #10 11-03-2002, 05:26 PM

I am talking about hard wax ... like parrafin....gulf wax.... it is pretty much going to clean the hole out... you can put a rag into it with lacquer thinner if you want to... but just running the tap into it again will probably be fine... or stick the wax in twice if you think you need to....
It is going to mash both dirt and grime into the wax and force it out the flutes in the tap.... a little film left in will not hurt your torque readings... wax is just a blink away from oil...

I agree that a bottoming tap would be best...

If you want to really get fancy... get a bottoming tap with a spiral flute... much easier to line up on the initial threads straight...

Anyone that is getting excited reading about this ought to get a copy of the Bass Tool company catalog out of Houston... very good prices and great catalog for ideas on what is available...and how to do it...

I got the wax idea out of Latuard's " The Machinist's Bedside Reader"... one of the three , don't remember which...all of them are gold mines of information for do it yourselfers in metal...

Tomguy · #11 11-03-2002, 07:30 PM

I usually just use grease. The "crap" sticks to it rather well and helps clean it out easily. When you're done just wipe it off the tap and go to the next hole.

240 Ed · #12 11-05-2002, 05:25 AM

I agree with Tomguy, and use grease if I am cutting a lot of swarf.

Usually though, you won't be getting much from just freshening up the threads.

On the bolts. Clean them up on your bench grinder, you know, the one on your bench which you have finally purchased...the one with the wire brush wheel on it...

A note on "hydro-lock". You don't want it.
It usually comes from a ham fisted mechanic who installs head bolts with a lot of oil on the bolt before he fits it.
You only want one drop on the thread, and one drop on the washer under the bolt head.
Another tip. suck up any old oil in the bottom of the hole with a Q-tip until it gets dry.
For some reason the head gasket maker does not recommend oil on the washer surface which contacts the head. I read this AFTER I put them all in, ...shoot.
Oh well, I got consistent torque readings, so hopefully I won't blow my gasket.

240 Ed · #13 11-05-2002, 05:28 AM

You can get away with just buying a bottom tap.

And you don't need the handle either. Use a 1/4 inch socket with your ratchet wrench.