Author Topic: Anyone ever had to drill out a snapped torque converter bolt??  (Read 568 times)

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Offline sb001

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I got the 18 ft/lb spec from the Bentley manual, which is basically thought of to be the "official" VW service repair manual. Doesn't mean everything in there is correct though.
I posted about my broken bolt over on the samba as well, no one else chimed in saying they had the same issue-- course you have to consider that probably only a small handful of posters there either own or have worked on an autostick... had to straighten lots of them out about the hatred and misunderstandings about the autsotick in my early days over there...  ::)

Offline 68autobug

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  • 68AutoBug - Lee in Australia
    • My 1968 Autostick Beetle

Yes, I haven't heard of anyone breaking off a Torque converter bolt before... I had a nut come loose...on a FLEXPLATE... maybe that was a first also... I had used LOCTITE on the bolts....!!!


Lee in Australia

-- Helping keep Autostick beetles on the road --
   -1968 Silver metallic 1600 single port Beetle - with BOSCH  SVDA and new BROSOL H30/31 carburetor with GENIE Extractor exhaust system with a quiet thunderbird muffler

http://photobucket.com/68autobug

Offline 68autobug

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I did some experimenting on the topic a while back. I wanted to replace the TC to FP bolts with something a little more robust. I got some hardened hex bolts because it is difficult to strip them, both the threads and hex socket. Not usable even when cut down because they cannot be made to clear the inside of the bell housing. I tried a couple different options to no avail.

So, my guess is that VW got themselves in a spot and had to create or special order those bolts with the narrow head. With a head that small I think 12 points were necessary to get any significant torque on them.

I really do believe that the spec torque on those bolts is an error by at least X2. Look at any similar or larger bolts on the car and compare. As before, the rod nuts which are hardened, under much more stress, have much more contact area and a 24ft.lb spec. Others are similar. There is a fairly linear relationship between the size of bolts and their torque spec. The TC-FP bolts are off the charts for torque spec IMO. They are for a fairly low stress application. It would be interesting to search this site and the samba to see how many have had the threads stripped, broken the captive nut off or stripped the points of the bolt while torquing to spec.

The newer replacements. I have some and have tried them but did not use. They appear to be of softer steel and do not have a taper at the start of the threads so they are difficult to get started although I think you could grind a slight taper on the end like the OEM ones.

Tom
I did some experimenting on the topic a while back. I wanted to replace the TC to FP bolts with something a little more robust. I got some hardened hex bolts because it is difficult to strip them, both the threads and hex socket. Not usable even when cut down because they cannot be made to clear the inside of the bell housing. I tried a couple different options to no avail.

So, my guess is that VW got themselves in a spot and had to create or special order those bolts with the narrow head. With a head that small I think 12 points were necessary to get any significant torque on them.

I really do believe that the spec torque on those bolts is an error by at least X2. Look at any similar or larger bolts on the car and compare. As before, the rod nuts which are hardened, under much more stress, have much more contact area and a 24ft.lb spec. Others are similar. There is a fairly linear relationship between the size of bolts and their torque spec. The TC-FP bolts are off the charts for torque spec IMO. They are for a fairly low stress application. It would be interesting to search this site and the samba to see how many have had the threads stripped, broken the captive nut off or stripped the points of the bolt while torquing to spec.

The newer replacements. I have some and have tried them but did not use. They appear to be of softer steel and do not have a taper at the start of the threads so they are difficult to get started although I think you could grind a slight taper on the end like the OEM ones.

Tom
... had to straighten lots of them out about the hatred and misunderstandings about the autsotick in my early days over there...  ::)


Yes, there were and probably are many people who don't understand anything about the autostick.. I just read where a disabled fellow in the UK had a type 3 fully automatic fitted to a beetle at great cost $$$$$$$$$$$$   as  He had heard of the problems associated with the autostick....!!!!! He could have saved Himself a lot of Money and greif...as the job had to be redone as the first time it didn't really work....  People who know nothing about them say they were very slow compared to a manual...!!!! and many VW Mechanics who have never done a course on autosticks don't like to even touch them...

cheers

Lee in Australia
-- Helping keep Autostick beetles on the road --
   -1968 Silver metallic 1600 single port Beetle - with BOSCH  SVDA and new BROSOL H30/31 carburetor with GENIE Extractor exhaust system with a quiet thunderbird muffler

http://photobucket.com/68autobug