TheSamba.com :: View topic - flywheel came loose, crank dowel holes out of round

Tue Jun 16, 2015 9:04 am

Now is your time to point and laugh, I "jacked up" my flywheel/crank connection bad.

I replaced my crankshaft seal ( front main seal ) and must not have torqued the gland nut correctly ( please don't ask me how I torqued it :oops: ). On first drive bad noises, oil leaking. Pulled engine and found the flywheel quite loose.
The engine did have kind of a crappy gland nut in my defense, but oh well, live and learn. Transmission housing a little gouged but not too awful.

The dowel holes on the flywheel are egged, flywheel is probably junk. The crank, three are egged out, and one looks ok.

Should I
Drill the crank for 8 dowels with the block assembled and fit a new flywheel?
Remove crank and drill for 8 dowels and fit new flywheel?
Remove and replace crank?

Tue Jun 16, 2015 9:05 am

Replace the crank. Lesson learned (the hard way).

Tue Jun 16, 2015 9:25 am

[email protected] wrote: Replace the crank. Lesson learned (the hard way).
thanks, ](*,) ](*,)

Tue Jun 16, 2015 11:11 am

I'd make sure the surfaces are flat and put them back the way they were. Then drill them. Check for runout and go from there. Put a good nut and torque it well. I had a motor before with egged holes and the machine shop drilled it for bigger dowels. Depends how bad.

Tue Jun 16, 2015 5:53 pm

I had a f/w come loose due to my part stuck throttle in 3rd gear push in clutch let car slow and it reved so i let it back out fast and coasted down the dune.Lets say it instantly started knocking.

I towed it back to camp got home tore motor down luckily it was fixable by drilling for the larger dowels i think 11/32 and had it wedgemated by my machinist.He told me that was the only way to fix it and had i ran it a lil more it would have been junk.

Tue Jun 16, 2015 6:34 pm

It is fixable, however, I would replace the crank. Stock cranks are common, and not terribly expensive.

Then you can figure out how to fix the old one later, after it's cleaned, outside the engine.

It may be possible to fix cranks in the engine, but DUDE, please, please don't make me do it!!!! Mounting a complete engine onto the mill sucks, and it leaks oil everywhere. LOL
Even so, it is faster than making special tools to repair the crank in it's habitat, of course, if we got three in a row I'd make special tools!!! But rarely get two of the same thing ever.

Wed Jun 17, 2015 7:41 am

Repairing a few beaters per cust ok 4 this problem i redrilled 4 more , 1st one dr/reamed to size to hold alignment 4 others. I used an old gland nut/ mod washer to hold crank tight enuf to do others. Punch marking fw topully timing notch allows removal of flywheel & get it back on aligning holes,they were not evenly spaced like original but at this point its not a problem., allows another good run until crank isworn past fixing, my2cts, as usual no warranty offered at this time.

Wed Jun 17, 2015 8:47 am

thanks for the input,

I'm not going to hoopty-rig it.
Not going to put it on a drill press :-)

I think the Freudian interpretation is that I wanted that 74mm crank anyhow so thats what I'm going to do.

Wed Jun 17, 2015 5:34 pm

There are 84mm cranks you know...
;)

Thu Jun 18, 2015 10:15 am

why pull a motor apart . what do you have to lose but your time .I have fixed a lot of cranks by redrilling the holes and some of the motors I have redrilled . are still running after 5 years .like others have said to you redrill new holes or redrill for bigger doll pins. if you go with the bigger doll pins get the longer ones just my two cents take it or leave it spencerfvee iamdonquixote wrote: thanks for the input,

I'm not going to hoopty-rig it.
Not going to put it on a drill press :-)

I think the Freudian interpretation is that I wanted that 74mm crank anyhow so thats what I'm going to do.

Thu Jun 18, 2015 12:07 pm

spencerfvee wrote: why pull a motor apart . what do you have to lose but your time .I have fixed a lot of cranks by redrilling the holes and some of the motors I have redrilled . are still running after 5 years .like others have said to you redrill new holes or redrill for bigger doll pins. if you go with the bigger doll pins get the longer ones just my two cents take it or leave it

If mine, I'd drill or have a machine shop drill for me.

Thu Jun 18, 2015 1:05 pm

When I did this I had the crank and flywheel drilled for 8 dowels.

It lasted 20000 miles until the vibration caused by massive backfiring and misfiring shook it loose at 65mph

This was when a rocker arm spring broke and No2 exhaust stopped opening, and the inlet manifold boot blew out on No3 and No4.

A bus will drive just on 2 cylinders or was that 1 and two halves.

I bought another rusty lump described as a Camper Engine on eBay for $70 and got a nice AS21 case which did not need machining, and a nice crank and 215mm flywheel. And a lot of fun whacking rusted up cylinders off it.

Thu Jun 18, 2015 5:54 pm

I tore one up when I was a kid. Stock 1600. Just indexed the fly wheel and redrilled.... Ran good, eventually rebuilt the engine... But drove it for a few years like that.

Make sure you torque the the Gnut on that new crank!!!

Fri Jun 19, 2015 9:28 pm

You can buy the 8-bolt drill jig for less than $30. You also need 2 appropriate sized drill bits plus an 8mm reamer to allow you to redrill your own.

Thu Jun 30, 2016 4:42 am

Sorry to open and old thread ..

I also have a crank and flywheel that I've removed due to a loose gland nut (prev. Owner)

I'm now wondering ifor it's possible to weld up the holes and re drill using a good flywheel as a template.

Anyone tried this?

Another option I'm wondering about is threading the holes and using bolts?

Neither are probably good ideas but it seems a waste when these it's could make a cheap stocker.

Thu Jun 30, 2016 4:49 am

Yes it is possible to repair a damaged crank, but it is not cost effective. For a machinist to weld and machine everything true it would cost more then a new crank.

Thu Jun 30, 2016 6:31 am

Surely it can't cost much. I can weld it myself but not sure on the drilling fresh holes but am willing to try.

Nothing to lose really

Thu Jun 30, 2016 8:58 am

I thought every VW person had a few extra stock cranks laying in the corner? :lol:

You pay the shipping, and I will send you TWO usable cranks!! Then you will have a backup.

Welding the holes shut will create all kinds of other expensive issues. Drill the 4 egged out to 11/32, and add 4 more stock size with a SPG drill jig. Easy, and you wont screw up the journal or flywheel mating surface attempting to weld it.
I did one on an assembled type 3 engine on the bench last year. It worked out great. I drilled the 8 dowel pattern in the flywheel first on the drill press, and then bolted the flywheel to the engine. Then drill and ream the new 4 holes in the crank using the flywheel as a guide, and install the 4 pins. Then go back and enlarge the 4 egged holes to 11/32 in the flywheel and crank at the same time. Go slow, and use good tools and you will be fine.

Brian

Thu Jun 30, 2016 9:01 am

with no real good pics hard to tell. but if it were a oe crank I would opt for the 84mm 4340 crank you have always wanted and thus left this one loose for the wife.......

Thu Jun 30, 2016 9:10 am

You know the other day when you needed a door stop....

Dale