Hard chroming gear area: Type 1 crank

[Jim Ratto]

Has anyone ever sent a VW crank out to have a journal or the gear/pulley area to be hard-chromed? I have a good 78 crank, wedgemated, just a tick undersize at gear area. Not comfortable running it as is, but do not want to kiss it off either. I need about 0.004-0.005"

Thanks

Jim R.

[brian e]

What about knurling the area and turning it back down to the needed diameter?

Just a thought.

Brian

[Martin S.]

How sure are you about the crank's condition? Maybe get another opinion about saving it. That clearance is not ridiculously large for bearing clearance and too big is better than too small. When I was searching around locally, trying to get that kind of work done, the volume rebuilders and crank grinding shops were wrapping up with the old timers retiring and condo's being built on the property. I wonder how easy it is to find someone to grind a crank down to one under especially with the cheap price of cranks now. When I had some plating done, they talked about 12 ten-thousands as being hugely thick so it's hard to imagine building up a precision part like a journal 4 or 5 thou with any accuracy.

[Jim Ratto]

How sure are you about the crank's condition? Maybe get another opinion about saving it. That clearance is not ridiculously large for bearing clearance and too big is better than too small. When I was searching around locally, trying to get that kind of work done, the volume rebuilders and crank grinding shops were wrapping up with the old timers retiring and condo's being built on the property. I wonder how easy it is to find someone to grind a crank down to one under especially with the cheap price of cranks now. When I had some plating done, they talked about 12 ten-thousands as being hugely thick so it's hard to imagine building up a precision part like a journal 4 or 5 thou with any accuracy.

it's the gear area- not a bearing journal. The crank is STD/STD and perfect otherwise.

[Martin S.]

I see. so the gear is loose fitting. A machine shop might have a creative solution for you like tack welding it on, or.. loctite 

[Fastbrit]

I'd just use a touch of Loctite 'Bearing Fit'. It ain't going anywhere as it's keyed and retained by the snap ring. You worry too much, Jim. 

[Martin S.]

I followed Berg to a T and used the green loctite sleeve retainer everywhere. Including the Berg pulley onto the crank. When I had Steve install the Electromotive EFI, he needed to remove the Berg pulley and install the toothed wheel Scat one with the engine in the car. The loctite glued the pulley on so tight, I said to go ahead and crack open the acetylene torch. Here is what was left after the pulley came off. He said he gave up after some time on it, and his dad took over the job. It took hours to get off!

[Neil Davies]

I followed Berg to a T and used the green loctite sleeve retainer everywhere. Including the Berg pulley onto the crank. When I had Steve install the Electromotive EFI, he needed to remove the Berg pulley and install the toothed wheel Scat one with the engine in the car. The loctite glued the pulley on so tight, I said to go ahead and crack open the acetylene torch. Here is what was left after the pulley came off. He said he gave up after some time on it, and his dad took over the job. It took hours to get off!

Wish I'd known about that - I launched a Berg Equaliser pulley off the end of my crank years ago and destroyed the pulley,  as it was coming off it machined out the end of the case and bent the keyway open! That was following the Berg instructions for not tighening the nut up as tight if it wasn't a Berg nut...

[Martin S.]

Sounds like the 'Berg revenge' 

[brian e]

Jim started this topic a week or so ago, and this morning I go to pull the gears off a CBPerf 74mm crank, and they slid right off.  The snap ring and the key are the only things holding them in place.  This engine had a very tough life, but I think the crank was small from the beginning.  The inside of the distributor gear was fretted, and the crank under the cam gear is fretted pretty bad.  I will talk the owner into a new crank for his engine, but I think I will try knurling this one to see if it works. 

The crank will need to be ground .010/.010, so I think I will knurl it up, and have my crank grinder guy grind the knurls to the correct diameter while doing the other journals.  I think I will have to make a dummy key flush with the crank so the knurling tool will ride smoothly.  Then I can pull the fake key out and clean up the edges of the key slot and have it ground.   

Brian

[Udo]

I did this once on a type4 crank . Hard chromed the cam gear seat works perfect .

Udo

[Martin S.]

Good point Udo. Why not look at the gear instead of the crank? Seems easier to swap to another one that fits better, or plate the gear (cheaper and easier than the crank).

[Jim Ratto]

I did this once on a type4 crank . Hard chromed the cam gear seat works perfect .

Udo

Thank you Udo.

[Martin S.]

Jim, let us know what it costs to do that please.

[neil68]

Why not look at the gear instead of the crank? Seems easier to swap to another one that fits better, or plate the gear (cheaper and easier than the crank).

Good suggestion.  I found that my CB straight cut gear was very tight on the crankshaft.

[Udo]

Good point Udo. Why not look at the gear instead of the crank? Seems easier to swap to another one that fits better, or plate the gear (cheaper and easier than the crank).

The crank was too thin at that seat area , i do not know why and it was a good forged scat crank

Udo

[NAO]

knurling the crank...I have seen G.Berg welded crankshaft with it to correct the size.

[nicolas]

knurling the crank...I have seen G.Berg welded crankshaft with it to correct the size.

it wouldn't be my go to solution, but more a 'need to' solution… hardchroming can work. some of the parts we make need to be undersize to have them 'coated' or chromed to get the end size correct. i have a chromoly axle treated and measured and it stayed true (can't rememvber the process).
but as Keith says loctite it, if he key has no play you are save. that is what really holds the gear.

[Dougy Dee]

Last year I took 7 mainshafts to a local hard chrome shop. Needed  the bearing end built up.

They told me $225 CDN. Not bad for 7 mainshafts... Then they told me that was each!!!

[Martin S.]

Did they offer any other options? According to wiki there are cheaper, more modern spray coatings which keep the size better, rather than needing grinding back to size like hard chrome... https://en.wikipedia.org/wiki/Chrome_plating#Hard