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Jetfxr69 Samba Member
Joined: December 28, 2018 Posts: 1293 Location: White mtns nh
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Posted: Sun Dec 05, 2021 3:36 pm Post subject: broken oil screen thru-bolt boss |
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this motor came out of Crusher (daughters bus build) (2L GD). We broke it down and found it locked up due to a spun rod bearing. the crank is gouged but original size, so may be worth saving with a cut.
the other damage is due to PO over tightening the oil screen bolt.
we were considering having this repaired since the bores are all original size, albeit at the low end of tolerence, and the thrust surfaces are not hammered to death. no light seen through the mating areas of saddles when torqued up. my buddy in town has a welding shop and does wicked nice work, so we thought we would see what he thinks about welding that up.
and then we found this today…
WTF?! I guess when that boss broke out, the bolt danced around in there for a while and cracked the opposite side boss.
of course now we are thinking this may not be worth saving. we would have to get this welded up as well, and because its also the cam saddle torque, make sure that the flat surface was true to effect the crush on the cam bearing.
i have a few other cases kicking around that could be used instead. I just have a hard time letting original parts go.
gonna see what Richie (welder) says about what he can or cant do and then decide. if he can clean those two spots up then maybe its worth using.
i searched for any older posts that someone may have had success repairing this area, but didnt hit anything. since its a GD motor I believe its straight aluminum, no magnesium or exotic alloys. anyone had any luck with this repair? _________________ You can't be a real country unless you have a beer and an airline. It helps if you have some kind of a football team, or some nuclear weapons, but at the very least you need a beer. Zappa
‘77 westy Seamus
‘76 tintop Crusher
‘77 westy The Judge
‘72 tintop bastard westy Hudson |
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modok Samba Member
Joined: October 30, 2009 Posts: 26740 Location: Colorado Springs
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Posted: Sun Dec 05, 2021 3:45 pm Post subject: Re: broken oil screen thru-bolt boss |
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I think that could be welded up without causing too much distortion.
Finding somebody who is good at welding, and if it's worth doing..... is questionable. |
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Jetfxr69 Samba Member
Joined: December 28, 2018 Posts: 1293 Location: White mtns nh
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Posted: Sun Dec 05, 2021 4:36 pm Post subject: Re: broken oil screen thru-bolt boss |
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modok wrote: |
I think that could be welded up without causing too much distortion.
Finding somebody who is good at welding, and if it's worth doing..... is questionable. |
glad to hear that. were lucky enough to have fabulous welders up here, just dont know if he is gonna want to take this one on. _________________ You can't be a real country unless you have a beer and an airline. It helps if you have some kind of a football team, or some nuclear weapons, but at the very least you need a beer. Zappa
‘77 westy Seamus
‘76 tintop Crusher
‘77 westy The Judge
‘72 tintop bastard westy Hudson |
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busdaddy Samba Member
Joined: February 12, 2004 Posts: 51057 Location: Surrey B.C. Canada, but thinking of Ukraine
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esde Samba Member
Joined: October 20, 2007 Posts: 5927 Location: central rust belt
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Posted: Sun Dec 05, 2021 9:34 pm Post subject: Re: broken oil screen thru-bolt boss |
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Is that some weird filter, or is there some weird thing going on with all of the lifter bores? _________________ modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that. |
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Jetfxr69 Samba Member
Joined: December 28, 2018 Posts: 1293 Location: White mtns nh
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Posted: Mon Dec 06, 2021 2:26 am Post subject: Re: broken oil screen thru-bolt boss |
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esde wrote: |
Is that some weird filter, or is there some weird thing going on with all of the lifter bores? |
not sure what your asking. are you refering to the chamfering marks at the end of the bores? not sure what that is other than a manufacturing mark, or perhaps someone else has been in there. or, the fresh scuffed up flanges? i got in there with a dremel and sanding wheel to look for what i thought were cracks. turned out to just be casting lines. _________________ You can't be a real country unless you have a beer and an airline. It helps if you have some kind of a football team, or some nuclear weapons, but at the very least you need a beer. Zappa
‘77 westy Seamus
‘76 tintop Crusher
‘77 westy The Judge
‘72 tintop bastard westy Hudson |
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Beetspeed Samba Member
Joined: July 30, 2004 Posts: 429 Location: The Netherlands
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Posted: Mon Dec 06, 2021 4:53 am Post subject: Re: broken oil screen thru-bolt boss |
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Maybe user esde didn't notice these are pictures of a type 4 engine? _________________ '75 SB 1303 2,4ltr T4 turbo: 10.58 @ 129.9mph
'65 Ruska buggy 1192cc EFI 80hp N/A |
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esde Samba Member
Joined: October 20, 2007 Posts: 5927 Location: central rust belt
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Posted: Mon Dec 06, 2021 5:06 am Post subject: Re: broken oil screen thru-bolt boss |
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Beetspeed wrote: |
Maybe user esde didn't notice these are pictures of a type 4 engine? |
That’s it, mystery solved.
Haven’t been into a t4 engine for a few years. _________________ modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that. |
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Alstrup Samba Member
Joined: July 12, 2007 Posts: 7180 Location: Videbaek Denmark
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Posted: Mon Dec 06, 2021 5:39 am Post subject: Re: broken oil screen thru-bolt boss |
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If you weld that the case will need an align bore on both the cam and the crank tunnel and possibly a straightening of the case mating surfaces. NOT worth it IMHO. Find another and better case. _________________ https://www.thesamba.com/vw/forum/viewtopic.php?t=435993 |
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raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21474 Location: Oklahoma City
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Posted: Mon Dec 06, 2021 10:16 am Post subject: Re: broken oil screen thru-bolt boss |
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Do not weld it. As Alstrup noted.....welding in this spot on a type 4 case....never really works.
If the case in its current condition can be align bored and made straight....and when bolted together with bearings in it.....if you have oil passage seal from side to side.......I offer this for your perusal from the link that Busdaddy posted.
https://www.thesamba.com/vw/forum/viewtopic.php?t=645214&highlight=syndrome
While this modification was envisioned as a method to simply make this area less prone to breakage from ham fisted people.......it can also take that cross bolt out of the picture. That cross bolt is just a suspension method to leverage the bottom bolt tightness against.
By simply welding some feet on the oil pickup bell.....you can take 100% of the side load/strain off that cross bolt and transfer the tension load on the oil screen bolt to the bottom of the case.
Then ....if your case is still functional at that point....oil seal and cam bore warpage wise.....you can drill out what is left of the thread....and JB weld in a threaded insert. Then at least light torque can be placed on that cross bolt to help hold the case together and seal the hole in the case.
Ray |
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Jetfxr69 Samba Member
Joined: December 28, 2018 Posts: 1293 Location: White mtns nh
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Posted: Mon Dec 06, 2021 3:41 pm Post subject: Re: broken oil screen thru-bolt boss |
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i dropped off to my guy this morning before i read all these responses. when i showed him, he didnt even flinch. just looked at it and said “ ahh yup, we can do something there”. he also immediately mentioned about not getting it too hot to distort the area. he already saw and understood where that area is and how critical it is, so thats reassuring.
i understand the cautions mentioned above. i figure i got nothing to loose on this case, so gonna let him do it.
wish i had remembered the tag line “type 4 syndrome”. would have made searching easier. thanks for that. pics to come when he is done _________________ You can't be a real country unless you have a beer and an airline. It helps if you have some kind of a football team, or some nuclear weapons, but at the very least you need a beer. Zappa
‘77 westy Seamus
‘76 tintop Crusher
‘77 westy The Judge
‘72 tintop bastard westy Hudson |
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Vanapplebomb Samba Member
Joined: November 03, 2010 Posts: 5389 Location: Holland, MI
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Posted: Tue Dec 07, 2021 6:39 am Post subject: Re: broken oil screen thru-bolt boss |
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If he understands that you need to go slow, you might be ok. I have seen it done successfully with pulse tig, and only for a few seconds at a time, then letting it cool a minute before starting again. Took several hours to build it up, but it worked without distortion worth re-machining cam/main bores.
That said, I have also seen some bozo try and weld it up all in one go, and warp it to the point of needing both bores straightened.
I am of the opinion that it is worth trying because T4 cases are a limited quantity. Nobody is making new ones, and they likely will not be made again unless they are machines from a billet. Die casting new cases, as they were done from the factory, would be a prohibitively expensive investment for a limited market.
Sometimes I wonder what happened to the dies when the T4 went out of production. I wonder if VW still had them, or if they ended up in the scrap bin. _________________ 1800 Type 4 Berrien 295
http://www.thesamba.com/vw/forum/viewtopic.php?t=487021 |
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raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21474 Location: Oklahoma City
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Posted: Tue Dec 07, 2021 10:33 am Post subject: Re: broken oil screen thru-bolt boss |
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Vanapplebomb wrote: |
If he understands that you need to go slow, you might be ok. I have seen it done successfully with pulse tig, and only for a few seconds at a time, then letting it cool a minute before starting again. Took several hours to build it up, but it worked without distortion worth re-machining cam/main bores.
That said, I have also seen some bozo try and weld it up all in one go, and warp it to the point of needing both bores straightened.
I am of the opinion that it is worth trying because T4 cases are a limited quantity. Nobody is making new ones, and they likely will not be made again unless they are machines from a billet. Die casting new cases, as they were done from the factory, would be a prohibitively expensive investment for a limited market.
Sometimes I wonder what happened to the dies when the T4 went out of production. I wonder if VW still had them, or if they ended up in the scrap bin. |
Agree....try and save it if you can.
The cross bolt we are speaoing of serves two functions....simultaneously.
1. Its one more bolt give clamping force to a narrow/thin area of the engine to keep/maintain oil pressure at that cam bearing. The case mating area is so thin there that with temperature expansion it can leak heavily.
So to maintain this function.....if you can even get 10-15 pounds of torque on that bolt max....and then lock the bolt so it will not back out over time and heat cycling.....it will be enough for THIS function.
I would also build up a thin, even layer of something like Yamabond or Moto-seal just on the two case mating flanges at 6 and 12 on that can bearing boss to give it a compression seal gasket. Let them dry before assembly. You are not trying to fill a gap. You are making a thin gasket...like maybe a 0.003" thick max.
2. Then the bolt was "high jacked".....in my opinion..... to complete a second function. Its the upper locator for the oil pick up bell. This was stupid.
The cross bolt was designed to supply compression load to a narrow case area. Now they have added SIDE load to this bolt.
Not only does this risk the kind of breakage we see here.....it literally bends/stretches that narrow sealing boss sideways and distorts it anyway.
The ideal thing.....is to take the side loading of that bolt out of the equation.
The modification I listed in that link....putting adjustable feet on the oil pickup bell....literally takes 100% of the load off of that loop on the top of the pick up bell. The steel loop no longer even touches the cross bolt even all the way to 15-18 lbs of torque.
So once you do that.....you can use a fairly non heat invasive fix on that aluminum boss to make it work just for the limited compressive load it needs.
As far as the die molds.....likely worn out. Die cast and injection molding dies/molds wear constantly and constantly get worse for fit between cores and get crappier surface and less effective sealimg and pressure over time. They are constantly being reworked and repolished with sections replaced.
Very expensive and labor intensive.
As most factories are approaching the known end of a production run....meaning they can see it coming.....like this model will be discontinued year after next......they quit investing in die rebuilds.....and run it till it breaks or wears out. Likely the dies were junk by the end and scrapped. Ray
Ray |
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raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21474 Location: Oklahoma City
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Posted: Tue Dec 07, 2021 11:51 am Post subject: Re: broken oil screen thru-bolt boss |
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another fix you could look into.
A while back on this subject....Wildthings over on the bay bus forum thought /posted about drilling all the way through the case and making a long through bolt or threaded rod. I do not know how well or how that thought end u up but it had merit.
I will have to look at one of my cases later to see what is on the other side of or behind that threaded boss.
But....you "could drill the hole all the way through and swage a bolt into the hole sticking out...and make that into a "stud"...so you can put a nut on the side of the case the bolt goes into right now.
In fact...that bolt should have been a stud in the first place. On type 4 engines all of the case threads on the outside where parts have to come on and off like teh shroud etc.....have steel threaded inserts in them. Otherwise repeated removal will wear out the threads.
This boss in the case should have had a threaded insert at bare minimum or should have been made as a stud.
I would have to look and see if this bolt being a stud would make applying the pick up bell difficult or impossible...and the feet on the bell modification should be used either way. Ray |
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Jetfxr69 Samba Member
Joined: December 28, 2018 Posts: 1293 Location: White mtns nh
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Posted: Wed Dec 08, 2021 5:58 am Post subject: Re: broken oil screen thru-bolt boss |
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as always, thank you ray for some sound advice. im gonna let my welder try this one as a test to see if he can do it successfully. he is a good guy and a friend and will only charge me a couple bucks for his time. even if it doesnt work out and i have to pitch this case, its small money to try. im lucky enough to be tripping over type 4 cases right now, so there are other, better candidates for this build. i just want to see if this works, as im certain as i open more of these engines up, im gonna find another one broken.
as a novice and practicing welder myself, i am intrigued about trying your stand off bolt method. probably gonna go that road if necessary in the future. looks straight forward enough. _________________ You can't be a real country unless you have a beer and an airline. It helps if you have some kind of a football team, or some nuclear weapons, but at the very least you need a beer. Zappa
‘77 westy Seamus
‘76 tintop Crusher
‘77 westy The Judge
‘72 tintop bastard westy Hudson |
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Jetfxr69 Samba Member
Joined: December 28, 2018 Posts: 1293 Location: White mtns nh
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Posted: Tue Jan 04, 2022 7:15 pm Post subject: Re: broken oil screen thru-bolt boss |
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got the case back from my buds shop. one of his guys did a nice job on the weld. i ground the excess off and drilled and tapped for the bolt. did a runout check and got less than .001”. bolted the halves together and got no light through saddle mating surfaces. will do a proper bore and warpage check later. just wanted to see if he would do it, and im pleased with the results so far.
_________________ You can't be a real country unless you have a beer and an airline. It helps if you have some kind of a football team, or some nuclear weapons, but at the very least you need a beer. Zappa
‘77 westy Seamus
‘76 tintop Crusher
‘77 westy The Judge
‘72 tintop bastard westy Hudson |
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PEPPE Samba Member
Joined: August 24, 2003 Posts: 1068 Location: Roma Italy
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Posted: Wed Jan 05, 2022 11:11 am Post subject: Re: broken oil screen thru-bolt boss |
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good work, now would be better to weld some "foots" to the pickup tube. this will avoid future damage.
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