IZ/AHU ARP Main Bearing Studs

[TDIDaveNH]

OK gang,

I need a bit of advice...I'm putting in a set of ARP main bearing studs and notice one end can accept a 5/32 Ellen wrench for tightening....only question I have is...I don't plan on upsetting anything but swap out the bolts for studs. The engine is out and on a stand...do the studs go in and get tightened and how much or just hand tight?

 

[Mozambiquer]

There's several ways people do it, most just tighten slightly over hand tight for the studs, then torque the nut to whatever the spec for the application is. When I put head studs in my Passat, I tightened the studs to 10lb/ft before torquing the nut down. In theory it doesn't make a difference, except that the threads going in to the block are just that much more engaged.
Torquing the nut will tighten the studs down too. My coworker found that out when the big torque wrench at the shop was 80lb/ft off, and he broke an arp head stud in a Ford 6.0... that was a painful experience since it broke off under the block surface. It took a carbide pencil grinder and a lot of work to get that back out.

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[turbodieseldyke]

If it takes a 5/32" allen wrench to tighten, that hex is going to strip before you can shear the bolt.

 

[TDIDaveNH]

Mozamb: sounds good...sending it.

TDD: A-mazing lol.

 

[Mongler98]

clean out the threads really good with compressed air
if you have the head off, chase the threads with a tap (ARP's recommendation)
do not tighten the studs, finger tight is an overstatement, turn them with your fingers till they stop and bottom out, then back them off and put them back down with the lightest of light of a finger tight, no tools needed.
the reason they have an allen tool or hex head to them is if you plan on locking them in place with a thread locker, in that case, an aggressive finger tight is ok.
strait from ARP's rep when we talked

 

[TDIDaveNH]

That sounds about right Mongler...I can't bottom these out, if I do the end of the stud is flush with the bearing cap leaving no room for the washer never mind the 12 point nut so they actually have to be put in loose.

 

[Mongler98]

That sounds about right Mongler...I can't bottom these out, if I do the end of the stud is flush with the bearing cap leaving no room for the washer never mind the 12 point nut so they actually have to be put in loose.

i think you might have the wrong parts.
what the part number of the studs you got from ARP? when i was looking into doing my girdle plate i stumbled across a few posts that had an issue similar to this, because the thickness of the girdle plate and the shims required.

 

[TDIDaveNH]

Part number is 204-5402. Studs are 10mm diameter and there is only about 12mm of block thread engagement when the total available in the block is 23mm. I gotta call ARP tomorrow and see if what I've got matches what is supposed to be in the box and if these are the right studs a really good reason as to why the amount of thread engagement they have and not more.

 

[TDIDaveNH]

I see on the ID site that these have been replaced with 202-5401 Which is for a Nissan L20 engine, same studs just 5mm longer which would get me to about 17mm of block thread engagement...better...

 

[TDIDaveNH]

Well, it turns out that the Nissan L20 main studs are the ones to use for the TDI, I called ARP and they said they are actually 10mm longer than the 204-5402 and once they got here, that turned out to be the case...they bottom out in the hole with space for the washer and 12 point nut.

So to wrap it up, you want ARP part #202-5401 for the TDI bottom end. I'm sure at some point the longer studs will make their way into the boxes labelled for the VW water-cooled main stud kit, or maybe the longer studs are needed just for the TDI?

 

[Mozambiquer]

Well, it turns out that the Nissan L20 main studs are the ones to use for the TDI, I called ARP and they said they are actually 10mm longer than the 204-5402 and once they got here, that turned out to be the case...they bottom out in the hole with space for the washer and 12 point nut.

So to wrap it up, you want ARP part #202-5401 for the TDI bottom end. I'm sure at some point the longer studs will make their way into the boxes labelled for the VW water-cooled main stud kit, or maybe the longer studs are needed just for the TDI?

That's good to know! I was getting ready to get some for my alh build, and was going to be getting the 204-5402 studs.

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[TDIDaveNH]

That's good to know! I was getting ready to get some for my alh build, and was going to be getting the 204-5402 studs.

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If you get them from IDParts, they will send you the 202-5401 Stud kit since they list it as superseding 204-5402 Their description is not 100% correct but you'll get the correct ones and they seem to know what the deal is with them.

 

[MrBigTruck]

I got mine from IDParts and they sent 202-5402 so they aren't long enough. My order was placed April 23rd and I'm just now getting around to building the engine and finding out they don't work. So 202-5401 it is. Time to reorder. That set is cheaper anyway.

 

[Mongler98]

So i was right, they are not the correct part to use! Bookmarked for my build !

 

[TDIDaveNH]

It was well covered here, the info sounds like it is not moving up the supply chain.

 

[garciapiano]

What torque setting do I follow for these studs? 48 ft-lbs as shown in the Bentley for non-stretch bolts?

 

[TDIDaveNH]

it's been so long, I honestly forget what I torqued them too.