bluej (Forum Supporter)
bluej (Forum Supporter) PowerDork
6/22/21 9:13 a.m.

Hey all, I'm close to having my duratec 2.5 swap running in my e30 rallyx car, but hit another snag last night, this time with the driveshaft. I had sourced the correct slip yoke for the NC 5-speed I'm using, and the correct flange yoke for the BMW medium case diff. The flange yoke is for a 1310 joint, and the slip yoke takes a 7260. I sourced a correct length driveshaft with 1310 joints, and an adapter joint for the slip yoke.  I assembled everything, and dropped it off at a shop to get balanced. Couple days later, and it was ready to go... or so I thought.  That was almost two weeks ago now due to crewing at SOFR (yay rally friends again!).  I went to bolt the DS in place last night and discovered this:
 

 

The lip on the flange yoke centers the shaft to the input flange for the diff. Either they swapped the flange yokes, or machined out that lip.  I'm so, so frustrated. I've been hitting it hard for months to try and get this back up and running, and it seems like I just keep hitting stupid E36 M3 like this. I need to call the shop, obviously. The fastener holes all still align, so I could get fresh studs (shoulder bolts?) and still install it.

So that leaves me with a couple questions. Can I install fresh studs in the shaft as-is and safely run it? I'm guessing not since those studs/fasteners weren't meant to be relied on for the alignment. Second question is if I need to get the shaft re-balanced after replacing the flange yoke only (if the flange needs replaced as expected)? There's only one left in stock where I got the first one from.

grrrrr...

maschinenbau
maschinenbau UltraDork
6/22/21 11:19 a.m.

If I'm looking at this correctly, you are basically just missing the centering nose and studs on the flange of the new driveshaft (right image) correct? In that case, you can just have the shop turn you a ring that press-fits into the center of the new DS flange. You don't even need the studs if you have a centering nose. You can just run normal bolts/nuts.

bluej (Forum Supporter)
bluej (Forum Supporter) PowerDork
6/22/21 11:27 a.m.

You're reading it correctly, and that had been my plan ( use shoulder bolts and lock nuts). The only issue there is that the shop is an hour away, and I don't really have time for that again. I could make them do it while I wait, I guess. 

bentwrench
bentwrench SuperDork
6/22/21 11:30 a.m.

Just installing studs in that round flange will get you drive, but it won't center the shaft it will shake like a mo-fo.

It looks like one has an innie, and the other has an outie....

¯\_(ツ)_/¯
¯\_(ツ)_/¯ PowerDork
6/22/21 11:33 a.m.

That thing had a flange and they machined it off without you asking?  If you want to post the dimensions of the hub/snout/whatever maybe we can come up with an off the shelf solution like a wheel hub centering ring or something.

maschinenbau
maschinenbau UltraDork
6/22/21 11:40 a.m.

I agree if you absolutely need to move the car around the yard or onto a trailer, you could just throw bolts in it for now.

Your future custom centering ring could be press-fit into either the diff or new driveshaft flange. 

Or there might an off-the-shelf solution you can replace that half of the u-joint with.

bentwrench
bentwrench SuperDork
6/22/21 12:11 p.m.

Maybe the new flange the opposite of what is needed? Catalog mistake?

bluej (Forum Supporter)
bluej (Forum Supporter) PowerDork
6/22/21 12:41 p.m.

In reply to bentwrench :

No, it was correct with the male ring on the DS flange. I test fit everything prior to ordering the DS, and after assembling all parts before taking it to get balanced. They either machined it off (yes, no notice or ask), or swapped it. No mention when I picked it up. I think it's on them to make a ring. Going to call here in a bit. Thanks for confirming my thoughts, guys.

¯\_(ツ)_/¯
¯\_(ツ)_/¯ PowerDork
6/22/21 1:03 p.m.

Seems crazy to machine a customer provided part, I think it's more likely that it was disassembled and reassembled with a different flange piece or something- maybe your original part is sitting there just waiting for them to swap it on for you.

bluej (Forum Supporter)
bluej (Forum Supporter) PowerDork
6/22/21 1:08 p.m.
¯\_(ツ)_/¯ said:

Seems crazy to machine a customer provided part, I think it's more likely that it was disassembled and reassembled with a different flange piece or something- maybe your original part is sitting there just waiting for them to swap it on for you.

I agree, it's surprising. The swapped flange had occurred to me. I don't know where they would have gotten this flange that matches the specific (and sorta relatively rare) e30 diff flange bolt pattern. The holes in the new flange also seem to be the correct diameter for the press-in studs. I'm about to run outside and measure the now female flange I have before calling.

iansane
iansane HalfDork
6/22/21 2:34 p.m.

In reply to bluej (Forum Supporter) :

The e30 stuff might be rare but it's not far off of toyota flange adapters. I dropped off (as in, just a few minutes ago) some pieces like that for NWDrivelines to make me a new driveshaft for my e30. One of them was an adapter similar to that but not round. The counterguy commented that the centering ring was within a few thousandths of toyota stuff and the bolt pattern looked close. Maybe it did get swapped?

bluej (Forum Supporter)
bluej (Forum Supporter) PowerDork
6/22/21 2:45 p.m.

Some more pics.

 

pattern aligns.

 

can see the difference in diameters

 

 

 

innie that should be an outie. not sure what that hardened green crap is. i can also see where a sticker was on the mating face of the flange. I remember taking that sticker off, but don't recall if the green crap was there or not.

 

¯\_(ツ)_/¯
¯\_(ツ)_/¯ PowerDork
6/22/21 2:51 p.m.

By the look of it, they would have had to not only cut something off but then bore it out?  Doesn't look like a freshly machined surface either, I'm still voting switcheroo but am hunting for a centering solution in case one exists.

bluej (Forum Supporter)
bluej (Forum Supporter) PowerDork
6/22/21 2:53 p.m.

guy on the phone said they'd fix it, but the main DS guy already left for the day. I guess another trip down for them to fix it while I wait is still best. still so weird. I can't go till Thursday, but I'll update here after talking to their DS guy tomorrow morning.

bluej (Forum Supporter)
bluej (Forum Supporter) PowerDork
6/22/21 2:55 p.m.
¯\_(ツ)_/¯ said:

By the look of it, they would have had to not only cut something off but then bore it out?  Doesn't look like a freshly machined surface either, I'm still voting switcheroo but am hunting for a centering solution in case one exists.

that's what I thought (doesn't look machined). Now I'm wondering if he had to put a different flange yoke on to get it balanced, then forgot to swap back to the correct one. I'll find out tomorrow morning. If this is the case, I just hope they still have the correct flange there.

APEowner
APEowner SuperDork
6/22/21 3:13 p.m.

That green stuff looks like a loctite product to me.  I wonder if the outie was glued in and they had to remove it to fit in a fixture or something and it never got put back in.  The current bore looks like rough casting to me in the pictures so it's not machined .

Shavarsh
Shavarsh Reader
6/22/21 3:50 p.m.

In reply to APEowner :

There is also an inconsistency in the OD of the bore. There is a groove, and in one area it looks like there is an external fillet instead. Could be some left-over insert that got left in the bore... Just spit balling here.

 

Edit: Disregard, after looking more closely it seems to be an optical illusion.

bluej (Forum Supporter)
bluej (Forum Supporter) PowerDork
6/22/21 4:11 p.m.

I know what you mean re: the bore looking off center. In person you can see what looks like the cast center isn't aligned with the machined center of the rest of the flange.

bluej (Forum Supporter)
bluej (Forum Supporter) PowerDork
6/23/21 8:03 a.m.

That did not go well. The guy wasn't willing to entertain the possibility of him making a mistake. I'll have to show him in person tomorrow.

¯\_(ツ)_/¯
¯\_(ツ)_/¯ PowerDork
6/23/21 8:18 a.m.

In reply to bluej (Forum Supporter) :

This is mirroring my experience with driveshaft shops, except you actually got somebody to do something.  The first one I took a Merkur driveshaft to practically threw it at me a day later and told me to berkeley off, the second one still has it three years later.

bluej (Forum Supporter)
bluej (Forum Supporter) PowerDork
6/23/21 8:36 a.m.

He kept on at me about my "oddball" flange. Whatever, you did have the adapter on the shelf bub. 

bluej (Forum Supporter)
bluej (Forum Supporter) PowerDork
6/25/21 4:36 p.m.

Look what was stuck to the balancer adapter on the shelf at the shop? 

Too bad I had to be down there to actually get them to even try to look for that inner ring. Whatever, yay power to the wheels!

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