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Volvo 122S Build Thread: Scope-creep the Sequel

I've been a bit busy with work...and we added a new member to the team.

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He doesn't like the garage a lot just yet, but I have hopes.

So with the back finished enough for now, it's back to the front of the car. Before the frame can go in, the pedal box for the floor mounted pedals needs to go in and the transmission tunnel needs to be replaced. So let's get on with the show.

The engine position meant the pedal box needed to move towards the outside of the car about 1/2" No big deal, I had the room. Just a little more metal massaging.

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Final position - seems fine.

Fit is still good.

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The pedal mount plate welds directly to the frame - it's 1/8" plate and should be more than enough once fully boxed.

I had to create a relief in the box to cover a gap between the box and the frame - the box ended up going a little higher on the firewall than planned, so this was easiest.

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I'll fill in the sides and front so that crap doesn't collect in the gap.

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Here's the inside.

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I'm also working on the transmission tunnel. It's a bit tight on the drivers side...reverse switch is on the sheet metal.

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I think I'll just bend it out a little...this should do the trick.

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240 tunnel all cleaned up - looks like a good fit once the front panel was removed.

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I should get the sheet metal flange built to receive the trans tunnel this week. Then mount up the rear end and see what I have to do for the drive shaft tunnel.
 
Time to get the trans tunnel sorted out.

The 240 tunnel will work almost perfectly. I was amazed when I knocked out the lip where I lopped this off the donor car that was just about perfect.

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Both sides.

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I toyed with the idea of reusing the base of the old tunnel, but it just didn't make any sense to do that when I still had to build the flange to attach this tunnel to the firewall. It really isn't the right shape to match at the base, so better do it right.

Didn't take any picture of how I did this...watch the video when it's out.

Here's the top joining part.

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Getting it all levelled off was tricky - but worked.

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Took two stabs to get the shifter dead centre.

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Then the skirting got done. This will get tidied up and finished this week. Then the tunnel is a little closer - next up will be the drive shaft fitting.

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Still working on the side flanges...but each day, a little more gets done. First, a little sheet metal welding.

Front.
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Now that's welded. Tacks are clearly visible and the weld is fully penetrated.

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Wrapped corners (just for the welders...sort of an inside joke).

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These have very low distortion and can be effectively hammered. Not a gas or TIG weld, but it's a tunnel.

We're going to be needing a bunch of shape to get this to close up nicely.

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I hand hammered these (no E-Wheel yet) - just using a shot bag and hammers.

Getting there.

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That's more like it - a lot of shape actually.

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The shape added is a bit more evident from this angle. It's also clear that I need to shrink that top edge to get the flange to sit flat again. No big deal.

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Moving along - should have it all installed this weekend. Woo hoo.
 
Anyone reading this thread know anything about drivelines? Specifically, driveline angles for 2-piece shafts. The differential sits at 0? and the engine is at 3.4?.

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The Spicer calculator says that I've got to run the operating angles of the ends of the shaft at +- 1? with no operating angles greater than 3? for vibration free performance. This means the angle of the first shaft has to be 6? and the second shaft should be 3? to yield operating angles of 2.6?, 3? and 3?.

Has to come up a bit.
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Floor tunnel section needs to be cut - this is on the floor (it's really 2?).

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So before I cut things...does this make sense. I know the front shaft will need to be lengthened...I'd like to know have to do this over.
 
Craig, When I was doing mine I relied on this:

https://www.iedls.com/uploads/files/Power Train Setup.pdf
They get into two piece near the bottom of the page.

Of course mine is a one piece so a bit simpler. If your trans output to pinion flange is less than 51" (1295.4 mm) you could run a one piece, too, according to the link. If you can't change the pinion angle from 0* maybe you could play with the motor mounts to get the output angle to 0* as well. Then the difference in the heights of the two ends would provide some angle in the shaft, not more than 6*, so the needles will rotate. That's for a one piece, of course.

Sitting here scratching my head it seems that with the pinion angle locked at 0* you'll still have to change the trans output angle to close to 0*. Than the front shaft could drop so it's angle is 1* or 2*, within the tolerance to match the pinion angle. But then the distance between the two joints is much shorter and so the angle of the shaft will be much steeper, which I think will cause it's angle to be out of tolerance. This all depends on the difference in height between the trans and pinion. My head hurts now, thanks a lot! ;-)
 
The only way to change the "drive" (engine/trans) angle would be to raise the rear of the trans...we're a little tight up front, so there is no more down. If I raised the trans to the same angle as the diff, then the operating angle of the u-joints go up and the offset between the two (drive and driven) are increasing and this is also wrong. I ran the data through the Spicer torsion/vibration calculator and what I've got is as good as it's going to get...it won't be smooth, but I don't see a way out of this either. Tilting the diff up (which others have suggested), makes it worse not better in the calculator.
 
I'm not too sure how much further we need to go down the rabbit hole - the good books on the subject are locked up behind a pay wall and I can't get at them (for less than $100 USD - I hate that. So the next best thing is to call the guys at Tech Support at Spicer and lay it all out for them. Aside from the horrific elevator muzak, the tech was nice and knew what he was talking about.

They have a selection of calculators: https://spicerparts.com/calculators

First up - The Operating Angle calculator - https://spicerparts.com/calculators/driveline-operating-angle-calculator

Feed this thing with my angles (drive = 3.4 down, shaft 1 = 6 down, shaft 2 = 3 down and driven =0) so this leaves the following operating angles, first joint = 2.6, middle = 3, differential = 3. The details says that if I run the first joint and the last joint in the series no more than 1 degree different and nothing over 3 degrees...so all good. On the edge, but not against the rules. It's just operating angles - nothing fancy.

If it's outside of these parameters, the calculator tells you that death will ensue.

Next up - The Torsional Analysis calculator- https://spicerparts.com/calculators/torsional-analysis-calculator This tool will give an estimate of various predicted torsional and inertial effects that can damage many of the driveline components in a vehicle. You need more data - length of the shafts and distance the diff is off the centre line.

So to the above data we add, shaft 1 will be 26" long and shaft 2 is 22" long. The diff is 1.875" off the centre line. Bung this in putting all the off set to shaft 2. Then set the shaft RPM to 3000 for the first run.

Inertial Effects-Drive Degrees 6.39 Rad/Sec 1229.2
Inertial Effects-Driven Degrees 9.45 Rad/Sec 2684.3
Torsional Degrees 7 .69 Rad/Sec 1776.0

* Max Allowable Inertias - 1000 Rad/Sec/Sec
Inertia Effects (Drive) - usually caused by a large operating angle at drive end of driveshaft.
Inertia Effects (Driven) - usually caused by a large operating angle at driven end of driveshaft.
* Max. Allowable Torsional - 300 Rad/Sec/Sec Torsional - usually caused by large, unequal operating angles or out of phase driveshafts.

So at 3000 RPM, it's above the max allowable at the transmission and over twice allowable at the differential...let's not talk about torsional limits. Yikes.

I ask the tech - he says "If the calculator runs, it's going to be OK - it won't fail" - I reply that it may be like driving in a paint shaker...he doesn't respond to my witty retort. Hey, it was Monday morning...I understand.

So then I change a few things. Basically, I ran a quick and dirty sensitivity analysis - without changing the drive or driven angles. First, I varied the speed. 3000 RPM is around cruise on the highway - so not really smooth (hard to know what all this means, but most things in my car are not well isolated for NVH and I'm not all that sensitive to it, but let's be realistic). So I up the RPM to 5K...calculator still works.

Inertial Effects-Drive Degrees 6.39 Rad/Sec 3414.6
Inertial Effects-Driven Degrees 9.45 Rad/Sec 7456.5
Torsional Degrees 7 .69 Rad/Sec 4933

How about 6K

Inertial Effects-Drive Degrees 6.39 Rad/Sec 4917
Inertial Effects-Driven Degrees 9.45 Rad/Sec 10737
Torsional Degrees 7 .69 Rad/Sec 7103

7K - BANG - it gives the warning about death. :twisted:

OK - let's play a little with the offset. If I split the distance between the shaft at 3K (well, 1" to the front and 7/8" to the rear) things look great at 3k

Inertial Effects-Drive Degrees 4.89 Rad/Sec 719.7
Inertial Effects-Driven Degrees 5.27 Rad/Sec 835.9
Torsional Degrees 5.08 Rad/Sec 774.9

Wonderful - let's do this. No idea what it all means, but inertial effects are below tolerance and the torsional thing is only double what it should be...plus a little.

REV it up - 5K BANG :twisted:

6K :twisted: Well, if it wasn't going to do 5...I tried it anyway. WTF. I tried every which way to move angles and offsets and it all blows up. Nice. I found the optimal solution by looking at it. It still won't work well, but it will work. Just don't drive it fast. Ya, right.

So what about a one piece. I did this and the shaft angle is 4.6? (3.4 and 0? for drive and driven) - so I can't make it past the first calculator.

The angle results from the engine being higher than the diff...and I can't tilt the diff up 3? without having to cut apart the rear subframe for the 4th time.

Now looking at CV joints instead of U-joints.
 
Adapting a driveshaft from any old BMW (with a V8 or more) could be an option, they use a CV joint at the diff side. Making an adapter that bolts to your diff flange and accepts a CV joint should be pretty straight forward. No idea if you need a CV joint on the trans side too with that setup. That's what Im doing in my 740
 
Adapting a driveshaft from any old BMW (with a V8 or more) could be an option, they use a CV joint at the diff side. Making an adapter that bolts to your diff flange and accepts a CV joint should be pretty straight forward. No idea if you need a CV joint on the trans side too with that setup. That's what Im doing in my 740

Trying to work on this right now. I have, once again, run up against manufacturers that are a little puzzled by what I'm doing and aren't particularly helpful.


You'd think they made their living selling stuff to people.:roll::roll:
 
Craig, just how difficult would it be to raise the trans end of the drive shaft to 0* to 1* of drop? I know it would put a bit of stress on the front motor mounts (should have gone with those Jags!!) but that can be addressed as well. If possible to do that you could easily run a one piece and be within specs, JMO.

I have a pal who went with these guys for CV:

http://www.driveshaftshop.com/domes...e-cv-real-cv-in-your-street-rod-or-muscle-car
 
Craig, just how difficult would it be to raise the trans end of the drive shaft to 0* to 1* of drop? I know it would put a bit of stress on the front motor mounts (should have gone with those Jags!!) but that can be addressed as well. If possible to do that you could easily run a one piece and be within specs, JMO.

I have a pal who went with these guys for CV:

http://www.driveshaftshop.com/domes...e-cv-real-cv-in-your-street-rod-or-muscle-car

Ya, that's the guy I'm talking to...they're just more of a one line email reply when I'm more of a let's have a 5 minute discussion on the phone so we don't waste each other's time on this stuff sort of guy. I'll see what comes of it - it's starting to annoy me a little.

Moving the engine to 0? does a few undesirable things. If the back comes up (and it would be about 50 - 60 mm - then that's too high at the rear and the front would come down. I'd have to reset the trans tunnel, which I just finished. And the oil pan is set at 3? down. Then the front would also come down...and bang, into that damn steering rack.

I just think it's best to spend the money on the drive shaft and be done with it - I don't want this thing to be some underivable monstrosity. If driveshaft buddy doesn't smarten up, I'll just grab parts and fabricobble it together.
 
Last edited:
We've got an update video.

<iframe width="560" height="315" src="https://www.youtube.com/embed/I5k0xeVvD88" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 
Update time - here's the latest video update. I'll probably write a post when the rest gets done.

In the mean time -

<iframe width="560" height="315" src="https://www.youtube.com/embed/OqMjRqcSW20" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 
So if you didn't watch the video...here's the related post.

With the drive shaft clearly not fitting...I needed one inch more in the rear cross member to get the clearance that I needed to run a one piece drive shaft. The plasma came out, things got cut, and then I fabricated more stuff that got put back into the car.

They look like this.

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Yes, that's a big hole in my freshly painted rear seat pan. Oh well.

I didn't take any pictures of getting the back sheet metal put back in place. It involved a template, some shrinking and a little T-Dolly work. Oh, and a little welding.

Ta da.

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Here you can see what I've done a little better. There were some 16 ga box sections added inside the cross member and plug welded in place. Then the 3 mm steel hoop was bashed out and plug welded into those box sections. Then the sheet metal goes over all that mess. Just a little clean up and it's fitted. I've added a crease in the top of the sheet metal to get the fit perfect.

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The angle of the shaft will allow me to add the original drive shaft loop/cross member stiffener to the base of this when the foot pans are back in place. I will need to add some strength to the top.

So I used my tipping wheel on the bead roller to turn out these panels.

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That fit together with this strip.

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And get all welded up and finished off.

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That sits over this like so.

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So now..it's on to finishing up the trans tunnel and getting a drive shaft tunnel built.
 
I hate rework - but here we are. This pedal box has been doing my head in. I could have finished this a year ago, but something was just not right. I've done an episode on making the little shelf thing and was kidding myself that this would be OK as the area needs a false floor anyway. Well it's come time to fish or cut bait as I begin to wrap up the interior sheet metal. I don't like it. It doesn't feel right. So it's coming out.

Here we are now.

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The photo makes the fit look worse than it is...I just jammed the floor part in there last night in disgust/despair. Now, I spent two nights freezing my arse off on the frozen concrete looking at this mess muttering to myself. You get the picture.

At the far edge of the repair, we're 1" off the floor...but only fractionally off the rail.

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So why am I compensating for a floor (that I put there) that's clearly in the wrong place. That's got to go.

In case you're wondering...it all fits nicely - but this does need to be sorted before the trans tunnel goes in.

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So I'm not being random for once.

I wasn't sure how I'd make a silk purse out of this sow's ear either...so that'll bug me forever. No way to close all this up against moisture and dirt.

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And I'm super not pleased that the pedal box is 3/4" off the rail. I want it on the rail. So I'm going to fix all of this somehow. I've also discovered that the bulkhead closing panel is a bit pitted and really just the flange needs to go, so it'll go. Anyway, this will take a few days to put right.

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After two tries to get it right, the pedal box is finally done. I've replaced the bottom and made it 3/4" deeper and changed the angle to fit the frame.

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Turned out nicely.

I took the time to tune the flange fit when the bottom was separated. Much easier to move the flange when you don't have to fight the entire part. Got it to fit great.

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First fit - like a glove.

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Laying out the template for the new floor. Much better.

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Tomorrow the floor gets shaped and welded in. Then the pedal box will get a final fit and be ready to weld up.
 
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