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4.6 32V 240 Wagon

"Weight Reduction"

Note to anyone doing something similar: the wiring and vacuum manual is a life saver. It has just about everything you'd need to know about how the car works. This is extremely helpful for me since I'm trying to take the cruise control and a/c compressor control from the Mark VIII. Really hoping everything works when I plug it all in.

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It's been a long snow-filled winter here in Mid Missouri. The forecast doesn't have a low below freezing in sight which means it's once again pleasant to be in the garage. I've been keeping myself busy with some other indoor hobbies while I waited for the temperatures to warm up. I also sold our 99 Jeep XJ and purchased a used 2013 Nissan Leaf. One of the ideas behind buying the Leaf was for it to act as time insurance for this project...meaning that our Jeep inevitably would have broken and sucked up my time just like it's already done over the course of this project. The Leaf, being fully electric, is a very low maintenance vehicle. I owned that Jeep for 19 months and I'm happy I had the experience, but I'd never do it again. It's a Jeep thing, and I guess I understand now.

Anyways back to cool stuff. I removed the Mark VIII's fuel pump driver module so it can be integrated into the Volvo. Still need to figure out which pump I'm going to use. The stock 240 pump might be strong enough to idle the 4.6, but I don't think it would be having much fun at redline.

For cooling, at this time, I'm thinking early SN95 Mustang radiator and fan, since the radiator is "close enough" dimensionally, it was designed to keep this very engine cool, I can get them on RockAuto, and the fan will plug directly into the Mark VIII harness. Also, the Mark VIII coolant overflow bottle dang near bolts into the 240! I think I'll definitely carry that over with a new cap.

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Better late than never, I finally leak tested my oil pan after the TIG welding I paid for. No leaks! Paint will be coming next. I also filled it with 6 quarts of water, the Mark VIII's engine oil capacity. Here's what it looks like with the pan parallel to the ground. In the car it'll be tilted back some so it will be overfilled. Still, it's better than I expected it to be. I was ready for it to be overflowing.

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I tore into the interior and removed the seats and carpet with the help of a light bar I got for Christmas. I'd recommend getting one of these if you don't have one. It's so nice being able to see what you're doing. Also laid what's left of the IP harness and the PCM harness inside to see where things may end up. Everything looks promising...just need to figure out where I'm going to drill a hole for the transmission wiring.

This week I'm going to try to finish the engine and trans mounts.

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Made plenty of progress last week and weekend. The motor mounts are finalized! All they need is paint.

I've talked about this a little bit in earlier thread posts but I'll summarize here since I'm calling the motor mounts done. My goal was to find a way to mount the engine that wouldn't require any modification to the Volvo engine bay or subframe. I looked at the way the Mark VIII mounts worked with their "saddles" and U-brackets and realized I could easily replicate that with some metal boxes. I calculated the required dimensions of the boxes and cut the pieces out of 3/16" steel since I'm welding with a 120v wire feed welder. Would have gone 1/4" if I had something more powerful. I tacked those together and test fitted. Then I located the holes required for the long bolt going through the U bracket. I added 3/8" pipe to work as sleeving for the bolt so the U bracket would have something to bottom out on when being squeezed by the long bolt. Then I went under the car with a sharpie and marked the bottom faces of the mounts through the stock motor mount holes on the subframe. This provided me with the stud locations. For studs, I actually hammered out the studs on the original Volvo mounts and welded them to my new mounts. After that, they bolted right in with the original Volvo mount nuts and boom...the engine was mounted. There were quite a few mistakes made and shortcuts taken to get here and I would make these a little differently if I had the desire to go back and redo them. And yes, the welds are not great. But if I didn't think these would actually work, I wouldn't put them in the car. We shall see!

I didn't have time to finish the transmission mount like I had hoped, but I made some progress on it. For this one, the best way to make it happen is to modify the transmission crossmember. The Mark VIII mount lines up perfectly with the Volvo crossmember, so the path forward was obvious. I came to a road block when I realized the Mark VIII driveshaft does not want to clear the driveshaft tunnel on the Volvo for how high I want the transmission to sit. After reconsidering using the two piece Volvo driveshaft, I decided that I will still continue as planned with a shortened Mark VIII driveshaft but I will need to take my hammer to the tunnel and make it a little bigger. Or have the transmission sit lower.

In other news, I've purchased a stock late 90s Mustang radiator and fan. The core on this radiator is actually shorter than that of the Volvo's, so even though it's wider, I think I'll be able to find a way to make it fit. This also adds a level of convenience with the coolant plumbing since the inlet and outlet general locations are the same as they are on the Mark VIII. I might be able to directly carry over the Mark VIII transmission cooler lines and use radiator hoses from the parts store! More pics to come with that.

Speaking of pictures, here's some.

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A lot of slow progress that isn't exactly exciting to talk about or take pictures of is being made. The engine is back out and I'm working on firewall mods right now among other things.

The heater core fitting is out and is going to be relocated to the passenger side.

I drilled holes for the Ford hydroboost brake booster, but found that the mounting bracket puts the booster at an angle that would not allow the master cylinder to clear the hood. I'll need to take this bracket off and flatten it to get it straight with the firewall.

I worked on wiring a little more. I think I've decided I'm going to have the PCM live in the driver foot well near the Volvo fuse panel. This will require some cutting of the trim panel, but it will allow me to keep the wire harnesses unmodified since this is similar to where it was in the Mark VIII. Also plan to cut a hole in the firewall that will fit the Mark VIII PCM harness grommet. Any other wires from the engine compartment fuse box can go through the new holes created by the lack of a heater core fitting.


I've been doing some research on the one piece vs two piece driveshaft debate. It sure is a loaded one! It appears I have the ability to do what I've found to be the two best-case scenarios: one piece aluminum or two piece original steel.

1. The Mark VIII used an aluminum 3.5" driveshaft that I can have shortened. I could have a flange that fits the Volvo diff installed, new U joints, balance it, and call it good. I've already taken a hammer to the tunnel to address the clearance issues that Tom points out in his manual.

2. Shorten the original 2-piece Volvo shaft and have a slip yoke installed on the transmission end so that it can mate to the 4R70W. I actually have two Mark VIII driveshafts so if I wanted to do it on the cheap I could have one of the yokes transplanted to a custom flange. The only reservation I have over this is that I'd have two slip yokes in the system. Is that a problem?

I will say that it is extremely important to me that this car drives smoothly on the freeway between 55 and 80 mph. Goal number 1, if you will. I want to take the path that will give me the best chance of achieving this. Anyone care to share their opinion?
 
I shortened both the original Volvo 2 shaft version and shortened an original Ford single shaft version. Volvo first and never could get all the vibration out of it. Modifying the single shaft was cheaper, didn't have to screw around with center bearing and support and ended up with a perfectly smooth drive shaft.

Your transmission, if like my 4R70W, has a large diameter slip joint shaft and the big 330 sized U-joint that required the floor pan hammering. I found a tail shaft housing that used the small diameter slip joint and the 310 U-joint at a transmission shop. The 310 joint is not made for the large diameter slip joint shaft. The difference is the thickness of the slip joint shaft from splines to bearing surface. For $20 I got the smaller housing with new seals and bushing, installed the 310 U-joint slip joint and everything bolted right up and fit. The smaller housing is about an inch shorter than the large one so you have to get that resolved before planning the shaft cutting.

Start there.
 
But before I did that, a friend of mind sold me a beater 1998 Mark VIII with a healthy engine and trans with 114k miles. We pulled them out as shown.

<a href="https://imgur.com/ZMWgtuH"><img src="https://i.imgur.com/ZMWgtuHh.jpg" title="source: imgur.com" /></a>


Silly question for you. What is holding up the front end of that car? Thanks
 
Fred Gwynne said:
Silly question for you. What is holding up the front end of that car? Thanks

My engine hoist! We wrapped a chain around the front bumper of the Mark VIII and went from there.

---

Tom, I think you're right about the 330 U joints based off of some measurements I took just now, but it sounds like what you're saying is all I really need to do to get it to work with what I have now is take a hammer to the floor pan. Is that right? Out of curiosity, what kind of shaft are you using? 3" steel? etc.

Here's what my 4R70W looks like:

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And here's the image again of what my stuff looked like with the trans sitting pretty high in the tunnel. If I let the trans sit low enough, it would fit. I still haven't made the trans mount.

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Yeah, I guess if your slip joint fits the tail shaft denting the floor pan may work.

I started with a shaft from a Fox body car with the smaller joint and kept going from there.

Now, look at the other end and see if you can find a U-joint that will take the large tube down to the much smaller rear end flange. I suspect you are going to find that you are only moving my problem from the front to the rear.

There is quite a large difference between the 210, 310 and 330 joints. Your front joint is a 330, the Volvo differential flange is designed for a 210 joint.

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Now, look at the other end and see if you can find a U-joint that will take the large tube down to the much smaller rear end flange. I suspect you are going to find that you are only moving my problem from the front to the rear.

Yes, my plan is to take both shafts (Volvo and Lincoln) to a driveshaft shop and tell them I want the aluminum one shortened and a new rear end flange that will work with the Volvo diff. I'm hoping the rear end flange is something that can be had off the shelf or something that can be made custom. Then I'll probably look into the adjustable torque rods like you described in your manual if I find there are issues.
 
Very high likelihood that you are going to need the adjustable torque rods.

I had to get each joint down to about 1.0 degrees before the vibration went away. Your smart phone has an angle gauge app available. An analog angle gauge is never going to be accurate enough.

You cannot believe the amount of time this little part of the conversion took.

Had the wagon out for a drive Saturday and it still drives great and I still love it. Wind noise is about the only thing that I have not been able to tune into a perfectly acceptable modern auto.
 
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I spent the last two weeks working strictly on making final decisions about the wiring. After months of consideration, this is what I came up with. It's probably more complicated than it needs to be, but since this is being taken from a donor vehicle, the complexity made it simpler in the long run, if that makes any sense.

The Mark VIII powertrain electronics are broken up into three main harnesses:

1. Engine bay harness. Contains the cruise control module, variable load control module (VLCM, controls the AC compressor and cooling fan), AC pressure switch connectors, engine bay fuse box, starter solenoid connector, engine harness connection, IP harness connection, and PCM harness connection.

2. Instrument panel harness. Contains HVAC controls, transmission connections, instrument panel fuse box, OBD2 port, ignition switch, indicator lamps, cruise control switches, PCM harness connection, engine bay harness connection.

3. PCM harness. This harness contains a firewall grommet that allows it to connect to both the IP harness and engine bay harness. It also, of course, has a large connector for the PCM.

Starting with the engine bay harness, this one probably had the most stuff removed from it. It used to go through the firewall in two places on the Mark VIII in order to connect to the IP harness - both the driver and passenger sides. After trimming, the only thing going through the passenger side grommet was an AC pressure switch wire. This was easy to relocate to the driver side end of the harness. That end, however did not use a grommet. It used a very large connector that actually mated to the firewall by design. I wasn't about to cut a hole that big into the Volvo firewall, so I found two connectors from the Mark VIII that were no longer needed. I took the leftover grommet from the passenger side, fed all of the wires through it, and soldered each wire to a flying lead on the recycled connectors. Same thing was done on the IP harness. Here's a picture of the large connector that was removed next to the finished product.

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I then made the hole where the heater core hoses used to go a little bigger to fit the grommet. The end result will look pretty good, but it won't matter because the engine will be blocking it! You can see the PCM harness in that picture, too. More on that later.

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The instrument panel harness received the same connector mod that the engine bay harness did. A number of minor and major modifications happened with this one. The mods were done in a way that does not have this harness becoming one with the Volvo harness. Connectors were used in all places where the harnesses had to interact.

First, four ignition switch circuits had either to be spliced in with the Volvo wiring or replace the Volvo wiring all together in some cases. Those cases were the hot at all times power coming from the fuse box, and the starter solenoid relay wire. It made sense from a safety standpoint to get the Volvo ignition switch on fused power from the Mark VIII fuse box, so I cut that wire from the Volvo switch and soldered in the appropriate wire from the original Mark VIII fuse box. Looking back, I probably could have just put that Volvo wire on the Mark VIII fuse box and only cut three wires, but I didn't. Oh well. It'll still work. Starter solenoid relay wire was necessary, though. The two splices were for getting connections to the "hot in acc and on" and "hot in on and start" parts of the switch.

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The instrument panel fuse box was removed and replaced with six inline mini fuse holders, since only six fuses remained after all of the trimming.

Next, I used a mini mate-n-lok connector for the brake switch. The brake switch on the Volvo was re-wired to get its power from the Mark VIII fuse box, and return power was spliced in to the Mark VIII harness. Turns out the PCM wants to know when the car's brakes are being applied. The cruise control module also needs to know about this.

Two more mini mate-n-lok connectors were used for the dash indicator lights. These include check engine, oil pressure, battery, and cruise control. The Volvo doesn't have a light for cruise control, so I wired it into work with the overdrive light. If I understand the Mark VIII wiring manual correctly, the cruise control module actually needs its indicator lamp to work. The ground for that indicator light is controlled within the instrument panel. It will only give the cruise indicator light ground if the traction control and ABS lights are not turned on. Maybe all I needed to do was ground that wire.

Next big mod was adding connections for the fuel pump driver module (FPDM) and inertia switch. This module and switch were not originally connected to the IP harness - they were located in the trunk of the car. However, all of those wires originated from the IP harness. I decided to mount the FPDM and inertia switch where the old Volvo ECU's were. They fit quite well in there with some new, longer wires on the IP harness. Also connecting in that general area is the fuel pump. I found the wires from the main fuel pump, removed them from the Volvo harness, soldered some longer wires to them and ran them to the FPDM under the carpet.

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The strangest mod I did was in the interest of general safety. The Mark VIII ignition switch actually had two separate "hot at all times" wires going to it. It switched a lot more powertrain electronics than the Volvo switch does. One of those things is the coil driver. In order to reduce the amount of current going through the Volvo ignition switch, I added a relay that controls the coil driver using the same circuit that controls the PCM relay. This way, the coil driver gets power directly from the fuse box instead of having to travel through a switch and a bunch of connectors.

For the reverse lights, I actually cut one end of that connector right out of the Volvo harness and soldered it in to the Mark VIII harness at the reverse lights wire coming off of the transmission neutral safety switch.

The other wire that was changed off of the transmission electronics was the ground wire for the starter relay. It goes through the transmission so the car can only be started in part or neutral, but after that, it used to go to the SCIL module where it would control its ground. I simply grounded that wire since the SCIL is no longer in the car.

The most frustrating thing I found on the IP harness was the air conditioning controls. I want to run my AC compressor using the Mark VIII controls in order to get accurate fan control from the VLCM, but unfortunately, the PCM tells the VLCM to engage the compressor clutch when it gets a good signal from the HVAC unit, which is connected to the low side pressure switch. The HVAC unit reads this signal and sends a data signal to the PCM. Really? Why can't it just send on/off 12 volts from the pressure switch directly to the PCM? Ugh. So, basically, this module, with its now limited connections, will be tucked away somewhere in the passenger foot well. The idea is, if you want to run the AC compressor, reach under and push the "Max AC" button.

For the cruise control switches, I removed the switches from the steering wheel and simplified the connections down to just one since they used to go through the clockspring, etc. This is sloppy, but the idea is to have these switches live in the little storage cubby at the bottom of the cluster, and I can pull them out when I want to use cruise. Long-term idea would be to create a little push button panel that mimics the switches. That would look much cleaner.

The PCM harness is the only harness on here that will be completely unmodified. It's a very small and short, but it has a lot of wires going through it. I had to find a place in the car where it would fit as is. The driver foot well toward the outside of the car worked very well for this. I was able to cut a chunk out of the metal plate that goes in the corner, and it seemed to naturally slide right in. I cut a hole straight above for the firewall grommet and all is well.

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I did a brief test to see if the car still got power after all of this, and it did. Hooking a battery up to the fuse box gave me full body controls and brake lights! I'll see if the PCM shows signs of life later on. I still need to triple check everything on the harnesses and tape them up so they look nicer.

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After all this was done, I put the engine and trans back in to get my driveshaft length. It's at a driveshaft shop right now and I hope I measured correctly. It's getting closer to completion every day!

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While the driveshaft is being made, now is a good time to take care of some typical 240 stuff. I replaced the blower motor, blower motor resistor, and the odometer gears. Here's my thoughts on these.

Both my odometer and blower motor worked before I did these repairs. I figured that since I have the entire dash taken apart, I might as well take care of them.

Prior to being replaced, my blower motor was very slow in speed 1 and made some funny noises. It almost sounded as if the fans were rubbing against something. At full speed it was noisy, kind of like a loose bearing sound. When I installed the new motor and resistor, these noises went away and the fan turned at a reasonable speed in speed 1. Much quieter, too! I watched the Robert DIY video on YouTube for help with this one. It's a very good video: https://www.youtube.com/watch?v=EFprZjKKkbw

The repair went fairly smoothly. The hardest part in my opinion is manipulating all of the duct work and getting it to move in all the right ways. It appeared that my 240 was using its original motor and resistor. The motor squeaked when I hand turned the shaft, and the resistor had visible cracks in it. I'm glad I did this!

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I used an MTC resistor from IPD and a VDO blower motor from FCP Euro. That's where I found the best prices. I actually bought the resistor from FCP Euro initially thinking that "genuine volvo" would get me the Volvo brand resistor for less money than the IPD price. I was sent an MTC resistor instead. That part is $60 on FCP Euro and $30 on IPD. Peeved, I returned it and bought the same part from IPD for half the money.

The odometer gear was interesting. On IPD and FCP Euro, they sell the small 25-tooth gear. I bought this, went to change it out, and found my gear to be perfectly intact. It might have been replaced before. The 15-tooth gear pod, however, looked like it would shatter if it went through one more rotation. I found this part on Dave Barton's website. It just surprises me that this gear pod wasn't even included in IPD's instruction video on this repair. Very easy repair, though. I did not remove my speedo needle. We'll see if it works when I drive the car for the first time!

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Can't remember from earlier in the thread - did you give any thought to putting a heater core in it now -- or has that been recently done?
 
Can't remember from earlier in the thread - did you give any thought to putting a heater core in it now -- or has that been recently done?

I took out the firewall fitting and relocated it to the passenger side. The hole left behind on the driver side is now a hole for wires. I haven't decided on a final location yet, but I have drilled some holes to help give me an idea. I'll clean it all up with some sheet metal and my welder later.

Here's a picture of the heater core lines coming off of the engine with the firewall fitting hanging out in the firewall. You can see how short of a path the lines will eventually be taking - maybe too short to allow for engine movement now that I think of it. Air conditioning is on my mind, too, but that's another post for another time.

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