Driveshaft Replacement Experience/Info

[TostitoBandito]

I figured I'd start a thread to put information out there for others, since I've embarked on another semi-annual major car project. On my list this time:

• Replace driveshaft with rebuilt shaft from http://www.driveshaftspecialist.com/ ; includes new u-joints and a new CSB
• Replace guibo
• Install UUC Evo3 SSK with DSSR while the shaft is out and everything is easy to get at
• Cut out all the sagging foam insulation stuff aft of the transmission output shaft so it stops rubbing on the shaft/guibo
• Replace all four O2 sensors while the exhaust is out
• Coolant flush so I can replace a leaky thermostat housing with a new housing, thermostat, and whatever hoses need replacing
• Get the exhaust tips/muffler aligned properly when it all goes back on (currently too far towards the driver's side)

I'm about to go away for a few days and will resume when I return, but this far I've succeeded in removing the entire exhaust and the old drive shaft.

The exhaust was interesting because I was expecting to break a bunch of studs, but once I actually went to remove them I discovered that four out of six had already been replaced with bolts by shops/dealers in the past. That made life easier and they all came off pretty easy, except for the one on the pipe closest to the engine block which sits right below the O2 sensor bung. Getting a wrench over the head of that bolt was a challenge, and required the purchase or a short/stubby 16mm or 5/8 wrench specifically for that purpose. With a little maneuvering the whole forward exhaust comes out with the x-brace still in place.

The drive shaft was pretty straightforward, though the front bolts were super tight and were also in the wrong way. All the bolts were facing the same direction, as opposed to following the arrows. The guibo was looking pretty rough, as was the CSB which had pieces flaking off of it.

Here's a pic of the old shaft next to the rebuilt shaft showing what the sagging insulation did.

56324154935__7E0F3C0D-706B-4227-9898-DCEDA54CD684.jpg

I'll continue to update this with more feedback next week once I start on the SSK and thermostat.

[TostitoBandito]

This is what a dead guibo looks like.

IMG_1573.jpg

There were cracks like that on the edge of almost all the bolt pairs, and you could see the cracks flex open and move as you twisted it.

[tjm3]

Any particular reason you didn't use Driveline Service of Portland?

[TostitoBandito]

Hadn't heard of them, and I know of probably a half dozen people who've used the place in Texas so they seemed reliable. They also had a page specific for BMW's, pricing on their site, and were very responsive to my questions via email. No complaints, assuming the new shaft works as advertised. I see no reason why it wouldn't from looking at it. Seems like a great deal for $383 shipped (after $80 core refund).

If I had known about the shop in Portland I might've checked it out, but I can tell you from looking at the site that it looks like more work to get a quote and other details. Probably also why it didn't appear in searches, because they didn't have a page specifically detailing BMW shafts, layouts, pricing, etc...

[tjm3]

They used to advertise for quite a bit for BMW related driveshaft work but it looks like they've moved into a more broad market. The quote is just a call to make sure you get the right driveshaft but I've used them several times with excellent results.

[Braymond141]

Couple things.

Giubo, not guibo (said “jew-boh”). I made this same mistake for years.

Don’t cut the insulation, it just dusts out the insides for ages. Either remove it all or use something like what I made to hold up the original.

The arrows represent the flange orientations, not the bolt directions. All of the bolts install the same direction with the nuts at the front of the car. Arrow pointing backwards means line up with shaft side. Arrow towards front means line up with transmission side.

Not a fan of Portland service. My first rebuild failed within a year. They did warranty it, but I bought a brand new BMW replacement before the second one had any issues.

Nice work. Driveline maintenance is fairly rewarding to do.

[TostitoBandito]

Good info about the bolts. Makes sense.

Regarding the insulation, my plan is to start the cut aft of the furthest aft set of fasteners on each side, and then curve forward to the transmission flange in the middle to get rid of the sagging part that rubs. That way it should still be held in place to some extent. I’ve got some adhesive backed heat shielding that I’m going to see about putting in to replace the missing section, possibly reinforced with some extra screws if needed. We’ll see how it works. That part of the insulation has to go because in addition to sagging it’s also disintegrating. The stuff further forward is in better shape. I’ll take pictures of whatever I come up with.

[TostitoBandito]

On a slight tangent, I finished the cooling system portion of the job today, which was probably the biggest PITA out of the whole thing. Found the source of the leak too:

IMG_1582.jpg

That's the end of the lower radiator hose which connects to the thermostat housing. Looks like when my dad and I replaced the radiator years ago (my first DIY) we got the clamp on crooked and parts of the edge of the hose cracked and disintegrated, causing a slow leak. It was never a big deal and really just gave the top of my underpanel a light coating, but I'm glad to have fixed it. Also replaced the thermostat/housing, that hose, and the expansion tank and sensor while I was at it. And while I was mucking around in the engine bay I replaced the two pre-cat O2 sensors, which was pretty straightforward. I spent most of the time on those making sure the wiring was all where it was supposed to be.

It took me a bit to figure out how to extract the fan shroud and how everything fits together down there. Now that I've done it, I'm sure it will be a lot less painful if I need to again. Except for the fan. Getting the fan off is always the worst, even with the tool. It's not easy to get that thing to hold on to two water pump nuts and then hold it perfectly level so it doesn't fall off while you grab the wrench.

Anyways, on to my UUC short shifter tomorrow, and then I'll be able to start putting the drive shaft and exhaust back on.

[LockDots]

Couple things.

Giubo, not guibo (said “jew-boh”). I made this same mistake for years.

Don’t cut the insulation, it just dusts out the insides for ages. Either remove it all or use something like what I made to hold up the original.

The arrows represent the flange orientations, not the bolt directions. All of the bolts install the same direction with the nuts at the front of the car. Arrow pointing backwards means line up with shaft side. Arrow towards front means line up with transmission side.

Not a fan of Portland service. My first rebuild failed within a year. They did warranty it, but I bought a brand new BMW replacement before the second one had any issues.

Nice work. Driveline maintenance is fairly rewarding to do.

+1 to all of this. I don't think you can install the bolts facing the back anyway.

[TostitoBandito]

Driveshaft is back in and all torqued. The shaft from Driveshaft Specialists of Texas fit perfectly as expected. Put in a new flex disc and replaced all the fasteners as well. Wasn't hard to get in solo. I set the front end on a box while I put nuts on the diff end and then temporarily put the CSB in place so I could get a wrench around the big clamp/nut which holds the halves together. Then I could pull the extra length I needed to seat the centering bushing around the rod in the transmission output.

Skipped the UUC SSC for now because apparently UUC was out of the delrin carrier bushings so they shipped me an OEM rubber one instead until they get more in stock. Since I need to drive my car this week and I only want to take apart the shifter once, I'll do this in a couple weeks and try to work around the driveshaft I guess (in theory it can be done).

Just need to get the exhaust back on and then I can fill up the coolant and check for leaks before taking it for a test drive. I'm waiting until tomorrow on that because the post-cat O2 sensors are really in there good so they're bathing in PB blaster overnight. Need to swap those out with new ones before bolting in the exhaust.

[TostitoBandito]

Success, eventually.

After fixing a suspected leak from one of the connections on my new expansion tank late last night, I topped off the system, bled it (so I thought) and went for a quick drive around the block after I had already gotten it to temp in my driveway. I made it about halfway before the temp started to rise past normal so I immediately parked and left my car for the night. I grabbed it in the morning and drove it back to my garage, where I proceeded to add another half gallon or so of coolant mix by bleeding it with the ignition switched on and heat going. I suspect there was a bunch of air in my heater core, among other things. After that it was fine. I ran it for a while and did laps around my block for like 15 minutes to make sure.

Other musings:

• I drove about 70 miles today on the new driveshaft, and it's noticeably smoother in general. The vibration I used to get frequently when lifting while in gear is now gone or at least much milder. I'm guessing it was due to the old flex disc and/or shaft. Whatever's left is likely just due to my bolt-through trans mounts.
• Stupid x-brace never fails to drive me insane. I had to remove it to get the exhaust back to the headers solo, and it's always a pain to get the large outer bolts to go in at the right angle. One of the bolt holes is now partially stripped to the point where I just cross-threaded the thing all the way in there to get it on (the bolt wouldn't start straight, even with no x-brace in the way). It's on there at about the torque it's supposed to be so it's fine, but next time I have to remove it I'll have to tap those holes out to M12 or something. I might also get a new x-brace when I do that as well. I suspect this one might be very slightly bent, which impacts the fit just enough to be annoying. I did spin my car at the track a few years ago and basically bounce the x-brace off the curbing on my way to the gravel. However, I even remember the initial install when new to be an adventure getting all the bolts in.
• My rubber cat hangers were old and stretched. The new ones I got were like 1/2" shorter. This also led to my tailpipes sitting a bit lower, which leads me to...
• My exhaust tips are still too far to the driver's side. I tried everything I could with all the pipes loose but nothing really worked. My new plan is to get new rubber muffler hangers along with some longer M8 bolts than the normal ones which go horizontally through the hole in the rubber to hang the bracket. I'm gonna try to stack some washers on the longer bolts in order to displace the muffler more towards the center of the car where it belongs.

[JitteryJoe]

Success, eventually.

After fixing a suspected leak from one of the connections on my new expansion tank late last night, I topped off the system, bled it (so I thought) and went for a quick drive around the block after I had already gotten it to temp in my driveway. I made it about halfway before the temp started to rise past normal so I immediately parked and left my car for the night. I grabbed it in the morning and drove it back to my garage, where I proceeded to add another half gallon or so of coolant mix by bleeding it with the ignition switched on and heat going. I suspect there was a bunch of air in my heater core, among other things. After that it was fine. I ran it for a while and did laps around my block for like 15 minutes to make sure.

Other musings:

• I drove about 70 miles today on the new driveshaft, and it's noticeably smoother in general. The vibration I used to get frequently when lifting while in gear is now gone or at least much milder. I'm guessing it was due to the old flex disc and/or shaft. Whatever's left is likely just due to my bolt-through trans mounts.
• Stupid x-brace never fails to drive me insane. I had to remove it to get the exhaust back to the headers solo, and it's always a pain to get the large outer bolts to go in at the right angle. One of the bolt holes is now partially stripped to the point where I just cross-threaded the thing all the way in there to get it on (the bolt wouldn't start straight, even with no x-brace in the way). It's on there at about the torque it's supposed to be so it's fine, but next time I have to remove it I'll have to tap those holes out to M12 or something. I might also get a new x-brace when I do that as well. I suspect this one might be very slightly bent, which impacts the fit just enough to be annoying. I did spin my car at the track a few years ago and basically bounce the x-brace off the curbing on my way to the gravel. However, I even remember the initial install when new to be an adventure getting all the bolts in.
• My rubber cat hangers were old and stretched. The new ones I got were like 1/2" shorter. This also led to my tailpipes sitting a bit lower, which leads me to...
• My exhaust tips are still too far to the driver's side. I tried everything I could with all the pipes loose but nothing really worked. My new plan is to get new rubber muffler hangers along with some longer M8 bolts than the normal ones which go horizontally through the hole in the rubber to hang the bracket. I'm gonna try to stack some washers on the longer bolts in order to displace the muffler more towards the center of the car where it belongs.

For the muffler hanger, that is exactly what I did. Worked great as my tips are perfectly centered.
Also, I have an air lock radiator purge and fill tool. Works great. Puts about 25 ibs of vacuum in the system and then uses the vacuum to fill with fluid. It will also detect any leaks.
You are welcome to borrow anytime since you live so close.

[TostitoBandito]

For the muffler hanger, that is exactly what I did. Worked great as my tips are perfectly centered.
Also, I have an air lock radiator purge and fill tool. Works great. Puts about 25 ibs of vacuum in the system and then uses the vacuum to fill with fluid. It will also detect any leaks.
You are welcome to borrow anytime since you live so close.

Cool, good to know I'm on the right track with the exhaust. The muffler hangers in there now seem intact still but they may also be stretched like the cat hangers were. I just don't have a new hanger on hand to compare to. I'm hoping the combination of new hangers and spacers can give me the 1/4 inch or so I need.

Good to know about the purge tool. I think I'm all set now, as I just went down and checked while cold and didn't see any sign of leaks and put a final splash of coolant in to bring it just above the cold line. I'll keep it in mind if I ever do this again though, thanks. I think the only thing in there I could still mess with is the radiator if I want to go to a Mishimoto or something, though my current OEM radiator is only 4-5 years old. Oh, and the long hose that goes from the engine block behind the PS reservoir to the expansion tank. I didn't replace that because it was a pain to get to the other end. If I ever do the radiator I'll get it then.

[Braymond141]

You adjust the rear muffler tip position within the valance at mid pipe sealing flanges. There's no need to use any non-oem hardware or space the muffler. Just loosen the midsection hardware (and muffler drop clamps if applicable), position everything and tighten. The rubber hangers are there for height only.

[TostitoBandito]

You adjust the rear muffler tip position within the valance at mid pipe sealing flanges. There's no need to use any non-oem hardware or space the muffler. Just loosen the midsection hardware (and muffler drop clamps if applicable), position everything and tighten. The rubber hangers are there for height only.

Yeah I know, but for whatever reason the amount of adjustment I can get at the mid pipe flanges given the geometry of the pipes isn't enough. I've already gotten as much length as I can out of the pipe that has a slide joint (outside pipe I think) which would cause the tips to move inward like I want, but it isn't enough. The inner pipe has a fixed joint with a gasket ring sandwich and can't be adjusted, which also limits the range you can adjust the outer pipe since they're all attached to the same thing on both ends. The only other point of adjustment on my exhaust is on the joints between each of the pipes and the muffler section, which is again limited by the geometry of the pipes.

[RRSperry]

It's really hard to adjust the muffler when the suspension is unloaded. At droop, my UUC rear bar pushes the exhaust (Supersprint) to the right. On the ground it's centered... But every time I look at it on the list I think the outboard hanger is going to be ripped off.