1972 Riviera M2 Build

[jgerock]

Tom - great progress - are you going to add a Roundel and 2002 emblem to the rear panel?  

 

 

Jim

[M3M3]

or do you have a new "M2" emblem on order from BMW...

[02tom]

Jim, I was going to leave off the roundel and emblem for now. I can always drill the holes and put them on easy enough.

Marshall, I'll have to get back to you on that; haven't seen the M badge yet but I'm thinking it would strike me like seeing an M badge on a 525 or the like. Right make, wrong car type of thing, or at the least - too modern.

[02tom]

In going thru the rear axle, I've managed to degrease and install new boots on the half shafts.  A couple of notes about the bearing carrier rings - the beveled edge points toward the shaft, as does the narrow milled end of the splined attachments on each end of the shaft.  The flat edges faces the flange of the stub axle or the output flange of the differential.

 

I'd forgotten that I had some BMW boot kits that I didn't use the last time I did this.  After looking at my half shafts, I decided not to use them once again, as they would add quite bit of difficulty to the job.  The half shafts that I refurbished are of a different design than most it seems - and I found a set off a 74-76 only after I was completely done redoing the others (see below - they're like the one that's not cleaned up yet).  I don't know if the shafts I found from the '76 car are a later design for certain, but the BMW kit appears to be made for them for two reasons that I can see.  The first is the bigger end of the boot's metal interface piece that the boot fits over doesn't not have to be crimped, as it would if it were installed on the shafts I rebuilt - which I believe may be original to my '72.  The second is that the "c" clips in the rebuilt kit are too thin to fill the grooves in the shafts from my '72.  The "c" clips are half as thick in the rebuild kit as what is on the shafts from my '72.

 

BMW's rebuild kit has some advantages over the boot kit, but whether they are worth the extra cost is worth looking at before you do this.  The BMW kit has the new metal piece on the big opening of the boot; it also has an end cap (not pictured); new clips also included.  I can't remember the cost now, but the part number as seen in the picture is 33 21 9 067 911.  You will want the correct pliers to clamp the same end of the boots, whereas the Rein Automotive kit uses flat screwdriver clamps.  I'm guessing BMW's kit has the Hylomar flange sealant for sealing off the metal piece on the large end of the boot to the bearing containing part of the CV joint.

Note the metal piece is crimped where it meets the bearing carrier of the CV joint.  I don't know how you'd use the BMW kit and reproduce this factory look, so I left them in place and had to clean them really good/the best I could.

Late model design change - 74-76???  I should probably clean these up and install the BMW kits while all this is still fresh in my mind...

 

I also was able to remove the rubber differential bushing and press in some BMP urethane ones.  Someone local sold me the urethane mounts a long time ago, but they haven't degraded from age.  The hole for the bolts in the original mounts were no longer centered as I'd imagine they are when new.  At any rate, the urethane mounts center the bolts holes at this point. 

 

**A note on bolts: the original bolts for the diff. mount, rear subframe, and trailing arms are all originally 8.8 bolts, but as I've been ordering new ones from BMW they supply 10.8 bolts.

Edited September 9, 2016 by 02tom

[02tom]

Installed new bearings, stub axles, seals, 3.91 LSD, half shafts and started on the big brakes and brake lines!  I may have to go back and flip the subframe mount bushings back to the normal way after thinking about it.  My other car doesn't have them flipped and there was contact between the tires and inner quarter panels.  I don't want any more potential for the tires to rub the fender wells if possible until I get the car on the road and can get things sorted out.

Edited September 9, 2016 by 02tom

[M3M3]

LOL, we did the similar work today on our M2's.

 

i do not flip the mounts.  doing so decreases the room for the 2.5in exhaust tube above the subframe.  alson not keen on the angle it creates for the diff.

 

do you have another pic of your rear brake install? curious how you routed the lines.

 

btw, one thing i hate about those calipers...they are impossible to push the pistons back in on when changing pads.  piston must be screwed in, but there is no way to push down on them due to the outer caliper design.  you have to open the bleed valve and break your hand trying to twist the piston. 

Edited February 18, 2015 by mlytle

[02tom]

Must be subframe season? I'd love to do more with the sub frame like you are, but just trying to get it on the road for now. Thats a good thought too Marshall. Im going to need room for a larger than normal exhaust. The previous stock exhaust rubbed on the subframe for some reason. Afterthought about the mounts: maybe the engineers designed the extra 1/2 inch of rubber on top of the sub frame mounts may protect the sheet metal around the mounting points from cracking? I've seen cracks in e28 and e24s in that area so I think it's probably a high stress area that probably I should leave alone.

[02tom]

Marshall, I was surprised that I couldn't quickly find a special tool to push the pistons out when I Googled the Wilwood rear calipers. The universal tool I rented from the auto parts store didn't have an attachment that fits and as you've noticed, there's no way to apply pressure to the piston with the face of the caliper not being of an open design. I had looked into all this because I thought it would be similar to the vw calipers that are more commonly used and when I was trying to install the pads, I was looking at them wrong and though the pistons needed to come out - until I figured it out and realized I didn't need the tool - yet.

I'm still gathering parts to run the line to the calipers. I'm thinking I'll attach a bracket - that I'll cut in half - from the front struts to hold the end of the last flexible hose to goes the caliper and attach it to the trailing arm. My calipers are different from the ones in the install pictures from Ireland because there's two bleeders that point down and the port for the line is on the opposite side if the piston. The line won't have to make a 180 degree loop and almost touch the wheel weights on the wheel. At least that's what I saw yesterday wheen I was looking at it, thinking about the next step.

[M3M3]

I use one of the bleed ports for the feed. The lowest one. The single port is the bleed on top. Yes, really sharp bend needed.

[02tom]

Thanks, I was wondering about that when I was writing - if the bleeders were interchangeable with the line port. That makes more sense to get a high point to get all the air out.

[02tom]

Real slow progress with the rear brakes because I wasn't thrilled with the idea of having the 180 degree brake line loop so close to the wheel, and not real sure about the line being ran on the underside of the trailing arm.  Found a M10x1.0 banjo bolt and M10x1.0/M10x1.0 banjo union from brakeconnect.com that seems to be a good fit.  I'm not 100% on whether the surface of the bleeder port is square and will allow the crush gaskets to seal, and unfortunately that's a long way off from testing.  I'm sure that they'll seat on the intended inlet port, but want bleeding the brakes to be as easy as possible.  I'm going to run another hard line on top of the trailing arm, and have enough slack in the flexible hose to allow removal of the caliper if everything goes as planned.

 

This is the only banjo union like this that I was able to find after days of searching:

http://www.brakeconnect.com/product/banjo-union-10mm-banjo-hole-to-10mm-port

 

22mm long banjo bolts:

http://www.brakeconnect.com/product/banjo-bolt-m10-x-1-0

Edited September 9, 2016 by 02tom

[02tom]

I noticed last night that the one end of the brake line didn't fit very well into the banjo union, which prompted additional research this morning.  The learning curve is pretty steep on all this but fortunately with all the snow in the area, things are pretty slow at the auto parts stores today.  I ended up finding that the banjo union has an standard flare, which is the opposite of the way I was thinking and the adapters showing an inverted flare would be.  I guess from what I've read so far, most Japanese makes use the m10x1.0 standard flare, vs. the european makes using the m10x1.0 bubble flare.  So after way too much time spent on line, I went to the local parts stores to try to gather together enough parts to utilized the banjo adapters.  Simpler solution would be to take one of my 8" lines with m10x1.0 bubble flare and remove one end and replace the fitting with the m10x1.0 standard flare end and then flare the line, but my experience with flaring lines has not been good; possibly due to poor quality tools at the time.  At any rate, this is the current direction I'm going with this:  using a AGS brass adapter BLF-29C with a adapter brake line PAA-0380 - 3/8"-24 to 10mm x 1.0 / standard flare to bubble flare.  This will add an extra 3/4 to 1 inch to the line, and I still may try to fit it to the bleeder most obscured by the parking brake mechanism. 

 

 

Edited September 9, 2016 by 02tom

[M3M3]

simpler solution is to just bend a hard line and delete the banjo fitting......

[02tom]

Lol, I know it's starting to look so overly complicated that I was thinking about posting a picture with 4 or 5 more adapters attached just to see if anyone was reading this. It would be perfect - in my way of thinking -in there were a banjo bolt with the female euro bubble flare connection to gain more room between the line and any potential wheel weights. It's looking more and more like I'm going to have to run the line under the trailing arm though, in order to be able to drop the caliper easily.

[M3M3]