The Randy Forbes

I titled this post “The” Randy Forbes because Randy is so well known in the Z3 and M coupe community.  Randy has become famous for his rear subframe reinforcement design and installations, as well as his connecting rod bearing services.  I have been planning on taking my S54 to Randy for nearly 10 years.  Finally the stars aligned, and I made that happen in October of 2016.  For the S54, I had Randy perform 3 major services, none of which I am comfortable doing myself.

The first is rear subframe reinforcement.  In addition to the ~12 pounds of additional steel and numerous additional welds, I asked Randy to replace the rear subframe bushings with Ireland Engineering units, replace the differential cover bushing (with a new stock BMW unit), the rear trailing arm bushings, and the rear sway bar links and rubber mounts.

The second service Randy did for me was to replace the connecting rod bearings.  Randy recommends the later bearings that were designed and released as part of the E46 M3 service action.  These are different dimensions than the original M coupe / roadster S54 bearings.  Randy also applies a custom treatment on the bearings he installs for additional protection and more performance.

The last service I had Randy do was completely rebuild the VANOS unit on the car with all of the Beisan upgrade parts.  This includes the oil pump disk, all new seals, and upgraded S62 sprocket hub diaphrams.  All of the sprocket sleeve bolts were replaced and Locktite’d in place.  I don't think this service was necessary for the MZ3 S54 engine, but I didn't want to do this service myself so I "might as well".  Failures are pretty common on MZ4 S54s, and we are doing the same service with Randy on Rachel's car.  So, why not do 2 of them for twice the price?  LOL.

I will add one story of coupe magic.

After I dropped off the car, Randy sent me a video - and he was quite worried - because the speedometer in the car was not working.  "Worked fine when I left it" was my response.  "$1100 part plus coding" was what I was thinking.  Randy did some trouble shooting and eventually after a lot of trials and effort got it to work again with a diagnostic test.  Upon re-delivery of the car, it didn't work the first time I drove it.   I re-started the engine one time, and it worked fine.  It worked fine all the way home and has been fine ever since.  It is my perception that this is either (a) the car being pissed at me for having to go to Randy's and be in a foreign garage for ~8 weeks (highly likely) or (b) cracked solder somewhere inside the instrument panel which is apparently common in some E36s (no way it is that).  Hint: there is some sarcasm here, but I'd like to believe (a).

I will include the parts lists I used, and I am copying some of Randy’s pictures here so I have a record of them.  I did print every picture Randy took during the services (over 500 photos) and I made a photo album for the car's records.  The complete album of photos is here.

When you add all the work up, not including the cost of the parts, this was over $4000 of investment in my S54 M coupe.  Worth it, I think as I can retire a lot of risk and worry now.  I already took Rachel's S54 MZ4 Coupe (yes, capital "C" since it is a Z4, I have already blogged about that) to Randy for work.  My plan is to take the S52 coupenut car and also my E90 M3 to him as well, one after another.

Biesan anti-rattle.  Also used S62 diaphrams based on Raj's recommendation and also all new upgraded seals and o-rings.

Biesan oil pump disk

New bearings from the last E46M3 service action fix, with coating

Clean oil pan

Doubling up the factory differential ear mount

Factory steel removed

Added I-beam in place

All boxed in.

I went with a single differential ear.

Paint looks like the factory did it.

All back together

Rear Subframe Parts

Subframe bushings	Ireland Engineering	1 set
Subframe nuts	33331126136	2
Diff ear sheet metal x2	41118398664	2
Diff ear bushing	33172228425	1
Diff ear self locking nut	07129900047	1
Trailing Arm Bushing Set, Lemforder, FCP Euro	33329061945	2
Trailing Arm Self Locking Hex Nut	07129900047	4
Driveshaft locknuts	26111227843	4
Rear sway bar mounting bushings, set, BMW	33552228368	2
Rear sway bar link, Lemforder, FCP Euro, comes with nuts and bolts,	33551131131	2
Rear sway bar mounting bushing self locking nuts	07119905374	4

Connecting Rod Bearing Parts

Bearing shell blue (0)	11247835440	6
Bearing shell red (0)	11247835439	6
Oil pan gasket	11131437237	1
Oil dipstick o-ring	11431707164	1
Gasket	11137832023	1
Motor mounts	11812283798	2
Motor Mount Nuts	22116779973	4
Subframe bolts	31116781023	4
Oil pump o-ring	11411401769	1
Castrol 10W60		7
New oil drain plug
-769 Oil Filter Kit		1

VANOS Parts

Biesan S54 Vanos Seals Repair Kit BS021	BS021	1
Biesan S54 Vanos Rattle Repair Kit BS022	BS022	1
Biesan S54 Vanos Oil Pump Disk BS025	BS025	1
Biesan: Vanos gasket	11367831938	1
Biesan: valve cover grommet	11121437395	2
Biesan: oil drain hose crush washer	07119963129	2
Biesan: vanos oil accumulator pipe crush washer	07119963072	2
Biesan: vanos oil filter	11361401971	1
Biesan: S62 sprocket hub diaphragm spring and pressure plate	11367833218	2
Biesan: sprocket sleeve bolts	07129905536	12
Biesan: exhaust upper chain tensioner guide	11317830159	1
Biesan: Chain guide mounting bolt washer	07119963342	1
Biesan: Crankshaft chain tensioner washer	07119963418	1
Valve cover gasket	11127832034	1
Valve cover bolt seal	11127830972	13
Drei Bond