Ray , the green plastic on the bush of the upper arm suggests that they are suited to something other than an M5 ........I've got a key to what colour plastic relates to which BMW somewhere , so I'll have to check ........ IIRC the greens are for the E32 750i .
Last Thursday, I started with the removal of the coating on the lower wheel arches to uncover the true extent of the corrosion. I will use the same procedure as member BMWWGN as described in post 68 of his blog on this board. After degreasing and cleaning of the metalwork, I treated the exposed metal with Caprotec RX5, which is a rust converter and primer.
In the mean-time, the new tie-rod end s and associated small material arrived as well.
As I experienced difficulty with the removal of the old tie-rod ends on the car, I removed both tie-rods and placed them on a bench, but even there with lots of WD40 applied and a few whacks from the claw-hammer onto the affected tie-rod ends, they wouldn’t move. A commonly used method is to heat them up, but as this is not allowed I have no other choice then placing an order for new tie-rods. Until they arrive, I can continue working on the front suspension.
I also started working on the left drive-shaft by removing the cover of its coupling joint. The plan is to replace the boots and replace the lubricant. This is no luxury as the 25-year old lubricant lost its viscosity and was concentrated in small clogs with no even distribution on the balls of the coupling joint anymore.
The next step is the removal of the driveshaft from the coupling joint after which I can clean the coupling joints themselves. Please note that it is not allowed the disassemble the joints in single parts.
Due to the work on the front suspension, there was little progress on the refurbishment of the differential until now. To apply a coating of RX5, the surface must be slightly corroded so blasting won’t be required, however there is lots of rust that needs to be removed first.
In order to remove that rust, I started with covering the case its openings for which I use simple carton-board.
To replace the boots of the driveshaft’s universal joints, one has to push out the driveshaft from both coupling joints. Basically, this is rather simple. It first starts with the removal of the cover. This cover is made from simple sheet metal, but is glued to the coupling joint with Curil K2; hence why some gentle force may be required from a screw driver and a hammer. With the cover removed, the universal joint is exposed.
The next step is to push the shaft from the U- joint, for which the cir-clip needs to be removed first. It is wise to remove most of the grease first in order to spot the opening in the cir-clip in between the depressor tool can be placed.
The next step is to remove the inner cover from the U-joint. Like the rear-cover, this one is sealed with curil so some force from a screwdriver and a hammer is required.
It is now possible to separate the shaft from the U-joint. Although the splines contain Loctite 270, this went easier than expected, but bear in mind that it is not allowed to disassemble the U-joint so be careful in here.
After the opening the clam that secures the boot to the shaft, the boot can be removed. Please note the absence of ample-grease in the boot; this is IMHO not normal.
The removal of the other U-joint is just the same. Please note the presence of an ample supply of grease that also hasn’t lost its viscosity. This is normal.
The next step is clean and label both U-joints and clean and mark the shaft so it is known what U-joint was placed on one side. The splines and the U-joints must be closely inspected for wear and damages. This requires a thorough clean with brake fluid/degreaser.
The splines appear to be in excellent condition. The paint could be more shiny, but I think that after another good clean, they will look much better; therefore I have decided not to repaint them.
Since I like a clean working environment, I replaced the newspaper with a new one.
Although I wrote in an earlier post that I didn’t want to paint the drive-shafts, I reversed that decision as on a closer inspection, the paint on the right drive-shaft has faded away more than the left driveshaft. After sanding away the existing layer of paint to flatten the surface, I sprayed three thin layers of ‘Innotec’ paint.
The paint requires some time to cure into a scratch free finish, after which the U-joints can be reinstalled with the OEM revision sets. These revision kit contain all the required parts for the re-installation of the U-joints, including the factory approved grease in the correct volume. The kit also contains a replacement for the original specified Curil-K2 for sealing the cover plates to the U-joint. Only the Loctite 270 that has to be applied to the splines is not supplied, but that can easily be sourced from a hardware store.
I gave the anchor plates a mild clean instead of re-spraying them. This would have required their removal which is not possible without pulling and thus destroying the bearings.
Originally I wanted just to replace the tie-rod ends to the tie-rod lever, but as it was impossible to remove the old ends without damaging the tie-rods, this is the better (albeit expensive) solution.
With new ball-joints and bushings all over the place, I expect nothing else then a significant improvement in handling, braking and steering.
The next picture will answer Davidoli’s question about the bushings of the thrust arms. Clearly visible is the Meyle inscription (see red arrow). With other words, these are not originated from the M70 powered E32. However, it is possible that Meyle got the same idea and just installs more rugged bushings then the OEM variant.
Last but not least, the first reassembled U-joint for the left driveshaft. I will describe the process in more detail later, but this is a real PTA job, but the result is promising.
During the past week, I found some time to work on #231; she is now standing in her own feet again. Some minor points remain such as tightening the steering-nuts to spec and the reinstallation of the stabilizer bar, but that is about it.
I also cleaned the lower wheel arches a little further by removing all the dirt to until the A-pillar after which I sand-blasted the narrow gaps. After a thorough clean I added the RX5 primer paints.
I allowed 48 hours of curing before applying the final coat of Silver POR15 paint. This matches the original 203 color very closely, but bear in mind
that there I have new liners to cover the gaping hole so no one will see.
With the front-suspension almost finished, I can focus fully on the drive-train for which I am considering to outsource the overhaul of the differential to a specialized company. This will not only speed-up the process, but will also allow a thorough investigation in the diff’s actual condition.
A quick survey on the www learnt that there aren’t that many specialists for differential overhaul in the Netherlands; to find some, I enquired at a few Dutch forum’s. The members of driving-fun and the BMW E21 network added five leads to the shortlist. One of the respondents actually works for one of these companies and already gave some interesting information about the longevity of the LSD.
Due too personal obligations in the past few weeks, progress on #231 isn’t what I expected it to be. The front suspension is almost complete; only the stabilizer bar needs to be installed. The differential however still is untouched and with the spring of 2011 already in ‘motion’, I do not want to wait much longer so I have decided to postpone the diff-rebuild to the winter of 2011/2012.
Revision of the driveshafts
This job isn’t really rocket science; but there are some things to consider, hence why I have documented the process below in a few single steps.
Nothing is so nasty as components that look aged; so when possible start with refurbishing individual parts. This costs a little bit more time, but the reward will be fresh looking parts.
Before starting the assembly process, it is essential to clean the splines at both end with for instance brake cleaner. This will remove contaminations sufficiently enough to Loctite 270 later in the process.
Be prepared to make your hands dirty and remove the old grease from the U-joints as far as possible. I also used brake-cleaner and degreasing solvent before checking them for play and movability. Please note that these U-joints cannot be bought separate parts, so treat them with care to avoid buying new driveshafts.
The revision set contains almost all the required parts for overhauling one U-joint. Only the earlier mentioned Loctite 270 is not included and has to be sourced separately.
After cleaning the shaft-ends, the new boot can be pushed over the shaft. Wait with the hose-clamp; to avoid losing it, this part has to be installed just before placing the second boot.
Add a small amount of Loctite 270 over the splines, but prevent spilling it as it may not be mixed with the Molycote grease to avoid damage to the U-joint.
The next step is the U-joint that has to be pushed over the splines until the seat for the spring-clip is visible. Push it in with for instance a 30mm socket when needed.
The spring-clip is part of the revision set and secures the position of the ‘U-joint’ on the driveshaft shaft.
With the ‘U-joint’ well seated in position, the U’-joint’ lubricant can be injected into the protective boot. It is not possible to inject all of the 120 grams, so save some for……
The ‘U-joint’ itself. Please note that the following picture also shows the liquid hylomar that seals the protective covers.
Last but not least, rotate the protective covers in a position that allows the bolt to move freely though each hole without resistance.
All this work results in a nicely refurbished driveshaft that not only looks well, but also functions a lot better.
During the past few weeks, I have exchanged Emails with Hardemann Motorsport for the overhaul of the differential. Based on the information exchanged, I am confident that they can rebuild my differential to my requirements and satisfaction. However, I have decided to postpone that until the next Winter season:
1: Hardemann Motorsport estimates that they need 20-30days before returning the LSD. 2: The delivery of the drive flanges with impulse sending wheel has been postponed by BMW without giving a new estimate.
Since the spring season of 2011 has already started, I do not want to wait any longer . With the 20-30 days of turnaround time for the LSD, it will be well into May before #231 is drivable. At least when the drive flanges are supplied and that is highly uncertain at the moment. Therefore, I have decided to put that issue in the fridge until BMW supplies the new drive flanges. Since that requires the removal of the driveshafts, I can combine the rebuild of the LSD . These issues have not been cancelled, but just postponed as it is better to drive #231 with a compromise then wait for perfection to achieve.
As I wrote in an earlier post, I have separated the overhaul of the differential into three phases (1) research, (2) requirements and specifications and (3) actual rebuild. In order to use #231, I have reassembled the differential using new seals for the output shafts and a new gasket set for the rear-cover. Since the pinion seal is dry and a real PITA to replace, I decided not to replace that one.
The new output shafts alone give the rear a complete fresh appearance, so I am quite happy with that. The differential itself can wait when the drive flanges with the ABS-tooth’s arrive. Originally these were confirmed for delivery in the fifth week of 2011, however BMW postponed their delivery for indefinite time. I just hope that BMW will supply them sometime this year.
The next step is to fill the differential with lubricant that is suitable for LSD’s with preloaded friction-clutches. Replacing this oil is essential for longevity of the differential as the friction plates do wear in time because of aging and usage. Depending on the type of usage, this should not be postponed beyond any second inspection II service as otherwise, the diff will be lubed in its own dirt, which will result in premature wear of the internal bearings, especially the pinion bearing.
I have decided for the 75W140 viscosity rated Castrol SAX-XJ, which is BMW approved for LSD- differentials with preloaded friction-plates. Given its hefty price-tag, it almost is a waste for using one just one season, but things are what they are.
Filling the diff is rather straightforward and easy and can be done without making a mess.
After the last checks, #231 was submitted to the annual Dutch safety inspection for which an emission test is mandatory. Although the CO limit for #231 is such that it will pass it nonetheless, the four-gas (CO, CO2, hc and O2) test-results give valuable information about the health of the engine. Although it was subject to a full rebuild some time ago and I expected nothing was wrong, analyzing the emission results gives an early warning . The next picture shows the operating AFR as a function of time. The samples were taken with a digital camera and the time tag’s derived from the EXIF information. The samples are equidistant within one second, not bad.
I have similar graphs of the other parameters and confirmed that #231’s combustion is about the same as in May 2010. This confirms the stability of the petrol-injection and ignition. The above graph prooves that the engine operates at a rich mixture.
The last step is a full alignment of the front-suspension, but that cannot be done before the sixth of May as capable shops have a busy agenda and are always fully booked. Now that my winter project is completed, I will continue to update upcoming experiences in this thread.
Thanks for the update Raymond - looks like she's all set to go again.
My local BMW dealer also used the Castrol SAF-XJ fluid in my M5's diff during the recent Inspection II - it's "the good oil", as they say.
Enjoy the summer driving.
I assume you're still planning the trip down to the Mille Miglia?