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Date:         Thu, 12 Jul 2001 20:17:47 -0700
Reply-To:     Rennie Wible <volksdragon@EARTHLINK.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Rennie Wible <volksdragon@EARTHLINK.NET>
Subject:      Re: [Syncro] Re: How To Install Your New VC
Comments: To: sxs@concentric.net
Comments: cc: "syncro@egroups.com" <Syncro@yahoogroups.com>
Content-Type: text/plain; charset=us-ascii

The bolts are 8mm x 1.0 x 25mm N 010 102 3 $2.45 ea dealer list The nuts are 8mm x 1.0 self locking N 022 152 1 $0.67 ea dealer list

Rennie Peyton Cramer VW

sxs@concentric.net wrote: > > At steps 7-9 it might be noted that it is a little > tricky removing the casing to get to the VC. It can > hang up on the Diff. mount bar, the one in a "U" shape, > and I had to remove that bar to get it off and out of > the way. > > Any one have the part numbers handy for the drive shaft > nuts that must be replaced? > > I will be upgrading the syncro.org site soon and will > restore the photos for the VC change. The site where i > had the photos stored went under. Peter dug them up > for me and I can send them out till the site is fixed > again. Maybe I can use this description on the site? > > Steve > > Derek Drew wrote: > > > > OK Brian. You are one of many people asking me for a > > definitive guide to replacing your VC. So for the > > benefit of the archives, here goes the best most > > current version of these instructions. No special > > tools or automotive experience are needed for this > > job, and because it is so simple, it should not be > > farmed out to a transmission shop. The best thing I > > could say, going from memory, is to.... > > > > 1. Drive van up on 4 ramps > > 2. Put jackstands under van in case ramps fail > > 3. Record and mark the alignment of the driveshaft to > > the front differential so that you can put the same > > bolt through the same holes of each unit upon > > reassembly. This will reduce the chances of your > > ending up with an out of balance driveshaft on > > reassembly. > > 3. Unbolt the four forward bolts holding the > > driveshaft on with either a 1/2 inch or 13mm open end > > wrench and some liquid wrench. If the 13mm wrench > > doesn't work that great, try the 1/2 inch open end > > wrench. > > 4. Loosen the bolts holding the front differential so > > that differential may be shifted around. > > 5. Shift the front diff forward so that the > > driveshaft will fall away from the front diff. Shift > > that driveshaft out of the way. > > 6. Remove the oil from the front diff through the oil > > drain hole. Throw that oil away by bringing it to > > your nearest auto repair shop for disposal. > > 7. Remove the 13ish? 13?mm bolts holding the back > > half of the front differential onto the vehicle and > > then pop the rear third of the differential off > > backwards. Do not looosen the big bolt at the > > rearmost point in the front differential > > 8. Have something on the ground to catch the residual > > oil that will spill out. > > 9. Pull the VC out and replace, being careful to > > reinstall the little metal washer that is wedged in > > there. No special tools or measurements of any kind > > are needed. > > 10. Bolt everything back together, but bolt the front > > differential down last after shifting it around to > > properly seat it in relation to the rear > > transmission. When bolting the driveshaft back on, > > either replace the 4 driveshaft nuts with factory new > > ones the way VW says to do it (proper way), or just > > use Red Loctite the way about half the people on the > > list do it (universal list method) or reuse the > > original nuts with no loctitie the way the other half > > does it (pogo stick method; see below). > > 11. Refill the front differential with GL-5 > > Transmission oil using the factory specified > > viscocity. Mobil 1 makes a good GL-5 for the front > > diff. (Make sure not to use GL-5 in the rear > > transmission, however, as that takes only > > GL-4--eveybody wisely uses Redline GL-4 synthetic for > > the rear.) > > 12. The entire job should take you about 1 hour. But > > for some reason --I cannot predict in advance why -- > > it will actually take you 5 hours :-). Some members > > have reported broken bolts holding the diff in place, > > or broken rubber mounts, so be prepared to hunt these > > parts down if you decide you need to replace them. > > 13. Some people decide to remove the diff entirely to > > do this job. You can do that, but that means you have > > to disconnect the front CV joints, which is a pain. > > Still, those front CV joints probably need their > > grease to be renewed anyway. And as long as you are > > regreasing the inner front cv joints, you might as > > well do the outers too, and inspect the boots, and > > then why not the rears and HEY lets not loose focus > > here... > > 14. The best description on how to change your VC was > > originally posted to the list by Rainer about three > > years ago, but Steve Schwenks photo essay matched > > this post in utility and interest. Too bad it is not > > on syncro.org right now. I will copy Ranier's post > > below. > > ABOUT THE POGO STICK METHOD. > > This is actually a method of easily removing the > > transmission and engine from the vehicle. > > Essentially, the procedure is to skip using loctite > > on the nuts that hold the driveshaft on the front > > diff, and don't replace those nuts with new nuts > > either. Just reuse your old nuts even though the > > factory says to replace them. When the nuts or bolts > > eventually fail, the driveshaft will drop down on the > > highway and get lodged on a rock, crack, or other > > obstacle and remove your trannsmission and engine in > > about two seconds. This also works in the event of a > > front U-joint failure. If this does not appeal to > > you, install a strap that holds up the front > > driveshaft in the event its front attachment point > > fails. I haven't put my strap in yet myself, but I > > think about it from time to time. > > > > >> There is an excellent article by Steve on how to > > >> replace the VC at www.syncro.org in the Tech > > >> section called "Replacing the VC (photos): > > > > > > > Reproduced below is Rainer's version of the above. It > > differs from my version in some important respects so > > it pays to read both posts. Note that Rainer is one > > of the world's leading observers of the Syncro > > Viscous Coupling, and is of much higher intellect > > than the average Vanagon or Syncro poster so we are > > lucky to have him among us. > > > > > VW's original (German) repair manual doesn't say > > > much about how to test > > > the viscous coupling. They only recommend placing > > > the rear wheels in a > > > break testing stand. If you then switch to the > > > G-gear (creeping gear), > > > the front wheels should move the van out of the > > > test stand as soon as > > > the engine is revving slightly above idle. If the > > > front wheels fail to > > > do so the viscous coupling is to be replaced, VW > > > says. VW adds another > > > tiny sentence to this, saying that only when the > > > engine is revving at > > > idle and with the G-gear switched in, the viscous > > > coupling is able to > > > absorb all the torque to the front wheels and keep > > > them from moving. > > > > > > To me this last and rather ill-formulated (in > > > the German manual) > > > sentence is the key to testing the viscous > > > coupling. For in most cases > > > we are not dealing with viscous couplings doing > > > less than their share, > > > but rather with hard-going viscous couplings which > > > don't have a problem > > > at all in moving the van out of the test stand > > > with the engine just > > > idling. > > > > > > Thus the really important thing here is not the van > > > successfully leaving > > > the test stand. On the contrary, the important > > > thing here is the van > > > not moving and staying put in the test stand with > > > the G-gear switched in > > > and the engine just idling. If your Syncro > > > doesn't pass this test your > > > viscous coupling is probably worn out and ready > > > for a replacement. Or > > > put the other way round: as long as your van's > > > viscous coupling is > > > working properly you will not notice your van has > > > got one. > > > > > > As soon as you are encountering problems > > > with your Syncro when > > > cornering, in particular after a long and fast > > > drive, or as soon as -- > > > despite of power steering -- steering becomes > > > a bit difficult when > > > turning and the Syncro slows down considerably when > > > going round a corner > > > ... as soon as one or more of these things are > > > happening, your viscous > > > coupling is most probably due for replacement. > > > When the tires start > > > whining while cornering it might well be too late > > > already ... > > > > > > I once had all of these symptoms and it was > > > immediately clear to me that > > > the viscous coupling was the culprit. But it > > > took some time for me to > > > react, and it took some more time for the new > > > viscous coupling to arrive > > > at my door. Should you ever encounter similar > > > problems I would urge you > > > to immediately get under your van and remove > > > the drive shaft between > > > gearbox and front diff. If you fail to do > > > this and wait too long, > > > severe damage to the gearbox and/or front diff is > > > the probable result. > > > Removing the drive shaft is pretty straight > > > forward, just four bolts and > > > nuts (13 mm) on either end of the drive > > > shaft. Then loosen (just > > > loosen, don't remove them) the three nuts and > > > bolts (17 mm) which hold > > > the front diff in place, so the front diff can move > > > out of the way a bit > > > for the drive shaft to be removable. Don't forget > > > to again tighten the > > > 17 mm screws. > > > > > > When I was shopping for a new viscous > > > coupling (according to all > > > reliable sources I contacted they cannot be > > > repaired) I asked several > > > knowledgable people how long a viscous coupling > > > is expected to last. > > > Apart from "it depends" (an employee at > > > Steyr-Daimler-Puch in Austria, > > > the firm which was producing the Syncros and in > > > particular the viscous > > > couplings for VW) the answers ranged from "some > > > 60,000 km" to "between > > > 170,000 and 200,000 km". Mine was replaced > > > after 150,000 km but I > > > bought the Syncro with 80,000 km on the tach and > > > don't know for sure > > > whether or not this was still the first > > > viscous coupling. But I'm > > > assuming it was. > > > > > > As for the reason why the silicone in the > > > viscous coupling gets too > > > stiff and starts causing trouble the people > > > I asked unanimously > > > answered: to much strain. However, this is not > > > referring to relentless > > > off road driving in groundless mud, but rather > > > to small but permanent > > > differences in rotational speed between front and > > > rear axle while doing > > > normal on road driving. These differences in > > > rotational speed can be > > > caused by such things as unequal tire wear or > > > different tire pressure. > > > Tire diameters should be the same within a 2 to 4 > > > mm tolerance. Or, in > > > other words, if you're measuring the depths of > > > the grooves in your > > > tires, the differences should not exceed 1 to 2 mm. > > > > > > Thus people not caring tire pressure and tire > > > wear, people having > > > mounted different tire brands on the front and > > > rear axles, as well as > > > people never routinely using their spare tire so > > > it gets worn roughly > > > the same way as the other tires are most probably > > > ruining their viscous > > > coupling pretty fast. > > > > > > Removing the drive shaft as an emergency measure: > > > If you have to, and provided you're slim > > > enough, you can remove the > > > drive shaft on the bare ground (at least if > > > it's a Syncro 16"), just > > > with a little help of the factory jack. In case > > > your driveshaft was > > > balanced in its current position, it may be a > > > good idea to mark the > > > alignment points of the flanges before removal. > > > Then you'll have to use > > > a pair of 13mm wrenches (due to space constraints > > > only open wrenches are > > > usable) to remove four bolts and nuts at either > > > end of the drive shaft > > > (sometimes the nuts are only 12mm). If you > > > want to do it properly > > > you'll also have to loosen (only loosen, don't > > > remove!) the three nuts > > > and bolts (17 mm) which hold the front diff in > > > place via rubber stops, > > > so the front diff can move out of the way a bit > > > for the drive shaft to > > > be removable. However, when lying on the bare > > > ground just below the van > > > this might be hard to do. If your drive shaft > > > has got this rubber > > > element in it you may try to simply use a screw > > > driver to cautiously > > > separate the two flanges at one end of the drive > > > shaft. Knocking gently > > > at the flanges at the other end will then take the > > > drive shaft down. As > > > to the rubber element: in diesel engined and FI > > > vans the rubber element > > > was facing opposite sides. Thus you'd better > > > take some notes as to > > > whether the rubber element is at the gearbox end > > > or at the front diff > > > end. > > > > > > Replacing the viscous coupling: > > > To replace the viscous coupling you'll have > > > to pull the front > > > differential first. I don't think it's feasible > > > to replace the viscous > > > coupling right under the van with the front > > > differential in place. > > > > Derek's Note: > > Californians on the list proved otherwise so if you > > want to leave the diff in there go ahead. Sam Walters > > did it on the ground, but he indicated it was a pain. > > > > > In > > > particular, reassembly would thus be much more > > > difficult and would cause > > > plenty of cursing. And you'd have to drain the oil > > > first. By and large > > > there is no witchcraft involved in pulling the > > > front diff, but you > > > should do it with the van on a lifting platform > > > or above a grease-pit. > > > And it takes two people as well as a floor-jack. > > > > > > First of all losen but don't yet remove the > > > three 17mm nuts already > > > mentioned which hold the front diff in place. > > > Then remove the speedo > > > cable as well as the six screws in each of the > > > inner CV-joints. For > > > this screws you'll need either a 6mm hexagonal > > > or an 8mm multipoint > > > socket. If you haven't done it yet you should > > > now remove the drive > > > shaft as described above. If you have a > > > front diff lock (never > > > officially exported to the US) unplug it > > > electrically as well as > > > pneumatically (tag the pipes so you can't > > > confuse them later). Now > > > remove the screw holding the vent pipe of the > > > differential and then > > > remove the three 17mm nuts and bolts holding the > > > front diff. Get the > > > floor-jack in place and remove the front and > > > rear mounting brackets. > > > Then together with a second person cautiously > > > move the diff forward > > > along the skid plate and out. Look out for the > > > diff lock if there is > > > one. > > > > > > Place the front diff on your workbench in such a > > > way that the flange for > > > the drive shaft is facing upwards. You can now > > > easily remove the ten > > > 13mm bolts with which the housing of the viscous > > > coupling is attached to > > > the front diff without risking any oil leaking. > > > Lift the housing which > > > is containing the input shaft. You will now see > > > the viscous coupling > > > itself and a little spacing collar sitting on > > > top of it. Take this > > > spacing collar, grease the top rim of it and again > > > place it on the input > > > shaft in the housing and slightly press it with > > > its greased rim against > > > the bearing so it will stay there. This will > > > greatly ease reassembling > > > the diff later. Now remove the old viscous > > > coupling and put in the new > > > one. Then apply silicone sealing compound to the > > > contact flange of the > > > housing and, inserting the input shaft into the > > > viscous coupling, put > > > the housing back in place. Finally, gently > > > tighten the ten 13mm bolts > > > crosswise, applying 20 Nm (15 ft lb.), and your > > > front diff is ready to > > > be reinstalled. > > > > > > Perhaps you should use the opportunity while the > > > diff is still sitting > > > on your workbench to check what has been caught > > > by the magnet at the > > > oil drain plug. > > > > > > To reinstall the front diff in the van simply > > > reverse the steps laid out > > > above, at the very last fastening the screws > > > of the front and rear > > > mounting brackets as well as the three 17mm > > > bolts through the rubber > > > stops (apply 45 Nm (33 ft lb.) to these). > > > > > > Tools and torques needed: > > > > > > Installation of the front diff: > > > 17mm socket and ratchet, perhaps with > > > extension. Use 17mm wrench to > > > counter at the other side, 45 Nm (33 ft lb.) > > > VC housing: > > > 13mm socket with extension and ratchet, 20 Nm > > > (15 ft lb.) > > > CV-joints: > > > either 6mm hexagonal or 8mm multipoint > > > socket with extension and > > > ratchet, 35 Nm (26 ft lb.) > > > Drive shaft: > > > Two open 13mm wrenches (sometimes only 12mm for > > > the nuts), 35 Nm (26 > > > ft lb.) > > > Acknowledgements: > > > Special thanks go to Wolfgang Carolsfeld in Canada > > > <wolfgang@island.net> > > > who not only proofread this text, helped me with > > > some technical English > > > terms I failed to find in my dictionary, and did > > > the math involved in > > > converting the torques from Nm to ft lb, but > > > who also successfully > > > applied the underlying German version of this text > > > to his Syncro to make > > > sure it works :-) > > > ------------------ > > > --------------------------------------------------- > > > | Rainer M Woitok | Phone: > > > (+49-9131) 85-27811,-27031 | > > > | Regionales Rechenzentrum > > > | | > > > | Friedrich-Alexander-Universitaet | Fax : > > > (+49-9131) 30 29 41 | > > > | Martens-Strasse 1 | Telex: d 629 > > > 755 tf erl | > > > | D-91058 Erlangen > > > | | > > > | Germany | Mail: > > > Woitok@RRZE.Uni-Erlangen.DE | > > > -------------------------- > > > ------------------------------------------- > > If you would like to modify your subscription settings (including unsubscribing), visit: > http://groups.yahoo.com/group/Syncro > Please remember that rude or offensive language is not allowed on the Syncro list. Please try your best to resolve differences privately and keep them off the list. > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/


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