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funagon Samba Member
Joined: March 09, 2006 Posts: 1308 Location: SLC, UT
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Posted: Thu Jan 17, 2008 4:46 pm Post subject: Rebuild syncro driveshaft for $45 |
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last summer I bought a $200 syncro with the driveshaft laying in the back seat. Van looked like hell. Owner said the trans was broken and engine might not work. Turned out to only have a broken CV joint. Good trans, good engine, good locking diff, good VC. YEE-HAW! I gave it to my buddy instead of paying him rent (living at his place) and he's really happy with the van. Here's what it looked like on the day we discovered it sitting in an empty lot:
With the onset of winter we decided to rebuild the driveshaft ourselves. There are more expensive alternatives but we chose to first do a $45 experiment, rebuilding with u-joint NAPA part #2500070. (supercedes NAPA part #813.) 2 joints required, about $20 each. The results have been quite satisfactory. If you want to try here's what I did. Not too complicated, but maybe my description will help you decide what to do with your worn-out syncro driveshaft.
Removing the old u-joints: Remove c-clips. Drive out the old bearings by placing a small (17mm?) socket on top, and a much larger socket on the bottom for the lower bearing to exit. Your socket may be damaged when you beat on it, but a new driveshaft from VW costs $1000 so you decide if you like this method. The bearings don't come all the way out but they do come far enough that you can remove the u-joint. Then pound the bearing the rest of the way out from the inside.
The old syncro u-joint with two bearings still stuck in place.
New NAPA joint, including bearings, two kinds of c-clips, and grease fittings that won't fit the space in the Syncro driveshaft. (The hole in the middle is for the grease fitting.)
Clean the rust and crud out of the joint where the new bearings will go. Grease everything. I filled the new u-joint with grease, then greased the bearings inside and out. They have needle bearings inside that can fall out so work carefully. The new bearing housing has a tapered end so you can pound it in from the outside of the hole (in the same direction the silver socket is going in, three photos above).
Put the bearing in place, then place the 4-way joint inside the bearing (where it will be when you are done) and hold it in place while pounding the bearing in. This is to prevent the needle bearings from falling out while you hammer on the bearing cap.
When the bearing cap is flush with the hole you'll need to use the socket to pound it down past the c-clip groove. Then install c-clip. Then install a bearing on opposing side and pound it in. Shift the 4-way joint (which is between the bearings now) so that it is inside the bearing that you are driving in, to ensure that the needle bearings don't fall out.
These are a tight fit and at first I thought they would not go in far enough to get the c-clip in. Never fear, you need to hit them hard. Put a block of wood underneath.
Here’s the installation halfway done. When I got to this stage I injected grease into the body, cleaned the hole, then filled in the hole with silicone engine sealant (that's the blob of grey in the center of the joint). I made it a “sealed unit” since the grease fitting doesn't fit in the driveshaft joint. Should be good for a long time with quality grease in there. This photo shows bearings installed on two sides, but no bearings on the "open" ends of the joint.
Pound in the other bearings the same way. After the joint is assembled it is really stiff. So stiff that I worried they might be the wrong size joints/bearings from NAPA. My fear was unfounded. I tapped on the bearings to work them in a little, worked the joint back and forth, and they loosened up just enough to satisfy me. If you do this job remember that a 4WD driveline shop uses a strong hydraulic press to remove and install these. And after installation they’re not supposed to be “loosey-goosey,” they have to transmit the torque from the engine up to the front wheels.
Ready to install. And here's a close up shot:
I installed the driveshaft and discovered that the viscous coupling in this van works great. No binding in turns, not agressive at all. But if the back wheels are in snow and start to slip the front wheels pull the van confidently. Van has 130k miles so I wonder if a previous owner replaced the VC with a new unit?
There is a very slight, barely perceptible vibration from the shaft around 35-40 mph. I've been warned and read about the dreaded syncro driveshaft vibration. But the slight vibration felt in this van makes no noise, and can hardly be felt unless paying close attention. I'll keep monitoring it to see if it gets worse -- but it's really not an issue. (I wouldn't have noticed any vibration if I hadn't been warned, and scared, and vigiliantly expecting it.)
This thing is so fun. Driving up to the ski resorts there's no worry about when to switch to 4WD. The front wheels engage automatically when needed to pull the vehicle forward before it loses traction. A huge difference from my 2wd vanagon and a great winter snow vehicle. Even if I rev it up and dump the clutch the back end won't swing around wildly like in a 2wd van. Instead the front wheels pick up and pull the van forward. (And I can peel out with all four wheels spinning and spitting up snow. But I don't drive it like that . . . Honest!)
Would I recommend this fix? I've heard of people who tried this only to have excess vibration in the drivetrain. Lucas at Gowesty thinks the excessive vibration is caused not by worn u-joints, but instead by a non-serviceable, worn bearing and shaft that's under the rubber donut. Other folks have proposed that vibration is caused by an imbalanced shaft, or by misalignment of the front and rear diffs. But for $40 and a few hours work I thought this was worth a try and it worked out really well. Not too hard other than kneeling on the pavement and hitting things with a hammer. If you're willing to risk $40 and a few hours labor it seems worthwhile to me.
Last edited by funagon on Thu Jan 17, 2008 8:43 pm; edited 1 time in total |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50352
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Posted: Thu Jan 17, 2008 5:37 pm Post subject: |
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Just have to love the claim in the Bentley that the joints can't be replaced using normal shop tools. It is this kind of bull that has caused VW to lose tens of thousands of repeat sales. |
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Tristar Eric Samba Member
Joined: July 25, 2004 Posts: 1242 Location: Portland, Or
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Lanval Samba Member
Joined: June 09, 2007 Posts: 905
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Posted: Fri Jan 18, 2008 1:10 pm Post subject: |
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Rat Van, Baby! I love it!! Home brew is the best... nice work. Very nice work indeed.
Best,
Lanval |
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getset Samba Member
Joined: March 07, 2005 Posts: 437 Location: PNW | OLY
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Posted: Mon Mar 10, 2008 3:23 pm Post subject: |
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Hello funagon,
I was hoping to get an update on the driveshaft repair you posted last March. I started having the most violent vibrations in my van, and when I returned home I removed my driveshaft to find the u-joint in shards. how has your repair held up over the past year? did those u-joints suffice. Thanks
J--- |
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funagon Samba Member
Joined: March 09, 2006 Posts: 1308 Location: SLC, UT
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Posted: Mon Mar 10, 2008 4:58 pm Post subject: |
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The driveshaft is holding up just fine! It still has the same very slight vibration that I described, but it hasn't gotten any worse since the day I put it in. The van has been driven almost every day.
The repair isn't a year old yet. I did this in the Fall of '07, before it snowed in SLC, so it's been about seven months.
When we got the van the driveshaft was in the back seat so I don't know whether it vibrated, or how much it vibrated, before the repair. This was an experiment with a sample size of 1. In other words, it worked for me but I can't guarantee it would work on your driveshaft. The NAPA joints I listed are the correct part, though. I'm not the first person to use them, I got the info from the "other" vanagon mailing list.
After this repair I tried to balance the driveshaft by putting a big hoseclamp on one end of the shaft, near the original weight. The idea was to leave the hose clamp just loose enough to rotate to a point of balance while spinning, but just snug enough that it would stay put where it comes to rest. After a few tries at getting the clamp "tight enough" but "not too tight," I went for a drive with no vibration whatsoever. I thought I was a genius. But then after tightening the clamp down in this supposedly good position, the vibration immediately returned (I suspect the clamp slid out of place before I tightened it). This homebrew method of balancing might work, but the vibration in this van is so slight that I said "so what" and stopped worrying about it.
I just re-read my original wordy post describing the job. You probably don't need my confusing instructions. I could have wrote one sentence: "beat the old bearings out, clean it up, beat the new ones in." _________________ 1990 GL 7-passenger
2.2 liter WBX |
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msinabottle Samba Member
Joined: September 20, 2005 Posts: 3492 Location: Denver Area, Colorado
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Posted: Mon Mar 10, 2008 9:59 pm Post subject: Funagon's Hymn... |
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Halleluja, Praise the Lord!
Another van is saved!
Halleluja, Praise the Lord!
Another van is saved!
And this one is Syncro!
It don't care if the road's paved!
Another van in from the cold
Back to utility!
Halleluja, Praise the Lord!
And ingenuity!
Oh no. I've let that Poet Laureate thing go to my head.
Best! _________________ 'Winston,' '84 1.9 WBX Westy
Vanagon Poet Laureate: "I have suffered in
many ways, but never, never, never in silence." |
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getset Samba Member
Joined: March 07, 2005 Posts: 437 Location: PNW | OLY
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Posted: Tue Mar 11, 2008 2:10 pm Post subject: |
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Thanks!
I have done ujoints before, so I should be able to handle this without any problems. Hopefully It won't need much balancing. |
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foulplay Samba Member
Joined: March 17, 2007 Posts: 9 Location: Farmington, NM
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Posted: Wed Sep 24, 2008 5:28 am Post subject: |
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If you try this repair you might want to take the old u-joint with you so they can measure it and get you the right one. I didnt do that and when I got the parts the new u-joint was narrower than the old one. The guy at the d-line shop told me someone had already done some work on that driveline, so I am not sure if my d-line is stock. To replace the u-joints at the shop is only going to cost me about $60! Not including the parts, so I figured why not pay the pros to do it right and not risk damaging the new parts. The shop will also spin the shaft after the repair to make sure it is balanced. I will update you after I get the shaft back and install it. |
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funagon Samba Member
Joined: March 09, 2006 Posts: 1308 Location: SLC, UT
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Posted: Wed Sep 24, 2008 7:24 am Post subject: |
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I would also let a shop do it for $60. The shop here said they can't do it because the driveshaft won't fit on their equipment, so they can't spin/balance. Hence the homebrew method.
Update: while doing a Bostig conversion on this van an inspection of the driveshaft showed one joint sticking and moving poorly. I beat in another u-joint and now there's no vibration. Hallelujah. _________________ 1990 GL 7-passenger
2.2 liter WBX |
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tencentlife Samba Member
Joined: May 02, 2006 Posts: 10078 Location: Abiquiu, NM, USA
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Posted: Wed Sep 24, 2008 8:23 am Post subject: |
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I have a Syncro driveshaft that has already had the U-joints replaced by someone. I bought it this way and haven't driven it yet, but I was told it has that same characteristic 45mph vibration. Going to have to wait 'til I have a new engine in it and so on before I know. But my machinist knows about a Chevy driveshaft that is a direct fit for the Syncro shaft, brand new at only $450, vs. $700 for rebuilts and $1100 for new VW shafts. The Chevy shaft doesn't have a Guibo disc, just a splined sliding joint in the middle. So, we'll see how this one does, and whether the reported vibe is the shaft or something else, but if it is a problem I may just spring for the new shaft, which is of a more "normal" construction and easier to rebuild and service.
I've replaced more U-joint spiders than I could ever count. It's pretty straightforward, much easier if you have either a press or a large enough vise to squeeze everything together with. One warning about doing it with hammers and sockets: you do need to be careful about the bearing cups. They are usually a brittle cast metal, and it's pretty easy to crack one if you strike it the wrong way. Make sure whatever socket or pipe you use as a drift is pressed flat against the backside of the cup when you strike it. Hitting in the center of the back face is the surest way to crack it there, so use a socket or piece of pipe that is close to the OD so the force is borne by the wall of it. _________________ Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/
Please don't PM here, I will not reply.
Experience is kryptonite to doctrine. |
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Zero419 Samba Member
Joined: January 11, 2008 Posts: 2160 Location: PA
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Posted: Wed Sep 24, 2008 9:13 am Post subject: |
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This is the way my dad taught me to do it 15 years ago, except to use a vice to put it back together. To take it apart I put one half of the shaft in a vice and bang on the other one with a big hammer until the cups pop out. I never broke anything yet doing it this way, of course I've only done 10 or so. _________________ 1987 Westy Auto Bostig 2.0 Ztec |
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Sodo Samba Member
Joined: July 06, 2007 Posts: 9618 Location: Western WA
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Posted: Thu Sep 25, 2008 9:08 am Post subject: |
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This is an excellent post, thank you all! _________________
'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb |
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TopBud Samba Member
Joined: February 28, 2004 Posts: 1111 Location: Flagstaff AZ
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Posted: Tue Dec 28, 2010 11:36 pm Post subject: |
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I just did this today and it went really smooth. I drove it around and no vibrations like the old U joints. Two things worth updating. The price of the U joints from NAPA went up. $35 a piece, $70ish for the two. The supplied czirks wouldn't fit (as noted) so I ended up using a set screw http://www.google.com/imgres?imgurl=http://www.air...CC8Q9QEwAw
Thanks for this post. It works well. _________________ 86 bostig SYNCRO
66 convertible Karmann Ghia |
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syncrodoka Samba Member
Joined: December 27, 2005 Posts: 12008 Location: Santa Cruz, CA
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Posted: Tue Dec 28, 2010 11:42 pm Post subject: |
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...still a super cheap driveshaft rebuild price. |
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Syncroincity Samba Member
Joined: April 15, 2007 Posts: 1557 Location: New York City
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Posted: Wed Dec 29, 2010 1:18 am Post subject: |
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Replace the rubber donut too, if you need to, it's a BMW part...
BMW manual transmission disk from 1970 to 1980 will also work Part Number 26111106113 (~$40)
Nice write-up. I did this when I first got my van back in '01 but the vibes never went away, I think my inner axle was shot. Ended up getting a slip-joint shaft made locally. The shaft was cheap, the machined adaptors are what costs $300. Big, burly, greaseable U-joints now! _________________ '86 Syncro CHC Top AAZ Turbodiesel
'04 Passat Variant 4Mo 5MT
Vanagon Build: http://www.thesamba.com/vw/forum/viewtopic.php?t=466866&highlight= |
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tencentlife Samba Member
Joined: May 02, 2006 Posts: 10078 Location: Abiquiu, NM, USA
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Posted: Wed Dec 29, 2010 8:13 am Post subject: |
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Wel to follow up on my own story, I finally got the Syncro on the road a few months ago, and the driveshaft had some mild vibrations from the start, at about 50-55mph. I borrowed a laser alignment tool and centered up the casings relative to each other, that cut the vibes down in intensity. Then I took out the shaft and I could see that the spider at the Giubo end had one cup not equidistant from the centerline, which would bind a little when I swiveled it. It's tough to take a spider apart without damaging it but with care I got the cups out, added more lube (they didn't have nearly enough) and put it back together with more careful alignment.
I also took apart the slip-joint and measured the play there; it seemed pretty moderate, not perfect but not too bad, so I just added a lot more lube there because it also seemed too dry.
Put it back in and it runs pretty smooth now.
By the way, I didn't need to use them but if you need shims to put under the circlips to get a spider centered or adjust its preload, VW rocker shims are a pretty good fit. They come in assortments of several thicknesses: .015, .030, .060", from lots of VW aftermarket vendors, and you can find .010" ones too, the only place I know of that has those is Dan's Performance Parts:
http://www.dansperformanceparts.com/buggy/epc/buggyep%206%20rockers.htm _________________ Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/
Please don't PM here, I will not reply.
Experience is kryptonite to doctrine. |
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candyman Samba Trout Slayer
Joined: December 20, 2003 Posts: 2694 Location: Missoula MT
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Posted: Wed Dec 29, 2010 7:05 pm Post subject: |
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Wow. Simply wow. Chris (10c) I think I speak for all of here in samby land, YOU are our internet hero. I sleep better at night knowing you are here. I gave up on my shaft I had rebuilt and just bought a new one from vanacafe. I kept the old one though with the new ujoints installed and now may try 10c fix on it, it was a just a very slight vibration but it drove me nuts. Chris, thanks for being here! |
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TopBud Samba Member
Joined: February 28, 2004 Posts: 1111 Location: Flagstaff AZ
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Posted: Wed Dec 29, 2010 7:42 pm Post subject: |
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I didn't replace the rubber disk. It looked fine. Drove all over today, no vibrations at all. _________________ 86 bostig SYNCRO
66 convertible Karmann Ghia |
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tencentlife Samba Member
Joined: May 02, 2006 Posts: 10078 Location: Abiquiu, NM, USA
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Posted: Thu Dec 30, 2010 10:17 am Post subject: |
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candyman wrote: |
Wow. Simply wow. Chris (10c) I think I speak for all of here in samby land, YOU are our internet hero. I sleep better at night knowing you are here. I gave up on my shaft I had rebuilt and just bought a new one from vanacafe. I kept the old one though with the new ujoints installed and now may try 10c fix on it, it was a just a very slight vibration but it drove me nuts. Chris, thanks for being here! |
Thanks, but don't you mean to be praising Mr. funagon? He's the one who provided the great pictorial how-to, I think he did a great job.
Anyway, the thing is, rebuilding U-joints is not hard at all, takes a little patience and forethought but it's mosty just putting a little puzzle together. Balancing is a specialist job, but if your DS was balanced before and the trouble is just loose or binding spiders, and you index the main pieces before disassembly, most times you can replace the spiders and get back a smooth runner. _________________ Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/
Please don't PM here, I will not reply.
Experience is kryptonite to doctrine. |
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