TheSamba.com :: View topic - Syncro driveshaft options, reg or slip-yoke?

Tue Nov 18, 2008 9:26 pm

I'm assembling all the parts for a driveline rebuild. So far I have a new VC and decoupler. (contemplating a LLDS front locker from AATransaxle, but it's big bucks)
Since I'll have the driveshaft off anyway I might as well go whole hog and get a new shaft now also.

My question, for those who may know, is what's the difference between the rebuilt stock shafts that GoWesty has:

http://www.gowesty.com/ec_view_details.php?id=4277&category_id=70&category_parent_id=

and the slip-yoke shafts that VanCafe have?? :

http://www.van-cafe.com/home/van/page_193_1257/syncro_drive_line_aka___prop_shaft.html

Is one better than another, easier to install, etc.

I notice that GoWesty is requiring laser alignment with their tool, and VanCafe doesn't say anything?

Thanks for any enlightenment!

Tue Nov 18, 2008 10:10 pm

> My question, for those who may know, is what's the difference between the rebuilt stock shafts that GoWesty has: Is one better than another, easier to install, etc. <

I've been dealing with this off and on recently. I can't say for certain which is better, but based on experience and hearsay I'd say a good well made slip-yoke is my preference because it gets rid of the rubber donut on the stock which tends to wear out in time.

The donut provides vibration dampening which is replaced by the movable slip-yoke design. Both the stock and slip-yoke designs go on the same way. The slip-yoke is easier to install.

I have bought three slip-yoke styles (I have 4 syncros) in the past couple of years from Tom Lengyel [503-228-1102] with excellent results - I recall he charges around $475 US each which is competitive. They are beefy and have not caused me any vibration problems. Tom lives just south of Portland, Oregon.

Bob

Tue Nov 18, 2008 10:22 pm

Thanks Bob

What about this laser alignment business?

I have searched this issue and came up only with references to the need to do alignment, but no info how, or preferred method.

Does someone have instructions from one of these alignment tools?

Tue Nov 18, 2008 10:27 pm

> Thanks Bob - What about this laser alignment business? <

I have never used nor ever needed to use a laser tool. My understanding is people who are having vibration issues even after installing a new shaft use this to better align such with the transaxle among other things. But perhaps someone more knowledgable than I can comment.

Bob

Tue Nov 18, 2008 10:36 pm

I have used a laser tool, they are very easy to use. One of the puck like pieces is attached to a tranny flange with embedded magnets. The other flange gets a "target" board that hangs plumb, it might have a bubble integrated into it or you can use a torpedo level.

Turn on the laser and you should get a red spot on the target board. The board should also have a ruler on it so you can tell how far away from center you are. To zero the laser, turn the flange and watch the laser point, if it traces a circle it is out of whack, it should remain a point or close to it.

Swap the laser and target pieces and measure. Your looking for distance from center of flange (up/down)and distance off the plumb line(left/right).

Both flanges should be pointed down and you should be looking for a vertical distance of about 3.5" each and of course the horizontal should be dead center both ways. General consensus is that the vertical distance should be equal but can vary from van to van.

I didn't use GW tools but they look very similar to the one I used.

I was one of those people who had vibration issues after a new slip joint shaft from GW, the alignment fixed it. Installing the slip joint is probably a "little" easier due to the adj length than the stock unit. I have no complaints.

Wed Nov 19, 2008 5:32 am

For those looking to rebuild it themselves, here's a write-up of someone fitting South African poly bushing in place of the bronze bushing in the propshaft donut to eliminate ringing:

http://homepage.ntlworld.com/aidan.talbot/syncroprop/

Wed Nov 19, 2008 9:14 am

One of the guys at my machinists said he could get the right spiders for the Syncro prop shaft, or a complete slip-joint American replacement shaft. The slip-joint replacement was about $450, so its probably the same one as the other guy is selling. I didn't rain on his parade by asking what vehicle the replacement is normally intended for, but apparently some other 4WD vehicle uses a shaft functionally identical to the Syncro's.

I'm going to try out the shaft I already have that reportedly was rebuilt but vibrates a bit at 45mph, which sounds pretty typical. One of the spider joints is slightly stiff in one area of swing, which may be why, but I also understand that long-term there is wear in the slip-sleeve of the OEM shaft that does account for a lot of the vibration problems these shafts exhibit. If the existing shaft doesn't work well I may just buy the full-on replacement, which is allegedly easier to service because it uses a common spider, and eliminates the Guibo disc. If I do buy it, I'll find out then what other vehicle it's intended to fit.

Wed Nov 19, 2008 12:09 pm

Thanks fairweather,
I now have a better understanding of how the laser alignment works, and the numbers needed. However, I'm still unclear how to adjust the alignment.
I have yet to pull the driveshaft, so I have no working knowledge. Please forgive dumb questions.
I understand that both flanges need to point downward to allow for movement, and centered horizontally.
But, how is the adjustment made? Do I loosen the diff and adjust that way?
The Bently says vaguely to align final drive, but doesn't say how. Is it just the two mounting bolts? It seems that would allow for horizontal adjustment but not vertical. Are there spacers?

Any extra info on realignment would be greatly appreciated!

Wed Nov 19, 2008 1:19 pm

So I read with great interest about The GW Laser alignment tool,they offer a buy back program on the tool,essentially a $75.00 rental fee.
So my question is,will they be selling the returned tool at a discounted price because now it is not new anymore. I'd be peeved if I spent that money for a tool that I may use once or twice and find out it has been used before.
I have a new slip yoke shaft and it is much nicer than the OE so I am not concerned so much. But if someone does buy one of these and is going to return it ,I'd be happy to share in the "rental" fee.

Stacy

Wed Nov 19, 2008 2:22 pm

Quote: how to adjust the alignment.

The side to side can be adjusted by loosening the tranny mount bolts (17mm) that go through the rubber mounts and the open ended ears on the tranny. Once loose I used a small pry bar to move it around. I didn't have to adjust the height at all in the back, if you need to adjust for height try to do it at the front diff. Wiggle the bolts to make sure they are vertical, they can get angled when the tranny moves and it'll pull it out of alignment when you tighten them down, been there done that.

The front diff hangs off a crossmember that has elongated holes in the ends. Loosen the two 17mm bolts that go through the rubber mounts and you should be able to shift it around. To adjust height get some fender washers with the same OD as the rubber part. Mine had to go up just a hair so I have one washer between the top of the rubber and the crossmember.

Going down is trickier, I didn't have to but I think the only way to do that would be to shave some material off the bushing and rubber of the mount.
There might be a little play in the center area where the two bolts that hold the front diff to the xmember are, if not you could possibly elongate those holes to allow it to drop.

I also remember reading somewhere of someone measuring from the edge of each flange to the jack points as a low tech way to get them aligned though that doesn't help with the vertical part.

75 is a little much for rental but it's a no brainer way to know for sure that it is aligned as best as it can.

Wed Nov 19, 2008 9:45 pm

Thanks for the info fairweather!