TheSamba.com :: View topic - Adjusting the ring and pinion backlash 010 Automatic.

Wed Sep 17, 2008 10:07 pm

When the rebuildit shop had our van, (PO had the rebuild done) they did not adjust the R&P backlash. Now (After I rebuilt the Auto section) it has excessive click at freeway speed. Anyone know the adjustment or should I be a Cheap freak and go to thicker gear oil?

Thu Sep 18, 2008 1:01 am

I seriously doubt you are hearing excessive ring and pinion backlash.
But if you are, you are in luck. Just put it up on stands, pull the axles, drain the oil, and remove the pan. You can move the side cone adjusters and lighten or loosen at will. Getting the setting fixture and using it would be a bit more of a task. But if it is loud enough to hear it at highway speed, it must be very loose.
I'd suspect a bad CV joint.
Al

Thu Sep 18, 2008 8:07 am

If you go the route Al recommends, assuming the differential bearing preload is correct, if you turn one retainer in, you will want to turn the opposite retainer out. This allows you to adjust the backlash while maintaining the bearing preload. If the backlash is off, I would be suspect of the bearing preload as well. I have not done one of these in 20 years, so I could be completely wrong. Does the noise change when you liff off the gas? Clicking does sound more like a CV running dry. Regards.

Thu Sep 18, 2008 9:50 am

The sound actually sounds like streight cut gears that have a sloppy mesh. The sound really became apparent when I switched to the Moble 1 Synthetic gear lube. The sound happens when the Van gets around 50 MPH. I did notice that it quiets down a bit if the van is on a slight incline.

Thu Sep 18, 2008 10:28 am

George, I am a little confused by your original post. A shop overhauled the differential some time ago? Then you just recently overhauled the automatic section yourself? If so, was the noise there before you redid the automatic section? Did you shim between the two sections? If you leave the transmission in 2nd is the noise still present. Usually back lash being out of adjustment the noise changes from under load to no load. So you accelerate to the magic speed of 50mph and hold it there on a flat surface, the noise is present? What happens if you lift of the gas and then get back into the gas? Sounds like a case of too many chefs. Differentials are complex to setup to get to run quietly. The VW automatic requires very special tools to adjust both pinion depth, back lash and bearing preloads on the ring gear and the pinion shaft. If a shop was in to the differential and did not check the backlash, the simplest of the measurements to make, then I'd be suspect of all the work. Regards.

Thu Sep 18, 2008 12:45 pm

O.k. A shop that is no longer in the area overhauled the trans and torque converter in 1995 (I have the receipt documentation). I purchased the Van two years ago with the knowledge that it had not been Driven since 1998.When I purchased the Westy, I flushed all of the fluids and replaced with sythetics with the exception of the engine oil in which I use the Shell Rotilla brand. All was well with the exception of a whine at 50 MPH and up..
Let's fast forward to this Year.
On our way home from the Mid America Motorwork's show in Effingham Illinois we had a hell of a time with Headwinds and by the time we got home a KNOCK was coming from the trans. I pulled the trans and discovered the the Torque converter was AWOL and that the Fluids from both sections had mixed! but the noise was always there, before and after. The Flex plate was broken around the hub and rivets. A teardown and rebuild of the automatic section was in order for peice of mind! End play was measured on the engine and found to be within spec. CV joints at the trans end were re-packed with the proper lube. The whine of streaght gears still persists, at one point I used the 50/50 gear lube blend and a noticable difference was heard. My big fear on this is that the Diff will gernade on a BIG FAMILY TRIP.

Thu Sep 18, 2008 1:38 pm

George, there is a shim setting between the auto section and the differential. If you were mixing fluids, most likely you were getting ATF into the differential. There are back to back seals on both ends of the differential. Did you change those out? You should remember because it is a bit complex to do properly. Perhaps at this point, something like this might do. http://www.thesamba.com/vw/classifieds/detail.php?id=667343 It came up for sale today. Might be worth looking into. I hate to sound negative on these transmissions, but to service them properly requires some special tools and experience along with the Bentley Manual. Sorry I can't be of more help. If the differential is coming apart, you should see lots of shinny stuff in the gear oil. Since it does not have to work with synchros, you could try a 140 wt in there. See if it quiets up. Regards.

Thu Sep 18, 2008 11:11 pm

It seems like you could take a sample of the gear oil and look at it under different light in order to see if there is any metal suspended in it. Lacking any, I'd look to the outer CV joints.
A too loose pinion bearing will make a whining noise that changes pitch or even goes away by varying the load the engine puts on it.
Fixing it will get pretty involved, but first you need to determine what happened. If the backlash was simply set wrong, it's not too hard to move the ring gear over to take up the lash.
But of course, the next question would be: What else is set wrong? Or is a bearing failing?
So, I'd modify my original answer to: yes you can, but****
Al