DSG gear drive

[BobND]

I was working on a 6.2 yesterday with a DSG gear drive, mileage on the gear drive unknown.

The brass thrust washer behind the cam gear was hollowed out on the side in contact with the gear.

The washer appears to have originally about .090" thick, and worn .030".

The backside of the brass washer looked good. It runs against the camshaft thrust plate, which has an oil hole connecting it with the front cam bearing area for oiling.

The front side in contact with the hub area of the timing gear has been worn, I'm thinking 'cause there's less oiling there, and the gear, while not terribly rough, has noticeable machine marks.

I called up to Saskatoon, and they said they didn't have a washer on hand, but they would rob one out of a new set, and send it down. So far, so good!

Then, the shocker... $38.00 (I can't remember if that was before the currency conversion, or not), and as much as $10 to $12 to get it down here!

This is not my main vehicle, just sort of a plaything, and paying $50 for a brass washer, 1.75" ID, 2.5" OD, and .090 thick was hard to swallow.

I punched up McMaster.com, and checked out their stock of brass thrust washers, and found a pretty close match, but about .030" too thick, for $3.78.

For that price, I can chuck it in the lathe, and get it to the thickness I need.

There was a choice of "841", "863", "932", or "954" material, and, apparently "954" is some pretty tough stuff. I hope that works!

I have thought of notching the ID of the thrust bearing, and the making a couple of depressions on the gear side, for better oiling. Any thoughts on the material, and the notching for better oiling idea?

[tom.mcinerney]

I have no experience here. NICE that McMaster ended up cheaper (for once)!

Your plan seems to be in good direction.
Would a hole thru the washer at an inner location allow pressure lube of the gear thrust face?

Am i correct in thinking the gears are simple spur cut, or are they cut on an angle so the teeth overlap but create thrust??

Is the brass a good material? Maybe another brass or bronze alloy composed specifically for bearing service would be more appropriate.

I recall reading instructions about checking/setting clearance between timing cover and gear; maybe this should be checked before you face off the washer....

[BobND]

The crank and cam gears are straight cut. The injection pump drive geartrain is helical. I didn't look to see which way that load thrusts the cam.

With solid lifters, the cam lobes are ground with a bit of an angle, to spin the lifters, and also keep the cam towards the back of the block. I don't suppose that applies here, though, with the roller lifters.

The washer I ordered IS designed as a thrust bearing, and is "954" alloy, which the site rates as the toughest of the materials they use for the thrust washers.

My thought was that a notch or two on the ID of the washer, and a corresponding depresion or two on the other side of the washer would get oil to that side.

[john8662]

Interesting..

I remember thinking that the thrust washer had worn on my engine quickly too.

How many miles of service do you think was on this set? What is the condition of the gears?

[BobND]

I have NO idea of miles, and no way to check, as the engine changed hands a couple of times before I bought it.

The gears appear PERFECT.

[BobND]

I got my new thrust washer from McMaster yesterday, but have too many PAYING projects to do to find time to machine it!

http://ndtc3500.stellarnet.com/~blweltin/Bob/DSGwashers.jpg

The old thrust washer is on the left, flipped over, in relation to the gear.

The outer, unworn area, marked in red, measures about .091 thick, about the same as the "step" machined in the back of the cam gear. The inner area measures about .064", so it's worn about .027".

The new washer is the same OD, needs the ID machined out, and the thickness reduced by .029".

The delivered cost was $8.03, compared to about $50.00 for the factory replacement part.

Probably not worth my labor, but this is a low-budget project on my own vehicle!