B7 A4 Timing Belt Change

[aviator79]

May already have been noted, but as I just spent 2 hours looking for the bottom metal cover.

06 after VIN 8E-6-165 000 has a single plastic cover

Split cover shown here:



My plastic cover goes all the way down.

Took car apart months ago to replace head so was following this and went to set crank at TDC and thought I was missing the cover (06D109175).

Now just need to figure out how to rotate crank to TDC without hitting valves. Not sure issue as think with head TDC no valves are fully extended as when a cam lobe is fully down it tends to rotate due to valve springs. Want to be sure of this before I start turning crank thou.

I also do not see an obvious way to align crank to TDC. I assumed could use the crank accessory pulley, align it with the hole that aligns it to the set screw sticking out of crank TB pulley and align with mark on cover, but acc pulley has no mark on it that I can see. So I guess will check it thru spark plug on cyl 4 with a rod. There is not a removable set screw on block that you put a bolt thru to hit crank counter balance weight to hold crank TCD when installing crank bolt? Maybe not as it is keyed...

Yes, I should have set both crank and head to TDC before installing head but was not thinking. Had assumed could set easily after.

Can anyone confirm that when the head is TDC none of the valves are extended far enough to hit the pistons? Already installed VC so cant see cams to check lobes.

Think I am ok:
https://www.audizine.com/forum/showt...=1#post5207107

edit,
confirmed crank rotates fine with no interference issues when head TDC.

Setting crank TDC:
26 teeth on crank (52 on exhaust cam)
=13.84*/tooth on crank.
TDC on crank is easily ~5* "play" using rod to measure but would need over 10* to be off a full tooth so dont think it is easy to be off that far. After setting tension check TDC with rod and cam after rotating crank at least full 360* and should be obvious if off.
"play" i just mean how cylinder is TCD for ~5*, not as in play as we normally think of it. Just do not know proper term...

[aviator79]

Posting info here as when doing TB should do accessory tensioner

Rather than replace accessory tensioner you could just replacing bearing in pulley.
I had replaced tensioner twice as I got wobble after replacing with non OEM. Not sure if my OEM had a wobbled but the bearing in pulley on replacement had so much play it was not going back on car. Luckily still had my OEM when doing this again due to having to replace head. Bearing still felt good but pulled seal and grease was shot so decided to replace bearing.

It is a 6203 bearing.

The original was an INI made in Germany. Replacement INI I found were made in Taiwan. $15 online. Im sure would be fine but I bought an NTN 6203 for $7 at Grainier as was in stock so got same day.
NTN 6203LLBC3/L627:
https://www.grainger.com/product/NTN...-Bearing-6L025

Was going to buy this SKF as has tolerance spec but for this any good bearing should work. SKF, Timkin, NTN, INA...
SKF 6203 2RS JEM:
https://www.grainger.com/product/SKF...Bearing-23Y203

I had to learn all about the C0/C3 clearance and trying to decipher PNs but think any good 6203 single row sealed bearing will work. I would not buy anything but SKF, Timkin, NTN, INA and im sure a couple other good quality companies.

C0 should have less clearance uninstalled and should be fine as the pulley is not going to compress the bearing much if at all (spec is 1-7 thou). C3 should have 3-10 thousandths clearance so could have more play but will be fine for this and probably ideal as a C0 could very well end up too tight after pressing in. Id say a C0 is meant to be held by outer race and inner race. This application has inner race held by bolt, but outer race is pressed in.
Anyways thats what I learned. I know some stuff about bearings and preload and what not as rebuild spindles but there are a million different kinds of bearings and wanted to be sure I bought the right bearing.

As I said I think any good 6202-2RS will work fine and the $7 NTN I bought is a good price vs replacing whole tensioner.

Kaman sells a Timken 6203 I was going to buy but they did not have any in stock locally even thou I live next to the HQ.

I pressed out and pressed in but can use bolt method.

We will see how works but pulley has zero play.

[DownhillA4]

Props to this thread and the A1 Auto Youtube Video. Thank you.

Just did the complete Timing Belt / Water Pump / Idler Pulleys / Tensioner / Harmonic Balancer on my B7 A4 and the job was a piece of cake.

[fly300kts]

Props to this thread and the A1 Auto Youtube Video. Thank you.

Just did the complete Timing Belt / Water Pump / Idler Pulleys / Tensioner / Harmonic Balancer on my B7 A4 and the job was a piece of cake.

You are most welcome

Phil

[Supersquid]

Phil-
Looks like I now owe you TWO cases of beer. This past weekend is the second time in four years your DIY has guided me through the process.
Also did my thermostat housing, after center hose o-ring failed. Lower hose is now not sealing - both new and old o-rings. That's another story, though. I'm convinced Audi's four rings are actually o-rings.

[Joe Church]

Phil,

Thank you for this write up. This plus a couple of YouTube videos helped immensely.