Mark R.

Glen - "Replacing" versus "Rebuilding" the stock system..?

ROG100

PKT with AP (includes Audi parts) $408
PKT no AP (includes Audi parts) $395
Never been $495

87 to 95 stock system - boot, O ring, clamp, gasket, bush x 2, small roller & large roller $240 - add the later WP v using an earlier WP with a PKT and it becomes more expensive. $430 v $395.
85 to 86 32v S3 - same parts $340

I did not add the tensioner bolt as nobody does this - or if they do very rare.

SeanR

This is a perfect example of how people get confused. The factory tensioner is not just that cylindrical thing bolted to the car. It's the entire set up from the bolts/bushings/rollers/orings/idle arm/gasket/etc.

When it's stated that the factory tensioner has never caused a failure, it's BS. I've seen multiple parts of the system fail, but those that say this already know this.

GlenL

OK... I mis-remembered the price.

So you're comparing the new parts for the T-belt job that you don't need with the PKT.

Personally, if the bearings feel smooth, the rollers and water pump go back in. All I plan on is the boot, gasket and nylon bushings.

ROG100

Luckily, for us 928 parts suppliers, the vast majority of customers do not think like this 8>) You are also dealing with a much earlier none interference engine.

GlenL

My #1 car is a Euro S so a "maybe" interference that's got '84 Euro pistons and has been machined enough to become a "likely" interference.

Lizard928

Those of us that do this for a living would never consider doing this.
I have seen a perfect water pump get bearing play in 5k km and 2 years. Due to this I will never reuse a water pump.
The tensioner bearing is small and with the loads the stock system has should be replaced every time.

SeanR

Troof.

hacker-pschorr

My local shop jokingly states that if anything were to be re-used when doing a timing belt job, it would be the belt since it's the most trouble free part of the system.

#1 on the list - the rollers followed by anything else that touches the belt.

Think about it....there is less than a thimble amount of grease (of what quality nobody knows) squirted into those bearings. At some point the bearing is going to fail and take the belt with it.

Only in very, very rare occasions does a belt fail without any outside assistance.

We should call it a roller and water pump job, the belt is just along for the ride.

GlenL

Probably right. When was the last time a belt failed and all the other parts were good? It's more like a 5-year inspection period and do the belt while you're in there.

Still... I'm working in a different set of motivations than the pro mechanics. I've done some work for friends/acquaintances and I use the "as-needed" approach. And I let them have the final say and responsibility on what gets replaced. As for my own cars, my mechanic works cheap and actually gets a bonus for money not spent.

I'd really like to see hard data on belt failures and the root causes. Following along for a few years, the failed parts in the majority of cases are the pivot bolt and the water pump. That pivot bolt gets over-tightened and then bends or fails. The water pump simply wears out.

This is a good point.

Lizard928

There was an old member on here who had someone do some work on his GTS, demanded he reuse a bunch of parts, then blamed him for it not lasting and causing bent valves.

I will never make the mistake that fellow did.

I do it all, or I don't do it at all.

Bill Ball

I do it like Glen in my 89 as well. I evaluate the rollers, plastic bushings and water pump and don't replace them unless there is reason to do so. I used to replace them, as has been the zeitgeist around here, and, other than the plastic bushings, rarely found any evidence of wear to justify it. So, I started to reinstall the existing parts if they were still performing well. A water pump with a firm bearing with no discernable radial or axial play and that does not free-wheel and with its impeller intact and no evidence of a leaky shaft seal, goes back in on my car. Often I end up with a just a "rebuild" (disassemble, clean, new o-ring and end cap) of the tensioner and a new belt. The only problem I have ever had with the timing belt system is a relatively late life (25K miles) stretch out of a Conti belt that set off the low tension warning. Scary, but no harm done thanks to a warning system that worked. So, I stick with Gates now, standard belt, not racing.

I have installed Ken's system on a couple of cars. One was a GTS, done years ago with no word of any problem, the other an early 16 valve a week ago. Also, I have a kit on my parts shelf that I bought very early on intended for my car, never installed. I'm watching this thread for how the upgrades/mods/revisions settles out. I don't know now what would prompt me to install it. I tend to be an early adopter, so I bought the kit, but haven't felt impelled to install it on my car. I have no strong feelings one way or the other. I can see potential advantages for Ken's system as well as potential pitfalls; hence, the discussions here and my several years of delay in installing it on my car. I just regret the name calling and personal attacks that have appeared. Like Charlie said in one of these threads: It's like watching your parents fight. Very disturbing, especially when it veers away from facts and technical discussions into nastier digs from one side or the other. Hopefully it will settle down and some positive result will be found.

Adamant1971

Update:

Tensioner extension is 10mm.

Had to go in to change a failed Laso water pump.

PorKen

Note there is a low priced core exchange program for the final 'S' bracket which covers a wider range of engines (at the expense of a couple more steps during installation).

(Limited number available, with or w/o the new air-pump accessory bracket. See web page for details.)

Adamant1971

Thanks, I put it back together with a new pump and belt. It's now at 7mm (cold).

I'm going to do my cam gears this winter so I will upgrade the bracket then if I stay with the PKT.