geekapalooza

First off, sorry for throwing out a subject that has probably been whipped within an inch of it's life, but some expert advice is needed and appreciated.

My 6 months new 87 S4 had a new TB, NEW (not rebuilt) WP and complete idler replacement right at 5 years ago, but that was only 10K miles ago. No sign on the receipt of them ever touching the tensioner though.

I retensioned the belt about 500 miles ago. The belt looked in good shape, no apparent coolant leaks, excessive signs of wear, etc. Amazingly, the PO never had the belt retensioned, but it was still (barely) within the OK window, accdg to the trusty Kempf tool!

Do I need to do the whole thing again already? Can it go – say - another year? Should I go by the 5 year rule and replace it all right now? If I need to get to work on it, can I ignore the NEW WP, just rebuild the Rollers and tensioner only. I want to do a first class job, but at the same time, not get into any overkill.

Best route to take? Any advice appreciated. Thanks!

Chris Lockhart

IMHO, I would change it all now, just to be sure where you are "actually" starting from on time/mileage. Not sure if I would be comfortable with the car without changing it all out. If you do the work yourself, it's not a very expensive procedure. Just my 2 cents.

MBMB

In much the same situation, I did WP, TB, tensioner, and rollers. My cost-benefit analysis went something like this:

"It'll probably be okay for another year, but imagine how I'll feel if the WP seizes up six months from now and I lose my top end. That'd really suck."

Do the WP too. WP replacement is a breeze (other than the $200 rebuilt pump cost) once you have the TB off, and you won't have to go into the front end again midway through the timing belt's useful life. Also, you can make sure the WP bolts are healthy and snug.

What part of town are you in? I just completed this job, and would be happy to lend a hand.

Old & New

<don flame suit>

I would consider that the water pump did not have an early failure as some have reportedly had. The next one you install might, and with only 10K miles on a NEW pump, I'd leave it in.

The rollers only have 10K miles on them and are not age dependent the way the rubber belt is, so I would leave them alone, too.

Jerry 87 928S4

I was faced with a similar situation. The PO said he replaced TB and WP about 2 years before I bought it and that it was only 4k miles ago. I drove it about 2 years and 12k miles. Finally, I decided to change both.

To my surprise the water pump looked like the original so I was glad that I replaced it. The timing belt looked just fine but was stretched quite a bit from the new one. However, a couple of the rollers were definetly in need of replacing and I made sure that the tensioner was properly rebuilt.

Bottom line, I much happier now that the job is completed and I know it was done properly. Now will I change it again in 5 years if I drive it quite a bit less than 45k, probably not.

Garth S

....10K on everything, not an issue: 5 years on the belt and the tension is OK, not a bad idea to replace whenever's convenient for you.
If you approach it this way, you end up with a new belt to hold up for ~5 years, and an opportunity to examine the smoothness of each bearing (rollers/idlers/H20 & oil pumps) - if any of these components are less than perfect, then replace them. As Old&New said, these are wear items, not generally time dependent - and 10K is not a lot of wear.
Examine the four drive gears for any wear pattern.
If the tensioner is not leaking, and has oil in it - flush the oil, and install a new boot/clamp 'in situe': this boot is a 'time' issue, the gasket behind is not.
Check for any side play in the carrier arm bushings that would allow the belt to mis-track( I think these are often overlooked - but neither do they seem to wear out frequently).
This way you've committed <$100, can verify everything, and still have the time to replace anything that shows up.
Be kind to your water pump bearings and seal - assure the coolant is flushed on its 2 (or 5) year cycle.
As an aside, having followed the above, the orriginal water pump is still smooth and leak free in my '80 - and has got to know several TB's over it's 24 years.

Old & New

Bless you, Garth!

UKKid35

It is possible to check the condition of the tensioner boot without removing any of the covers, you can get a finger to it from underneath. If it is solid or cracked, which it almost certainly will be, then you need to rebuild it. I reckon that a tensioner with no oil in it will cause the belt tension to be exessive most of the time (because the washers won't heat up properly), causing sprocket wear. This was probably one of the main reasons my belt failed.

geekapalooza

Thanks for all the great information, this helps a bunch guys.

MBMB - SugarLand area here. I'll PM you when I get the parts and the time (both together are no small feat these days). The more help, the better! I'll supply food, beverages, and 928 stories. Any other takers in Houston area, just lemme know.

MBMB

You're right down the road from me.