Big Dave

Just retensioned my TB after I installed a new belt about 2K miles ago.

In case any of you were curious, yes the belt stretches a good deal. I'd say that 2K miles is probably the longest anyone should wait, at least based on my experience. <img border="0" alt="[nono]" title="" src="graemlins/nono.gif" />

Using the aftermarket tool, tension was about 1-2mm outside the correct tension range. I was surprised at how loose it felt and thankful that I hadn't had a problem because of it.

Rotating the engine to TDC using only a socket wrench (12" long) without a cheater bar was tough. My biceps feel a little bigger today. <img border="0" alt="[jumper]" title="" src="graemlins/jumper.gif" /> <img border="0" alt="[king]" title="" src="graemlins/r.gif" />

Hardest part other than turning the engine was getting the TB cover off without removing the upper radiator hose. I had to loosen the ignition coil to make enough room. YMMV.

ViribusUnits

Deffently do NOT wait a long time.

I waited 4k miles. The belt was so lose, the letters printed on the back side had been flooping, and hittin the cover. This smeered them up a bit.

The car still ran like a scared rabbit, but that was not cool when I pulled the TB cover off!

Gretch

I retensioned after about 2500 miles. I needed about a half a turn to get it in spec with the "inexpensive" tool. I admit it though, I was nervous and would have felt better if I just did it at 1500 miles.

TJQuill

After that initial re-tension, is there a rule of thumb for how often/how many miles it should be retensioned as part of preventative maintenance?

BrianG

I checked my '86 after 500mi when the " ! " started coming on for no apparent reason, last week. I found the tension still within the window.

Big Dave

TJQuill:

I believe the Porsche recommended interval is to check the tension after 30,000 miles and replace the belt after 60,000 miles (or four years).

Lagavulin

I recently replaced my timing belt, and using the Kempf tool (..thanks again Jay for a great tool; I actually gave him a hug when I met him at SITM), I tightened it all the way to the 'tightest' end of the window-range. And yes, I rotated the engine at least 720 degrees and re-checked, twice.

300 miles later and some semi-spirited driving one Friday with our 928 GLOC group, on the way home during a blast thru the gears the belt tension light came on. I wasn't overly concerned as I did all the work myself by-the-book, and calmly preceeded home

The next day I checked it, and found the tension to be exactly at the 'loosest' end of the window-range. I was surprised it took so little for the light to come on. I did check the tensioner's wire connection and it was good.

Well, I re-tensioned it to the tightest end of the window again, and off to 'Sharks in the Mountain' where some VERY spirited driving ensued with no problems at all, thankfully.

By the way, what a GREAT time!

Jersey Joe

I guess I should do this soon. My 1990 has 135000 miles, and the previous owner did the belt at 85000. It does not look that complicated. Where can we rent/borrow the tensioner tool.

ViribusUnits

The Jay one is a little under 60 bucks. It's well built, and easy to use. It's only good for the 928's timeing belt, but it's worth the investment if you ask me. Course I belive I'll hit the 15k mile mark right about the time I've had the car for a year, so I'm going to be useing it alought.

I think you can probably pick it up from any of the big three. Deffently not an autozone part!

Eric_P

LOVE the Kempf tool. My 'ole bugger ('79) just wasn't worth the $400 factory gauge..(I can find alot better places to spend that!) Since my odometer gear is stripped (surprise!) I usually just check the tension every oil change. Fast, easy, and helps me sleep better!

Jersey Joe

Is there anyone out there with a manual that can forward the step by step for checking and changing the belt? Is there already published info opn this?

Lagavulin

There are two posts you need, one by John Pirtle, and the other by WallyP.

I do not know where they are, but if you do a search on 'timing belt', you'll be able to find the links. Believe me, it'll be time well spent.

John gives you a step-by-step account, and WallyP's illustrates how the camshafts should look when lined up at 0 and 45 degrees, arguably the most important step of the entire procedure.

Count on spending about 20 hours for the job.

Big Dave

Jersey:

It took me roughly 13 hours to do it with a friend. It was my first time doing it and I spent a fair amount of time cleaning and BS'ing along the way.

I used Pirtle's instruction page. Very informative. <a href="http://members.rennlist.com/pirtle/tbelt.html" target="_blank">Timing Belt Replacement</a>

One thing I would recommend is, if you are so inclined, to pull the spark plugs out. The engine is tough to spin as you alternatively build up and release compression in the cylinders. With the plugs out, you won't be compressing air with each turn of the wrench.

Aside from the tension tool, you'll also need a flywheel lock....costs about $30 or so if I remember correctly.

In addition to a standard set of metric sockets, make sure you have a 27mm socket for the crankshaft nut as well as a strong socket and breaker bar. That crankshaft nut is torqued to over 200 lbs!

A call to one of the "Big 3" (928 Specialists, Devek, or 928 International) will give you a list of all the parts you'll need. Make sure you replace your water pump at the same time. The previous owner of my car didn't at the last TB change, so my pump died and forced me to replace the TB 15,000 miles early.