Timing belt repairs

[BjtheDj]

I decided to buy the parts to replace my timing belt. So far I have the belt and a water pump. As a admitted dummy to this are they're any other parts i need to purchase ! Please help..

[AaronM]

All the rollers. Balance shaft belt.

$600 tool to tension the belt.

[BjtheDj]

This is for a 1983

[Eldorado]

Aaron tells you everything you need to do the complete job...

do you know how old all the rollers are? what about the other 3 belts? if you dont know how old the rollers and other belts are, you'll want to replace those too.

and if you've never done it before, you're going to want one of the tension tools... either the porsche tool aaron suggests, or an alternative like the Krikit (sp?).

[BjtheDj]

The guy I bought the car from said the belts should be replaced. He said it was at the 50,000 mile point of replacing them

[onZedge]

If you go to the Gates website and find the description for the Krikit tool, you will see that it is NOT reccommended for timing belts. I would get the Arnworks belt tensioning kit instead if I was going to do the belts myself. A lot less expensive and as accurate (in my opinion) as the Porsche tension gauge.

[wizkid918]

they say its not recommended, but its been used fine by many, myself included. or you can do the 90* twist method and do it by hand. timing belt issue has been worked up to be more severe than what it actually is imo... thats because everytime one breaks, they end up on here or rennlist with "are my valves bent?" questions. either way, 9021 tool is the "safest" method i guess. krikit was easy enough for me. and i'll trust it again in 2 weeks when i retension

[Eldorado]

right, it's not reccommended for timing belts...
but many people have used it with success...

it's all up to you in what you can do, what you can afford, what you're brave enough to withstand.

[Eldorado]

oh, and buy new pulleys and rollers... that way when you have the front end apart and you need to replace them then you have them.. if not, then you have them for next time... me? i'd replace them if you didn't know how old they were or just "weren't sure" about anything.

[AaronM]

Originally posted by BjtheDj
The guy I bought the car from said the belts should be replaced. He said it was at the 50,000 mile point of replacing them

If they've been on the car for 50,000 miles, they are overdue. The change interval is 45,000 miles, and they need to be re-tensioned every 15,000 miles.

[swimmingly]

Originally posted by BjtheDj
I decided to buy the parts to replace my timing belt. So far I have the belt and a water pump. As a admitted dummy to this are they're any other parts i need to purchase ! Please help..

Word around town is that swimmingly has a timing belt tensioning tool (9201).

Also, I would recommend checking out clark's garage (http://www.clarks-garage.com/) for the list of other things you want or need to replace. Just search under "camshaft belt" in the "garage shop manual" and you'll find everything you need to know. Good luck

[SoCal Driver]

Don't need no stinkin' tension tool!

Timing belt slack: take the tension off of the timing belt by turning the engine a slight bit anti-clock wise. This tensions the water pump side of the belt. Press the belt toward the water pump pulley. Should just touch.

Balance belt: Use the 90 degree twist method in the long span at the top. Remove the large smooth roller first. You don't need to back the engine with the balance belt. Just be sure it is aligned correctly -- pulleys on the shafts as well as rotation.

It's better to have slightly slack belts than tight belts. Engine expansion will soon seperate a tight belt even if it's new. A slack timing belt hitting itself going around the water pump is the reason the metal divider was designed in. Also why you have the smooth idlers.

[Dark Skies]

Originally posted by SoCal Driver
... Press the belt toward the water pump pulley. Should just touch....

Interesting. I've been thinking of buying up tools so I can do this job the next time around.

How much pressure should you use to get that belt to touch the pulley? As much as required or what Haynes pleases to call 'moderate pressure' whenever talking about tensioning mo'bike chains?

[SoCal Driver]

You will know when you run out of belt. You will also know when it touches.

[Paul Glasson]

Socal-that was really useful info I have not seen posted before. Always wondered how to judge the tension correctly without the krikit.
The idler rollers-what sort of mileage should one expect berfore replacement? I know it is a bit like asking how long a piece of string is. I have 175000km(approx 110000miles) on the clock and do not think they have been changed. Does an idler on the way out give any advanced audible or other warning when going? Just being cautious, as I have had balance and timing belt replacement about 15K km ago.

[rudidelange]

Also replace the oils seals (on the the balance shafts, cam shaft and oil pump) as well as the spacers. The spacer normally develop a groove and a new oils seal will develop a leak.

[rudidelange]

Paul
My rollers were replace several times during 200 000 kms. One is again due for replacement. You should be able to feel the worn bearing in the rollers/tensioners after removing them and spinning then in your hand. The are prohibitively expensive in SA (porsche dealers) but quite affordable from our host.
I am currently rebuilding my head, pistons are out etc.

[Gene Alvarez]

I agree with rudidelange; there is no better time to replace oil seals. My son wishes he had done it on his car.

[SoCal Driver]

Originally posted by Paul Glasson
Socal-that was really useful info I have not seen posted before. Always wondered how to judge the tension correctly without the krikit.
The idler rollers-what sort of mileage should one expect berfore replacement? I know it is a bit like asking how long a piece of string is. I have 175000km(approx 110000miles) on the clock and do not think they have been changed. Does an idler on the way out give any advanced audible or other warning when going? Just being cautious, as I have had balance and timing belt replacement about 15K km ago.

What??? That many miles/klic's with out replacement???

Must be something different in the southern hemisphere. Localized time rifts or something.

Anything over 50,000 is just asking for a head full of bent valves.

As to setting the timing and balance belts by hand: If you want to see how tight the timing belt gets on a hot engine just leave the front covers off and check it right after you get out of the car. Quite surprising.

On checking rollers (bearings): Was a mech that I worked with once that would clean bearings in the solvent tank, hold them between his thumb and finger then spin them with an air nozzel to purge the solvent. One locked up on him. Cut the crap out of the ends of his fingers. Never did that again.

[Paul Glasson]

Rudi,Socal-Appreciate the feedback.Do you guys have the part numbers so I can order from Pelican. One of those things I would always say"if only I had done the job and not thought about it", and how often have I been caught out that way.
Wish I had the opportunity to be up your way Rudi. There is no one in Durban I know who works on his own 944 so swapping info is done on this board, and there is nothing better than working and chatting to someone more experienced.