Grrrr, Distributer belt snapped!

[AVI_8]

Took my car out for a test drive yesterday after servicing the engine, replacing cv joint boots etc, noticed very quickly that I had a slight pre detonation from 2700 rpm, realising something wasn't right as it's never done that before I drove home slowly, pulled the HT lead from the primary distributer.....It wouldn't start, tookm the dissy cap off and sure enough the rotor was spinning freely....arse!

I've got the engine turned to TDC no1, intend to replace the belt myself when time permits.

I'm guessing that the belt must have been ready to break as it wasn't when I fitted the new rotors and caps, I can only assume that there was more resistence/friction with the new caps and it was the staw which broke the camels back so to speak.

All going well I'll take some pictures of the job as I do it.

 

[jagman]

Sorry to hear about the belt, you seem to be having one problem after another. Have you got the vent kit fitted? and how many miles have you done?

Regards

Keith

 

[AVI_8]

Just over 100,000 miles, yes the vent plug was fitted to the distributer, but it had a blank plug fitted over the end of it, so totally useless, I'll buy a T piece and a piece of hose to connect it up when the new belt is fitted.

The job doesn't seem too complex just a bit fiddly (not unusual for a 964), just hope that the dizzy comes out without too much force........unlike my CV joint!!!

 

[bernard tester]

Hi the belt is not to bad to change but as you say takes a little time the belts are quite cheep and easy to time up I find the hardest thing to do is to compress the shaft to get the shims back in but ok when you get the hang of it. Regards Berny.

 

[AVI_8]

Hi Bernard, thanks for your reply, my plan is to take out the distributer and once I've had a look at what I have to do, go and buy a clamp of some sorts, looked back on a post made by Ian during his engine rebuild, think he used a valve spring compresser. The belts ordered, noticed eurocarparts want £500 for a new distributer so hopefully I'll save myself a lot of money by doing this myself

regards

 

[iangray100]

And the valve compressor works a treat ...actually £500 for a complete new distributor I think its quite good if you do need one due to worn bearing issues, as you can't buy the bearings that the distributor uses ..they an odd Porsche size and I tried many bearing supplies as well.

 

[AVI_8]

Had some time today to get started on my belt replacement, was going to do a full write up on what to do but basically I've been following the tips on this helpful post.

http://p-car.com/diy/dualbelt/

Was expecting my distributer to be difficult to remove but after removing the one retaining bolt it slid out without problems.

The drive gear was not so easy to remove, I had drilled out the metal plug holding the gear to the primary shaft however the gear was very tight to remove, I used some heat on it to expand it which helped, there must have been a small piece of metal which got caught between the gear and shaft.

Once it's off the primary shaft can be removed after removing the plug on the side of the dizzy which comes off after the retaining clip has been removed from the inside and the 3 philips screws accessable from inside the distributer......use a good screwdriver the correct size, not a worn one as you don't want to strip the head off of these screws

 

[AVI_8]

At the base of the secondary dizzy is a copper coloured plate which has to be removed, I used a filing disc on my dremmel to remove the 3 notches which had been stamped into the housing to hold the plate in place, it took a bit of fiddling about with a couple of thin screwdrivers to remove it but it's not held in too tightly, it was impossible not to scar the housing slightly whilst doing this but it's not a problem.

Housing plate removed

Clean out the old grease and use a pair of circlip pliers to remove the circlip, This is held in extremely tightly.

Once its out you can remove the secondary shaft........Be extremely careful in removing both shafts, there are washers top and bottom of both and some are directional so make sure that you note the order and direction of the washers!!!!!!!!

When both shafts are out you can split the housing, 5 Allen bolts, again this is not a time to be using worn tools you dont want to strip the heads.

Old belt was probably origional, "Knight Knicken" written on it was a bit of a giveaway, if your belts been replaced it will probably say "Gates". My old belt...19 years and over 100,000 miles old

The bearings on the housings should be re-greased before the shafts are refitted.

Once the new belts in place you can bolt the housing back together, remove the drive gear from the primary shaft again it's directional so make sure that you don't get it upside down. Put the washers in place in the correct order, sit the drivegear in place and put a large screwdriver down through the lot and into the shaft, then put the belt in place, once you've done this use the screwdriver to align the washers with the drive shaft housing then gently insert the primary shaft making sure that you've aligned the notch on the shaft with the point on the gear which it seats into, don't forget to put the electrical plug back through the housing before fully pushing the shaft back in place.

 

[AVI_8]

Now fit the top washers and the secondary drivegear, again a screwdriver will hold them roughly in place while you correctly set the timing which isn't difficult, to do this turn the primary shaft until the notch on the top is aligned with the Cylinder 1 position on the external outside part of the top of the housing, now the secondary drivegear has to be aligned properly, to do this the notch in the drivegear has to be positioned 180 degrees away from the marking on the distributer housing, refit the secondary driveshaft and again check the timing for accuracy, if you're one tooth out it'll be obvious.

Before I refitted the frimary shaft I used a sanding disc with the dremmel to remove any burrs, which there was, I then used a piece of sandpaper wrapped around a screwdriver to smooth out the inner drivegear, pic here

It fits ok now but I havent attached it yet with the new pin as I need to get a suitable clamp in order to put the circlip on the end of the secondary shaft, it'll need to be compressed quite tightly.

And thats as far as I've got today, hopefully tomorrow I'll have a running engine again!!

 

[AVI_8]

Finally got the distributer rebuilt today, the hardest bit of the job was getting the circlip on the secondary shaft, I don't have a valve spring compressor and they're £45, eventually used a c clamp with a 13mm socket to compress the circlip into place, took a while and a lot of bad language but got there in the end.

When fitting the dizzy you need to position the rotor arm about half a width left of TDC as it will rotate when you push it into place, I had to tap it gently with a soft hammer to get it the last inch or so.

What a difference it has made to the performance of the car with new caps and rotors, it now idles evenly and has a much better acceleration, it really does feel like a different car, hopefully now I can enjoy driving the car instead of working on it as I have been for the last month!

 

[Steve Brookes]

Well done mate....you deserve some driving time! []

 

[C2dweller]

Thanks for another great write-up.

My Dizzy caps have arrived today, so I'll be fitting them soon ... I just hope my belt holds-out

Cheers, Lee

 

[AVI_8]

With the rotor and plastic shield off the secondary distributer (the lower one) you can see the belt, it might be worth turning the engine over by hand using the fan drivebelt until you can see the markings on the distributer belt, you should be able to insert a long screwdriver in there to twist it slightly in order to check, I was surprised at just how loose the belt was when I put the new one on, there's plenty of movement so you won't damage it by carefully doing this, if like mine it has a long yellow band on it, it's probably origional and you should maybe think about having it replaced before it breaks, at 20 years old it'll not have much life left in it if it is.

I'm sure that I read somewhere the service life is 50,000 miles or 5 years?