Stan,

I got the bit about the clamp being at the 11.00 position. Not sure I like those crimped clamp things although doubtless better than the nylon tie that was on there when I opened it up.

We do have a Honda dealer here- can check whether they have the stuff you mention. To be fair my experience with RTV has been very positive on the places I have had to use it.

Regards

Fred

 

If the pictures of the cam gears are representative of the entire surface, the passenger side gear with just some small spots of wear through looks perfectly usable till the next 60K belt interval. BUT you did say there was some "sidewall" wear. That would change my opinion. The passenger side gear wears far slower than driver as it is on the "looser" side of the belt. You could leave that gear there if there was on small spots of coating wear through and no sidewall wear. Do not "rotate" the decent passenger side gear to the driver side, like you might do with tires. The driver side definitely needs replacement. My experience is the passenger side gear lasts at least twice as long as the driver side (opposite for RHD cars). But that's just my observation and approach. The passenger side gear could be recoated to "like new" condition before reinstallation. The driver side gear could be too worn for that.

 

Fred, my tongue was jammed in my cheek when I suggested another 10k on those gears. Replace them. The drivers side gear sees more loading than the passenger gear, since the pass side gear has only the water pump drive behind it. Drivers side sees that plus the pass side cam drive loading.

 

I have a few brand-new ones of the same gear as yours (from before Roger/Porsche brought out new ones). If you want I can stick some calipers on one when I get home later to compare dimensions.

 

Bob,

I kind of figured that but when my friend made his comments about what he has experienced on a good number of 928's locally I also figured that such might get me by for a couple of years or until I can change out gear wheels.

Rgds

Fred

 

Hilton,

Might be an interesting test to measure the diameter on a new piece and compare to what I read to determine whether there is a cruddy build up layer.

I remain interested to understand why the valleys show virtually no signs of polishing. I expect the teeth to do the pulling or the leading edge at least, with the belt teeth cushioning into the valley as it were. What I see suggests the teeth are not "biting" as I would expect. On the other hand, if the flat surface wears, does it reach a point where the teeth eventually start to engage as may be expected?

Looking at the way the belt wraps on the cam wheel I would epxect that about 2/3 thirds of the teeth engage at any point in time- is that a reasonable assessment?

Regards

Fred

 

144.15mm is what I measure between two opposite teeth, on a brand-new unused gear (928 105 530 01).

There's some minor variance but 144.15 is what I most commonly measure from the center of the tooth on opposing sides. It does seem that on some teeth the coating is slightly thinner towards the face of the gear (144.12ish).

 

Hilton,

Interesting- I consistently measure 144.2mm on my dial gauge vernier so probably the same within the limits of accuracy of my kit so maybe I have a little crud build on the edges up but nothing of significance.

Regards

Fred

 

Well, as I try to sort out a few details thought I would try putting everything back together again as a trial. Went back quite easily to my surprise. The one thing that was making life difficult was trying to get STP into the stock tensioner- used my mityvac as a pump to push it in but still it did not seem to want to go- any suggestions?

I also had to check the cam timing given I had the wheels off- marked them first. Timing was zero on bank 1/4 and retarded 1 degree for bank 5/8. Not sure how to set with a new timing belt but probably better to get some miles on the clock and then set as a stretched [as in run in] belt.


Regards


Fred

 

Well I was finishing off this round of maintenance today [or so I thought]. Figured I would take a look at the alternator cooling hose- what a dog's dinner! Can anyone advise what that sensor is in the duct and what is does?

I found the hose routed through a gap just round the corner from the alternator- this looked a bit suspect- how is this hose normally routed?

Regards

Fred

 

Fred,

That's the AC external temp sensor.
Now, what it does, can't help much on that right now!

 

Look a bit and found this from another thread:

"the hose from it goes to the alternator which, when running, pulls the air over the sensor to give the HVAC system a temp reference for the string comparator of this reading, the inside temp reading and the setting of the HVAC temp lever."

Thanks Malcolm.

Edit: Also found this:

"As I understand the system, at least in my '84, the sensor tells the heating and cooling system what the outside temp is....if there is no sensor at all the system "thinks" it is very cold out and will turn on the heater and open the heater vents. There will be a 2 conductor wire behind the driver side headlamp assembly if you had a sensor..."

Thanks Jim.

 

Ah- it is probably the sensor that tells you what the outside temperature is- Indeed PET says it has something to do with the a/c [edit]- the location just acts as a protective shroud and if air is moving over it. gives a more accurate reading.

Rgds

Fred

 

The sensor which gives you the outside temp readout on the digital dash is in the driver's door mirror - sticks out slightly on the underside of it.

The one in the alternator air duct is purely for the HVAC input.

 

Hilton,

what pray tell, does the system do with this signal?

Any idea how the ducting is supposed to route into that area? At the moment it runs thorugh a small gap but that does not look a natural routing.

Regards

Fred