firemn131

Good Morning,

So I have never seen the bracket that ties the water pump into the tensioner used.
What is the application for this bracket? Pre-S4?
Would it be advantageous to trim the plastic TB cover to accommodate? would this provide more stability to the tensioner roller shaft that is incorporated on the water pump?

Inquiring minds need to know...

Mrmerlin

in order to use that later S4 system ,
the earlier tensioner arm assembly must also be changed ,
IDK if that would also include a different tensioner body

firemn131

I guess it doesn't really matter at this point.

Just have never seen it used in any photos or threads.

GregBBRD

It changes that post in the water pump into "double shear" versus "single shear".
This started in the S4 models and continued to the end of production.
Much more stable.

firemn131

that's what I was leaning to.

Are the belt covers different then?

A cut out?

Can someone post a photo of the bracket installed and cover notched?

PorKen

Very early 87 used the early water pump. There is a service bulletin showing how to notch the cover for the new pump.



(If you use a PKT you can use a less expensive early pump on any year )

Geza

Considering that pin does not see much in the way of load (other than the weight of the assembly and possibly an imbalanced vertical component from the belt tension), that upper support bracket is very important. Without it, any load the pin does see is cantilevered off the base of the pin, which creates a bending moment with increased deflection. However, the real purpose of that support is to increase stiffness, driving up its resonant frequency. So, if/when it does resonate during operation, its deflection and stress will be lower.

Petza914

Don't know why anyone would use the stock tensioner with the Porken unit out there and available. Install and done - no belt tension checks or adjustments between water pump service intervals.

firemn131

Well, not an expert, but:

Many stay stock as;

1. It seems to work
2. $$$
3. keeping it original

In my case, unfortunately it is about $$.

Petza914

Yep, I get it. In my case, I have less time so am willing to pay a bit more for something that saves me some of that.

My car doesn't even have a roof, so don't have to worry much about originality anymore.

firemn131

hahaha,

Yup I get it.

Just looking through my WSM for the bulletins.

I may have an earlier version, that doesn't have them.

Anyone have a link or other information to lead me to the tech bulletins?

Specifically the timing belt cover modification.

Thanks

firemn131

Never mind,

I think I found them on my cd's
I am bouncing between two different computers.

Work computer doesn't allow downloads

firemn131

found it.

Thanks for getting me in the right direction.

You guys rock!!!!!!!!!!!!

Geza

Seems to me that Porsche put that roller there specifically to protect the TB teeth from getting hosed up when the TB resonates wildly at certain RPMs during operation.