leperboy

Below are a photo of the idler that came off my car, the idler that I ordered, and my tensioner arm. The old idler was mounted behind a washer on the 19mm idler spindle bolt, but it was just hanging off the bolt, loosely.

The one I ordered is the correct number per the PET, but the inner hole is larger than the washer so it can slip right over it and bump against the arm. No clip and nothing to fill the gap between its inner hole and the bolt,

So, what am I missing? Is there a bushing or sleeve that goes between the idler roller and the bolt that I am missing?

Is this the correct tensioner arm for an 86.5?

GregBBRD

The roller on the right is 928 105 571 04. The roller on the left is a 928 105 571 02. It would appear that the idler arm is correct for the roller off your car. Take a picture of the water pump that is on your car, but it would appear that you need to think '85, when you are getting parts for your engine.

leperboy

The water pump that I ordered for an 86.5 is identical to the one that I removed. I'm curious why the entire engine would need 85 parts based on what is shown.

Of importance to me is what is missing that would hold the roller onto the spindle bolt. It doesn't just hang from it, does it?

Matt

GregBBRD

The correct water pump for the roller and idler arm that you have pictured has an aluminum boss that the roller fits over. The washer holds the roller onto this boss. From what you are telling me, it would appear that you have a mixture of parts, which is why I wanted to see the water pump. BTW--the tensioner also is different.

greg brown

jon928se

OK I can't make head or tail of the above.

it looks to me like somebody before you has drilled the rivets out of that belt tensioner pulley and succesfully failed to replace the bearing.

You need to replace the pulley (comes with it's own new bearing that you can't replace with out your own shop)

All the other T Belt pulley bearings can be replaced without your own shop.

Garth S

What is the number stamped on the two bearings? It should be #6004 for the old one ..... and a good chance that the new one has the same number: if that is the case, there is a bushing inserted into the inner race of the old idler that you must press out to install in the new one. That is how the 'slack' is taken up as the idler fits over the ~3/4" boss on the correct water pump.

If the bearing in the new idler is #6905, it is for the S4 pump which does not have a boss - rather, it uses a pivot stud vs a 19mm head bolt: the latter idler secures to the tensioner arm, not the pump.

The earliest idlers have #6303 bearings, which are a direct fit over the boss on the pre S4 pump.

edit: The pump boss is 17mm diameter: The early 6303 idler id is also 17mm; however, the 6004 bearing is 20mm id .... so the bushing shown in the idler on the left can be pressed into a new $6 bearing - which is pressed into the old shell if one chooses.
The S4 idler with a 6905 is 25mm id - and looks to be the one on the right.

leperboy

Greg, you were correct the first time, and I was not. The water pump does have the boss. In my first response I was only thinking of bolt placement and didn't even look at the boss sticking out. That solves the mystery.

So, now I need to exchange my roller and water pump for 85. I also need to do some more examining to see ifthe block is 85, or someone just replaced this front end stuff with 85 parts.

Thanks for solving that.

Matt

Mike Frye

Matt,

It sounds like you're having the same kind of weekend I'm having. 'The big three' are going to be getting a lot of phone calls tomorrow.

Good luck!

H2

I have an '85...and my tensioner parts came from the '84 model year. I have most the parts to change over to the later design but haven't had the need to change them yet. I think the factory slopped over parts from one MY to the other to save money. Caused me a lot of confusion at first...so buying parts ahead of time can be a pain when this happens.

Harvey

GregBBRD

Matt:

Good. Your do need to swap the water pump and bearing for the earlier '85 style. BTW...I don't think I've ever seen an '86 model with the later parts installed. I have always assumed that the PET was incorrect, however probably really late production '86's made the change. You might want to look closely at the boot for the tensioner that you are (hopefully) changing. There is a different boot for early and late, also.

Sorry, Jon, that you couldn't make heads or tails out of my ramblings. I'm fairly familiar with the different models and changes and was trying to descibe something quickly that Matt could check to solve his issue.

greg brown

JKelly

No, you just need to exchange the new roller (because it is for an S4, 87+ ??). Your water pump sounds correct for an 86 (see below). The roller on the right in the first photo has the wrong bearing size,......or is lacking a bushing, whichever the case, the way it is now it is wrong for your water pump. The roller on the left (your old roller) has a bushing already in it. The new roller, if it was the correct one for an 86', should have come with a new bushing in it and the bearing should be a #6004 like Garth said.
The tensioner arm in your pic looks correct too.

This is the correct water pump for an 86' 32v:

928drvr86.5

YES! Same thing happened to me on my last belt/pump job.

leperboy

Actually, I have to return the water pump, too. I had asked for a pump for an 86.5 and got one without the boss that the idler roller sits on.

So, I need the pump with the boss (85), and the correct idler to go on that pump. I think this is an easier solution than getting a new tensioner and arm to have all S4 stuff in the front. Certainly it's cheaper since I can return what I have and just pay shipping for the correct ones.

Matt

GregBBRD

If you guys read what Matt has said, he already has compared the pumps and he has a different water pump than the car came with. He has a '85/most all of '86 water pump and tensioner arm set-up, with matching parts. No need to make it more complex than that.

greg brown

928drvr86.5

I read that he received the same type pump (with boss) that he had removed from the car. I guess i should have read his later post stating the two pumps were infact different. I agree, a picture would have alieviated the confusion.


YES YOU NEED TO EXCHANGE BOTH THE PUMP AND ROLLER.