How to replace the friction gear spring assembly

**artemis** · 11-14-08, 15:39

I was doing some digging around and found this on the Mazda forums. It is a well documented thread with pictures, diagrams, part numbers, TSB references etc of one guy working through the fix for the loud tapping caused by a worn friction gear spring. Usually people on the forum diagnose tapping immediately as HLA noise, but friction gear noise is just as common. TONS of awesome info, give it a read, and add it to your favorites. The guy answering all the questions must have worked for Mazda.

That would be great if a moderator could put this in the how to section or something.

Here you go: Cam friction gear spring ??'s

And here is some other great info on the friction gear workings, problems, replacement etc.
Pics of the part, install
So for all of you considering the friction gear spring replacement, here are some photos of what we're talking about and some c

Great posts by Mike94PGT on a thread from 2000 on how the friction gear works. Rule of thumb: give this guy karma every time he posts, because he probably deserves it.
http://www.mx6.com/forums/2g-mx6-gen...otor-what.html (knocking noise in motor what is it)

And for those that don't already have it:
Welcome to Probe - MX6 - The original Julian bradbury makeover site

**nate_v8** · 11-14-08, 15:45

I've got the parts laying around, I figure when i rebuild my DE I will take care of this.

**artemis** · 11-14-08, 15:47

I need to do it too, did you just get those babies from mazda?

**nate_v8** · 11-17-08, 9:40

Quote:

Originally Posted by artemis

I need to do it too, did you just get those babies from mazda?

yeh, you can order them from mazda no problem. I have the part numbers here

Spring= KLY1-12-417A
Nut= KL01-12-412A

**artemis** · 11-17-08, 17:24

I ordered a set. Woo hoo! Quiet engine 'hear' I come.

thingsthatfly2 · 11-19-08, 10:57

haha nice pun.. how much were they?

**artemis** · 11-20-08, 3:36

Um, I just picked up the pieces today. Invoice says the springs were 15 bucks a piece, and the nut, 9 bucks. [fizzle]ing expensive, but a price I am willing to pay for a silent V6. I'll maybe post some pics, just because I heart mx6.com, and I would rather do that then homework.

**artemis** · 1-5-09, 0:02

I tore 'ole bessie down today, swapped out the friction gear springs and nuts, and buttoned her all back up. NO noise. If you have tick-tick-tick, that is HLA noise, but if you have clack-clack-clack, then you have a worn out/old style friction gear spring and nut, and replacing them with these parts will make the noise go away. I'll post up pictures of the install, and a video of the noiseless V6 when I get the chance!

**KLZE 30x** · 1-5-09, 7:13

Did you remove the timing belt to do this?

My MX-6 seems way past it's timing belt change time so I might as well do it all when the time comes. Am guessing you do the same thing for the rear head's cams too?

*reads guide*

**artemis** · 1-5-09, 23:22

Alright, so anyone that wants to fix this in their engine, go read those links above, then meet me back her, I'll be waiting...........

Welcome back.

For those that didn't read the threads above, the Part numbers for the revised Spring and Nut are:

Spring: KLY1-12-417A
Nut: KL01-12-412A

Do do this, follow these steps.

1. Remove the intake air duct
2. Remove the intake manifold
3. Remove the passenger side engine mount by first supporting the engine, then unbolting it
4. Removed the drive belts, timing belt cover, and timing belt.
5. Remove the camshaft sprockets
6. Remove the valve covers
7. Remove the camshafts.

Here we are, if you need help with any of those steps, consult your Haynes manual, or factory workshop manual etc.

Here is what they DON'T tell you though. The old style spring would wear out, and begin spinning on the nut, not doing a whole lot for the friction gear concept.
Here are the camshafts, sitting in the engine. You can see the friction gear in the upper left hand side of the photo

So you take them out, and put a 27mm ( or crescent) wrench on the the hex portion of the DRIVEN camshaft. you know, the one with the friction gear on it. You COULD go out and buy a 46mm socket for the friction gear nut, but that just seems silly. I used a big ass crescent. Torque that baby off.

You can see the old friction gear spring and nut and the new ones. The "spring" is actually conical, and when torqued on acts as a spring loaded surface.

These are the differences.

Put the new assembly on, then torque it to 55-61 ft-lbs. I didn't have that socket, so I had to estimate. 60 lbs @ 1 ft away on the wrench seemed pretty accurate. While you do this, you want to have an assistant hold the other camshaft's gear meshed with the driven camshaft in the position you are going to put the 2 back in the engine. You do this so that the friction gear is in the right position for installation. Otherwise, good luck getting them to mesh!

Repeat for the other cylinder bank.

While you got everything apart in there, it may be a good idea to also:
Change any squishy hydraulic lifters
Change the water pump
Change the timing belt
Change any old bearings in the timing belt idler pulleys
Change your camshaft seals

There she is all buttoned up.

Put everything back together, and enjoy your buttery quiet engine!

I'll snag a video/audio of the thing before and after to show you all how worthwhile it is to do it. It took me 5.5 hours today to pull it all apart and put it back together. Definitely worth it!

**unamedplaya87** · 1-8-09, 14:16

I wish I did that. I did my valve seals over the summer.The FGS never came into my mind.
You work really fast too