The M3cutters - UK BMW M3 Group Forum

The M3cutters - UK BMW M3 Group Forum (http://forums.m3cutters.co.uk/index.php)
-   E90 Saloon / E92 Coupe / E93 Convertible M3 (2008-2013) (http://forums.m3cutters.co.uk/forumdisplay.php?f=7)
-   -   S65/S85 throttle actuators. (http://forums.m3cutters.co.uk/showthread.php?t=94742)

alpina527 24th January 2014 09:10 PM

S65/S85 throttle actuators.
 
As many of you know, the S65 is an extremely reliable engine but still with one major flaw. The throttle actuators wear out relatively quickly. Having two of these on every car poses the question as to whether to replace them both when one fails or just do the one and hope for the best. The only answer is to buy a new one from BMW at Circa 700 plus fitting. The story is the same on the S85 V10

This is the first signs of a failed actuator.

http://i22.photobucket.com/albums/b3...EAF540E461.jpg

I've been looking into this project for a few months now and I've finally get there. Finding a spare S65 throttle actuator wasn't easy because of the BMW policy of keeping the old units replaced under warranty. I wanted to find what's happening and make something better.

BMW dealers sometimes call it an electrical failure of the actuator but it's usually nothing to do with the electrics. They are very well sealed and look well made.

The plastic moulded gears in the unit are made to a price, not longevity.

Here are the parts laid out after dis assembly.

http://i22.photobucket.com/albums/b3..._9913Large.jpg

The white compound gear in the middle of the picture is driven by the hard steel gear of the dc motor. Attached to the white gear is a 13 tooth reduction gear that drives the black output shaft with a lever on the other end of it's shaft which opens the bodies. The motor is driven against a hefty spring which keeps the throttle steady at any given throttle opening through the gear train.

http://i22.photobucket.com/albums/b3..._9920Large.jpg

Here's the reduction gear. There is heavy wear on the teeth which is difficult to see in the photo.

http://i22.photobucket.com/albums/b3..._9919Large.jpg

Any wear that happens on this reduction gear gets transferred to the plastic output gear. Again it's difficult to see but on close inspection you can see how thin the teeth are in the normal driving speed portion of the gear.

http://i22.photobucket.com/albums/b3..._9917Large.jpg

The main white gear that runs on the steel motor gear shows no signs at all of any wear. This is mainly down to good engineering practice of using a plastic gear on a steel gear. This eliminates most of the wear and runs clean with no dust.

However, the small reduction gear is part of the same moulding and runs on the plastic output shaft also made of plastic. Not a disaster, but plastic on plastic is a bit of a no no. This small gear not only takes a lot of torque through it when opening the throttles but also has to maintain speed by gently reciprocating backwards and forwards on the same teeth to do this.

So, basically there's nothing wrong with the large white gear in itself. The problem stems from the attached reduction gear and the output gear which is moulded to the output shaft.

I'm under warranty and have just started getting the dreaded idrive warning. If I take it to the dealers they will only replace the one actuator (still with the plastic moulded gears) . That means I will be back soon for the other one.

Having spoken to various applications engineers, most of them favour making the gears out of Brass and Delrin 150 plastic.

This is my brass and Delrin 150 reduction gear. Much stronger than the original and hopefully it will see me out.

http://i22.photobucket.com/albums/b3..._9910Large.jpg

http://i22.photobucket.com/albums/b3..._9909Large.jpg

http://i22.photobucket.com/albums/b3..._9906Large.jpg

This is the oem output gear and shaft. The gear width is 10mm so by carefully offsetting the gears I've managed to get this width up to 11.3mm for some extra strength.

http://i22.photobucket.com/albums/b3..._9925Large.jpg

This is my replacement gear viewed from both sides.

http://i22.photobucket.com/albums/b3...924Large-1.jpg

Comparison between new and old with the shaft fitted.

http://i22.photobucket.com/albums/b3..._9922Large.jpg

Finally assembled.

http://i22.photobucket.com/albums/b3...923Large-1.jpg

Now I just need a spare morning to upgrade and fit both my actuators.:peace:

Neil McRae 24th January 2014 09:15 PM

top job mate, delrin is good stuff and will give a lot of longevity, are you worried about wear from the brass to delrin though?

Ash m3 24th January 2014 09:32 PM

Excellent post :thumbsup: are you planing on selling them :confused:

alpina527 24th January 2014 09:35 PM

Quote:

Originally Posted by Neil McRae (Post 1269974)
top job mate, delrin is good stuff and will give a lot of longevity, are you worried about wear from the brass to delrin though?

No, apparently it's more than up to the job of the surface finish is good enough. I've polished the teeth so it should be much better than the plastic. It's certainly stronger that's for sure.

The reduction gear doesn't carry out the same kind of function as it would in a regular gearbox. Once you are cruising, it's hardly moving. Hard to explain, but the applications engineers recommended the combo with manufacturing and longevity in mind. It would be better in hard steel but It's overkill

Quote:

Originally Posted by Ash m3 (Post 1269995)
Excellent post :thumbsup: are you planing on selling them :confused:

Well I did make a few spares, so pm if you need any

Chezlar 24th January 2014 10:11 PM

Fair play. Impressive

Z4M 24th January 2014 10:25 PM

You missed a bit. :D

Toffeeman 24th January 2014 10:31 PM

Wow Ian, that is a fantastic build. That setup looks like it will outlast the car.

I look forward to seeing how you get on with them on a daily basis.

alpina527 24th January 2014 10:35 PM

Quote:

Originally Posted by Toffeeman (Post 1270108)
Wow Ian, that is a fantastic build. That setup looks like it will outlast the car.

I look forward to seeing how you get on with them on a daily basis.

Cheers. I like to make things to a quality not a price. They run very smoothly.

It's taken far more work than I envisaged.

I'm looking forward to fitting them.

Schuey 24th January 2014 10:38 PM

Quote:

Originally Posted by alpina527 (Post 1270116)
Cheers. I like to make things to a quality not a price. They run very smoothly.

It's taken far more work than I envisaged.

I'm looking forward to fitting them.

Well done mate.

Some clever people on this forum that could teach BMW a trick or two :thumbsup:

Arkenphel 25th January 2014 12:04 AM

Bloody awesome work, Ian!

I'm interested and would like a set please! What sort of work is involved in fitting these? Can my local Indy do it?

Seeing as I'm gonna be keeping my M3 for a quite a few years more, this would be an excellent idea, seeing as my current set of actuators have another 20k miles left in them, based on how long the first set lasted.

tonyjacko 25th January 2014 08:45 AM

Gents how long can you expect the standard actuators to last on average, mine is still under warranty but it's good to know for the future?

Cheers Tony

Arkenphel 25th January 2014 09:17 AM

Mine went about 40k miles in. Seems to last about that long, though some people have had failure with much, much less mileage.

Snowman 25th January 2014 09:50 AM

Top Job Ian, Will be keen to know how they run/operate on a daily basis.

daz05 25th January 2014 09:55 AM

Great post Alpina. Many have been scratching their heads on this, you get a unit last week and this happens. :)

Mattys 25th January 2014 10:19 AM

Hats off to you Ian, thats a amazing job. :thumbsup::thumbsup::thumbsup:

In a geeky way they look quite sexy in black and brass. Sad I know, but I do love a nice piece of engineering.

Why BMW / Siemens haven't updated the units yet is frustrating and quite sad really. I now there is a cost element, but it gets my back up that they knowingly keep making something that has a high failure rate.

Anyone planning on keeping a S65/S85 running for a while would be smart to invest in a few of these just in case.

Keep us updated on how you get on mate!

RAWM3EVO 25th January 2014 10:36 AM

Ian,

Great job !

you say you started getting issue ... did it throw a code?.. if so what was it?

alpina527 25th January 2014 12:53 PM

Quote:

Originally Posted by RAWM3EVO (Post 1270317)
Ian,

Great job !

you say you started getting issue ... did it throw a code?.. if so what was it?

The idrive faults shown in the first post indicate what's coming.

The actuators self test by going through a full opening of the throttles. Any resistance and they will throw a code which puts you into limp mode. It can disappear next day though.

At the moment my car drives fine but the idrive fault list will be back soon.

mpy32 25th January 2014 02:40 PM

Quote:

Originally Posted by alpina527 (Post 1270383)
The idrive faults shown in the first post indicate what's coming.

The actuators self test by going through a full opening of the throttles. Any resistance and they will throw a code which puts you into limp mode. It can disappear next day though.

At the moment my car drives fine but the idrive fault list will be back soon.

Great job Ian
I have
DSC failure ! Drive moderately
DBC failure ! Drive moderately
FTM system error !
start assistance inactive !
45000mls
New Actuators ??

Not used the car since last Sunday went to go out this afternoon and won't Start just turns over
Got BMW monthly warranty thankfully

chrisc 25th January 2014 02:55 PM

Great work Ian :thumbsup:

Isher 25th January 2014 03:24 PM

Top job Ian, really well done :thumbsup:


All times are GMT. The time now is 05:28 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright © 2007 - 2018 M3cutters. All Rights Reserved.