Alternator Belt Replacement

[Alba]

My bike is a 02 1150RT and it time for alternator belt change, I [stupidly] thought it would easy to locate [in the UK] a replacement belt and the tricky part would be the tensioning. Unfortunately I am failing at sourcing the belt. Current installed belt is a Contitech 11.28 1341 779 692 637 4PK611SR.

 

Now the fun

 

Looking at contitech website i see the main reference is the 4PK611 and my bike and age is listed along with some car models, great.

 

I cross check the part number on a new website I found RealOEM and the part number list does not exactly match the current belt. Doubt starting to creep in!!!

 

I search ebay and internet for exact current part number no joy.

 

I then use ebay for the 4PK611 reference, many returns from all over the world and looked into a car mentioned by contitech website Accent but the packaging imagine shows non matching detail numbers.

 

I then checked a bike related ebay link for the RT but there is no detail part number.

 

I am now having a woods / trees moment .......

 

Some guidance would be appreciate from the collective Can i get a basic 4PK611 and be done?

 

[dirtrider]

Morning Alba

 

Just about any 4PK611 poly-V belt will work on your (non freewheeling pulley) 2002 1150.

 

The 4 PK is the rib, spacing, & profile & the 611 is the belt length in MM.

 

12311341779 belt 4PK611 is a common belt used in the U.S. but the good news most of those seem to originate from your side of the ocean.

[AndyS]

Just go to Motorworks.

or James Sherlock

or Motobins

or yuor local BMW dealer.

 

https://www.motorworks.co.uk/vlive/Shop/Parts.php?T=6&Q=4PK611&x=16&y=23

 

These belts are also readily available at many Power Delivery specialists, such as:

Brammer

Premier Power

Transmission Developments

[Alba]

Thanks dirtrider and AndyS, the sanity was needed.

[oilhead1100s1150rt]

I have the same r1150rt 2002..... Any other proactive maintenance recommended while changing out the alt belt? "Why you're in there" type work.....31,000 miles.

 

Dave

[dirtrider]

Afternoon Dave

 

You might check the HES sensor clip (clip that holds the HES wire pig tail) as there was a BMW service bulletin on a run of those cracking & breaking. (the wire clip sits just below the alternator )

 

 

[Alba]

Part 2 = frustration

 

I have got the old belt off, took me a while to remember the top bolt and not just the two side ones .....

 

Now I am struggling to get a socket into the bolt at the rear of the alternator to set the torque.

 

What should this bolt size be? And do I need to source a stepped thin socket?

 

I seen somewhere on tinternet [subsequently found https://www.youtube.com/watch?v=0Zz-Hg_Af6c] a fitment which goes on the front to set the belt tension is this an option?

 

[dirtrider]

Morning Alba

 

I have the correct (later) BMW tool that goes on the the front (no need for the old rear access to adjust).

 

But you can use a SIMPLE acorn nut on the adjuster bolt FRONT to set the torque from the front.

 

You might even be able to use a double nut on the front of the adjuster bolt if you can't find an acorn nut.

[Jim Moore]

Part 2 = frustration

 

I have got the old belt off, took me a while to remember the top bolt and not just the two side ones .....

 

Now I am struggling to get a socket into the bolt at the rear of the alternator to set the torque.

 

What should this bolt size be? And do I need to source a stepped thin socket?

 

I seen somewhere on tinternet [subsequently found https://www.youtube.com/watch?v=0Zz-Hg_Af6c] a fitment which goes on the front to set the belt tension is this an option?

Big-ass screwdriver under the alternator. Lift with one hand and tighten one of the nuts with the other hand. You should be able to line up the witness marks from the old belt. If you get it right you should be able to twist the belt about 90 degrees. It's a belt, don't overthink it.

[Charles Elms]

 

Big-ass screwdriver under the alternator. Lift with one hand and tighten one of the nuts with the other hand. You should be able to line up the witness marks from the old belt. If you get it right you should be able to twist the belt about 90 degrees. It's a belt, don't overthink it.

 

That's what I did and my belt lasted over 50k miles.

[Alba]

Jim loving the simplicity in your approach, I'll also research the acorn nut Dirtrider references.

 

Thanks, I truly do appreciate this forum in keeping my bike running.