Should I weld the IMS shaft? Need advice

[martsink]

Hi guys,

I'm just in the process of putting back together a 99 M96 engine post IMS bearing failure. I got the engine ultrasonic cleaned and purchased a replacement IMS shaft. The old shaft looks to be in good shape, but I've read reusing the shaft after the bearing failure is a bad idea.

Now, should I have the replacement IMS shaft welded? I can't find much info on this online. How is this done properly? Does the shaft need to be balanced after? Can I just do this at any good welding shop (I'm in the Bay Area).

I've also seen some people using a set screw, but there seem to be mixed views on this one.

[BYprodriver]

Chain drive gears should be tig welded in place

[Zedsta]

Hi

The web link below has Flat 6 Innovations stating that they "weld and/ or pin every sprocket and drive. Overkill does not exist when I assemble one."
https://rennlist.com/forums/996-forum/928373-has-anyone-had-their-ims-gears-welded.html

My M96 IMS shaft has the larger sprocket pinned 9 and 3 weld points on the two smaller sprockets. Each weld length is pretty much equal and spaced roughly equally around the sprocket circumferences

What is not clear is whether or not the shaft would need to be balanced after the tig welds are applied.

I intend to use the LN Engineering IMS Solution bearing. Not sure if that would make a difference as to whether the shaft should be balanced after welding or not ?

Your expert advice would be very much appreciated.

Thanks

[cnavarro]

Originally Posted by Zedsta

Hi

The web link below has Flat 6 Innovations stating that they "weld and/ or pin every sprocket and drive. Overkill does not exist when I assemble one."
https://rennlist.com/forums/996-forum/928373-has-anyone-had-their-ims-gears-welded.html

My M96 IMS shaft has the larger sprocket pinned 9 and 3 weld points on the two smaller sprockets. Each weld length is pretty much equal and spaced roughly equally around the sprocket circumferences

What is not clear is whether or not the shaft would need to be balanced after the tig welds are applied.

I intend to use the LN Engineering IMS Solution bearing. Not sure if that would make a difference as to whether the shaft should be balanced after welding or not ?

Your expert advice would be very much appreciated.

Thanks

We pin the main IMS sprocket after inspecting the IMS for runout and taper. Any shat with more than .005" of runout is disqualified for use with anything other than an IMS Solution.

We've been pinning IMS shafts for probably a decade and we've never had any issue with balance. In fact, most intermediate shafts (with exception of one fitted with the IMS Solution and plug for the tube), fill up with oil, so balancing it wouldn't help much.