Pushed the top plate off my xr upper , pushed the front 2 bolts out . Is this a common thing for these drives ????

Are you talking about the top cap that is held on by four bolts ?? If so I am gonna guess that you have a twin engine set-up and this is the port side drive?? If so the twisting force is transmitted upward when in forward gear.

To fix it drill it out and helicoil the case and replace the bolts with studs. Then torque and check frequently as they will loosen over time from the upward torque.

Smitty

Yes it is the top cap but it is on the starbourd side. thanks for thereply jeff

I changed mine to 7/16 studs and billet top cap,Smitty

Jeff,
the drive that has the LH prop on it, uses the top gear for fwd. There is a lot of presure on the top cap. The cap is a very weak piece and should be replaced with a better top cap. I use the Merc XR top cap and a stud kit. It has a steel tower in it and is a very strong piece. So I would helicoil the holes and use studs with a good top cap. If you replace the top cap you have to measure the depth of the race on both caps and change the shim accordingly.
Did your top cap come completely off or just pushed up.. either way you better check for damage to other components in the upper gear set and bearings..

Hope this helps.
Dick

Looks like i will put 7/16 studs in them and try that , thanks again for the help Jeff

When you drill it for 7/16" the case gets real thin. I recommend the heli coil and studs. Cause once you go to 7/16" you cant go back..
just my .02

We use a 1/4" longer, grade 8 stainless cap screw for our billet water cooled topcaps. We do offer a 7/16" for already drilled cases but do not recommend the modification...
Curtis @ www.billetmarine.com

Curtis, I was just going to ask if anyone here was running your billit top cap? I was looking at your site, and it looks like a very strong part. Does a standard drive shower line/ fitting screw into your top cap?




Darrell.

Max Machine Worx makes a nice piece http://www.maxmachineworx.com/upperTopCap.htm