Go Back  Offshoreonly.com > Technical > General Q & A
What exactly is needed...b1 to xr >

What exactly is needed...b1 to xr

Notices

What exactly is needed...b1 to xr

Thread Tools
 
Old 03-11-2018 | 05:25 AM
  #1  
BBYSTWY's Avatar
Thread Starter
VIP Member
5 Year Member
VIP Member
 
Joined: Jul 2017
Posts: 1,740
Likes: 298
From: Sodus MI
Default What exactly is needed...b1 to xr

I have a 97 heat that I'm upping the power on and I need to convert from my standard bravo 1 to an xr....here's what I have, what else do I need??

brand new case with steel tower installed
old guts out of my stock bravo 1 that blew(input shaft and yolk, upper shaft seems to be undamaged by upper shaft I mean the short gear stack shaft, shift arm, shift ramp seems undamaged)
max machine works billet top cap

Do I just need these things or what am I missing??

upper bearing set
obviously XR gearset
pinion gear yolk

I can get merc parts at cost so unless I need a huge amount of more parts it may be beneficial for me to build my own upper VS buying a used one...that's what I'm trying to figure out

Thanks!!
BBYSTWY is offline  
Reply
Old 03-11-2018 | 05:52 AM
  #2  
Registered
 
Joined: Jul 2009
Posts: 8,527
Likes: 706
From: Taunton Ma
Default

Input shaft, bearings, input shaft retainer
Unlimited jd is offline  
Reply
Old 03-11-2018 | 06:19 PM
  #3  
BBYSTWY's Avatar
Thread Starter
VIP Member
5 Year Member
VIP Member
 
Joined: Jul 2017
Posts: 1,740
Likes: 298
From: Sodus MI
Default

do I need the whole shaft or can I just change the end that goes in the pinion gear?? also the retainer...I'm assuming I need the one that requires the spanner instead of the "castle" one??

What about the gimbal bearing?? I've read before that I need a specific gimbal bearing??

Also last question...may be stupid but I'm assuming I need an xr bearing set correct or are they all the same??

Thanks!!
BBYSTWY is offline  
Reply
Old 03-11-2018 | 06:31 PM
  #4  
Registered
 
Joined: Jul 2009
Posts: 8,527
Likes: 706
From: Taunton Ma
Default

It depends on what shaft and U joints you have now, that will dictate what you should replace for input shaft components. Their used to be 2 different gimbal bearings but that was quite a while ago. All the same now, especially if you are using the smaller u-joint input shaft.
Unlimited jd is offline  
Reply
Old 03-11-2018 | 06:44 PM
  #5  
BBYSTWY's Avatar
Thread Starter
VIP Member
5 Year Member
VIP Member
 
Joined: Jul 2017
Posts: 1,740
Likes: 298
From: Sodus MI
Default

I have the 97 model bone stock B1 compnents...not sure of the drive serial number off hand but I'm assuming its the "older" style
BBYSTWY is offline  
Reply
Old 03-11-2018 | 11:24 PM
  #6  
VIP Member
20 Year Member
VIP Member
 
Joined: Nov 2002
Posts: 4,176
Likes: 333
From: ankeny,ia.
Default

You’ll need the thinner thrust races used on the OM ^ s/n drives, and I’m thinking the shift fork and cone also, I know you get these with the updated thick floor gear kit, the tower thrust races are also different and have to be placed lower to allow the gears to fit.... the instruction for the x style gear update goes through this pretty well, I have it but am out of town.
JaayTeee is offline  
Reply
Old 03-11-2018 | 11:24 PM
  #7  
VIP Member
20 Year Member
VIP Member
 
Joined: Nov 2002
Posts: 4,176
Likes: 333
From: ankeny,ia.
Default

bulletin is on line, I can’t get it to paste though, google mercruiser x gear upgrade kit instructions, BAM s site has the bulletin

Last edited by JaayTeee; 03-11-2018 at 11:35 PM.
JaayTeee is offline  
Reply
Old 03-11-2018 | 11:55 PM
  #8  
BBYSTWY's Avatar
Thread Starter
VIP Member
5 Year Member
VIP Member
 
Joined: Jul 2017
Posts: 1,740
Likes: 298
From: Sodus MI
Default

I gotcha..so if I buy an XR upper bearing set it should come with all the necessary upgrades correct?? as long as its OM and up??

thanks
BBYSTWY is offline  
Reply
Old 03-12-2018 | 07:42 AM
  #9  
Registered
20 Year Member
 
Joined: Jun 2004
Posts: 1,948
Likes: 37
From: Omaha, Nebraska. Boat on the Mighty Mo! Longest river in the USA!
Default

Don't forget spacers for trim cylinders.
1BIGJIM is offline  
Reply
Old 03-12-2018 | 09:06 AM
  #10  
VIP Member
20 Year Member
VIP Member
 
Joined: Nov 2002
Posts: 4,176
Likes: 333
From: ankeny,ia.
Default

Originally Posted by BBYSTWY
I gotcha..so if I buy an XR upper bearing set it should come with all the necessary upgrades correct?? as long as its OM and up??

thanks
the regular bravo case has a thicker snout where the pinion bearings are housed, the X cases are thinner, the bravo cases use the castle nut type retainer nut the x cases use the nut with pin holes in in, you’ll need to use the bearings for the type of case you have....I posted the link to the instructions to show what is different, they don’t make an XR kit to go into the old style case, but it can be done though, I did it a couple of years ago... the thrust race thickness needed determines backlash, the range is .009-.015”

Last edited by JaayTeee; 03-12-2018 at 09:17 AM.
JaayTeee is offline  
Reply


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.