Go Back  Offshoreonly.com > Technical > Drives and Lower Units
Best Combo?  X upper w/XR Lower? >

Best Combo? X upper w/XR Lower?

Notices

Best Combo? X upper w/XR Lower?

Old 12-12-2019, 01:32 PM
  #11  
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha
Posts: 17,711
Received 224 Likes on 117 Posts
Default

Originally Posted by Apexwarrior View Post
Thanks for the info. I did not realize the cost differential. Also, how could they be stronger, but lack longevity as compared to the XZ's? Is the best combo then an XZ upper and an XR lower as indicated in an earlier post?
XR's gears have straight cut teeth that are thicker. The problem is the hardening on the gears wears faster and then when a tooth breaks it takes out the entire upper. XZ's gears don't seem to have the same issues.
Griff is offline  
Old 12-12-2019, 02:00 PM
  #12  
Platinum Member
Platinum Member
Thread Starter
 
snowrunner's Avatar
 
Join Date: Aug 2013
Location: Lake St. Clair, MI
Posts: 433
Received 8 Likes on 6 Posts
Default

Originally Posted by Griff View Post
XR's gears have straight cut teeth that are thicker. The problem is the hardening on the gears wears faster and then when a tooth breaks it takes out the entire upper. XZ's gears don't seem to have the same issues.
what does the XR lower provide than, other than a stronger 1.25 prop shaft? Just better at retaining the prop in the event something is hit?

the upper shaft is already the 1.25 in all Xs? Anything different in the diesel X, other than a sticker (1.5 ratio)?
snowrunner is offline  
Old 12-12-2019, 02:48 PM
  #13  
Registered
iTrader: (5)
 
Join Date: Jul 2009
Location: Taunton Ma
Posts: 7,833
Received 141 Likes on 75 Posts
Default

Nothing in the drive is designed with taking a hit in mind. At 500+ hp you will start to twist the splines of a standard 1 propshaft. I think an Xz would be your best choice, stronger input retainer, steel tower, helical cut upper gears with the stronger propshaft in the lower.
Unlimited jd is online now  
Old 12-12-2019, 04:00 PM
  #14  
Platinum Member
Platinum Member
Thread Starter
 
snowrunner's Avatar
 
Join Date: Aug 2013
Location: Lake St. Clair, MI
Posts: 433
Received 8 Likes on 6 Posts
Default

Thx to all for the great input! Youve confirmed what the majority of my drive rebuilders told me. Many said if an XR gear fails theyd rather not reuse the housings, much more damage than the helicals typically do.

Im going for the XZs.
snowrunner is offline  
Old 12-12-2019, 06:54 PM
  #15  
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha
Posts: 17,711
Received 224 Likes on 117 Posts
Default

Here's link with the specs on all Bravo type drives https://www.go-fast.com/mercruiser_b...terndrives.htm
Griff is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


OSO Sponsor
OSO Advertiser
OSO Advertiser

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.

OSO Advertiser