Sierra 18-2174 U-Joint
Price: $49.95
Save: $16.24
(24% Off $66.19)
Part # 18-2174
This item is found in the following Product Families
Replaces OEM part #
  • OMC 915717
  • OMC 3850812
  • VOLVO 3850812


  • Includes straight grease fitting and 90 degree fitting (Rockwell)
  • Heavy Duty
For: OMC Cobra and King Cobra Drives (1990 & above), and Mercruiser ALPHA I Units S/N B418819 & above, ALPHA I SS & BRAVO.

For: Volvo 3.0L GS, GL, 4.3L GL, GS, GI, 5.0L GL, GI, 5.7L GL, GI, 5.8 FL, FI, FSI
Average Customer Review for Sierra 18-2174 U-Joint
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Just fine U-Joints
by Robert from Murfreesboro, Tennessee on June 07, 2016
The U-Joint worked correctly on my 1990 Alpha One Mercruiser outdrive that is a 1.84-1 ratio drive. Purchased 2 to totally rebuild the Universal shaft
(1 of 1 people found this review helpful)
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Defective Part - Made in China
by Glenn from Carmichael, California on July 22, 2015
I have a 1992 Marlin 20-footer with a small block Chevy and an OMC Cobra outdrive. I had to replace the u-joints and gimbal bearing after they got wet because of a puncture hole in the bellows. The first time I took the boat for a cruise with the new u-joints, I started noticing a vibration every time I turned right or left. But it was fairly smooth as long as I was going straight. We met some people for lunch a few miles down the river and as we were coming back up the river (at 25 mph) the vibration got worse and worse. Something let loose before we got back to the dock, so I turned off the engine and got a tow back. I took our boat into the shop the very next day and my mechanic said he'd never seen a brand new u-joint just break apart before, like mine had just done. Two of the caps (opposite from each other) had just broken in half, allowing the u-joint to separate from the yoke and flop around inside my outdrive casing. I always save my old parts boxes, and when I read the label to see where the u-joints were made, I wasn't at all surprised to see that they were made in China. Steer clear of these Sierra u-joints!
(2 of 4 people found this review helpful)
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wrong size
by Dale from Carver, Minnesota on June 28, 2015
The joints were to big for my application so I returned them for credit. It has been more than two weeks now and I have not had any communication on the credit for the joints.
(1 of 1 people found this review helpful)
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by Alan from Pembina, North Dakota on February 25, 2015
pressed right in, nice to have both types of grease zerks.
(2 of 2 people found this review helpful)
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Alternative U-joint part #'s for situations like Jennifer from Gilbert, Arizona had.
by Paul from Moreno Valley, California on January 09, 2015
Hi there Jennifer, though it's a bit to late to help you in your situation, I'd like to take a little time to try and save future customers from going through the same situation that both you and what appears to be many other "iboats" and "non iboats" online competitive companies that sell the same sierra marine U-joints that would fit a Volvo SX stern drive. As an helpful boating service adviser/forum member/moderator for iboats, I've run across others like you that were in need of U-joints for the Volvo SX stern drive. Unfortunately Volvo has discontinued selling U-Joint spider OEM Volvo part number 3850812 and now recommends buying and installing a complete input shaft assembly part number 3860842 per Volvo Penta's Parts Bulletin..."Group P-44-1", Number 5, Version 02 hopefully linked below if the link works here in the "reviews". Despite the parts bulletin saying that spider part number 3860232 will not work on the SX/DP-S/XDP u-joints, we have concluded that they will in fact fit/work perfectly on the SX style stern drive models as the U-joint spiders have been matched up by both marine professionals and non professionals that work on their own boats with the help of iboats boating forums used as a secondary user guide to complete their boating projects. We'd like to invite you and everyone else to come join and participate in iboats boating forums.:) To summarize, Though it's said it will, old OMC/Volvo part number 3850812 which is sierra part #18-2174 found both online and in the Volvo service manual will not fit a later model SX stern dive but Volvo number 3860232 which crosses over to sierra part number 18-6406 will fit the later model Volvo SX stern drives that use the GKN style U-joint assembly with external clips. Again' despite the parts bulletin saying otherwise. Please know that iboats isn't the sole company to blame in this/your situation due to the problem is industry wide starting with Volvo Penta not selling or providing U-joint parts numbers that would work and sierra marine not having/receiving/knowing the exact information to provide it's retailers. On behalf of, Please accept our sincere apologies for any inconvenience this had caused you. Thank you. Here is a link to the Sierra U-joints that will fit the SX stern drive. 18-6408. Here's a link to the forum that covers most everything mentioned above, The first link should be to the Volvo part bulletin # 44-1 5 02 Hope this information will help others during their online searches...Take care... And Happy Boating.
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by Jennifer from Gilbert, Arizona on April 25, 2012
I ordered this to put into the Volvo Penta Engine that I have on my boat... The people at iboats AND the people at Sierra (the manufacturers of this part) BOTH promised me "without a shadow of a doubt" that it would work to replace the old U-Joint's in my engine. THEY DO NOT FIT!!! We ended up having to eat the money we spent on these and just order an entirely new shaft for my engine from Volvo themselves. DO NOT BELIEVE ANYONE WHEN THEY SAY THAT THESE WILL CROSS REFERENCE WITH YOUR VOLVO MOTOR!!!
(4 of 8 people found this review helpful)
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