After 5 hard running seasons behind my 650HP 540, the stock Bravo U-joints were growling in turns and needed replaced. So after a bit of online research, I sauntered into my local NAPA auto parts back in early May, and purchased a set of SKF "Brute Force" u joints. While the drive was out, I checked the alignment (it was dead on), pulled the gimbal bearing (it was in excellent condition), installed a new gimbal bearing, and r&r'd the u-joints with the new SKF units.

Over the 4'th of July weekend, I started hearing strange noises again. Pulled the drive again....the "Brute Force" u-joints were toast. As you can see below, the aftermarket "Brute Force" u joint is nowhere near as beefy as the stock Merc part# 75832T1 75832T2 18-2174, etc. After running around to Advance, Auto Zone, Car Quest, Oreilly, NAPA, and Bumper-to-Bumper, the situation was the same......all were typical chinese made, pot metal junk. At the local Marina, all of the 18-2174's that were in stock were chinese made junk as well. Even the Moog 246/315G style, while American made, is still nowhere near the quality of stock Merc type u joints. I had to scour ebay to find a pair of American made Rockwell/Meritor (forging# L15N1-1F) stock style ujoints. The set I found was NOS from 1998 (part# 75832T1) and cost me $65 including shipping.

The lesson: Just because it fits doesn't mean it will work well. Stick with stock type Merc u joints and save yourself a lot of hassle.

Stock Merc u-joint:



SKF "Brute Force" u-joint:



Side by Side:

WOW - BIG difference there.

was the lube hole drilled ? had that happen to me on my gibson, has a short drive shaft from trans to V-drive, 2 joints, one broke a couple years ago, had been lubing regularly, when looked at it saw one side never drilled, lasted years before blowing up..

Mercruiser has used NON greaseable U joints for years. The Non grease U joints are 10 % stronger than the grease ones.

I see the difference in the U Joints, but I dont see how the one you have pictured shows that it is failing and would be making noise?

I haven't had time to replace them yet. When I bought the brute force units back in the spring, I bought a second pair because I had a 20% off coupon. I have a spare Bravo drive on a stand, so I pulled the yoke while I was investigating this issue, and the comparison is pretty obvious.

I know the manager at NAPA pretty well, and went back over there to show him the situation. He pulled a few other u joints/brands off the shelf and we figured out what is going on. It appears that all of the auto parts manufacturers are using what appears to be a "universal" forging, and then machining whatever sizes are needed from that forging. The forgings vary by oem, but, the needle cups, needle bearings/races/journals, appear to all be the same size.....undersized and not suitable for performance use. So whether the ujoint is going into high power or low power use, the bearing area appears to be the same.

Being a design engineer myself, the oem's do this to save cost. 80% of the cost of a ujoint is the finish machining and precision tolerances in the bearing cups/races/journals on the ujoint. Since ujoints are not as popular as in years past, they can use one forging and one set of bearing cups to cover 10 different sizes/part#'s. This is iffy at best for a car/truck much less the kind of power in a performance boat.....add in typical poor chinese QC....and they lasted barely 2 months in my boat.

The 4WD guys have access to Spicer and some other aftermarket brands that appear to be tailored to high HP performance use, but I was unable to find a size in these that crosses to the merc ujoint dimensions.

NAPA used to be a step above the typical Auto Zone/Oreilly/Advance stuff, but sadly, the local manager told me they have to compete on price, so they sell a lot of junk now as well.

I would like to see some pics of the newer Merc ujoints, sealed units, etc....to see if they are as beefy as the older design.

hard to tell in the pics but if the cup diameter is not same for the installment into the Yoke - it is not a U Joint issue - it is the size issue. In the bottom pic --- the cup sizes do not look the same to me but the pics are hard to tell. I would measure them.

Again in the pics hard to tell 100 percent --- the SKF U joint does not look to be the correct U joint for the app.

They are the proper size in terms of 2 1/8 yoke with 1.078 diameter bearing cups.......and are a Moog 246 equivalent cross reference part#. AFAIK the part#'s come from a 1970's Chrysler full size car application. So yes, while they technically fit, they are not suitable for heavy duty marine use. I first found the part#'s in this thread: http://www.offshoreonly.com/forums/g...der-drive.html

In that thread, the 315g/246 type u-joint was positioned as a equivalent part# at cheaper cost than the Merc u-joints. My purpose for this thread was to say they are not equivalent to the Merc U-Joints.....not even close......at least for Bravo-1 applications that use the older (non-metric) inside clip type u-joints.

mine had the grease fitting, just one side was never drilled so only one side was lubed

I hear you guys and thanks for posting. 2004 around that year when all drives started using GKN parts they went to non greasable U joints. Serial number dictates Just saying for a fyi

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