bravo u-joint questions
 

'91 Fountain, Bravo 1 behind a 502 mag

I'm wondering how i can tell if my u-joint is bad. My only symptom when running last year was on perfectly smooth water at WOT, if i trimmed the drive up or down from perfectly straight, or turned, it would vibrate a little. not bad, not noticeable at idle, and not audible, but you could feel the vibration in the boat. Is this normal?

I will be pulling the outdrive to inspect the u-joint, gimbal bearing, and bellows before summer. If i determine the u-joint is bad, how big a deal is it to replace?

Can i press out the old u-joints and press new ones in like on a driveshaft for a truck? Or do i need to buy the whole shaft assembly thing? What part numbers should i be looking for, and who should i buy from?

Also, what should i look for when i'm inspecting the bellows? Should these be replaced periodically? I'm leaning toward replacing both bellows as preventative maintenance, the exhaust bellows is starting to show signs of cracking anyway.

Re: bravo u-joint questions
 

Vibration is not normal. Probalby U-joint or gimble bearing.
You should be able to tell when you pull the outdrive.
Replace U-joint, if you have never done it, take it to a dealer and save yourself the headache.
Bellows, again if you have not done it take it to a dealer.
There is more to it than it looks like. Read the manual to get and idea on both topics. I have done them both several times and without the proper tools its a pain in the ........ :D

JIM

Re: bravo u-joint questions
 

I guess my main question then is do i need to replace the whole assembly, which looks to be damn near $500, or can i get a way with a $50 u-joint from an auto parts store?

Re: bravo u-joint questions
 

Could be the gimbal bearing too. when the drive is off, spin the bearing with your hand to see if you feel any rough spots. Also, make sure it is greased well.....there is a zerk fitting on the outside of the housing (right side) that shoots grease into the bearing.

Re: bravo u-joint questions
 

also, do a search here on u-joints. I seem to remember someone finding a cross reference # to automotive joint that was 1/2 the cost. I've never installed the u-joints, so i cant help you there.....but i believe they do press out / in

Re: bravo u-joint questions
 

sometimes you can turn the wheel hard at idle and if you hear a clicking it prob does need U-joints ...m

Re: bravo u-joint questions
 

The local shop i use said stay away from automotive u joints, they'll dynamite. He said he has u-joints in stock, it takes 2 and they're $50 each. $350 parts and labor. About $900 parts and labor actually, since i'm going to have him do all the bellows, etc. that are in there at the same time. Probably gimbal bearing as well. Some of those parts are bad, the rest are preventative maintenance. Plus another $300 for the water pump, installed. it's tight enough in that area to make it worth that. Now i just need to come up with $1200.

Re: bravo u-joint questions
 

Just had both drives done this week. $1,240.00 per drive which included gimbles, seals, u-joints and bellows. $900.00 of it was labor.

Re: bravo u-joint questions
 

you can get the whole assembly for 401.00 from Bam and maybe less somewhere else .... It was about the same $$ ...saved the labor on rebuilding the U-joints ... however .. I was resealing the drives so maybe that was the savings because the drives were apart ...

Re: bravo u-joint questions
 

Well, one of the nice things about spending the money on labor, is that i don't have to do the work myself. My time's worth something, and i don't want to be dicking around with a wrench while i could be out boating.

Re: bravo u-joint questions
 

When I had to have new driveshafts installed on my XR's they were smaller in diameter compared to the earlier version of XR driveshafts and they came with non-greesable u-joints (no zerts). The earlier u-joints had a zerts greese fitting on them and now the newer version does not. Don't really know if the non-greesable u-joint is good or bad, but it looks to be Merc's latest design.

Re: bravo u-joint questions
 

yup ....means mo bucks for merc .... :rolleyes:

Re: bravo u-joint questions
 

Bravo 1 ujoints are still available, XR/XZ are not, then you replace the whole shaft as Kaama said.
The ujoints are not that hard to change, by the time you finish with the last joint you will have it down pat, well if they are all back together the way they came apart.. I guess I need to charge more??

Bellows is another matter, not for the faint of heart. Not part of the drive, so I dont do that. Still think I need to charge more..

Hope this helps
Dick

Re: bravo u-joint questions
 

What would cause a bellows to go bad (leak) at 55 hours?

Re: bravo u-joint questions
 

Cruising with drive trimmed and bellows exposed, hit a small piece of debris, it kicks up and pokes a hole in the rubber bellows.

Or sabatoge.....I had someone cut my bellows while the boat was on the rack. replaced 3 in a month.

Re: bravo u-joint questions
 

I had both go bad the same week (Last week) within two days of replacing the first one. Less than 60 hours on them. All U-Joints gimbels seals had to be replaced. Apparently they had been leaking since the last lower unit oil change (Or sooner) that I had done end of last year at 50 hours. Thought it was strange.

Re: bravo u-joint questions
 

critters

muskrats will sometimes chew on the bellows. i've heard a few tales of people leaving their drives trimmed up at the dock, and coming back to find their boat on the bottom because a muskrat chewed through the bellows.

Re: bravo u-joint questions
 

They better get a bigger bilge pump then :D
Unless someone could tell me difference I would think it would be a tale.
The water would only drip through the gimble bearing and I was told that was part of the design.
The exhaust bellows would not allow water into the boat.
I have heard of the old OMC :eek: where the big rubber boot sprang a leak. That would fill up a boat fast.

Re: bravo u-joint questions
 

Smart choice. This work does not require a PhD, but you can get into trouble if not familiar with the process. Doing it it all at once is more cost effective, long term, than one piece at a time. The only thing worse than being the one dicking around on a nice day is being the one dicking around fixing what you just finished dicking around with, on another nice day.

The Muskrat deal was fairly common with the older OMC stern drives, I have seen a couple go down after a good chewin by the little critters. The Merc design would take longer for sure, and only thru the driveshaft boot.

Re: bravo u-joint questions
 

So those U-Joints are Merc only sizing and not a standard U-joint that can be bought from a bearings supply house? Seems odd. Sucks haveing to spend $400 to get a $10 part.

Re: bravo u-joint questions
 

the pricing is on the money for a good experianced shop / tech

Re: bravo u-joint questions
 

whether the size is the same or not, it's a different duty cycle. I would imagine the marine pieces would have to be significantly tougher. Wider angle of operation and possibly more RPM than a typical automotive u-joint.

The tales i've heard of muskrats chewing through the bellows were generally not model-specific. Just old-timers yapping about how i should make sure to tilt the drive down and how "this one fella" had his boat sink. good to know that if that happens it'll take a while to sink with a bravo.

Re: bravo u-joint questions
 

the ujoint it self is the same for alpha, omc cobra and volvo the all use the same heavy duty ujoint manufactured by rockwell