'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.

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 ........

JIM

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?

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.

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

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

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.

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.

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 ...

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.