OMC Cobra Gimbal Bearing / U-joints

[ajkolar]

I plan to remove my '88 Cobra drive this spring before boating season begins. How do I inspect the gimbal bearing to make sure it is ok? Or is it cheap/easy enough to just replace no matter what? <br /><br /><br />Also, I have heard by looking at the U-joints you can not always determine if they are bad or not? Are these something I can inspect myself, or should I just take the drive into a shop and have them inspect it (just hate to get a biased answer)

 

[Haut Medoc]

Re: OMC Cobra Gimbal Bearing / U-joints

Just stick your hand in there & see if it spins freely....No rough spots or play....JK

 

[rdc]

Re: OMC Cobra Gimbal Bearing / U-joints

I just did my 88 Cobra drive 2 weeks ago. This maybe more than you wanted to know, but if yours is all original you may want to change it just because. As mine was original which lasted 17 yrs. I got a kit on e-bay both bellows, gimbal bearing, clamps, and gaskets to sevvice the tramsom assembly. If you have a manual, or do a search I asked the same question, and have good responses. Disassembly is pretty straight forward. I had to rent an internal gear puller $16.00 to pull the gimbal bearing. 5lb. slide hammer type. After I install all the new stuff I couldn't get the drive on. Ends up that the inner race of the bearing is movable, and needs to be aligned to the enginge coupler. Thats easy to do also, but you need an alignment tool about $65.00 e-bay. Insert tool thru the new bearing, and tap with a rubber mallet at 0,90,180,270 degrees. Until the tool slides into the splines nice and easy. Hope this helps.

 

[ajkolar]

Re: OMC Cobra Gimbal Bearing / U-joints

rdc (or anyone else), how much did the kit run you with the bellows, clamps, gaskets, etc... Do you happen to have a part number for that (or maybe you could send me the item number on Ebay if it was recent). Where did you rent the slide hammer at (is it marine specific, or should any Rentall have one?) I already have the alignment tool so I will probably go ahead and do this just because I am not sure how old the bearing is. Thanks for the reply!

 

[newport dave]

Re: OMC Cobra Gimbal Bearing / U-joints

Sierra make a bellows/gimbal bearing kit for the Cobra - part # 18-2771, it's about $200.00. Assuming you buy an alignment tool and rent a bearing puller, you still need a bearing installer. You can make one fairly easy, it just needs to be something that drives the bearing in by the outer bearing carrier, not the bearing itself, so you don't damage it.<br /><br />Dave

 

[murphini]

Re: OMC Cobra Gimbal Bearing / U-joints

AJ--I live in Overland Park and was thinking of doing that same work on my 89 OMC in the spring. When you do it, I'd love to come by to either help or watch. Part of my help could be bringing some Gates as my tuition to learning how to do this.<br /><br />Let me know

 

[hoot]

Re: OMC Cobra Gimbal Bearing / U-joints

on my pre alpha, the rear end made a rumbling noise when turning. forum posts indicated that this was probably u-joint related. pulled drive shaft. joints looked fine and moved smoothly. however, when disassembled, the hardened surfaces under the caps had ripples. replaced all u-joints. water had gotten into the belows the year before and i just replaced the gimbal bearing. lesson learned, if water gets into the bellows, might as well replace u-joints also!

 

[ajkolar]

Re: OMC Cobra Gimbal Bearing / U-joints

Hoot brings up exactly the point I was worried about. If I take the drive off is there anyway I can inspect the U-joints without taking them apart? How much did it cost you to replace the u-joints?<br /><br />Rdc, what did you use to install the new gimbal bearing?<br /><br />Murphini, if you want to send your email address to ajkolar@gmail.com we can discuss getting together sometime rather than doing it on the message board. Thanks!

 

[rdc]

Re: OMC Cobra Gimbal Bearing / U-joints

AJ I just looked on e-bay where I got mine under boat parts type OMC cobra. The kit # 18-2771 is there with no bids. Right now $106.00 + shipping. The parts were all Sierra brand. The puller can be rented at about any tool rental place, even some hardware stores rent them. As far as installing mine I got creative. I had an oil filter wrench. The kind that fits on the end of the filter that was about the same outside diameter of the bearing. There was a square hole for a 1/2 drive socket extension. I used that.

 

[rdc]

Re: OMC Cobra Gimbal Bearing / U-joints

I forgot to mention pay attention to where the screw heads of the clamps are on the bellows. One calls for the 1:00 o'clock position, and one at about 2:00 o'clock position. Manual will tell you its so they don't interfer with the turning radius of the boat. Also use bellows adhesive on the driveshaft bellows both ends. You can use 3M, or Permitex weatherstrip adhesive too. Also make sure the hole in the new bearing line up with the filler tube for grease.

 

[llerrad]

Re: OMC Cobra Gimbal Bearing / U-joints

 

[ajkolar]

Re: OMC Cobra Gimbal Bearing / U-joints

Does anyone have any opinions on the Sierra brand bellow and gimbal bearing replacement kit? It seems like I heard someone say, when it comes to bellows, to use ONLY OMC parts? Thanks!

 

[horsefly38425]

Re: OMC Cobra Gimbal Bearing / U-joints

sierra parts work fine /u-joints 24.95ea.Yes i would r&r them /both. gimbal 34.95good 55.00better.bellows go ahead and replace /cost 200$///fun on the water [PRICELESS]

 

[lakelivin]

Re: OMC Cobra Gimbal Bearing / U-joints

One other thing on the Cobra u-joint bellows:<br /><br />Most are not symmetric w.r.t. the number of rings on top & bottom. Position so that the most rings are on the bottom, thereby placing less stress on the bellows when the drive is raised.