ComfortablyNumb

I have a bravo1x (in 2002, serial no. OM167435) on 496mag ho. I ordered it with the 1:65 ratio for the altitude here in Denver. I've added a whipple 2 summers ago. To make a long story short I decided this spring to change the ratio to a 1:50 to help with the performance. I searched for a few weeks in the Denver area for someone to do the switch for me. Didn't have much luck. Found someone, reccommended by a reputable dealer, who works out of his own shop. Talked to him, got on his schedule and after 3 weeks I brought the drive in on June 1st. Few days later I paid him a grand to order in the upper gear set, expedited. Check cleared the next day and now 3 weeks later I'm still waiting.

I've got a string of reasons for various delays. I'd to think that since I waited until he was ready and then paid up front I would be at the top of the list. I guess not. I don't know if he has some bigger jobs that keep pushing my job back or what. But I don't have all summer, especially here in Colorado.

I may just go and get my drive back and take the gears if he has them. Hopfully I'm not screwed out of my money.

So, getting past the sob story, I was wondering about doing the work myself. I have a decent set of tools, I can follow instructions and I have patience to do it right. I installed the whipple kit on my 496 successfully. I know I may have to purchase a few tools specific to the job at hand. My understanding is that only the uppers in the Bravo 1x need to be changed for the 1:50 ratio. I have the Mercury Service manual #28 for Bravo sterndrive units. This details a complete tear down and rebuild. It seems that I don't need to go that far to change the gears and the drive has a little less than 50 hours on it.

So I want to ask if anyone has seen or knows of a set of step by step instructions for just changing the upper gears? Am I asking to much or in over my head?

Thanks in advance for any advise!

Pat

tblrklakemo

Dont know, but good luck. Im moved to MO from Denver (Tech Center Area) and cannot imagine too much boating....let alone boat shops. We used to go to Cherry Creek Reservoir to Jet Ski. Where do you take the Rage? Chatfield?

racesdad

You Better Have A Pro Do It. There Are Shims And Rolling Torque Settings. If You Screw It Up It Will Cost Alot More

excursion

The shims will stay with the upper, if you have the late model cases. You can find what are in yours by pulling off the back cap and there are numbers stamped in the case. . There are no rolling torque settings on the upper just 200 ft#'s on the spanner nut. You will need special merc. tools for some of this. If I can help you let me know. You could ship me just the upper and I can turn around it around in 2 days. $250.00 gear swap out.

oldandtired

Assuming the bearings are good, the only special tools needed are the spanner wrench for the input shaft nut and a 0-15 in lb torque wrench (ebay around $50). I used the number 11 manual when repairing my Bravo 1 which had everything layed out step by step. The shims should be the same since you have an x drive. It's about a one hour job or less once you have the drive off of the boat. Take your time setting up the preload on the input shaft bearings and you'll be fine. Go ahead and put a new seal in the upper while you are there and work clean. I found that the work in the upper was actually very easy. If you still have doubts, go ahead and ship it out for peace of mind, but I would do mine again in a heartbeat.

Rene

ComfortablyNumb

Thank you for the advice everyone. I'm going to give it a couple of more days and see if I can get this resolved or completed. I looked up the prices for the tools, a spanner wrench and a shifter adjustment tool (don't have my book with me). Not to bad actually. The gears cost a bit though.

Can I tell if I have the late model case by the serial number?

My real concern is that by putting about 600 hp though the drive I should have an experienced person do this, although I really enyoy being able to do some work myself.

tablrklakemo;

I do go to Chatfield just to get the boat wet, usually early on the weekends, thats when the local hot air balloon clubs like to launch. I also go to Horestooth in Fort Collins, Lake Granby up off of US40 and then Blue Mesa Reservoir west of Gunnison. I've not been down to Powell for 6 years. I want the lake to come up a bit more before I spend the money to tow that far again.

excursion

15 in lb's ???? What are you torqueing down?? That spanner nut is at 200 ft lb's
You also have to make sure that the gears are aligned.

Mr Gadgets

Numb,
the torque wrench is for setting the rolling torque on the pinion bearings. The retainer nut is torqued to 200' lbs and is done by measuring the length of the handle on your 1/2" drive torque wrench. There is a conversion chart in the manual.
The setup at your torque and hp level is pretty critical. You can just reuse the shims in your case. It may or maynot have numbers on the back to indicate the shims to use. I never go by the numbers, I always lash the gears with Merc's latest setup proceedure. Any time I change gears or bearings I do a complete setup. That is the only way you know it is right. And with a blower motor, you may have the power to break things!! Although up there in the thin air, it may not be a problem..
If you want discuss what your options may be, give me a call during the day. My cell is 616-403-1006. I can give you a feel for whether or not you might want to tackle the job yourself, or have it done by someone else and the more you know about it, the better choice you will be able to make when and if you do select someone to do it for you...

Hope this helps.
D*ck

Mbam

Hi Gadgets - your post's are always right on the money and much apreciated. I just wanted to point out that the chart in the Merc manual is wrong - completely invalid theory. The final torque applied has no relationship to the length of the torque wrench used. They have blindly included this in every shop manual for the past 30+ years.

The distance from the centerline of the fastener to the point where the torque is applied does matter, this is the fixed distance to the ½ drive hole in the spanner and is a factor in the final torque calculation, but it does not change. I can’t remember if the final torque spec Mercury supplies is supposed to be at the spanner nut or at the end of the spanner wrench.

In any case if a fixed bar was used, and we were measuring the weight (force just to keep it simple ) applied at the furthest end of the bar and measuring from the centerline of the fastener this would apply, ie - 1 lb @ 2 feet would be 2 ft lbs, 1 lb @ 3 feet would be 3 ft lbs etc.

However we are not using a fixed bar, we are using a torque wrench and are already measuring the torque at the output end of the wrench. We are not measuring how hard we push on the handle. Example - clicker type wrench, set it at 100 ft lbs, put it on a bolt, push till it clicks. Assuming it is calibrated properly it will click when there is 100 ft lbs at the bolt. Now put a 2' pipe on the end of the handle, we won’t have to push it as hard (but we are not measuring that) it will still click at 100 ft lbs. Make it a 10 ft handle, we will barely have to push at all, still 100 ft lbs on the bolt when it clicks. Make it a different wrench, longer, shorter, does not matter - still 100 ft lbs on the bolt.

If I remember correctly Snap On has a chart that is used with offset adapters & stuff.

I feel like a myth buster

ComfortablyNumb

Thank you gentlemen for your informative posts. I sat down and read through the manual again last night and that along with what I've read here leads me to believe that I'd be much more comfortable sending the drive out to someone who's done this before. I'd be in over my head on this one. I'll see what happens in the next couple of days.

Question. I've been told for two weeks now that it's really hard to get a new upper gear set this time of year. (availability) Does this ring true?

Thanks again,

Pat