Bravo Prop Shaft Play
 

I just had my upper and lower unit tore down and inspected (Bravo 1). After I received it back from the marina I noticed that there was some play in the prop shaft about a 1/16 in and out and when the shaft is pushed in there is some play side to side. Should there be any?

Re: Bravo Prop Shaft Play
 

NO! The propshaft bearings are preloaded to take up any play in the shaft. I would march that thing right back to the Mechanic and stand there while he fixes it. Unless the wrench that put it together can remember that he didnt set the preload properly. I would question the assembly proceedure. If he wants to just tighten the nut that holds the whole thing together, I would suggest he tear it back down and do it right. Although it may be ok to just tighen it to specs, you dont know what else he forgot, if he forgot the most important step. I am sure you paid good money to have it done right, tell him you want to watch as he corrects his mistake.
I hope this helps.
Dick

Re: Bravo Prop Shaft Play
 

Thanks Dick for the info. The mechanic said that there should be 1/16" to 1/8" in and out play and .030" side to side. When I spoke to him today he informed me that all you have to do is put all the pieces back in and tighten the nut down. He also mentioned that when it is tight is when you will have problems. How is the preload set on the Bravo 1's? This is a licensed Mercury mechanic that is working on this.

Re: Bravo Prop Shaft Play
 

You have got to be kidding! .030 side to side play. Damn, just take your prop and throw it overboard.
The preload is set 1 of 2 ways, depending on yr. My '99's use a crush ring. Use a retaining wrench that turns the large nut behind the prop until the required turning torque is acheived on the propshaft. Older yrs use shims. BTW, I had to use a 3' cheater bar to turn and tighting the retainer nut. That tells you the amount of force needed to set the propshaft preload.

Find a different mechanic!

Re: Bravo Prop Shaft Play
 

Mike, what US1 said!!!

Find another mechanic - FAST

Oh, tell his boss too

Re: Bravo Prop Shaft Play
 

US1 Fountain,
Yes I know on the .030". My numbers are showing me for the side to side play not to exceed .007" and if it does replace the bearings or properly adjust the preload which is what I feel it is. The scary part is these guy's are suppose to know what they are doing, that is what they get paid for.
You know good help is hard to find any more. The torque specs for the cover nut is showing 210 ft-lb. My drive is a 1998.

Re: Bravo Prop Shaft Play
 

Mbaam,
They are not getting off that easy.

Re: Bravo Prop Shaft Play
 

Be absolutely sure yours has the shim then instead of the crush ring if you decide to just torque to 210. You don't just tighten it down to 210 if yours does have the crush ring. It takes an inch pd torque meter to set. We are only 1 yr apart, that is why I question your spec, which leads me to think you are assuming yours is shimmed. I realize you already paid for the rebuild, but at this point with your mechanics above statement, you need to pursue this abit more before you let him back on it.
Good Luck

Re: Bravo Prop Shaft Play
 

.007 is allowable run out due to a bent shaft, not play. Big difference. There is .000 play as the bearings run in a pre-loaded condition. This means once zero clearance is reached an additional "squeeze" is applied.

As US1 says, the amount of this squeeze is determined by shimming in the early drive, and by the use of a non-reusable crush washer in the later drives to locate the propshaft bearing carrier. The amount of preload is NOT determined by how much the bearing carrier cover nut is tightened.

Re: Bravo Prop Shaft Play
 

Mike,
What they are saying is you need to tighen the nut until you get the proper squeeze resulting in the proper preload. It is measured with a rolling dial type in/lbs torque meter. The older bravo's used shims to determine the proper distance you could squeeze the whole mess. Now a days a crush sleeve is used to squeeze once and if you go too far, well another crush sleeve. I cheat sometimes and use a .010" shim to get one more use out of the crush sleeve. Your drive came stock with a crush sleeve and your highly educated mech would not go to the trouble of shimming it properly. Who knows, he probably reused the crushed crush sleeve??

Bail on this guy and find a new mechanic to work your drive. If he made this mistake and owns up to it as "proper setup" I would have the whole drive gone through again. If you want to know more about how it is done, so you can ask the right questions, give me a call, I can give you some direction or explain what you might not understand.

Dick
616-335-8446

Re: Bravo Prop Shaft Play
 

Thanks guy's for all your help. My guess is he didn't replace the load ring when he had the bearing carrier out. I understand the set up procedures on the lower unit. I'm heading back to the marina to pursue this Wed.

Dick if I have any further questions I will give you a call.
Thanks,
Mike

Re: Bravo Prop Shaft Play
 

Ok. Mike. Good luck with him.. whew..

I am leaving Thursday nite for FL.. and should be home during the day off and on..

Dick

Re: Bravo Prop Shaft Play
 

I have some more Questions I swaped out a difrent lower and set up the gears what are we looking for for on backlash on the pinion vers the propshaft gear ,I understand the peload or zero lash on the propshaft, im concerned with the shim in the back bearing I took out a 13 th and used a 16 th and got a little tight im only just a couple of thousandth backlash I was thinking about 8-10 ??

Re: Bravo Prop Shaft Play
 

Any help would greatly be apreshiated

Re: Bravo Prop Shaft Play
 

Backlash=.012- .015. You are using the backlash adapter that clamps to the drive shaft right? Pinion height set?

Re: Bravo Prop Shaft Play
 

ok pinion hight you talking about shim under bearing on verticale shaft

Re: Bravo Prop Shaft Play
 

B-stubb,
The pinion gear height is set with a tool that measures how deep the pinion sits in the case in relation to the centerline of the propshaft. The shims under the bottom race in the case for the upper bearings determines how far down the pinion gear sits. With the depth setting tool this should be .025", then you add or subtract shims from behind the race in the front of the bullet to get the proper gear lash. That is the .012" - .015" mesured with the wing clamped to the top of the vertical shaft. The preload must be correct to get an accurate mesurment. You do this by adding shims to the top of the bearing stack on the vertical shaft and clamping down on it with the clamp plate.

The procedures are explained in Merc's shop manual, it would be a good idea to get one if you are planning on DIY. There are a lot of tools needed to do it right..
I hope this helps...

Dick

Re: Bravo Prop Shaft Play
 

B-stubb, Mr. gadgets is right, if youre getting into do it yourself drive work you defenitly need a Factory manual. they are not that much money and they will show you everything you need to know like wich back lash flag to use fo that drive and what position to line the dial indicator up too. there are alot of important details to building drives right. And even if you could get all the answeres to your questions on here it would take you months to sift through what is fact and what are opinions so go get yourself a manual.

Re: Bravo Prop Shaft Play
 

You will need those specialty tools to do it right No way around it without them. Once I got the measurements, I made a set. It's really a piece of cake, if you have the manual and tools.

Re: Bravo Prop Shaft Play
 

Keep in mind that if you take shims out from the bottom, you will need to add them to the top.

Re: Bravo Prop Shaft Play
 

Ok Im geting a lot here I have the big spaner nut tool I made it ,the hose clamp with the flag ,makin it tonight Im not understanding the last tool much yet .I do have a manual just never read it Im a guy you know. I guess I will break it out .

Re: Bravo Prop Shaft Play
 

I also made a tool out of a coupler to hold the vert shaft to tighten nut .I built last lower and it held together .If thats good for anything?

Re: Bravo Prop Shaft Play
 

The last tool is used to set the pinion hieght. Basically once the pinion is in and tight, this tool slide the lower housing in place of the carrier. While holding it tight against the shoulder to keep it sqaure with the world, which you orientate with one hole at top. The 2.450 dia will be directly under the pinion gear. With feeler gauges inserted thru the hole, you are now measuring the gap between the tools 2.450 dia and the bottom of the pinion. Thats your pinion height. That locates the pinion at the right height for the correct mesh with the drive gear. Now might be a good time to read the manual. ;)

Re: Bravo Prop Shaft Play
 

us1 fountain / mr gadget,
I hooked back up with mechanic on my shaft issue.
He said that it was set up correctly when he set it up but he feels that it may of been in a bind??????
So I went over all of the numbers with him on the preload and run out and he agreed that they all sounded correct. Wasn't real sure what happened but has no problem making it right. Order another load ring and when the part comes in I'm going down with him to tear it back down to see what happened. I'll follow up when I get it back together.

Re: Bravo Prop Shaft Play
 

us1fountain / mr gadget,
Heres what happened on my lower unit prop shaft play. I end up hooking up with the mechanic today and we pulled the prop shaft back out. The nut wasn't all that tight. He mentioned that he mostly worked on alphas that the bravo's never gave him any reason to work on them. So trained but not fresh in his mind???? He didn't have the bracket to place on the drive shaft to create the needed preload with the inch lbs gauge (it was being borrowed) so we just checked it with what ever resistant there was to subtract from the prop shaft resistant. There was 1/2" on that. We then replaced the load ring and slide everything into place. It took a lot to get the cover nut tight to where we generated a total of 7 to 7 1/2" lbs of resistant on the propshaft. Bent the tab up and I hope I'm ready to mount.
Anything spacial have to be done on the upper gear housing when it was disassembled and put back together other then getting all the pieces back into the right order?
The drive was blasted and painted and when the guy blasted he never covered the upper vent hole and got sand in the upper housing. Of course I had the marina tare it down and clean and replace any worm parts which he said looked in great shape, (royal purple max gear). So that is what got me to this problem.

Re: Bravo Prop Shaft Play
 

Mike,
Sounds like it should be ok. The preload on the verticle shaft should have ended up right at the spec 3-5 in pds if it had the required .001 additional shim height on the upper retainer. ( The pinion height is adjusted there with shims and then the top retainer has to be reshimmed to eliminate any play) He could have bolted the bottom to the top, but left the verticle drive shaft coupler out. This would have held the shaft, shims, bearings the same as if he had the clamping plate, yet still allowed both shafts to turn w/o being engaged to the upper gear housing to get set the preload, providing he did shim the top retainer correctly. Then simply separate and reinstall the coupler.
BTW, I'm assuming he reused yr old carrier bearings, otherwise the propshaft preload is higher.

Re: Bravo Prop Shaft Play
 

Wow! After reading all of the above I wonder if I'm messed up. I have twin Merc ProMax 300's with about 100 hours each. My prop shafts have in-and-out (forward-reverse) play of 1/16" or less. Side-to-side play is minimal but there is some. Normal?

Thanks, TJ

Re: Bravo Prop Shaft Play
 

Not sure on outboards bravo not good (I checked my egg beater it has some play too)

Re: Bravo Prop Shaft Play
 

All the Alpha drives I've seen have some in/out play, but no side/side. Other than that tid bit, never tore in to one.

Re: Bravo Prop Shaft Play
 

us1 fountain,
the original carrier bearings was used as everything looked good in the drive.