mc-1, question on upper

[ziggy]

started working on impeller replacement the other day. drive is in the basement.

drained gear lub. no metal feel to lub it at all. pretty much the same color it went in (maybe a shade darker). green (mercruiser hp gear lub). no water intrusion. no issues last season. gear lub did get changed mid summer last season just as pm. pressure tested prior to disassembly. no loss of pressure.

with the drive, upper and lower together. when i rotate the drive shaft. i feel like i'm feeling gear teeth. with upper and lower separated. when i rotate the drive shaft on the upper. i still feel like i'm feeling gear teeth. or maybe brgs.?

is this normal? do i have any reason for concern? i don't remember it being that way.

used it a 100 hrs + or - last season, that's a guess...
driven gear yoke and ft. seal and brgs replaced, 2 seasons ago by me. did reshim. couple hundred hrs on it since i did that to it..

 

[jerryjerry05]

Re: mc-1, question on upper

You have oil in it when you do this?The oil will cushion it so you won't feel the teeth.Jerry

 

[Don S]

Re: mc-1, question on upper

You shouldn't be able to feel the gear teeth. I would be concerned.

 

[ziggy]

Re: mc-1, question on upper

You have oil in it when you do this?The oil will cushion it so you won't feel the teeth

yep, the gear lub was in place. this 'feel' was noted after pulling the drive, still full of lub. w/o lub it (the odd feel when rotated) is more pronounced.

You shouldn't be able to feel the gear teeth. I would be concerned.

that's the way i remembered the way it felt. as in no feel. yep, i'm concerned...

game plan at this point is to pull the top cap, see what i see, next step, pull the driven gear yoke and brg. assy., dissassemble to inspect.

my gut feeling was/is something is amiss, but i wonder why i don't see any metal fragments or dust in my gear lub. unless i'm catching it before real failure..

thanks for the comments.

 

[ziggy]

Re: mc-1, question on upper

well, i pulled the top cap. don't think i like the looks of the brg. or race..

they (the rollers and race) don't feel particularly bad, can't feel any pitting or grooves. though i am still feeling them out a bit. they just look like crap though.

disassembled the drive gear brg. stack. best i can see w/o de lubing yet. they look pretty darn good. gear teeth look good on drive and driven gear also.

after removing top cap, the gear feel was still present albeit much less pronounced.

so whats my next step? i been reading the s/m. looks like special tools required to pull the race from the cap. i'm confused by is there springs or just shims under this race. assuming i R&R the brg. and race, i assume it must be re shimmed. or at least tested with the cap torqued in place and 6-10 in. lbs of force to turn or reshim is nesseary.

i've not pulled the driven gear shaft yet. looks like it just pulls out? nothing will fall out?

any insight?

i've not looked at the lower brg. or race yet either. i need to do that i think..

 

[Don S]

Re: mc-1, question on upper

That bearing alone is enough to give you that "Feel".
Did you by chance turn the double bearings before you took them apart? If not, post a picture of the bearing surface of the races.

 

[ziggy]

Re: mc-1, question on upper

That bearing alone is enough to give you that "Feel".

sounds like i could be heading in the right direction.

Did you by chance turn the double bearings before you took them apart?

yes i did. felt grindy. i thought that was my issue from that. (may have had the brg. stack rubbing on the retainer nut). disassembled the brg. stack and they look good imho. i'll do ya some pics here in a while.

took the driven gear drive shaft out and initial inspection of the lower race and rollers looks ok. off to the store for some break kleen to clean them up for better inspection...

 

[Don S]

Re: mc-1, question on upper

yes i did. felt grindy.

You need new bearings, there too. The preload on those bearings amplifies any roughness at all.

 

[Bondo]

Re: mc-1, question on upper

yes i did. felt grindy.

You need new bearings, there too. The preload on those bearings amplifies any roughness at all.

Ayuh,... That Sucks.....

SEI time,..??

 

[ziggy]

Re: mc-1, question on upper

Ayuh,... That Sucks.....

yep, i'll agree with that for sure...

SEI time,..??

this is crossing my mind. i've for sure got lower drive shaft wear at the seal under the splines too. so i'm treading on thin ice there too.

You need new bearings, there too. The preload on those bearings amplifies any roughness at all.

i'm not sure i wasn't dragging on the retainer nut while it was loaded poorly on my screw driver in the vise. my mistake for note being more note worthy and careful while rotateing the stack. darn.. + they were kinda slippery to hold onto to get them to turn. anyways.
the pics.

seal side of brg. stack from one angle

seal side of brg. pack from opposite angle

gear end of brg. stack.

to me, these look like they may be serviceable.

then the driven gear and brg. + race

i'm thinking the brgs there may not look so good either. same with it's race.

 

[muc]

Re: mc-1, question on upper

Looks like there was water in the drive at one time.
Might want to tear down the lower to?
Double bearings look good in your picture.
The one picture of your gear looks like the wear pattern is in the wrong place.
Might want to check the gear height on those two gears.
Good Luck Muc

 

[Don S]

Re: mc-1, question on upper

The pictures of the double bearings looks good, from what I can see in two pictures. I would clean them back up, with some gear lube on the bearings and reset the preload. Then turn the bearings. You should be able to feel resistance from the preload, but there should be no roughness or bumps in them when you turn the bearings.
Same with the vertical shaft. Put it together and torqued down the cap and see if it is rough and has "the feel" that caused you to take it apart.
I agree with muc, it does appear that the double bearings have been replaced and possibly due to water. If that happened and gear height of the input shaft was not set and/or a shim was left out, the gears could also be too close together which would also cause "the feel".

 

[ziggy]

Re: mc-1, question on upper

Looks like there was water in the drive at one time.

not that i'm aware of since i've had it. gear lub has never appeared contaminated. changed at least once a year, last year 2 times. here's my guess. the boat sat for 15 year w/o use. condensation? or just plain condensation from sitting over the winter lay up. the top of the brg. i would think would be the first place to go dry w/ the drive stored down. which i do. that's a guess on my part.

Might want to tear down the lower to?

perhaps. i'm not looking to spend extra dollars if i don't have to. or extra work that require specialty merc. tools that i don't have. (do need to consider it though in the large scheme of things though)

Double bearings look good in your picture.

thanks. i'm hoping they are. only thing i don't like is that line on the roller cage on the seal end.

The one picture of your gear looks like the wear pattern is in the wrong place.
Might want to check the gear height on those two gears.

a little to far outside towards the end of the gear tooth. agreed. i would think closer to the center of the tooth too (end of the tooth looks constant thickness though). the driven gear has not been messed with by me. the brgs and drive gear yoke were touched and replaced by me. when shimming drive and driven gear. i was absolutely positive that i had .025". .024 was loose, .026 wouldn't go. used my merc. dealers marine techs mercruiser shim tool. very nice of him to let me borrow that (his own tools too)... anyways...
looks like i will be disturbing near everything this time (assuming i don't give up and just do an sei for to much being wrong with what i have). so full shim will be required + driven gear shaft resistance measured.
i'm reading over and over (s/m #2), observing, thinking, and asking question on iboats trying to formulate the cheapest proper repair.

do ya think that driven gear is serviceable?

thanks for the comments.

if i were rich, i would go though it all. but i'm on a real minor buget..

 

[Don S]

Re: mc-1, question on upper

Those bearings do not have to be ordered from Mercruiser, or even an after market marine company like Sierra. Merc doesn't make bearings. The bearings have the name of the company (ie Timken, SKF, etc.) and the part number. There is a separate number for the bearing and a different one for the race. Get those numbers and head for your nearest bearing supply. Much cheaper and the same exact parts.

 

[ziggy]

Re: mc-1, question on upper

The pictures of the double bearings looks good, from what I can see in two pictures. I would clean them back up, with some gear lube on the bearings and reset the preload. Then turn the bearings.

good, another vote for the double brgs. looking serviceable. they're clean.today i'm gonna go lub'em up and put back together. new nut and washer ordered yesterday so when they come in i'll torque it back up and hand spin test again.

You should be able to feel resistance from the preload, but there should be no roughness or bumps in them when you turn the bearings.

as to the resistance felt. i'm assuming it's quite a bit of resistance? like in hard to get ahold of with your gear lubed up hands, and grip it hard enough to turn them? i understand, no roughness or anything other than smooth feel. i will recheck when i get my new washer and nut.

Same with the vertical shaft. Put it together and torqued down the cap and see if it is rough and has "the feel" that caused you to take it apart.

good idea. i will try that out. anyone know of anything other than a used drive shaft out of the lower to use to turn the driven gear shaft? wish i had a dial indicator in. lbs. torque wrench (an obstical for me).

I agree with muc, it does appear that the double bearings have been replaced and possibly due to water.

they have been. 2 years ago. by me. replaced due to color. blue. again, no water intrusion that i've noted during my ownership.

If that happened and gear height of the input shaft was not set and/or a shim was left out, the gears could also be too close together which would also cause "the feel".

i shimmmed the drive gear to driven gear due to replacement of the double brg. shim stack was the same as prior to replacement of the brgs. shims were adj. to out of tolarance and then back to tolerance. .025'' was slightly snug. .024'' went is to easy. .026'' wouldn't go in. triple checked... i don't know why the mesh looks poorly. does this wear require gear replacement?

 

[Don S]

Re: mc-1, question on upper

today i'm gonna go lub'em up and put back together. new nut and washer ordered yesterday so when they come in i'll torque it back up and hand spin test again.

Use the old nut for the test, if they are smooth, then just remove the old nut, loosen the bearings, and replace with new nut. If the test is bad, you haven't wasted your new nylock nut.

anyone know of anything other than a used drive shaft out of the lower to use to turn the driven gear shaft?

Just reach through the front opening and turn it by hand. If you replace the bearing, you will need an old shaft to set the rolling torque before setting gear height.

 

[ziggy]

Re: mc-1, question on upper

ok. i'll use the old nut for the test. thanks.

Just reach through the front opening and turn it by hand.

that i tried. but i didn't have the top cap torqued down. i'll retry that too. w/ the cap torqured down.

If you replace the bearing, you will need an old shaft to set the rolling torque before setting gear height.

i understand. looks like more reading is in order. i do have another mc-1 drive from my last boat. it's never been tore down by me. just sitting wasteing away. i have no tools for the lower either. just from memeory and glansing at the book. looks like special tools to go get that drive shaft out. food for thought for me.

thank you...

 

[ziggy]

Re: mc-1, question on upper

well, what should i think now?

put the old nut and washer back on the double brg. set and torques it to 75 ft. lbs.(has small spacer) double brg. spun by hand and seemed smooth, no feel, no sound. looked at ea. brg. race and spacer too. i see nothing abnormal..

put the driven gear shaft back in and torqued down the top cap to 20 ft. lbs. w/o driven gear assy. in place. spun the driven gear by hand. it had no feel or sound and felt smooth. w/o replacing the top brg.

took top cap off, lined up the hash marks on the gear and put the driven gear and brg.s back in the drive. did not torque up the retainer nut. put it on pretty hard.

feels nice and smooth like it should...

what happened? any ideas?

side note. i understand i should have put the retainer nut back on to 200 ft. lbs. i will. probably my next step. but my large craftsmen torque wrench is broken..... last time i used it was a year ago easy. stupid thing has the plastic broke where ya line up the hash marks to know where to set the torque at... grrr... took it back to sears for a replacement and low ans behold. a torque wrench isn't a hand tool.. least not according to sears. it has a 1 year warranty... grrrr. it's older than that. so now i'm hosed and gotta buy a new large scale torque wrench.... money i didn't want to spend but i know of no other alternative. suppose i could use the bar type torque wrench i got. but they seem not so accurate. specially when yer leaning on the bar trying to get that much torque... anyways. that's my daily whining... darn thing was made in USA too...

edit. how about this for an idea as to why i had feel before and don't now, when nothing changed. but it did. i lubed up the brgs. real good w/ new gear lub. the top brg. for the driven gear shaft had sat for between 3 and 4 months. drive in a drive stand. so the gear lub wore (ran) off that brg since it's above gear lub level. so it was dry. or dryer. so a dry brg that's almost (is) spent, due to rust and pitting gave me the feel back through the driven gear shaft. now that it got lubed up, i've lost the feel. which is good. but i still need to know why.

have i got this right? if i change the top brg and race. i won't need to reshim the driven gear, but i will need to do a rolling torque test on the driven gear shaft?

 

[ziggy]

Re: mc-1, question on upper

follow up.....

$134 later from my local dealer. i have a new upper brg and race.

that looks more respectable imho... i hi'm ha'd on the lower brg and opted not to do that one. probably should have, but funds are tight like usual and imho that brg. looks at least somewhat serviceable. still no feel when i put the cap on and put the double brg. set back in.

i did check rolling torque on the driven gear shaft (shim stack was said to be the same as old brg.). best i can tell it's about 4 or 5 in. lbs. i did the test using my dealers inch lb torque wrench and his drive shaft from a lower. he also did the test and agreed. it passed the rolling torque test.

interesting note. i use s/m #2. i have both book and pdf. the book calls for 2-6 in lbs. (pp 6A18). pdf calls for 6-10 in lbs. (pp6A18) . both s/m are 90-71707. the pdf version is 90-71707 286. i wonder which version is newer or more relevant. not that i guess it makes any difference as my rolling torque falls in between both...

so anyways, put her all back together, pressure tested @ 14 psi for 24 hrs. perfect.

failed vacuum test.... likely a new thread i recon...

thanks for you folks help on this.....

 

[Don S]

Re: mc-1, question on upper

The input shaft seal is probably where you are loosing your vacuum. Merc doesn't even recommend it because of the input shaft seal design, it was not meant to hold any vacuum. If you are real lucky, you can sometimes get them to hold 4-6 inches of vac, but that's about it.
I will check out the rolling torque question and post back here.