Redband 50hp Gearbox problem

[oldman570]

Re: Redband 50hp Gearbox problem

Glad that the prop shaft came out for you. Like maxz states, a new E clip would be best and do not forget to greese the DS splines when putting it back on the motor. If the case is cleaned up and a light coat of LU oil is put on the new O ring seal, the prop shaft and carrier bearing should slip back inplace fairly easy. Make sure that all the shim spacers are put back in where they were as the set the backlash clearance for the gears.A new spanner nut might be in order if any damage to it is present, and remmber that it is left hand therad on most motors. Hope the con rod and top end are easier to do.
Best of Boating,
Oldman570

 

[Bosunsmate]

Re: Redband 50hp Gearbox problem

Thanks Oldman, when i felt that spanner move more i thought i was surely bending something not moving the carrier.Its really nice to finally get a look inside one of these gearboxes.

What i think happened is that someone has pulled the shiftshaft out before and not put the clip back. Im virtually certain its no where in the LU,as ive being rolling it over and banging it with a rubber mallet, looking in the drain plug hole with torch etc.
What also leads me to the conclusion that it was not reinstalled is that i cant work out the upper cam system on the top of the shiftshaft before it enters the middle leg.
Is the top black thing on back to front? Im thinking the person who did the shiftshaft has put it on upside down. Im picking it should be facing that reverse locking cam thing below it. The other thing i cant work out is what the yellow washer thing is in the photo.
Also the diagram carholme mentions m12-64 looks like mine but it has the reverse cam thing up the top not the thing that is up the top of mine. Also on mine the bit of the shiftshaft that the other section of shiftshaft slides into is on this section whereas in carholmes diagram its not (maybe that bits not a biggie but i really dont know as the original mercury master service manual i have is so sparse, a lot of it seems to be advertisements of men and pretty woman driving boats with mercs)
Thanks to all for any suggestions
Ps the reverse locking cam wont slide down the shiftshaft, it will only go up, but then it hits that metal connecting tube for the top section of shiftshaft so if its set up wrong looks like il be firing up the candles again to get that tube off

 

[Maxz695]

Re: Redband 50hp Gearbox problem

The upper metal sleeve is the end of the upper shift rod it should be separated from the lower shift shaft and lubed up. (Newer modles like my 79 is a one pice shift rod). There may be a hex nut on the shift rod end there you have. The next plasti item is the shift rod guide and goes up into the midsection to keep the shiftrod centered. The next plastic thing is the lockdown cam. The hi spot is for reverse and should be facing the front most point of the LU when the shift shaft is in reverse. To the middle dentent in neutral and the lowest dentent in fowards. Front point of the LU <-$ HI Rev <-$ Mid Neu <-$ Low Forwards < = front $ = Prop Next is the black washer. The lock down cam rides on this. I am fairly sure the yellow washer is the base for it goes on to the shift shaft first then washer then cam. You shift rod guide looks chewed up pretty badly and frozen to the shift rod splined coupler There no to expansive on ebay and I threw my extra one out a few weeks ago not totally sure this wil be right for yours but there is a chance it will http://www.ebay.com/itm/Mercury-Out..._Accessories_Gear&hash=item2a1ba114c1&vxp=mtr GUIDE, PUSH ROD Yours is facing the correct way but it looks like it,s corroded to the shift shaft coupler that did the damage to it. The coupler should have splines in both sides or as stated in the next post it broke off

 

[carholme]

Re: Redband 50hp Gearbox problem

You could always use the parts manual to see how the parts fit.

In your picture in post 22, the washer lies on top of the seal which is embedded in the seal housing. Then the yellow guide and the cam rides on top of the guide.

You should look up inside the driveshaft housing and see what the bottom of the upper shift shaft looks like as it appears that you have broken the coupler off of it.

In this link you will see what the upper shift shaft for your s/n should look like. See item 55 and if you blow it up, you will see the coupler attached to the shaft:

Mercury & Mercruiser Parts, BOTTOM COWL ASSEMBLY AND SHIFT LINKAGE, MERC 500-7/8

Gerry

 

[Bosunsmate]

Re: Redband 50hp Gearbox problem

Thanks for that. The uppershift shaft is actually in excellent condition, ive already given it a good go with cleaner. The upper and lower came out seized in the connector as one piece and when i tried to separate it the upper actually came out and the lower was left in there so reversing that order will be my first order of business for the day.
I will post a picture of the final set up, my manual incredibly only does the propshaft parts picture so those links are much appreciated.
The only thing i dont get is how this push rod guide can work if its facing up as i would of thought it needed to face down when locked in the midsection housing grooves to turn on the reverse lock cam
Off to get started
Cheers

Mercury Outboard 35 40 45 50 60 HP Push Rod Guide | eBay

 

[Maxz695]

Re: Redband 50hp Gearbox problem

The reverse lock cam when moved afects the push rod still in the midsection it is also guided by the shift rod guide. Have a look up the midsection to see the pushrod. The cam does not move the guide. The guide is a stationary fit in the midsection and should not be stuck to the shaft coupler The coupler should rotate inside of it using it as a center guide for the shaft

 

[Bosunsmate]

Re: Redband 50hp Gearbox problem

Excellent thanks. Ive separated the parts and here is the set up for reinstall, il put the push rod guide into the midsection facing like this on reinstall. I couldnt work out if the yellow washer was one directional it seemed like it would work fine facing in either direction. I also will add a circlip to stop this happening again while also putting some antiseize in the connector so it will pull hopefully out as meant to next time i do the impellor.

Ive made sure ive put the connector on the end of the upper shift rod that doesnt have the hole in it for the pin at the gearlever in the cowling.
Thats the manual which i cant find any picture of this shaft setup in.
Its very nice to be starting the reassemble.

 

[Maxz695]

Re: Redband 50hp Gearbox problem

View attachment 176080 Fork goes up in the midsection like this picture. The yellow spacer has a grove this facing up will hold greese in the well for the cam and spacer. Take a litlle fine sand paper or steel wool and hit that coupler a bit to smooth it out and let it ride in the guide nicely. Be sure to rinse off sand or steel wool left behind. Do not reverse the guide put the forked ends upwards as it is meant to be. Good luck on the re assemble Last picture in the last post is incorrect position for the guide View attachment 176081

 

[Bosunsmate]

Re: Redband 50hp Gearbox problem

Ok Max thanks for that,excellent point too about the washer and grease.
Ive put the fork now facing up.
The sticking point i dont get is how does the reverse cam get affected by the fork. All i can see happening (as in photo) is that the two parts would spin individually Am i missing a pin or something that goes in this hole? There definitely wasnt one on disassemble so perhaps the last person didnt put that back in too if there is meant to be one.
I just get curious as though im missing something important when i see a part with a specific manufactured shape to it but i cant see the reason for it

 

[Maxz695]

Re: Redband 50hp Gearbox problem

The shift rod from the top goes through the center hole The lock down pin goes through the forward hole The cam when turning to reverse (High spot) lifts the pin and pushes down the reverse lock clamp on to the hold down pin between the tilt arm and the midsection. First picture looks to be correct. The lockdown pin is connected in the midsection where the shift shaft goes. when you push it up it should spring back down as there is a spring on the locking clamp. Here are some photos of my lockdown mechanisim and the long pin to the cam #1 View attachment 176085 #2 View attachment 176087 #3 When in reverse the cm lifts the rod and makes the clamp come down on the locking pin when the motor is in a downright position.View attachment 176088 View attachment 176089 The shifter rod runs through the steering shaft and yoke

 

[Bosunsmate]

Re: Redband 50hp Gearbox problem

Thats it, solved i think.
I have no locking pin, looks as though reverse will have to be easy goes it.
Talk about past poor workmanship.

 

[Maxz695]

Re: Redband 50hp Gearbox problem

I may have one in my shed but i cant give it away. Write my messages for info. It,s off a 70 HP and should fit. I,ll have to check it against mine. Question do you have trim tilt?
If so you don,t need the lockdown.

 

[Bosunsmate]

Re: Redband 50hp Gearbox problem

Hi thanks for the offer. Il see what the local wrecker has first as im passing that way in a few days - sometimes you get him on a good day.
I havent got trim and tilt but i may look into that too, thatd be great boating

 

[Maxz695]

Re: Redband 50hp Gearbox problem

all I have is the pin and the cap where there is another pin that slides through the clamp.View attachment 176096

 

[Bosunsmate]

Re: Redband 50hp Gearbox problem

Ok thanks il see what the list is at the end of the whole motor and LU rebuild.
It looks as though its something i can do afterwards by just dropping the LU.
On with the rebuild-just soaking the shims.
cheers

 

[Maxz695]

Re: Redband 50hp Gearbox problem

yes it can be installed without removing anything at any time in the future.

 

[Bosunsmate]

Re: Redband 50hp Gearbox problem

I put it back on the merc500 powerhead i rebuilt. It wouldnt select reverse gear and then i found out that the large carrier bearing lock nut needs to be done up really tight or it wont select reverse. I think its something like 120 foot pounds but please dont take that as the correct figure. I took it out on the water and it wouldnt idle when put in gear so i backed out both carbs about 1/3 a turn and it then went great although it would suddenly rev very high in forward when giving even half wot.
I thought it was a slipped prop but after marking it with paint it wasnt that. It was then that i came across the figure of over 100 foot pounds on the carrier nut. So i tightened it again and that solved the problem. Mine is the older metal carrier lock nut so i tightened it with a wide flat chisel and a soft rubber mallet, i suppose if someone did that with the plastic ones they would crack.
I thought i would write this up as getting that carrier lock nut very tight is extremely important as without doing so you wont be able to select gears properly and the clutch dog and gears will then wear out very quickly as it slips in gear.
Ive given her about about a one inch jackplate, sort of visible in the photo
If anyone can tell me whats required for the grease in this unit that would be great thanks, they say grease in the handbook but in all other outboards i have had i have run standard marine gear oil, so is that ok?

Shes an absolute pleasure to run and shes a beauty to look at- thanks to everyone