what causes the thump thump thump???

[jigmister]

Re: what causes the thump thump thump???

UPDATE:


I messed with the cables and all was well at home on the garden hose,


first time out on the water and it was very ugly. grinding and not hiting F gear at all. Same symtoms I had before but worse. Puzzled because it appeared good at home I ran the boat down to the shop.

They found metal shavings in the gear case. they are going to inspect and report back.
Looks like I may be in for a lower end rebuild.

this maybe hard to describe but I am going to try.

I learned about this when I first had a problem.

with the cable off, I twisted the shift shaft R N and F.
R and N both had a positive CLICK and locked into postion. F has no CLICK or locked position. from N it just kinda slides into F and has not definate spot or postion. I found this alarming.
I tried to describe this to the boat shop and they said that it is normal.

any comments?

Jim

 

[Texasmark]

Re: what causes the thump thump thump???

Yepper. when you twist the shifter splined shaft, you are rotating a 3 stepped cam against a somewhat pointed tube. The cam is supposed to have 3 specific detents. You only found 2 on yours. Obviously it has failed you.

This cam is what makes the clutch dog (shifter) align with the respective gears FNR that you select. Obviously in your case it'is worn out.

Gonna have to gut the box as this cam is in the very front; but once you're done, you have essentially a new lower unit good to go and enjoy. The money you spent just fades away into the sunset.

Glad you found it.

Mark

 

[jigmister]

Re: what causes the thump thump thump???

what is a fair price for a shop to rebuild the lower end and install?

 

[gss036]

Re: what causes the thump thump thump???

It probably would be cheaper to find a used lower leg than to rebuild a 1986 unit. Still would expensive. About 3-4 years ago, I had asked the Merc guy who does some work on my 200hp Merc what it would be worth if I should blow the power head and he said then that he would give me $1,000.00 for the lowered end as they are in demand. Might be worth looking in to.

 

[jigmister]

Re: what causes the thump thump thump???

they are quoting 1,500-1,600 to rebuild and install the lower end.

 

[Texasmark]

Re: what causes the thump thump thump???

For that kind of money I'd be tempted to do it for you. It's not that complicated . You can rip it apart and then if you think you are in over your head pay to get it put back together.

Sometimes you will be amazed at what you can do with a couple of good beers, a little time to think and a little common sense.

I have been boating since 1955 and never sent a boat or engine to a dealer to get it fixed. Sorry guys in the industry, but I did it on my own.

Need more help, ask.

Mark

 

[boattech]

Re: what causes the thump thump thump???

whether that is a good price or not depends on what they are rebuilding? that is unfortunatly not going to mean sqaut. what parts are they replacing? what are they saying went wrong? It sounds to me like you had multiple problems. maybe your control box has a issue, but the thumping noise you were hearing was your foward clutches chunking around trying to lock in gear. clutches in an outboard arnt like a car, there is no clutch plate to slip. when a clutch skips in a outboard it is two metal teeth chopping away at eachother. so if it happens repeatedly the edges of the clutches get rounded, and then it gets worse and worse the more it skips till eventually you cant fully engage. all that to say this. if all that happened was rounded clutches then you have more options than if you had a complete meltdown of gears and bearings. In alot of cases shops that see worn clutches want to sell you a whole new gear set and reseal the lower unit. which the prices you gave arnt horrubly unreasonable. I have a local guy who recuts clutches on a milling machine and have been using him for 15 years recutting lots of gear sets. as of yet I have not had a return. anyway. just saying that there are cheaper options. So my next step would be to go see the shop and ask them to show you your parts and explain what they are wanting to replace. I ask all my customers to come see there stuff so they know what they are paying for. A good shop should be willing to sit down and go over everything with you to make you comfortable.
As for the comment posted about doing it yourself. I am the first to help my customers with advice to do it yourself projects. but there are a few things I recomend they leave to professionals. Lower units require a shimming proceedure that must be followed and requires very expensive special tools. If you wanted to reseal your lower unit I would say give it a try, but rebuiling requires expertise and tools. you get no second chances when you put something together wrong with a lower unit.
Good luck and let us know how it goes

 

[jigmister]

Re: what causes the thump thump thump???

well I got the lower end rebuild. They showed me all the old parts. The pinion gear had borken teeth.
They said that I could not shift into F gear because a bunch of metal shavings where in the clutches preventing them to engage.

At first they were just going to replace a few parts. But they called me up and said they could no longer get individual gears. They orderd a entire gear kit including bearings and clutches.
what they did:
new gear set
new spring ?
new clutch
new bearing kit
reseal
water pump
bearing assembly.

They advised me that there is now way possible that the controler could cause the problem I had.
I asked what would cause the pinion to go.
Mechnic said that is a hard question to answer and that about the only way he knows of is just plain old failure due to age and use. OR prop impact.

I paid about 1,500 for the job.

comments? suggesntions?

thanks
Jim

 

[Texasmark]

Re: what causes the thump thump thump???

Does it work to your satisfaction? Nuf said. Money is spent and only thing left is to enjoy it. What it cost will just become a sweet memory of money well spent.

Yours was the exception. A lot of times simpler things could solve the problem.

Just keep tabs on your lower unit oil. Lots of folks suggest annual draining/refilling with new blue gaskets always. Not a bad idea. Personally it depends on usage, where you store it, how long it sits in the water over any period of time, and what you found the last time you looked at it.

Mark