Tachometer drive

[Nonchalant1]

Yesterday my starboard tach failed, so of course I can't use the synch either. It turned out to be that little flex cable marine gear oil pump to the tach drive. As noted by somebody else, the squared end had rounded off and just spins in the drive.

How do you get that little cable out of the pump end? I trid just pulling it out but was afraid to really pull hard. \

Also, did anyone find a source for the cable? I'll try DD and Sams, but I'm on a cruise and don't have a good address to mail to.

Thanks,

Doug

 

[Genesis]

Lock a pair of vice-grips on the broken end of the shaft and pull HARD. It will come out.

Second, if it rounded off or sheared it is HIGHLY PROBABLE that the drive adapter (the piece that the stubby shaft goes into) is worn and bound up. Replacing the drive cable will just cause it to do it again. There's a worm gear drive in there and when it gets sloppy it binds. The cable is the "weak point" so that the result isn't a destroyed oil pump or worse.

Now for the bad news - that little adapter - which you almost certainly really will need to replace - is $400!

I had this happen to one of mine, and ate a second stub cable as well before biting the bullet and buying the adapter....

Saunders in Panama City can get you fixed up.

 

[Nonchalant1]

Karl,

Thanks much!

When DD couldn't find the part number, I called Steve McPhereson. He found DD's part number and I called my favorite DD guy in Illinois. He found that a DD in Grand Rapids had the part and their Service Manager lives near here so he's going to bring me the part at my transient marina in Muskegon, MI this evening! Is Detroit Diesel great, or what?

Doug

 

[Nonchalant1]

So the WW Williams DD Service Manager, John Talbot, brought the part to my boat in Muskegon, MI on his way home to Fruitport, MI (it was actually out of his way). Part cost $12.28. It's installed and everything's working again. He wouldn't even take a $20 tip for it. Excellent service on a 28 year old boat, and another reason to keep those Detroits.

Doug Shuman

 

[Hatisfaction]

I had the same problem and got the replacement directly from Glendenning..inexpensive and good service.

 

[Genesis]

Yep - that little stub shaft is cheap.

If you snap another one, the 90 degree adapter on the end of it (which screws onto the gear pump) is dead. That's the $400 bill you need to budget for, because odds are high it's on its way out.

 

[Nonchalant1]

Karl,

I think I'll replace the adapter over this winter. Us guys up North have to have something to do while it's snowing outside.

Doug

 

[Genesis]

Actually replacing it is a 5 minute job.

Paying $400 for a worm gear in a piece of metal is enough to really pizz you off though..... I seriously considered making up an optical encoder when it happened on mine, but decided against when I started thinking through also ripping out and replacing the Glendinning with electronic controls (necessary to retain the sync function)

Suddenly $400 didn't sound so bad....

 

[SKYCHENEY]

Doug,

Glad Williams DD got you all fixed up. I thought about you today on my way home to Lansing, MI from White Lake. I drove right by Muskegon and almost stopped by to see if you needed anything but I didn't know what marina you were in. Oh well, hope the rest of the trip is less eventful and more enjoyable.

Sky

 

[Woody Wheeler]

Does anyone have the tach/synchronizer parts for the 871n engine takeoff.One of the tee parts has stripped gears but the rest of the unit is in excellent shape.My engines are 1972 vintage

 

[Boatsb]

Call glendenning. Its a t joint and they are reasonable. You need to know the drive type.

 

[Freedom841]

Hi All:

My tach drive cable tip broke off and I can't get it out of the camshaft/ I've tried pulling with a vise grips with no luck.

Am I missing anything or do I just need to keep pulling? Glengenning mentioned a slide hammer might work - how do I make one up for this application?

Also pictured is the drive adapter. I plan to service it - any suggestion on how to clean out the grease inside? What type grease goes back in?



Thanks,
Mike
MV Freedom
48 LRC
Pacific NW