Can I rotate Tach Sender?

[rustybucket]

posted this on boatdiesel too.

Ok, so we lost a tach cable this weekend, when I was down removing the cable for replacement I kinda see why it let go, it is slighly bound right at the connection point on the trans pump. If I can rotate it approx 90deg it will be a MUCH nicer/cleaner/smoother run to the glendinning sync.

It ´looked´ like I could just loosen the allen screw to rotate, loosened it, and nothing. Then I noticed the thru-bolt allen bolt, loosened it and it was still snug.

Not wanting to break anything figured I´d just leave it as-is and ask here.

Anyone have experience installing/rotating these things? Any secrets or just apply more pressure? Any guidance is greatly appreciated.

This is on 8v92´s with allison MH20´s

This piece is inserted into the piece below
https://dieselpro.com/allison-5102051-adapter-for-tachometer-drive-angle-m-mh.html

I loosened the allen bolt, but still wouldn't turn, maybe I need to remove the bolt completely?
https://dieselpro.com/allison-marin...46787-tachometer-drive-m-mh.html#.WsuIdMgh0Vw

 

[tonytrakovich]

Yes, you can rotate as much as you want. Problem is that over the years they get gunked up and sieve in the hole. When I replaced the adapters on my 1292's they took quite a bit of persuasion to get out. After installing the new ones, they would spin freely, even with the retaining bolt installed.

 

[rustybucket]

Yes, you can rotate as much as you want. Problem is that over the years they get gunked up and sieve in the hole. When I replaced the adapters on my 1292's they took quite a bit of persuasion to get out. After installing the new ones, they would spin freely, even with the retaining bolt installed.

Awesome, thanks, that is what I needed. I'll start adding persuasion in small increments this weekend, hopefully get it to turn a little.

 

[rustybucket]

Just wanted to update this. I tapped the senders with a rubber mallet to loosen them. Stbd turned with no problem at all, port was stuck. I took port completely off and clamped it in a vice and was able to get it broken free and was able to rotate it too.

Thanks for the guidance guys!

 

[Tim Powell]

Just wanted to update this. I tapped the senders with a rubber mallet to loosen them. Stbd turned with no problem at all, port was stuck. I took port completely off and clamped it in a vice and was able to get it broken free and was able to rotate it too.

Thanks for the guidance guys!

sink them !!!! go to http://www.glendinningprods.com/ get two new ones the tacks will jump all over the place never stay steady....i promis they will waver. while you are there change the cables use the ones at glendenning they are a little stiffer and will not let the tacks shape or waver.
trust me i been there

 

[tonytrakovich]

What was stuck on the port one? Was it the inner workings of the adaptor? Or the adaptor in the engine? My adaptor was driven with about a 6” cable with squared ends. The adaptor has matching female squares. If the Inner workings of the adaptor freeze up, the cable will break or the square ends will wear off. That will give an erratic tach and cause your synchronizor fits.

 

[rustybucket]

What was stuck on the port one? Was it the inner workings of the adaptor? Or the adaptor in the engine? My adaptor was driven with about a 6” cable with squared ends. The adaptor has matching female squares. If the Inner workings of the adaptor freeze up, the cable will break or the square ends will wear off. That will give an erratic tach and cause your synchronizor fits.

The sender is a two piece unit, the insides were good, I was just trying to rotate the sender itself.

My issue was that when the engines were re-manned (or possibly always been that way?) the tach senders got moved and the angles at which were not condusive to a straight run to the sync. They had to make about 4-5 tight bends to get there. One of the cables had indeed broken, hence the reason I was in there. I'm sure the breakage was primarily due to the extreme bends.

Once I spun each sender about 90deg the cable run is now a single smooth S with no tight bends at all.

I'm going to go ahead and replace the second tach cable next time I'm down, but it is functioning properly but I'm sure doesn't have much time left b/c of the way it was previously routed.