Shaft coupler

Heefus · Post by **Heefus** » Mon Mar 19, 2012 10:23 am

So I should be getting my new prop shaft in this week. Should I replace the coupler as well? The fit, on the old shaft, is very tight but I would not go so far as to assume that it will be on the new shaft.

Also, I am going to repack the shaft seals, what size flax for a 1" shaft?

prowlersfish · Post by **prowlersfish** » Mon Mar 19, 2012 12:58 pm

That would depend on the condtion of it ans if its running true .

Shaft packing is 1/4 on the 1"shaft

This may you help you get it done right

http://www.diybob.com/diyPackingGland.htm

BobCT · Post by **BobCT** » Mon Mar 19, 2012 1:56 pm

I think 1" shaft might be 3/16", I know my 1.25" uses 1/4" packing.

larryeddington · Post by **larryeddington** » Mon Mar 19, 2012 3:02 pm

There is advice on web to always use an new one. IMO I cannot see how it could get loose as it has a keyed slot and as I just found out heat the flange and it should drop on and shrink to what Bob at Beacon calls a "light press". They also drill down the locking bolt holes to make a dimple in the shaft under each one. Once the bolts are tight ane safety wired on I cannot see how they could be loose or come off.

However you are using a new shaft and I would be asking myself, do I absolutely want to be sure?

Heefus · Post by **Heefus** » Mon Mar 19, 2012 4:11 pm

I have no idea if the original coupler is true or not. i will stick a straight edge on it tomorrow and have a look see. Other than that, the shaft is keyed, sits flush at the end of the coupler, and is not egged out.

larryeddington · Post by **larryeddington** » Mon Mar 19, 2012 4:20 pm

The hole is about 3 in long if key and set screws were intact, IMO, it should be tight.

Others may disagree I am reusing mine but going back on same shafts.

I just finished cleaning my shafts and deburing couplers, they look perfectly good on mine.

Something unusual though one of my coupler set screws is 1/4 inch shorter then the other three. Going to get one the same lenght as others as I am not 100% sure it will tighten into the dimple on the shaft, just to be safe. Too much work to have a problem.

prowlersfish · Post by **prowlersfish** » Mon Mar 19, 2012 5:48 pm

BobCT wrote:I think 1" shaft might be 3/16", I know my 1.25" uses 1/4" packing.

Bob its 1/4 for sure as my 1 1/2 shaft .
shaft size---- packing size
1"--------------------1/4"
1 1/8"---------------3/16"
1 1/4"---------------1/4
1 3/8"---------------3/16"
1 1/2" --------------1/4"
1 3/4"---------------1/2"
2"--------------------3/8"

jefflaw35 · Post by **jefflaw35** » Mon Mar 19, 2012 10:36 pm

my brain hurts again

prowlersfish · Post by **prowlersfish** » Mon Mar 19, 2012 10:43 pm

Heefus wrote:I have no idea if the original coupler is true or not. i will stick a straight edge on it tomorrow and have a look see. Other than that, the shaft is keyed, sits flush at the end of the coupler, and is not egged out.

That won't tell you anything have the people making your shaft or someone else put it in a lathe

Big D · Post by **Big D** » Mon Mar 19, 2012 10:45 pm

prowlersfish wrote:
Heefus wrote:I have no idea if the original coupler is true or not. i will stick a straight edge on it tomorrow and have a look see. Other than that, the shaft is keyed, sits flush at the end of the coupler, and is not egged out.

That won't tell you anything have the people make you shaft or someone else put in a lathe

+1 Get the coupler resurfaced.

Heefus · Post by **Heefus** » Mon Mar 19, 2012 10:48 pm

prowlersfish wrote:
Heefus wrote:I have no idea if the original coupler is true or not. i will stick a straight edge on it tomorrow and have a look see. Other than that, the shaft is keyed, sits flush at the end of the coupler, and is not egged out.

That won't tell you anything have the people make you shaft or someone else put in a lathe

I what direction am I looking for deviation? The mating surface must be flush, and the hole must be centered in the coupler, gripping the shaft tightly. Is there some other axis involved somehow?

prowlersfish · Post by **prowlersfish** » Mon Mar 19, 2012 10:53 pm

Heefus wrote:
prowlersfish wrote:
Heefus wrote:I have no idea if the original coupler is true or not. i will stick a straight edge on it tomorrow and have a look see. Other than that, the shaft is keyed, sits flush at the end of the coupler, and is not egged out.

That won't tell you anything have the people make you shaft or someone else put in a lathe
I what direction am I looking for deviation? The mating surface must be flush, and the hole must be centered in the coupler, gripping the shaft tightly. Is there some other axis involved somehow?

the mating surface must flush and run true in relationship to the bore . the lathe is the way to do it , the right way .

Heefus · Post by **Heefus** » Tue Mar 20, 2012 3:15 pm

Understood. I spoke with a vendor today. He stated that they pretty much throw it on a lathe, check the bore for egging, and check the mating surfaces for trueness and burrs.

BobCT · Post by **BobCT** » Tue Mar 20, 2012 9:03 pm

hmmm... interesting chart on the packing. I always thought the packing size was always smaller or larger depnding on the shaft size. Not quite a linear scale now is it

good info...