Propshaft seals install question

[54fleetwin]

I tried the search function but was not able to find the answer to this question.

I am replacing the lower unit seals on my '58 bigtwin 35.
The sierra kit comes with 2 propshaft seals. I assume I am suppose to use both.

My question is about the direction of the seals when I install them. One installed in the direction to retain the oil and the other installed in the direction to keep out the water. EX: spring inward on seal closest to the oil and spring outward on the seal closest to the water.

When I replaced the water pump seals on my motorcycle, the manual was specific about the direction the seals are to be installed. In that situation trans oil is one side and pressurized coolant on the other with an air space between that allowed any leaks to exit a weep hole.

TIA

 

[lindy46]

Re: Propshaft seals install question

1958 should only use one seal - the one which keeps oil from leaking out (spring inward). I believe there is only room for one seal in the bushing. Then there is the big o-ring which goes around the bushing.

 

[Haffiman]

Re: Propshaft seals install question

Check the old seal.
If the old seal is double-lipped, use both.
Been some changes during the years when it comes to replacement seals.
Original 'thick' single seals have been replaced with 2 thinner ones, mounted back-to-back.

 

[54fleetwin]

Re: Propshaft seals install question

Check the old seal.
If the old seal is double-lipped, use both.
Been some changes during the years when it comes to replacement seals.
Original 'thick' single seals have been replaced with 2 thinner ones, mounted back-to-back.

original thick seal is what I am replacing

 

[Haffiman]

Re: Propshaft seals install question

If the replacement seals have a combined height equal the old 'thick' one, use both.

 

[54fleetwin]

Re: Propshaft seals install question

2 seals dont fit

 

[lindy46]

Re: Propshaft seals install question

Did you buy the whole seal kit? I'm thinking maybe the other seal is for the driveshaft. I've bought lots of seal kits for that vintage motor and have never seen one with dual propshaft seals.

 

[54fleetwin]

Re: Propshaft seals install question

Did you buy the whole seal kit? I'm thinking maybe the other seal is for the driveshaft. I've bought lots of seal kits for that vintage motor and have never seen one with dual propshaft seals.

Yes it was the whole sierra seal kit.
Came with 1 driveshaft seal(different size) 2 the correct size for the prop shaft, and 2 that fit the propshaft but are too small OD for the seal housing, I assumed these are used on another motor and they just package one kit.
I am unsure of the 2 small o rings in the kit

 

[jasper60103]

Re: Propshaft seals install question

Attaching a pic of the sierra kit (18-2686) and gearcase for reference.
Does this look like the kit you received?

Kit Contains:

(1) 18-0882 Shift Rod Gasket - replaces O.E. # 304764 <--- #51
(1) 18-2005 Oil Seal - replaces O.E. # 313284 <--- drive shaft seal #52
(1) 18-2021 Oil Seal - replaces O.E. # 302564 <--- prop shaft oil seal #50
(2) 18-4248 Washer - replaces O.E. # 311598 <--- vent/fill washers #55
(1) 18-7100 O-Ring - replaces O.E. # 301877 <--- lower shift rod o-ring #46
(1) 18-7115 O-Ring - replaces O.E. # 302588 <--- prop housing seal #48
(1) 18-7120 O-Ring - replaces O.E. # 307853, 322598 <---pivot pin o-ring #45

One thing they left off the list is the
spaghetti seal (#11), but you can recognize that.

 

[54fleetwin]

Re: Propshaft seals install question

I ordered the sierra kit but ended up with a kit by EMP 26-01729 which replaces 182686 and 87607

 

[lindy46]

Re: Propshaft seals install question

Not sure what the extra propshaft seal is for - maybe they just slipped and put two in by mistake. What Jasper outlined is what usually comes in the kit. The small o-ring is for the pivot pin (the Phillips head bolt) And the slightly larger o-ring is the shift rod seal.

 

[jasper60103]

Re: Propshaft seals install question

I ordered the sierra kit but ended up with a kit by EMP 26-01729 which replaces 182686 and 87607

yea, you received the right kit then.

 

[Tim Frank]

Re: Propshaft seals install question

I am unsure of the 2 small o rings in the kit

The pivot pin (the Philips-head-don't confuse- with-one-of-the-drain-plugs part ) has an o-ring and there is usually an o-ring on the shift rod.

The shift rod one should be replaced if there is one ...a long-time (and really knowledgeable) OMC tech told me that these are always suspect when you need to reseal a L/U.