Mercruiser 1 Drive Upper Housing Seal Replacement

[jobfish]

I am hoping someone can help me. I have a Mercruiser 1 Drive 1979 model and I am replacing the seals in the upper housing. I have removed the driven gear bearings from the uni-joint shaft. My question is, should the Bearing Pack be pressed on so tight that I cannot move it by hand? If so, can I just re-install the bearings the gear and torque them to 70-80lb ft or should they be slightly loosened and re-torqued down?

 

[Bt Doctur]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement

All depends if the gearset has been replaced with a late style unit.In most cases the gear slips off the bearings and you find 2 steel spacers.(old type)
If you need to drive or pull the bearing off the gear then its new type.New type requires "rolling torque method"because the inner ring was discarded.

 

[jobfish]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement

All depends if the gearset has been replaced with a late style unit.In most cases the gear slips off the bearings and you find 2 steel spacers.(old type)
If you need to drive or pull the bearing off the gear then its new type.New type requires "rolling torque method"because the inner ring was discarded.

Thanks for that, Bt Doctur. It sounds like I have the new gear set and will have to have the rolling torque reset by the merc mechanic. Is it normal for the bearings to be so tight on the gear?

 

[Bt Doctur]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement

The newer gear `s dia. was increased by .001 or .002(I think) thats why the bearings are pressfit instead of slip fit. If you only found 1 large steel ring
between the bearings you have a newer gearset that eliminated the small inner ring.Without the small ring you use rolling torque method

 

[Bt Doctur]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement

http://mercstuff.com/fiche.htm #21 and #22 the very first one r.mr.alpha

 

[jobfish]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement

Sterndrive Exploded Views : MerCstuff.Com #21 and #22 the very first one r.mr.alpha

Thanks for that info

 

[jobfish]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement

I have another question. What is the best way to remove the bearing pack from the drive gear shaft without damaging it? So I can inspect the bearings, they seem a bit rough.

 

[Fun Times]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement


Puller Plate
(OEM: 91-37241)
Pulls gears & bearings
for all makes & models.

Hi there, Using the tool above, an OEM service manual, a press and some suitable tools to fit the area your pressing on should get what you need done.

Have a look at pages 3A-20 - 22 for an example of how to.http://www.boatfix.com/merc/Servmanl/6/6A3R3.PDF

 

[jobfish]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement

View attachment 224638
Puller Plate
(OEM: 91-37241)
Pulls gears & bearings
for all makes & models.

Hi there, Using the tool above, an OEM service manual, a press and some suitable tools to fit the area your pressing on should get what you need done.

Have a look at pages 3A-20 - 22 for an example of how to.http://www.boatfix.com/merc/Servmanl/6/6A3R3.PDF

Thanks mate. Really helpful.

 

[jobfish]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement

Okay, I've separated the drive bearings and inspected and noticed they all have light pitting on the bearings and the cup. So I think I will have to replace them. The gears look in good condition other than some light pitting on some of the teeth. I have two questions. 1. Can I replace the bearings individually and use the original spacer? 2. Are the gears okay to use even though they have light pitting?

 

[achris]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement

Gears are probably ok, bearings will need to be replaced. Also check the condition of the driven gear bearings too... That's the ones in the top cover and bottom of the housing. If you have the drive gear assembly out and the top cover off the housing, just lift the upper drive shaft and driven gear assembly out...

Yes, you use the original spacer. I would not buy the bearings from Merc, too expensive. iboats sell them -> Mercruiser Drive Gear (Yoke) Bearings Or any bearing supplier, Timken #s 382A (bearing) and 386A (outer race).

Lower bearing from iboats -> Mercruiser Driven Gear Bearings Timken #s HM89449 and HM89410

Top drive shaft bearing, iboats -> Mercruiser Upper Cap Bearings Timken #s 09067 and 09196

Chris....

 

[s.hadley81]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement

Just my 2 cents but I recently did exactly what your doing now and any surface that's in contact with a seal or gasket I would replace also I had a big P.I.A with surfaces(yoke assembly) getting to seal properly luckily I found out on the pressure test but wish I would replaced so it was one and done just figured I'd throw it out there and forgot to mention any parts with pitting that contact any seals I'd replace not good ones that just need a little clean up

 

[Bt Doctur]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement

If you only found 1 large ring you will need the "rolling torque method" for re-assembly.

 

[jobfish]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement

Hi Chris, That's good news to hear that the gears can be reused. Yes...the driven gear and upperhousing bearings are also pitted and will have to be be replaced. It's good that I can use the spacer and just buy the bearings I need. Thanks for the info on the bearings and for your help mate.

 

[jobfish]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement

Just my 2 cents but I recently did exactly what your doing now and any surface that's in contact with a seal or gasket I would replace also I had a big P.I.A with surfaces(yoke assembly) getting to seal properly luckily I found out on the pressure test but wish I would replaced so it was one and done just figured I'd throw it out there and forgot to mention any parts with pitting that contact any seals I'd replace not good ones that just need a little clean up

Thanks for that. I had the drive seals and surfaces all reconditioned by the boat shop 4 years ago. All surfaces look good. For some reason the two botton seals in the top housing have failed.
P.I.A??

 

[jobfish]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement

If you only found 1 large ring you will need the "rolling torque method" for re-assembly.

No small ring only a large ring. It will be rolling torque method.

 

[s.hadley81]

Re: Mercruiser 1 Drive Upper Housing Seal Replacement

P.i.a = pain in the a**