Drive shaft seal Chrysler 120

[roverfj1200]

Hi to all

I have had this problem with two boxes now. I install a new seal on the drive shaft and on the first outing the lower lip of the seal is forced out the top lip along with spring. As if pressure has forced it out. I have read the manual and asked a few mechanics about it but no one seems to know why.

Any help would be appreciated.

Richard.

 

[huskerdaninva]

Re: Drive shaft seal Chrysler 120

Just a thought here, is it possible the prop shaft is not true, and perhaps rotating off kilter causing damage to the seal??

 

[carholme]

Re: Drive shaft seal Chrysler 120

Are you referring to seal item 9 in this parts listing and are you sure that you are installing the seal with the lip in the right direction?

http://www.crowleymarine.com/mercury-outboard/parts/1747_110.cfm

Gerry

 

[Frank Acampora]

Re: Drive shaft seal Chrysler 120

One piece or two piece lower unit? What year Chrysler?

 

[roverfj1200]

Re: Drive shaft seal Chrysler 120

Gerry looks like the seal. The one under the water pump.

Frank.
What I have is a 120hp power head on a 135hp leg. Two piece gear housing. I run Castrol marine gear oil. I had a old leg that was a bit tight and blow out a few seals so I purchased a second hand leg which seems OK. So i replaced the prop seal and main shaft seal. One good run and the main seal looks like pressure has pushed the bottom lip of the seal up and out the top lip. same as old leg. Same seal brand same oil. I install the seal with the steel face up (to water) not sure what lip down means. will try and get a pix up.

Thanks Richard.
this the seal I install it this way up (seal damaged by removal)

this like what happens the lower lip pushed up and out

Sorry pix a bit blurred .

 

[Frank Acampora]

Re: Drive shaft seal Chrysler 120

Ahh! Makes a difference when I know the lower unit it is.

The two piece lower unit has two tapered roller bearings on the drive shaft. The upper bearing is located by a snap ring in a groove on the shaft. The lower is held by the nut. The nut is a deformed thread nut and the degree of tightness controls the pre-load on both bearings. The pinion and shaft are splined and again, the nut controls the degree that the pinion slides onto the shaft. The nut is not run down all the way onto the shaft.

SO, if the nut has been reused and the deformed threads are not holding, or if it is not far enough onto the threads of the shaft, it will allow the shaft, circlip, and top bearing to ride up --guess where?--into the seal.

Disassemble the lower and remove the nut. Stake it with a punch on three flats to again deform the threads or break down and buy a new one. Maybe try a drop of threadlocker for insurance. Reassemble and --I forget the torque--run the nut down until the slop in both bearings is removed. It is just like pre-loading bearings on a car or trailer.
See if that doesn't help.

I believe on that lower unit the seal goes with the garter spring in -- towards the oil.

 

[roverfj1200]

Re: Drive shaft seal Chrysler 120

Thanks Frank..

But there is no end play in the main shaft. The seal I have pictured has a garter sping on both sides.

Has me scratching my head...

Thanks Richard.

 

[Frank Acampora]

Re: Drive shaft seal Chrysler 120

Are you certain that that is the correct seal? The only ones I have seen for the two piece lower unit have only one garter and are flat on top. You may be using a seal that is too thick. If money for shipping and time are not critical, contact franzmarine@aol.com and see what seal he has for you. This guy knows more about Chrysler engines than almost anyone and can probably tell you the seal without looking it up.

Of course, that being an Aussie Chrysler, everything will be backassward. LOL Sorry, just couldn't resist.

 

[roverfj1200]

Re: Drive shaft seal Chrysler 120

The seals have come from the importer. They use the model number for parts. It may be poor Taiwan made one..

Will ring supplier but I know what answer I will get.

Thanks for the help..

Cheers

 

[roverfj1200]

Re: Drive shaft seal Chrysler 120

Just as a follow on to this. I have dismantaled the box and main shaft bearings. The bearings are pitted and look to have overheated. The shaft has a odd wear mark where the seal fits. the shaft is in to be re machined and new bearings ordered. lower box and shaft see OK for a 35year old outboard.

With all the trouble I have had with gearboxes I hope this does the trick.