# Front Diff Propeller Seal Replacement



## crooklyn (May 3, 2011)

I followed the direction found on phreebsd's post Brute Force 750 - Changing the Front Oil Seal

I have removed the drive shaft and just want to make sure that this is the correct seal #92049D	92049-1573 SEAL-OIL,TCY 48X65X8

I have attached a picture with arrows pointing to the seal.
(going to try the self tapping screw trick)


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## NMKawierider (Apr 11, 2009)

Yep...that be the one. Whatever you use to remove it (I assume you don't have a seal puller) make sure you do not scratch the case surface or the coupler's surface.


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## crooklyn (May 3, 2011)

Thanks!
I'm going to pick up a seal puller now and also try the self tapping screw trick.
much appreciated!


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## crooklyn (May 3, 2011)

when putting the new seal in, do i just coat it with oil (same type that is used in the front diff) or do i use grease?

you mentioned to wipe it down with acetone on a rag (done)

not sure what you mean by "put some grease on the shafts only and between the wipe and guard of the seal only." do you mean grease up the drive shaft that was pulled out to access the seal?

and when it comes to putting on the red RTV on the outer part of the seal prior to installation, is that to be on the side that faces into the diff?

_*Sorry, I was in the I.T. industry so I'm not mechanically inclined (but learning)*_


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## NMKawierider (Apr 11, 2009)

crooklyn said:


> when putting the new seal in, do i just coat it with oil (same type that is used in the front diff) or do i use grease?
> 
> you mentioned to wipe it down with acetone on a rag (done)
> 
> ...


OK, a seal seals on two surfaces, one-the shaft or part the is rotating and two, the case the seal is pressed into. Lub the moving parts..obviously, and RTV the surface that doesn't move. If this is unclear, just grease or oil everything. It will probably still seal OK. Use a seal driver or socket large enough to apply pressure on the outer edges of the seal, not just the face. And be sure it goes in straight and even. Little taps..take your time. If you go in too far, you will have to get a new seal.


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## KawieKrizanek (Feb 2, 2014)

Hey all, i need to replace this seal on my 08' 750. will this part number work for the 08' 750 i dont see what year his is. Also i read that these go bad because of the shaft loosen in the diff. is the nut shown in the picture above the one that needs to be tightened to remedy this problem? Thanks in advance


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## NMKawierider (Apr 11, 2009)

KawieKrizanek said:


> Hey all, i need to replace this seal on my 08' 750. will this part number work for the 08' 750 i dont see what year his is. Also i read that these go bad because of the shaft loosen in the diff. is the nut shown in the picture above the one that needs to be tightened to remedy this problem? Thanks in advance


Those seals are all the same. That nut is not the one that can get loose, that one holds the end piece on the pinion only. It does have a bushing that if it gets loose, can cause wobble on the piece and take the seal out though.


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## KawieKrizanek (Feb 2, 2014)

NMKawierider said:


> Those seals are all the same. That nut is not the one that can get loose, that one holds the end piece on the pinion only. It does have a bushing that if it gets loose, can cause wobble on the piece and take the seal out though.


Seems as tho.all of my seals went bad at the same. It is a.2008 so maybe they did

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## NMKawierider (Apr 11, 2009)

KawieKrizanek said:


> Seems as tho.all of my seals went bad at the same. It is a.2008 so maybe they did
> 
> Sent from my SCH-I545 using Tapatalk


See if there is any play in it or the pinion it's self. A bad pinion bearing can do the same thing.


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## KawieKrizanek (Feb 2, 2014)

NMKawierider said:


> See if there is any play in it or the pinion it's self. A bad pinion bearing can do the same thing.


That would make all three seals go?


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## KawieKrizanek (Feb 2, 2014)

I tried looking for a "how to" on tightening the front and rear pinion nuts. But can not find. Could ya help me out?

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## KawieKrizanek (Feb 2, 2014)

Does the oil need to be drained from the motor before removing the propeller shaft?

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## brutemike (Mar 23, 2010)

No on draining the motor oil unless changing the front seal on the motor. As for the front diff I would pull it and put a bearing n seal kit in it there like 70 bucs on eBay being an 08 the bearings are probably shot. Tightening the pinion nut will not snug up the bearing. If you get to much slop in the bearings then ur asking for a major problem in the future cause those gears are not cheap.


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## nate.jager1993 (Jul 7, 2014)

NMKawierider said:


> Those seals are all the same. That nut is not the one that can get loose, that one holds the end piece on the pinion only. It does have a bushing that if it gets loose, can cause wobble on the piece and take the seal out though.


My coupling that attaches the front drive shaft to the pinion does have some side to side wobble and it took out my seal. In looking that the parts diagram on cheap cycle parts, I am unsure which part is the bushing you're referring to? 

Any help is appreciated.

2007 650i


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