3F main seal replacement, in situ?

[Usernametaken]

The front and rear main seals on the 3F in my FJ73 are leaking quite badly.
Can I replace them in situ or is this an engine out job?

 

[kbushnz]

I can see no reason why you can't do it insitu, but naturally the gear box will need moving back out of the way to get to the rear one.
Question you have to ask yourself...Is it easier to pull motor or gearbox...
I did the rear on my 1kz playdoh with the engine in the truck...

 

[upp17]

It'd be easier to pull the motor out mate

 

[Hulsty]

Can be done in situ, gearbox out for the rear, may aswell do the clutch etc while you are there. The front you "may" need to pull the radiator to get enough room for a puller.

 

[kolin]

To make sure everything is clean and to give the RTV sealer used in the main cap side cavities time to cure. The job is not hard to do if you just take your time.If you do not have knowledge so better to replace from an expert.

 

[Josie'sLandCruiser]

Hi all,

Yes, you can do the rear main seal with the engine still in the truck.

Do some searching here on MUD on doing the RMS on the 2F - the 3F is very similar.

When I did the RMS on a 2F it was easy to damage the replacement seal, so consider having 2 on hand "just in case." Also, I have heard that dropping the oil pan makes the RMS replacement a breeze (but I have not tried this method.)

Good luck,

Alan

 

[Usernametaken]

Cheers guys, the throw out bearing need replacing so I might as well pull the 'box and do it that way.
How hard is the front to replace?
I'm thinking now is the time to purchase a Haynes.

 

[LAMBCRUSHER]

find a toyta service manual if you can, the haynes is dodgey in some regards. on my 2Fs and my 3FE, I dropped the pan and yanked the rear main cap, cleaned everything up, put some RTV on the sides of the rear main cap where the FSM shows, put the new seal in place over the crank end bell and replaced/retorqued the rear main cap. no pullers, no drivers, no damaging the new seals, plus the bonus of being able to check the bottom end. when I did the front seal, the hardest thing was getting the big nut off the crank...with a socket on the nut, and a breaker bar in the socket and the handle of the wrench firmly against the top of the left side of the frame, bump the starter and the nut will become loose. might strap the wrench handle to the frame rail to keep it from wanting to bounce anywhere. getting the balancer off is the next hard thing and usually a puller will bring it right off with hand torque(big arms and no wrench) once it breaks loose, it'll pop right off. I would pull the outer timing cover careful to keep the bolts in order, clean it up, replace the seal, then loosely screw the bolts into the block but not so tight it doesn't move(the timing cover). then slip/drive the balancer back onto the crank, THEN torque the timing cover bolts. this lets the balancer center the timing cover to the seal so it won't try to leak again after you're done. might want to pull the rad to have all the room you will need...get on it, have fun.

 

[Usernametaken]

Perfect mate, thanks for the advice!

 

[roscoFJ73]

The Haynes is the old Gregorys and is not too bad.

 

[Usernametaken]

To be fair, I have been told that if a 3F doesn't leak, to check the oil as its probably low.

 

[roscoFJ73]

To be fair, I have been told that if a 3F doesn't leak, to check the oil as its probably low.

When they are in good condition they can be fairly leak free. If they are running hotter than they are supposed to ,they will leak.
They are based on an design from 1940s,so next step up from a vintage car.
They were designed by the same team in Michigan that designed the Holden red engine and they always leaked as well.