Rear main seal leak in 77 fj40 (1 Viewer)

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May 17, 2019
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You probably already know you have to drop the tranny. I was able to pop the rear main on my 3.4 v6 with a Lisle 58430 super easy. Looking at the FJ40, looks to be practically the same. If you've read any info online you have to be very gentle not to scuff the area around the seal where it comes in contact with the crank as any imperfection caused by you prying it out may cause future leaks. I was pretty intimidated after doing my google research but I took my time and was real careful and gentle with the tool, it popped right out with minimum effort. Putting the new seal in is also pretty easy, but also just as delicate. I used a flat punch and very gently and slowly tapped the new seal in while going crisscross in a clock fashion. 1-7, 2-8, 3-9, etc. Took a few minutes but I did not want to do this job again. I was replacing the clutch and other tranny components and they recommend changing the rear main while you are in there.

Again, looking at the Fj40 pics it looks practically identical. The tool I mentioned was totally worth the $15. Alternatively for putting the new seal in, you can get a pvc pipe of near same diameter and hammer in that way. I did this job in January and its been dry so far...Hope that helps
 
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I didnt see your other thread. The job is pretty labor intensive. Not sure if the engine has to come out on your application but the transmission/belhousing/ clutch & flywheel all have to be removed, good time to change any of these components. Also a good (and only) time to replace pilot bearing but that's the easiest of all.

Not familiar with the 40 series but driveshafts and exhaust also will have to be removed or atleast unbolted and shifted out the way. I did it in my drive way, my Tacoma has a lift so I was able to do it sitting on the ground. It took me a full weekend to drop everything, replace and put it all back together. If I had to guess, a professional shop that has experience in this job could probably do this in 6-8 hours, maybe?
 

1911

chupacabra
Joined
Aug 11, 2006
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6,247
Location
Parker County, Texas
 
 
77 FJ40 rear main seal (by the crank) is leaking engine oil. How hard is this to fix?
Thanks
Drop the transmission and transfer case as a unit, pull the clutch and flywheel for access to the rear main seal. Drop the oil pan and remove the rear main bearing cap to guarantee replacing the oil seal without damage.

If there's any doubt whatsoever about your clutch, replace it at this time. Replace the pilot and throw-out bearings in any event. If you take off the oil pan you can replace that gasket too.

You'll want a transmission jack to pull the transmission/transfer case; alternately you could use some heavy ratcheting straps from the roll cage above if you have one.
 
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Outstanding responses gents. Thats what I needed to know. Love this blog and the people on it. Thanks!
 
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Bakersfield, Ca
 
I've read a lot that this is the best way to do it. Looks like it's mentioned above also

"You do not need to remove the flywheel housing to replace a rear main seal...

Drop the #4 main bearing cap after you have the oil pan down, pull out the old seal with your hand, clean the seal area on the crank and install the new rear main seal with your hand, no banging, no reason to hit it, just push it into place...put the #4 main cap back up and torque the four bolts, and call it good."
 
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Sri Lanka
 
 
Dear bhsdriller
Is it the same procedure, removing #4 Main Bearing cap, for a BJ 40 too ?

Thank you in advance
 
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Broken Hill, Australia
Dear bhsdriller
Is it the same procedure, removing #4 Main Bearing cap, for a BJ 40 too ?

Thank you in advance
The BJ 40 rear main can easily be changed without pulling any main caps. Remove the gearbox, clutch and flywheel to gain access.
Change any suspect bearings while its apart.
I also recommend changing the gearbox input seal while the box is out
 

FJ40Jim

The Cruiser Whisperer
Joined
Sep 26, 2003
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10,857
Location
Lancaster, Ohio, USA
 
 
 
To install rear seal, if the oil pan & rear main cap are not being removed, it helps to have a special tool to start pressing in the seal uniformly. Fortunately every 2 F comes with the SST. It's also called a flywheel. ;)

To use the SST, place the new seal into the opening, present SST to the crank, start 3 bolts, then ratchet all 3 bolts all the way down, working around the triangle to keep the SST fairly flat to the back of the block. After all 3 bolts have bottomed, zap them out & remove SST/flywheel and gaze in wonder at the un-marred, perfectly straight seal that just needs tapped in another 1/16" until it is flush with opening.
Best to tap it home with hammer & a little scrap of 2x4 to avoid marring seal or crankshaft.
 

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