I turned FJ40 today

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So the dirty girl has been driving pretty good lately. I’ve been running small errands in it each day. Perhaps it’s my imagination (or wishful thinking) but it seems to drive a little better / smoother by the day.

In the meantime I’ve been working my way through all the fluid changes these last few weeks. Here are a few observations:

- Engine Oil - <1.5 quarts came out. 8 quarts went in (-w- filter change). The drain plug had a steady drip so I have a feeling that the plug leak depleted the reservoir while it was sitting all those years. I’ve observed no smoke whatsoever during start up or while driving so I don’t think it’s burning any. After finally finding the correct crush washer (thanks @cruisermatt) for the drain plug washer part number, the drip has been eliminated. (BTW in case you were worried, the engine oil was changed weeks ago immediately after purchase. I haven’t been driving it with low oil.)

- Transfer Case - <2 quarts came out. >2 quarts went in. Oil was darkish but not milky or rusty. Very little metal sediment on the drain plug magnet.

- Rear differential - <2 quarts came out. >2.5 quarts went in. Oil was darkish but not milky or rusty. Very little metal sediment on the drain plug magnet.

- Front differential - <2 quarts came out. >2.5 quarts went in. Oil was dark greenish and thick with a slight milky tinge. Very little metal sediment on the drain plug magnet.

Below are pictures showing the difference between the front and rear differentials. I’m glad I got to the front one when I did. I’m wondering if some water got in there. Or is that perhaps knuckle grease?

If that is knuckle grease mixed in, which rebuild kit does everyone seem to like the best?

Note: in the pics below, greenish thick oil is from the front axle, brownish thinner oil is from the rear axle.

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Wait, are you trying to tell me that I’m “#1”?!

People tell me that all the time while driving in traffic. Thanks!

You numba 1, GI.
 
So the dirty girl has been driving pretty good lately. I’ve been running small errands in it each day. Perhaps it’s my imagination (or wishful thinking) but it seems to drive a little better / smoother by the day.

In the meantime I’ve been working my way through all the fluid changes these last few weeks. Here are a few observations:

- Engine Oil - <1.5 quarts came out. 8 quarts went in (-w- filter change). The drain plug had a steady drip so I have a feeling that the plug leak depleted the reservoir while it was sitting all those years. I’ve observed no smoke whatsoever during start up or while driving so I don’t think it’s burning any. After finally finding the correct crush washer (thanks @cruisermatt) for the drain plug washer part number, the drip has been eliminated. (BTW in case you were worried, the engine oil was changed weeks ago immediately after purchase. I haven’t been driving it with low oil.)

- Transfer Case - <2 quarts came out. >2 quarts went in. Oil was darkish but not milky or rusty. Very little metal sediment on the drain plug magnet.

- Rear differential - <2 quarts came out. >2.5 quarts went in. Oil was darkish but not milky or rusty. Very little metal sediment on the drain plug magnet.

- Front differential - <2 quarts came out. >2.5 quarts went in. Oil was dark greenish and thick with a slight milky tinge. Very little metal sediment on the drain plug magnet.

Below are pictures showing the difference between the front and rear differentials. I’m glad I got to the front one when I did. I’m wondering if some water got in there. Or is that perhaps knuckle grease?

If that is knuckle grease mixed in, which rebuild kit does everyone seem to like the best?

Note: in the pics below, greenish thick oil is from the front axle, brownish thinner oil is from the rear axle.

View attachment 3656839
View attachment 3656840
Question:
My project is getting closer to starting its rebirth. Is it just a drain and fill or are any cleaning agents introduced into the drained areas to remove slug prior to the fill?
Thanks
 
Question:
My project is getting closer to starting its rebirth. Is it just a drain and fill or are any cleaning agents introduced into the drained areas to remove slug prior to the fill?
Thanks
I didn’t use any but it sure doesn’t sound like a bad idea.

Interested to see what others suggest…
 
I didn’t use any but it sure doesn’t sound like a bad idea.

Interested to see what others suggest…
Mine has 42 year old oil in the front and rear axles. Wondering if it would hurt seals or anything.
What type of product would be best? Or not at all.
 
Mine has 42 year old oil in the front and rear axles. Wondering if it would hurt seals or anything.
What type of product would be best? Or not at all.

Not remotely an expert, ...
But what has worked well for me when I have bought a new-to-me Cruiser with questionable maintenance is start by changing the fluids (same as you), but I change them all again on a shorter service cycle. For example, I might drain the axles/tranny/transfer case in a few thousand miles. This should give the fresh oil an opportunity to circulate across all internal surfaces and get lingering crud into circulation so I might see it in the drained fluid. If the used oil looks clean at the shorted cycle, I refill and run for a normal service cycle. If the used oil again is noticeably loaded with crud, I refill and run another short change cycle. <repeat if needed>

I have been lucky because I have not encountered a situation where I have had to continue the short service cycles or had issues with my new-to-me Cruisers. I hope you are just as lucky.
 
HPL (advanced lubrication) sells a "differential cleaner" that is good stuff from what I can tell. I have a quart of it, but haven't used it yet as I was going to use it for my UTV that was abused before me. In any event, they make GREAT oils. I don't know how much to tell you to to use, but they are great to deal with on the technical side. Though sometimes they are slow to respond to emails...phone might work better.
 

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