front crank seal

[tomrichardson]

good day people.
i seem to have an ever increasing amount of oil splattering itself around the front of my engine.
i therefore am concluding it to be the front crank pulley seal.
can anyone please confirm the big nut holding on the pulley is a std RH thread, and if i can remove it as one lump or do i have to split it in half as per the manual?
need to phone around in the morning to get myself a seal and then i can give it a bash.
cheers, Tom.

 

[karl webster]

Hi Tom

The nut is normal thread. These can be super tight tho. I forget the torque setting but alot. You may have to make a tool to stop the engine turning as i have in the past as you just carnt get them undone at times. As for the job you talk about i havnt done one myself sorry. Dont think ive come accross it coming from the front before. Is it comming from the timing case cover?? Is it defo engine oil?


Karl

 

[tomrichardson]

Thanks karl.
Its defo engine oil. I need to do some investigation but it does look like the crank seal. Unless its an obscure leak from higher up just being flung off the pulley? Its getting worse now quite quickly so i need to sort it.

 

[Towpack]

Torque setting is 362lb/ft but if it's never been off it'll probably take a lot more than that to shift it!

 

[tomrichardson]

Thanks towpack. Thats handy to know.
I'm now hoping the mysterious squeeky noise i get on stopping the engine isn't a loose pulley as i dont need a new crank at the mo!!

 

[Cptsideways]

Often the ONLY way to get them off & I have tried many times on various Toyota's is with heat from a blowtorch, you don't need much mmmppph once there is some heat on them. Then they just fall off pretty much. Depending on the rotation you can sometimes use the starter motor to undo them (risks involved though!)

Alternative is to get a long bar that'll reach to the moon, then as the moon passes use that as leverage. It does'nt work as well as the blowtorch method though.

 

[Ben]

ive used the starter motor technique many times and never had a problem!

simply position the ratchet so that the handle is pushing against the chassis and give the key a very quick turn.

 

[Jon Wildsmith]

disconnect power to the fuel shut off solenoid first if you use the starter method

 

[tomrichardson]

well i had a seal delivered to me from toyota today and got the truck over my mates pit ready for an hours work................
mmmmmmm
found the pulley was loose, or the keyway worn???
after the hour, much swearing and deliberation, the bolt will not move.
well, it move about a 1/4 turn either way before locking up solid.
i made a SST to hold the pulley, out of 10mm x 50mm steel. that finished off the woodruff so the pulley is now free to be in any position it likes.
we had a 3/4" drive ratchet with a 4' long bar, whilst holding the engine on the starter ring via the inspection hole.
still no movement. so on went the scaffold pole.
still nothing.
been and borrowed a fancy induction heater to heat the bolt up. fantastic bit of kit, and should be for the price. hit it to shock it. still nothing.
i'm about ready to go mad.
decided to let it cool down properly overnight and give it another bash in the morning before i start stripping out the rad etc, for a session of drilling.
if anyone has any other thoughts i'd really appreciate it.

can anyone tell me how long the bolt is and what thread it is? i am assuming as its toyota it would be a 16mm or 20mm metric fine or extra fine. at least if i know what it is i can sort out a tap etc in readiness, and also know what dia to drill out to.
thanks, Tom.

 

[Cptsideways]

It'll be metric fine, not sure on the diameter though. 16mm would be my bet if I had to.

Did you try the blowtorch

 

[tomrichardson]

daredn't get the burners in there. thats why we borrowed the induction heater.

 

[Towpack]

You dont want to heat up the bolt. You need to heat up whatever it screws into to expand it, obviously in this case the crank which is impossible to get to so try heating the pulley surrounding the bolt then hit the bolt head with freezer spray, available from electronic shops. There may be a rubber damper built into the pulley so be wary of this. I've used this technique on several occasions but never had to remove the crank/plulley bolt. If you apply heat to the pulley remember to remove the secondary pulley beforehand which bolts to the primary.

 

[frank rabbets]

Hi Tom

You first described the fastener as a nut; then a bolt. I have got monster nuts off by drilling in line with the crank' through the wall of the nut being careful not to damage the crank' threads. Then I have ground up a tapered punch to split the nut. All quite easy. If you have a bolt it may be possible to soak the whole thing with EP 90 and slowly work the bolt back and forth.

Let us know what works!!

Frank

 

[Cptsideways]

Heating the head of the bolt lengthens it & releases its tension

 

[tomrichardson]

i apologise, it is a bolt.
the idea of heating it all is as cptsideways says, to expand everything together and then as it cools it "cracks" the bond i.e. rust between the two. to heat the end of the crank to cherry red would knacker the hardening of the crank.

anyways, it seems it has been an underlying problem for some time.

i stripped out all the front end so we could get in a 3/4" drive air gun. after about 1/2hr of backwards and forwards working the bolt, it came out. the last 3/8 to 1/2 of the thread was absolutely shot, so was picking up all the way out. I was less than impressed.
i have now run a tap into the crank to clean a new thread which has been rather successful.

it would seem someone has been in there before, and wound in the bolt to where they thought it was tight, due to the shot threads. but it was within about 1mm of the pulley. This has allowed the pulley to move ever so slightly over time side to side, which has worn the woodruff key.it has culminated with me having a broken pulley flange, a knackered bolt and shot thread in the crank.

i am now in the process of rebuilding her, and need to source a pulley and bolt, and away we go again.

 

[tomrichardson]

just to add.
this explains the funny clonking noise i got when stopping the engine, the continuous slight oil leak that was impossible to find, and the reason i could never quite get my pump timing absolutely spot on!!

 

[Towpack]

Heating the head of the bolt lengthens it & releases its tension [/quote

I don't see how heating the bolt will free it. Heating it will expand both it's length & diameter. How is this going to loosen it? It isn't. Cooling and shrinking the bolt and expanding the nut (or whatever it's screwed into), that will crack the seal, beit corrosion or loctite or whatever. Works every time and you don't need that much heat, certainly not red heat anyway.

Tom,

Glad to see you've got the better of it, sounds like someone else's bodge has become you're problem.

 

[tomrichardson]

I think someone elses bodge has become my headache!!

Anyway, i think maybe the whole heat idea is slightly misunderstood.
If you can say heat an exposed nut to expand it, then undo it whilst warm that works ok. Nut gets bigger on the bolt.
In my case, heating the bolt in the crank expands everything together. Now i didnt know if someone had used loctite, or it was just rusty. The expansion stretches the bolt and expands the crank slightly.
Then i let it cool down overnight back to a normal state. This shrinkage breaks the bond between the two, as they will cool at different rates.
If i tried to undo it whilst warm, then yes the bolt would be extra tight in the crank.

I hope that is understandable. It was explained to me in better terms by an old engineer.

 

[Cptsideways]

These are stretch bolts, so there is a good 30mm of shaft length before it reaches into threaded length. Heating the head is the ONLY way I have got these things undone (many many times) with ease. They simply pop undone with one blast from a snap on electric windy gun or a crack with a not so long spanner & a hammer. Alternative is the moon option as mentioned before.

It appears to be an Identical bolt to the one used on Toyota JZ engines, of which I have seen & worked on many.

 

[tomrichardson]

I fear the moon did not pass by my truck that night!
Oh well