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Oil pump (crankshaft front) oil seal failures


Chris Wilson
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Is there any correlation between the companies carrying out the work and the failure rates?

 

Are things being installed properly?

 

No finger pointing, simply curious.

 

 

 

Fair shout, the way im looking at it at the moment is turbofit have done loads of rebuilds/oil pump changes and this problem is only a recent one, they have the proper seal install tool from toyota that has been used with the install and ive watched Pete the engine builder taking the upmost care to fit them so i cant see it really, from searching this forum and others it seems a lot of people have suffered with this problem, im up turbofit now trying to sort this, the boys are stripping it down again now.

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OK, what you COULD have done, Greg, is run Jamies car with the oil cap off and a rag over it to catch any oil spray. that way you would have eliminated crankcase pressure as a cause, as there is no WAY the engine could internally pressurise with such a big open vent. Sincerely hoping you don't get another problem, but if you do, change the seal and try that... You then cheaply eliminate crankcase pressure as a cause, and it's either mechanical forces (God knows what or how) or oil pressure building behind the seal through excess pump leakage, or the seal moving due to an oversize seal location hole (just measure it with an intrernal micrometer) or an undersize seal OD (same thing, measure it). I will go and look at the new pump on peter Sharps engine, he was asking why it was taking so long for me to put the sump on it, now I hope he knows why i have been hanging fire ;)

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I never rise normally to comments made like this but enough is enough:

 

" Is there any correlation between the companies carrying out the work and the failure rates?"

 

Why not just come out and say Turbofit are not doing it right.

 

"Are things being installed properly?"

 

We have been doing this for a long time and we only use the right parts and tools supplied by Toyota.

 

These oil seal and pump problems have only just started in the last couple of months and then only with the new parts supplied by Toyota, I have lost count of the number of front seals and oil pumps we have replaced in the past but there have been quite a few and all with no problems.

 

Perhaps you might like to try and be consturctive for a change and not desturctive.

 

 

Is there any correlation between the companies carrying out the work and the failure rates?

 

Are things being installed properly?

 

No finger pointing, simply curious.

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Anyone have the seal dimensions handy? (especially width)

is it single or double lipped? Just wondering if its possible to fit a double seal in the hsg.

These seals are blowing the tension ring rather than blowing the whole seal from the hsg right?

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Thanks Chris we will get Jamie to give the car a run with the new seal in and the oil cap off once we have put in the new seal.

 

I will messure the OD on the pump and the seal once they are removed and post the results.

 

 

 

OK, what you COULD have done, Greg, is run Jamies car with the oil cap off and a rag over it to catch any oil spray. that way you would have eliminated crankcase pressure as a cause, as there is no WAY the engine could internally pressurise with such a big open vent. Sincerely hoping you don't get another problem, but if you do, change the seal and try that... You then cheaply eliminate crankcase pressure as a cause, and it's either mechanical forces (God knows what or how) or oil pressure building behind the seal through excess pump leakage, or the seal moving due to an oversize seal location hole (just measure it with an intrernal micrometer) or an undersize seal OD (same thing, measure it). I will go and look at the new pump on peter Sharps engine, he was asking why it was taking so long for me to put the sump on it, now I hope he knows why i have been hanging fire ;)
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Anyone have the seal dimensions handy? (especially width)

is it single or double lipped? Just wondering if its possible to fit a double seal in the hsg.

These seals are blowing the tension ring rather than blowing the whole seal from the hsg right?

 

I'll post up the seal size later, i can't recall from memory, but i think it's a "bastard" size and not available from normal seal manufacturers (Toyota will have specified one dimension as a none stock figure, so they get to sell all the seals at an elevated price, common practice with engine and gearbox seals I'm afraid).

 

In the one instance of a seal going on an engine I have had in here it was the tension ring that had come off. It's impossible for the seal to be blown / pushed far enough forwrd as to come out of the pump bore, there's the crank trigger star wheel a few mm in front of it, it would just rub against it.

 

The one that leaked I just fitted a new seal, did a little race trick in reverse on the seal spring, and, AFAIK, the car did about 200 / 300 miles of mixed driving with no problems, but the owners in Iraq, probably with other things on his mind right now :)

 

Only thing that was a common denominator was his engine had had a sever overheat, and had had the head off, a light skim, and a reassemble, by A N Other Garage Limited. Engine ran fine, no blow by obvious at all.

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Why not just come out and say Turbofit are not doing it right.

 

Had I wanted to say that I would have done, I didn't because my question was a general one in a an attempt to understand where this sudden issue has come from.

 

We have been doing this for a long time and we only use the right parts and tools supplied by Toyota.

 

Good news for all involved, obviously a bit of knowledge too, give me the right parts and tools and I'll still screw it up.

 

Perhaps you might like to try and be consturctive for a change and not desturctive.

 

Perhaps you'd like to stop being all defensive when you aren't being attacked?

 

I'm trying to understand... just like everyone else.

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Chris in no way would I ask you to butt out as I value your input on this subject and feel that some light may be shed and other people will benifit from the information.

 

On to the pump and seal sizes.

 

Old Pump and Seal.

The OD of the seal is: 63.02mm

The Od of the pump recess is: 62.73mm

 

New Pump and Seal.

 

The Od on the seal is 63.29mm

The OD on the pump recess is: 63.05mm

 

Quite intresting the results above although there is bound to be some expansion on the old seal due to heat, which means that the new seals are slightly bigger.

 

 

 

 

Just for the record I don't want to put my nose in, especially with another engine builder, if it's unwanted. Tell me to butt out if you like. My nickname isn't Rhino for nothing (thick skinned and always charging ;))
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Just a quick change to my post about the difference between the old and new pumps:

 

I said the the left hand side of the new pumps had an extra fitting, it is in fact the right hand side.

 

Just goes to show how left and right can get mixed up whilst upside down.

 

:)

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he one that leaked I just fitted a new seal, did a little race trick in reverse on the seal spring, and, AFAIK, the car did about 200 / 300 miles of mixed driving with no problems

 

Chris, Can you enlighten us with how you do that trick with the spring please.

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Jesus, what a nightmare situation Greg, feel for you.

Have you tried sourcing old stock from America? Is there a part number difference?

 

 

 

I have been doing a bit of hunting regarding old stock, but turned up nothing, all new numbers in US and Japan.

After talking to Greg and Steve Manley, its a bit of a mixed bag between seal failure and cracks in the castings.

As for my engine, the first seal failed when i went BPU, but i also changed the oil grade! after new seal and going back to thinner oil, i also checked compression, all was fine for a year.

I then changed the turbos and also the oil grade again, by by seal!

Changed the oil grade back and seal, tested crankcase pressure via a gauge coupled to the dip stick tube, and found none! but shortly after the seal failed again!

Now i have observed two things, the failure occurs only when RPM is high and so is oil pressure,

and that initially about 1/2 Lt of oil will be expelled from the seal, but after the RPM drops no more oil is expelled, and this is also true at idle when engine is cold, as i have moved the car a couple of times since and no more oil has come out, but i know that when the seal is removed, the spring will be off!

Now i can hear Chris and others saying that this must then be due to crankcase pressure, but as i have explained in an earlier post that i cannot subscribe to this as i have measured crankcase pressure at zero!

 

It will be interesting to see some pics of the oil pumps, i will certainly post up pics of mine when it comes out, after doing a fair bit of research now, i am convinced that the seal failure's are due to bad, pump tolerances, or wear, so that the rotors allow to much oil to pass the casing, coupled with the drain being to small or partially/fully blocked by swarf or even sealing compound (has anyone checked this?)

Chris is right about the seals being an odd one, as i have been asking a couple of bearing companies and still not turned up an equivalent, and they are a double liped seal.

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That's a 0.24 mm difference in pump bore sizes! nearly nine and a half thou inch. A LOT, no a HUGE amount in terms of production tolerances. I wonder why that happened? How are you measuring the bore? A dial gauge vernier caliper is notoroiusly inaccurate on internal diameters. Have you got internal mikes about to use?

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Chris, Can you enlighten us with how you do that trick with the spring please.

 

 

 

I think he may be referring to shortening the spring, but not always a good idea as it can cause premature wear on the seal and shaft, but probably OK on a race engine that gets rebuilt on a regular basis.

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I've been watching this with interest although I have nothing to add technically as I still don't really know much about the oil pump.

 

Michael had a good point, if one place is pushing a lot of failed crank seals out the door then all this could be for naught as maybe they are just installing them upside down or something and it's nothing to do with tolerances and oil pressures. Please don't jump down his throat on the defensive when he didn't name any names or point any fingers, and has nothing to gain from doing so. Looking for a common cause is a basic troubleshooting tool :)

 

You aren't installing them upside down are you? :D ;) :innocent:

 

From what I've seen Envy, Turbofit, and CW have all seen failed crank seals from a variety of sources?

 

-Ian

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On race engines and rotating assemblies people looking for the absolute minimal drag, before the latest generation trick seals came about, would stretch a spring in a seal to give less lip tension, and hence less drag. Tiny frictional changes, but hey, racers are obsesive :)

 

You can ADD tension. Take the new spring off, very carefully. Look at it, even more carefully. You will see the spring isn't a one piece affair. There is a join. One end of the spring is full diameter, the other end has a coned "tail" on it. The coned tail screws into the plain end. Unscrew it, anti clockwise. You then have a straight spring with a coned tail one end. Using SHARP side snips cut 5 to 8 mm off the PLAIN end. Hold the plain end, twist the coned end about 3 turns ANTI clockwise. Screw the coned end CLOCKWISE into the newly cut plain end, for 3 turns. Voila! A relaxed spring with a smaller ID, that, when refitted will give more clamping pressure on the lip seal. Too much tension can burn the lip, so don't go mad ;)

 

Have you looked at your new seals? Some are roational and have an arrow on them. It should point in the same direction as crankshaft roatation. Check this. The old seals that come off untouched earlier engines all seem to have a rotaional arrow.

 

Have the cranks in engines that leak been ground or polished? I can polish or grind a cranks oil seal journal, if I feel like being a total *wat, so I can almost guarantee it will leak oil, very badly. 90% of people will never find out why. It will be to size, look perfect, but leak. If your crank grinder is not a *wat, but just incompetent, he may inadvertently polish or grind the crank wrong, and cause an impossible to cure leak. If he didn't ask engine rotation he's an idiot....There are lots about, and they breed.

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Tricky made an interesting point above. When the crank oil seal blew out on my import I had just recently changed from Castrol Magnatec to Valvoline, basically dropping to a lighter oil.

 

I did find the oil seal failure was more severe, I dumped two lots of 5l of oil in about 4 miles and so stopped the car and waited for the recover truck.

 

Not sure if that helps.

 

JB

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Are the seals with the larger OD any thinner in section?

Depending on the seal embodiment a larger OD seal (or indeed a tighter seal bore) can still have the same compression in a bore (or on a shaft) if it has more room to expand axially when installed.

 

I still don't know enough about the 2JZ setup to be useful but am hoping to have a chat with CW and look at some parts when I pop up to see him in the near future...that alright with you Chris?

 

Edit: What do the failed seals look like - any scoring or witnesses on them at all? Has any ever replaced just the seal and managed to cure the problem or has it always been swapping out the pump for example that helped?

 

In some of my seal applications we have to specify no polishing spiral on the shafts - by plunge grinding. In some cases if the shafts are hand polished or ground with a certain lay then the resultant spiral can pump oil past the seal - could this be the case here, pressurizing the back side of the seal?

 

Anyone checked surface finishes on the cranks of these failing seals - does anyone have that capability?

 

Again - I am only throwing ideas around, I'm not totally familiar with these parts so could be on the wrong track altogether. :)

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