How to check end play

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TrollFromDownBelow
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How to check end play

Post by TrollFromDownBelow » Mon Sep 21, 2015 12:37 pm

I did a search of the 'engine' forum, but didn't find a 'how to' post....if there is one out there in IAC land, would appreciate it if you could point me to it ... maybe make it a sticky?

Would like to know:

- proper way to measure
- improper ways i need to avoid (common mistakes)
- acceptable tolerances
- why is this important to measure
- what it means if i am outside tolerance
- process to correct - i.e. how do you add shims to bring back into tolerance
1976 VW Bus aka tripod
FI ...8 completely solid lifters.... now it's both kinda noisy and leaky, but she sure runs good!
hambone wrote: There are those out there with no other aim but to bunch panties. It's like arguing with a pretzel.
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dingo
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Re: How to check end play

Post by dingo » Mon Sep 21, 2015 8:25 pm

the red Wilson book gives a good explanation
'71 Kombi, 1600 dp

';78 Tranzporter 2L

" Fill what's empty, empty what's full, and scratch where it itches."

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asiab3
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Re: How to check end play

Post by asiab3 » Mon Sep 21, 2015 11:05 pm

Like the Bentley, Wilson gives moderate instructions for setting up a new engine, but not a lot about what to do and why it's important on an existing engine.

End play is the amount of room the crankshaft (with flywheel, pulley, rods, etc.) can move fore and aft in the case bearings. It is regulated in front by the flywheel and shims/bearing surface, and in the case by the crankshaft/bearing surface.

Ideally, end play is measured with a dial indicator mounted to the case, while you push the crank pulley/fan in and out. The dial indicator needle should be at a distinct 90* to the flywheel, with the tip fully engaged. From here, you read the numbers on the dial for "fully pushed in" and "fully pulled out" and compare them. The difference must me .0028" to .005".

Common mistakes include push/pulling on the flywheel while the dial is reading it. Flywheels flex far more than you think, so your readings can be inaccurate. You may mount the dial indicator on the fan/pulley end of the crank if you wish to fondle the flywheel, but please don't measure and push from the same end.

In the grand scheme of engines, flagrantly large end play can reduce oil pressure and increase bearing wear. I imagine that a gargantuan end play could even really upset the rods/pins/pistons/crank. I do not know the extent of the dangers. I keep my engine between .003" and .004" because...

...There are many considerations to using shims when setting end play. Without getting into too many details, we must use three shims. Repeat after me: We Must Use Three Shims. Shims come in a handful of sizes, and differ from T1 to T4. Three shims creates a buffer from the 4,000 rpm flywheel to the 0 rpm main bearing. Each shim spins successively slower, while cradling an oil film between itself and the next rotating (or bearing) surface.

If you are out of tolerance by .001", schedule a Sunday morning in the next few weeks to bring it into spec. Importance of correcting play increases exponentially with every thousandth of an inch. Yes, the air-cooled VW power plant is robust, and hundreds of engines have clanked around the planet with gaping end play. Don't tempt fate, your car will thank you.

Achtung! One of the biggest caveats to setting end play is making sure what you're actually measuring IS the crank/flywhe moving back and forth. In some cases, the #1 main bearing (visible if you take the flywheel seal out when you set end play) has worked itself loose in the case, and it can "walk" for and aft and act like additional end play. Colin (And BellePlaine, right?) have both had reliable engines with this issue, but the importance is in compensating for and monitoring it. To ensure you not have a loose main bearing, add a fourth shim to the Mandatory-Three-Shim-Stack and reinstall the flywheel. Full torque when measuring end play, always. NOW check for a few thousandths of an inch movement with your dial micrometer and a push/pull of the crankshaft. If have ANY movement, you have a loose bearing. Write down the number. For our examples, we will say "no movement, bearing is good" or "oh no, we have .002" play."

First scenario:
No bearing movement is detected, so you remove your Fourth Test-Only Shim and use any combination of three shims to get .0028"-.005". Install a new flywheel seal (is this necessary on T4s?) and reinstall flywheel.

Second scenario:
You have .002" of bearing play. This does NOT count as end play, so you must take it into account when measuring for end play. Your personal custom asiab3 approved end play specification is now .0038-.007". See what I did there? We know the bearing is moving, so the crank still has to have the .0028"-.005" play, no matter where the bearing is. You are now to set your new end at specification, as well as make a series of Sharpie marks along the bearing and case that show the orientation. Next time you have the flywheel off, you will be able to tell if your main bearing is rotating in the case, and how much. You are also now given an Executive Order to triple check the transaxle for neutral engagement, and now never start with the clutch in again.

Also, regardless of which scenario you're in, shims must be flat, clean, and free of any burrs. If a shim grabs on to another shim, you're greatly increasing wear to the bearing and thrust surfaces.

I have exhausted my thumbs and this dang cellphone battery. I will be back tomorrow to check on how many autocorrect issues I've ignored, as well as add some smileys and maybe a picture or two.

Robbie.003"
1969 bus, "Buddy."
119k miles with me.
296k miles on Earth.

TrollFromDownBelow
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Re: How to check end play

Post by TrollFromDownBelow » Tue Sep 22, 2015 8:41 am

Wow! Thank you for the clear and articulate guidelines! This was very helpful! And to think you typed all that in from a cellphone .... that's pretty incredible.

Thanks,
Mike
1976 VW Bus aka tripod
FI ...8 completely solid lifters.... now it's both kinda noisy and leaky, but she sure runs good!
hambone wrote: There are those out there with no other aim but to bunch panties. It's like arguing with a pretzel.
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asiab3
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Re: How to check end play

Post by asiab3 » Tue Sep 22, 2015 11:09 am

TrollFromDownBelow wrote: And to think you typed all that in from a cellphone .... that's pretty incredible.
Thank you. I don't take lightly to "read the manual" posts when they're not painfully appropriate.
1969 bus, "Buddy."
119k miles with me.
296k miles on Earth.

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dingo
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Re: How to check end play

Post by dingo » Tue Sep 22, 2015 6:45 pm

painfully appropriate ?? what you blabberin about ? whats wrong with picking up a book and reading a chapter or two...and Wilson is clear, concise and accurate..unlike the 'manuals'
'71 Kombi, 1600 dp

';78 Tranzporter 2L

" Fill what's empty, empty what's full, and scratch where it itches."

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asiab3
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Re: How to check end play

Post by asiab3 » Tue Sep 22, 2015 8:57 pm

"Painfully appropriate" would be a "what's the lug torque" question.

I think end play is important enough to warrant a thorough explanation online. Apologies for lack of brevity, I try most earnestly to be concise. Sometimes I get there. Sometimes I keep working on it...
1969 bus, "Buddy."
119k miles with me.
296k miles on Earth.

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Amskeptic
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Re: How to check end play

Post by Amskeptic » Wed Sep 23, 2015 10:37 am

dingo wrote:painfully appropriate ?? what you blabberin about ? whats wrong with picking up a book and reading a chapter or two...and Wilson is clear, concise and accurate..unlike the 'manuals'
Easy there, fellah. As you know, when a person is not fully aware of the nuances, nothing beats a dialogue.

Robbie, good write up. I must add a little . . . painfully appropriate painful experience.

a) please try to read the end play from the opposite end of the engine, if it is out of the car. Then you will not suffer from inaccurate readings due to the bending of flywheels and pulleys. I like reading the end play from the pulley end while I click the flywheel back and forth. One screwdriver, between the case and the flywheel, lightly pulls. The other screwdriver, between a case-to-bell housing stud, pushes the flywheel. It is subtle, and it does not take force. You will feel a nice little click. Read and re-read the dial indicator to get your reading.

b) the endplay is only to allow the #1 bearing/case saddle to expand between the cheek of the crankshaft and the nearest flywheel shim. It does not relate to "crankshaft expansion" for any other bearing. The actual expansion of the crankshaft by the time we are at the #4 main bearing is far greater than any .003", but it has lots of designed-in room to expand back and forth down the engine (you note this when the flywheel is off). The connecting rod bearings have a minimum of .016" to slide back and forth on their journals, so you can see that the crankshaft is able to grow longitudinally all day without a problem. But, as you note, keeping the end play to a minimum is critical for a couple of reasons.

The most important reason is that excessive end play will pound out the thrust surface on the #1 main bearing in a rapidly accelerating fashion past the wear limit. This progresses to a loose bearing in the saddle, wallowing out the dowel pin holes in both the bearing and the case itself.

Belle Plaine, jivermo, and Darren are our recent poster children for #1 main bearings being able to rotate in their saddles a good 1/8" ++.

Belle Plaine
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jivermo
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BobD - 1978 Bus . . . . . . . . . . . 111,155 miles
Chloe - 1970 bus . . . . . . . . . . . 206,820 miles
Naranja - 1977 Westfalia . . . . . 108,000 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,885 miles

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Re: How to check end play

Post by Jivermo » Wed Sep 23, 2015 4:03 pm

Dang. I hate being a poster child.

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dingo
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Re: How to check end play

Post by dingo » Wed Sep 23, 2015 7:55 pm

just sayin..there is room for both..and having checked out a book only adds to the dialogue. Is someone just idly contemplating end-play tectonics..or perhaps frantically trying to get an engine back in before the streetsweeper comes around ? hahaha i have done both for sure. There are definately some good books worth consulting,,,my dad had a library of hundreds..from Aston-Martin to Volga..my personal favourite bedtime reading was 'Weber Carburettors By John Passini '....fantastic reading, and no, you wont find it on Kindle
'71 Kombi, 1600 dp

';78 Tranzporter 2L

" Fill what's empty, empty what's full, and scratch where it itches."

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Amskeptic
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Re: How to check end play

Post by Amskeptic » Thu Sep 24, 2015 4:42 am

Jivermo wrote:Dang. I hate being a poster child.
You are THE Poster Child for an array of challenging exercises in the air-cooled Volkswagen canon.

Image
BobD - 1978 Bus . . . . . . . . . . . 111,155 miles
Chloe - 1970 bus . . . . . . . . . . . 206,820 miles
Naranja - 1977 Westfalia . . . . . 108,000 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,885 miles

TrollFromDownBelow
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Re: How to check end play

Post by TrollFromDownBelow » Thu Sep 24, 2015 5:15 pm

From this horses mouth :pirate: it was an 'idle' question .... however, seriously planning on pulling the engine in the next few months and want to do this correctly. Wilson or Bentley would have addressed half of my questions, but don't think it would have addressed my three bullet points below...

- improper ways i need to avoid (common mistakes)
- why is this important to measure
- what it means if i am outside tolerance

I'm a theory/big picture kinda guy.... if I understand the 'why' and what the end game is, it is much easier for me to grasp the 'how to' (which Bentley and Wilson would have addressed). Some folks have photographic memories, and tell you "don't give me theory, just tell me how to do it". Show them once, and they will reproduce flawlessly. Me? yeah, not so much ... I will eff it up everytime. However, give me the big picture, context, what the end game is, then I can figure it out. :flower:
1976 VW Bus aka tripod
FI ...8 completely solid lifters.... now it's both kinda noisy and leaky, but she sure runs good!
hambone wrote: There are those out there with no other aim but to bunch panties. It's like arguing with a pretzel.
::troll2::

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Amskeptic
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Re: How to check end play

Post by Amskeptic » Sat Sep 26, 2015 7:12 am

TrollFromDownBelow wrote:From this horses mouth :pirate: it was an 'idle' question .... however, seriously planning on pulling the engine in the next few months and want to do this correctly. Wilson or Bentley would have addressed half of my questions, but don't think it would have addressed my three bullet points below...

- improper ways i need to avoid (common mistakes)
- why is this important to measure
- what it means if i am outside tolerance

I'm a theory/big picture kinda guy.... if I understand the 'why' and what the end game is, it is much easier for me to grasp the 'how to' (which Bentley and Wilson would have addressed). Some folks have photographic memories, and tell you "don't give me theory, just tell me how to do it". Show them once, and they will reproduce flawlessly. Me? yeah, not so much ... I will eff it up everytime. However, give me the big picture, context, what the end game is, then I can figure it out. :flower:
You are the reader I write for . . .
Colin
BobD - 1978 Bus . . . . . . . . . . . 111,155 miles
Chloe - 1970 bus . . . . . . . . . . . 206,820 miles
Naranja - 1977 Westfalia . . . . . 108,000 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,885 miles

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BellePlaine
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Re: How to check end play

Post by BellePlaine » Wed Sep 30, 2015 11:17 am

Jivermo wrote:Dang. I hate being a poster child.
Me too. Great write up Robbie!

Chris, now 0.0032
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Re: How to check end play

Post by Jivermo » Thu Jul 04, 2019 5:26 am

I have a new friend down in Florida, who I am helping along, and hope to enlist him to join the throngs of Itinerant clients in order to get his bus into the best shape possible. He recently blew his engine, and got a rebuilt one somewhere, which a mechanic is installing. I have asked him to ask the mechanic to measure the end play on this engine. Herein lies the rub. We are not getting the measurement we need. “It’s all good.” is not good enough. I sent him the link to this thread, and asked him to read it. The thread sums things up quite well, but will others weigh in on why we would like to have this information, as his “new” engine begins its service life, in his treasured bus? I thank you.

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