Lessons Learned - Crankshaft Repair Sleeve

[Samurai7one]

Unused NATIONAL on left  /  Previously installed SKF on right

I ordered a sleeve for the rear crankshaft seal.  I first ordered the SKF brand sleeve from Rock Auto.  I was shocked to see how narrow it was.  I tried to line it up on the crank so it covers the inner spring seal side and the outer wiper side.  maybe it only needed to be on the spring seal side - i don't know.  I got it centered with the seal and it had maybe 1/16" or less hanging out of each side.  Making matters worse, when the flange is torn away it leaves the edge wavy.  so, i took a small hammer and tapped around the edge to get it flat.  I was not happy with this and was left having a mental battle within my head about leaving it alone or not.

 

  I eventually came to the conclusion that I am better off fixing it right while the engine is on the stand, than in the car.    On the second try I ordered the National brand sleeve from Rock Auto.  Take a look at the picture, you can see how much wider the national is than the SKF (although note that the national sleeve shown still has the flange attached).  The flange on the National sleeve tore away much cleaner then the SKF brand, but not perfect.  I just, very gently,  tapped it down anywhere it was raised up.  but, it probably wasn't necessary, since the sleeve is so wide, the torn edge is far away from the seal.

 

My 2 cents: if you need a crankshaft sleeve, buy the National brand.

Edited July 9, 2015 by Samurai7one

[Gareth. J.]

How big was your crankshaft groove? Does the larger sleeve cause any issues with the flywheel?

 

I've heard of people cutting some gasket paper and installing that before the rear main seal so it doesn't sit where the groove is.

[Tony D]

You can order alternate oil seals with multiple lips as well as moving the location.

[Samurai7one]

Gareth,

   I have about 1/2" of crankshaft aft of the oil seal.  The sleeve takes up half of that leaving me 1/4" of crankshaft for the flywheel to wrap around.  I have a lightweight flywheel not a stock one, but it laps over the crank shaft 1/8".  No problems for me.  The sleeve could have been initially installed further forward also.

 

  I don't know about the gasket behind the seal trick but it seemed like I could have just not driven the seal all the way to the bottom of the groove and that would have put me over virgin material.   

 

  My crankshaft was only lightly scored.  I probably didn't even need a sleeve,  My machine shop said "it's probably fine", I just really don't like rear main seal leaks and I have a fascination with making money disappear. 

[Chris Duncan]

Sleeves can cause problems. They make the sealing surface diameter larger and thus the seal is pushing harder because it's spring is more stretched out. Also if the material it's made of is soft then the seal will cut through it in relatively low miles. Another option if there's room is to drive the seal further in. Generally you don't want to leave the seal hanging out (not fully driven) because then there's less contact area where it has to hold onto the bore and crankcase pressure fluctuations can then push it out.

Edited July 20, 2015 by Chris Duncan

[Tony D]

^^^^ Where is this information coming from?

Redi-Sleeves and SKF Speedi-Sleeves have been around and are industry accepted repair methods. The diameter difference is minuscule as I recall around 0.010"-that's not an issue on most automotive lip seals. Universally they are made from stainless steel, abrading through one or premature wear likely is more a function of the environment it's being used in (VW Sand Rail comes to mind...) than any inherent sleeve issue.

 

Sleeving the snout is far more practical than rechroming and grinding which is the "prior" method....

 

Short of a wily mechanic getting a half-width seal and overdriving it to put the new seal on undamaged seal journal.

 

Never Forget: Improper PCV operation will cause leaks.

 

"Crankcase pressure variations" won't move any properly installed or even half driven sleeve. <Edit: Rereading this it appears it meant under-driven seals, but as previously mentioned getting a narrower seal and overdriving it slightly gives full diametrical engagement for sealing...if your crankcase pressure is enough to "blow out" a seal driven even only 1/8" into the bore....you got problems FAR more important to address than a shaft seal leak!> I routinely used Speedy-Sleeves on Dekker Pumps at 15+ psi, but had to manually trim the sleeve to half width because the available shaft was not wide enough to install it all the way. They are usually designed to withstand 50 psi and shaft speeds of 1,000 ft/min. The pressure actually improves sealing, as it increases the lip pressure if seal is installed properly. If a sleeve moves, it wasn't the right diameter to begin with.

 

They're not suitable in some applications, but I'm highly suspect of the claims here based on my experiences using them since forever.

 

Edited July 19, 2015 by Tony D

[Chris Duncan]

^^^^ Where is this information coming from?

 

Just personal experience, admittedly haven't dealt that much with repair sleeves. But the ones I did didn't go well. They cut through with low miles on a dirt free street vehicle. I don't think the sleeves were stainless. YMMV.

 

The reference to not driving the seal all the way in is also experience. Some Hondas are particular about that. I would think if you are going to line up the seal in a different place from where it's worn then you would prefer to go further in as opposed to less than full engagement.

[Tony D]

As I mentioned, most seals can be had with thinner housings, allowing a different positioning.

 

Also specifying a thinner housing width, and a double or triple lip,seal can give not only a different position for the lip to ride upon, it can give you several lips to affect the seal.

 

I can't think of a sleeve I've installed that has burned through. And I Put them in some pretty dirty environments.