rear main seal leaks because crank was overturned

[chris777]

I have had a small rear main seal leak ever since my engine rebuild 5 years ago.

my mechanic is in the middle of putting in a new H55 5 speed transmission. He delivered it to me with the new tranny two weeks ago, but I heard a whine when on hiway in 5th gear and let off the gas. He offered to remove it and make sure everything was ok. When doing so, he noticed that my new rear main seal is leaking slightly. He says my brand new Toyota Rear Main Seal is not snugging up to the rear end of the crank very well, probably because when my engine was rebuilt 5 years ago, by another mechanic, it was over turned at the machine shop causing it to be too small in diameter.

question? is there any solution to this besides replacing the crank or just living with the leak????

is there such of a thing as a Rear Main Seal that is a little thicker? or that is tighter than OEM?

My mechanic says that the previous seal had two rubber wipers, wheras the new Toyota one has a rubber wiper AND a felt wiper. He believes that the previous wiper was probably not Toyota. So there IS a difference in seals. Maybe someone makes one that is tighter than others. my truck was built in 9/85, a month before they started using the double seals.

Question: does anyone make custom rear main seals?

Question: is there any other solution other than living with the leak or replacing the crank on an othewise peferctly good engine?

Question: any change that the double seal used in trucks like mine built after 9/85 would work?

Chris ( Photo-man )

PS: I just saw the new cover of the latest Toyota Trails Magazine that I shot of the Blue 45. Looks good!

 

[iaintscared1969]

Also verified rear end cap was tight and pan gasket is not leaking. When the seal was installed slightly lubricated rubber and intalled with rubber mallet till flush. I would compare the "leak" To a very small build up near tne seal edge. I did measure the crank and seal surface and there is a slight diffrence between the two. I would say they cleaned up the mating surface. Can't be sure but the problem as Chris has stated has been present since the rebuild. We discussed the difference between the seals and I would say the double wiper rubber would be better. If anyone has a suggestion we would appreciate it. The leak after two weeks of driving has not built up enough oil to drip out of the inspection cover.

 

[tonkota]

speedy sleeve?

 

[chris777]

what does your reply mean? speedy sleeve? I don't get what you are trying to say.

 

[tonkota]

A speedy sleeve fits over the sealing surface to repair a damaged surface. They add thickness. And since the crank was turned under, this may be the way to go. Federal Mogul makes some and they should be easy to get. I'm suprised that your mechanic didn't think of these since they are pretty common.

Sorry for the breifness of my first post.
Link:
http://www.federal-mogul.com/aftermarket/us/index.htm?Country=USA

I found this for you:


View: Federal Mogul Full

Vehicle: 1985 TOYOTA TRUCK LAND CRUISER 6-4227 4.2L

Lookup Type: Group - Individual Gasket & Seals

Part Description Part Number Years Qty Per

NATIONAL OIL SEALS
Rear Main Seal 231004 80-87 1
Rear Main Seal
REPAIR SLEEVE 99393 80-87 1

 

[chris777]

oh good. thanks! and the crank doesn't have to be removed in order to put it on?

 

[tonkota]

nope. infact, to make it a little easier, put the race in the freezer for a couple hours and then put it on. They work well.

Good luck!!

 

[FJ40Jim]

Good advice.

Except for the bit about the freezer. Because the speedisleeve goes over the crank, if it is larger, it will be easier to install. So put it in the toaster oven for a few minutes before whacking it on there. The SS will cool instantly when it hits the massive crankshaft, so heating it won't help much beyond the first hit.

And yes, the 85-newer 3F rear seal can be used in any F/2F/3F engine

 

[tonkota]

Jim, take a closer look at your old Physics book When the metal is in the freezer, it shrinks in all directions. Weird huh? I just took the mechanical portion of Physics.

To gain any effects of the cooling, you will have to be fast.

 

[Godwin]

And yes, the 85-newer 3F rear seal can be used in any F/2F/3F engine

I was under the impression that the diameters between the 2F and 3F cranks differed with the 3F crank being larger. I've not measured the crank ends (which would give the answer) and this impression comes from having installed a 2F rear main seal on a 3F engine which resulted in a nice little multi-quart oil leak within 100 miles. Could be the seal was for a pre-85 2F instead of an 85-newer.

 

[chris777]

Good advice.

Except for the bit about the freezer. Because the speedisleeve goes over the crank, if it is larger, it will be easier to install. So put it in the toaster oven for a few minutes before whacking it on there. The SS will cool instantly when it hits the massive crankshaft, so heating it won't help much beyond the first hit.

And yes, the 85-newer 3F rear seal can be used in any F/2F/3F engine

I am suprised to read this. You are saying that the 10/85 and later cruisers had 3F and not 2F engines????

 

[chris777]

I was under the impression that the diameters between the 2F and 3F cranks differed with the 3F crank being larger. I've not measured the crank ends (which would give the answer) and this impression comes from having installed a 2F rear main seal on a 3F engine which resulted in a nice little multi-quart oil leak within 100 miles. Could be the seal was for a pre-85 2F instead of an 85-newer.

I was told that the dividing date is 10/85, and mine was made in 9/85. 10/85 and after has two piece, and 9/85 and before is one piece seal. I was thinking that both were for 2 F engines, but that it might be possible that the two piece would mght help me somehow with my leak caused by an overturned crank.

 

[zebrabeefj40]

Jim, take a closer look at your old Physics book When the metal is in the freezer, it shrinks in all directions. Weird huh? I just took the mechanical portion of Physics.

To gain any effects of the cooling, you will have to be fast.

You are correct, the metal shrinks if you cool it. But the Speedi-Sleeve goes OVER the crank. Rather it grew a little than shrank to install it. That's why Jim is suggesting a toaster oven... Your freezer would be great for installing pilot bushings though!

HTH,
Nick

 

[chris777]

well speedi-sleeve does not make a sleeve for the crank on this engine. I can measure it and see if they have one that will work.

I also found out that machine shops do not "turn" the end of the crank where the rear main seal comes in contact. I am about to ask the machine shop that did it if they normally do that end of the crank.

So I don't know what to do now. starting to look like I will have to live with this leak for forever.

 

[Mr. Toad]

You are correct, the metal shrinks if you cool it. But the Speedi-Sleeve goes OVER the crank. Rather it grew a little than shrank to install it. That's why Jim is suggesting a toaster oven... Your freezer would be great for installing pilot bushings though!

I think tonkota was saying that the metal itself would shrink if cooled. To get to what he sees, you have to picture the sleeve like a wedding band. Cross-section the band in the plane that would slice the ring into two, equal semicircles. Look at just one cross section of metal. If you cooled the cross section, the metal shape would retract towards its center from both surfaces of the band: the inside and outside would head towards the center, and tonkota thinks that the inner diameter would expand.

Of course, this the opposite result that you would get if you instead "peeled" the sleeve. In other words, "peel" off the ring's metal into an infinitely thin strip: for all practical purposes, it's a very long wire that if you wound it all back would re-form into the shape of the sleeve. If you cool the "peeled" wire, it shrinks in length. The whole length shrinks, including the innermost "peel". If the peel/wire got shorter, the inner diameter of the sleeve would have to shrink too.

Integrals . . .

 

[FJ40Jim]

I am suprised to read this. You are saying that the 10/85 and later cruisers had 3F and not 2F engines????

In the real world, 85 and later cruisers have 3F. The oddball 85-87 USA 2F shares many components w/ 3F. Like cylinder head, head gasket, main bearings, upgraded rear main seal, timing cover w/ accessory mounting tab...