Rear seal replacement

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Vali68

Vali68

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I have a slant 6 on a stand upside down in my garage that i am getting ready for paint to go in my 68 Valiant. Would it be wise to replace the rear seal? If I do replace it, how hard is it to do with the engine on a stand and upside down? I can see where the seal goes. but not sure if I should do it or wait until it fails. Which could be way down the road or as soon as I start running the motor in the car.
 

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I haven't bought the gasket kit yet. It's been so hot in the garage lately, I haven't felt like getting out and doing any work. But this weekend is when I pick it up again.
The guy at the auto part store gave me the numbers for the kits sold for FEL-PRO. IS THAT A GOOD KIT TO USE?
 
I used the Fel Pro kit for mine. Have it almost complete.. I did decide to get a better gasket for the manifolds. Don't have that yet, but I ordered one from Hemi Performance (Aussie) that is a stainless/graphite. In the US, about the only other improved gasket I am aware of is Remflex.

Not sure how easy it is, but I believe you can slide the upper rear seal half out/in without disturbing the crank. If that is what you would be doing, best to wait for someone who has done it to chime in. I had mine completely apart. As much as I was not looking for all the 'extra' work, I was even less interested in doing it again....
 
Absolutely not. Put it in the car, hook everything back up and wait until it fails. Then pull it all back out and fix it. Good grief.

On a serious note, do you have a factory service manual?
 
Lol. Yes I've done the rear main (on a 318 ) while in the car. Was a major PITA for a simple seal. It was the old rope seal and wouldn't come out except in pieces. I had to loosen the main bearing caps so it was easier to remove the seal, then retorqued them down to factory spec.

This really is a no-brainer...replace NOW. Should be stupid-easy to do, and not an expensive seal either.
 
Sorry if my ignorant question rubbed anyone the wrong way. I will go ahead and replace the seal. Still on the fence if i should buy the whole fel-pro gasket kit though. Is the fel=pro gasket kit reliable? Or should i look for another brand?
 
Don't worry about it. At least you ask before making costly and troublesome mistakes. Replace the seal while the engine is out.
As someone asked, do you have a service manual? You really should get one, especially if you are going this deep into your car. Get the factory service manual too, not Haynes. It will help you many times in the future.
Use the Felpro gasket set. It's fine. Dennis
 
If a rear main seal is a rope type one, and not installed properly, you can " burn " the crank sealing surface, and still have a leak.
There is technique in installing a rope seal, that doesn't leak.....and it takes time.
 
I used FelPro Kit FS 7918 PT-4, which I believe covers all the slants (even 170) It included the rubber seal which can be done without completely removing crank.

Do you know the history of the engine, mileage, previous work etc? I was originally only planning to 're-gasket' mine, but found myself in your situation of 'where do I stop?' As previously discussed that seal is a 'no brainer' , but to me the head gasket and valve seals were also a no brainer,,,, now the question is how far do you go? I ended up doing a complete teardown and I am glad I did. Apparently mine was rebuilt previously and they did not bother to change the cam bearings. The babbit was still in place, but separated from the backing just waiting to get loose and cause havoc. So, unless you are sure of what you got, or there is a compelling reason not to do it, I strongly suggest that you tear down/inspect everything. Since everything was within tolerance, I did not do a full rebuild. (I did lightly hone and re-ring) I will probably run it stock for a while but eventually plan to pull it again to do improvements. For now my focus is to get the car back together with a reliable drivetrain.

cjh said:
If a rear main seal is a rope type one, and not installed properly, you can " burn " the crank sealing surface, and still have a leak.
There is technique in installing a rope seal, that doesn't leak.....and it takes time.
Click to expand...
 
I changed the rear seal in my 65 BB & 65 SB with engine in the car. I expect a slant is the same. You remove the rear bearing cap. Inspect the bearing to get a feel for the condition of all your main bearings (usually the rod bearings go first in my experience). Mine both had a rubber seal, so maybe had been changed before. The rubber seal is easy, the bottom half is in the bearing cup. You push the top half in to make it rotate around to get it out of the groove. Clean the space out good with gasoline on a rag, then alcohol. I recall using "anaerobic sealant" on the metal-metal gap between the bearing cap and block. I think is it basically high-temp super-glue. Not sure what the factory used in the 1960's. I recall also putting a drop on each side of the new seal where they touch, per the instructions in the gasket kit.
 
valiant1966 said:
Don't worry about it. At least you ask before making costly and troublesome mistakes. Replace the seal while the engine is out.
Click to expand...

Agreed. My comment about being a no-brainer was not an insult. Only an attempt to stress replacing it with the motor out of the car for a much easier time of it. For the cost of a new seal and the ease with the motor on a stand, replace it.
 
BillGrissom said:
The rubber seal is easy, the bottom half is in the bearing cup. You push the top half in to make it rotate around to get it out of the groove. Clean the space out good with gasoline on a rag, then alcohol. I recall using "anaerobic sealant" on the metal-metal gap between the bearing cap and block. I think is it basically high-temp super-glue. Not sure what the factory used in the 1960's. I recall also putting a drop on each side of the new seal where they touch, per the instructions in the gasket kit.
Click to expand...

IIRC, the rope seal on mine was also two piece, and that top half was the pain. I had to make a "special tool" out of an old screwdriver to use to rotate it around the groove. This was particularly tricky since I had to be careful so as not to scratch the seal or crank surfaces. Like cjh posted here, the rope seal was gummy and probably heated up which caused it to stick in there like it was glued to the groove.
 
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