Rear Main Seal

[xrwagon]

ok mine has leaked a drop or two most weeks, has been getting worse since racing it etc, what can i expect? Is it robbing performance? Is it more of a pain in the but to fix, as its a little oil etc, it has sprayed the under carriage and dropped a puddle. What brand should i use and, should i remove the whole engine and box?

 

[xctasy]

ok mine has leaked a drop or two most weeks, has been getting worse since racing it etc, what can i expect? Is it robbing performance? Is it more of a pain in the but to fix, as its a little oil etc, it has sprayed the under carriage and dropped a puddle. What brand should i use and, should i remove the whole engine and box?

No engine removal required. You've got the old rope seal, so its tough to get em out. Replace it with a neoprene Felpro or similar. Sizes vary, there are a different lenghts and sections, and some are cut to fit, which can be a pain. A note only for us AuNZies...the little 200 used a 2.75" pitch six bolt center flange with a 3.625" crank out diameter flange before the big tall deck change to the 250 based block in 1971 Aussie FoulCans. Don't let some counter wally give you the later XY/XA/XB non cross flow 200/250 item.

To get the old rope seal out, you only need to safely get the car high enough to drop the trans, sump, and end cap. You should be clear of the drag link, but if needs be, you can jack up the engine by loosening the mounts, but still keep the engine in the car.

To get the seal out, you have two options. Option 1, use KD Tools 492 Sneaky Pete Oil Seal Remover/Installer

http://www.sjdiscounttools.com/kdt492.html

Oil Seal Remover and Installer
Removes and installs upper rear main oil seals with engine and crankshaft in place. Works on both wick and neoprene type seals. "Chinese Finger" type grip won't slip from seal during installation. Set includes wick seal remover, installer, guide funnels, pusher, offset trimmer, and neoprene seal punches.

Option 2, you use Bhigdog's http://forums.aaca.org/f120/sneaky-pete ... 38028.html recommended piece of 14 gauge copper wire pushed through the end 1/2" of the rope seal. Have someone turn crank as you pull rope through. The new seals seem to be made of Kevlar or other "can't cut" material. A knife or razor blade can't cut them. A scissor will if you get the seal well back in the blades and work it through. This can't be done with the seal in place under the crank. What will work is to cut it off with a dremal abrasive wheel but be sure to put a thin shield between the seal and crank or you will nick the crank for sure. A feeler gauge works good.
After all that, apply a replacement two piece neoprene seal

Taking out the rope seal https://www.youtube.com/watch?v=JF-BE7o5GUE

Taking out a stock neoprene in a 66 289, and the replacement with neoprene, https://www.youtube.com/watch?v=7r7GiliZj48

The two piece seal is around. FelPro or National 3909 or Timken 3909 seal replacement. It suits all early 60-70 Aussie I6's and every 60-83 US small sixes with a shaft diameter of 3.625" and presses into a bore of 4.24"

FEL-PRO BS30135
http://www.rockauto.com/catalog/moreinf ... cc=1333370

or Felpro P30135
http://www.ebay.com.au/itm/200-Ford-Six ... 1448123339





You offset the two piece seal and use Bills wsa111 famed Lexus sealant that sticks like sh!+ to a blanket.

viewtopic.php?f=18&t=37888

Is it still leaking out the rear main? You could try the technique wsa111 espoused, where the seal ends are offset by about 1/32" from the block/cap interface, and they're given the lightest dab of Lexus "FIPG" sealant.

I'd also wonder about trying to get a good dose of moly grease into the seal groove before bolting up, and also dry cranking a few times to spread the lube about before your motor fired.

Although it's backtracking to some extent, got to be better than a rebuild - if that's not due yet.

Cheers, Adam.

 

[wsa111]

Go with the neoprene seal. The rope seal is ancient technology.
Make sure you remove the pointed pin in the rear main cap. The pin is only used with the rope seal.
When installing the seal make sure the butting ends are at 4:00 on one side & 10:00 on the other side.
Toyota or Lexus sealer FIPG is the best to dab on both ends of the seal. Grey permatex is an ok second choice. Make sure you also put a small amount of sealer on the edge where the rear main cap sits in the block on both sides, also put a very thin layer of sealant at the back of the rear main cap from the seal to the end of the main cap on both sides. That will prevent seepage past the machined surfaces where the rear main cap seat into the block.
Make sure the seal & crankshaft journal have a liberal amount of lube to prevent a dry start.
Give the sealer at least an hour to set up before you rotate the crankshaft.
How dry i am. No runs, drips if done right.

 

[edgewood bronco]

Good tip on the FIPG. I'd not heard of that but will likely pick some up. Word of caution (According to link below): make sure the parts are absolutely clean before assembly:
http://www.clublexus.com/forums/ls400/6 ... -seal.html

 

[xrwagon]

Thanks guys, with any luck my new engine crane will be here next week, biting the bullet and pulling it all out, that way all can be cleaned, this will be the first time this motor has been out in 46 years

 

[xrwagon]

Parts bloke today only had a rope seal, and said you can only use a rope seal without machining crank for a neoprene one, also stupid question, does crank need to come out? I am taking motor out to do this.

 

[bubba22349]

Parts bloke today only had a rope seal, and said you can only use a rope seal without machining crank for a neoprene one, also stupid question, does crank need to come out? I am taking motor out to do this.

First off the parts bloke is wrong! The neoprene seal will fit with nothing more then removal of the small locating pin in the main cap the benefit of the neoprene seal is that it lasts longer and frees up a little power (less friction to turn the rotating assembly). No matter which type of seal you decide to use the crankshaft doesn't need to be removed unless you want too, and job of replacing the rear main seal can also be done with the engine in the car. It you have it out and on an engine stand or in the car all you need to do is remove the rear main cap and loosen all the other mains so the crank can move enough so you can remove the old rope seal in the block. Good luck

 

[xrwagon]

ok thanks, reason to remove motor is the bad popping sounds when last raced, when i backed off over the finish line over the quarter it was banging under floor almost the pop was that loud, now i have the collectors modified, they are 2/14” with 2.5” collector, the pipe was removed a good 10 inches back and made larger, some reckon for a little six, thats to big and there is no back pressure and large amounts of air are being sucked in. I put my hand over the exhaust he other day and it wasn’t sucking it in. I am doing a comp test before doing the seal, as other guys think i might have burnt a valve, if thats the case i will pull it all out, do the seal, do the valve and keep racing