Rear main seal- 3rd time around!

[Anonymous]

Okay, I only did the 170 twice and it still leaked some, but the low mileage 200 I just bought is leaking so I have to do this a 3rd time. Besides the typical stuff- pulling out the old seal and locator pin, rotating the new seal so the mating surfaces are not where the main cap meet's the block, NOT using sealant between the mating ends of the two seal halves (this seemed to help a little the second time ), using a small amount of sealer (I used RTV Black) between the main cap and the block, and gooping up the area where the rubber pan seal meet's the cork gasket, is there something I'm missing?

Last time I started a thread on this subject, somebody mentioned that a sealant should be used on the threads of the flexplate bolts since they go through the crank and oil can seep through. What kind of sealant should I use there? The threads were pretty oily on the new 200, so that may indeed be the culprit.

S-man

 

[addo]

Permatex #3 on the bolts. MoFoCo used something just like it.

Also, rotate the motor many times before starting, to spread the assembly lube around the face of the seal where it contacts the crank.

 

[wsa111]

Hope this helps, install the rear main seal with the ends at 10:00 o'clock on one side & 4:00 o'clock on the other side. Then put a small daub of sealer which you need to purchase at a toyota or lexus dealership. Its called FIPG. Put a small daub at the butting surfaces of the neoprene rear main oil seal. Before you put the rear main bearing cap in place place a very small bead of this sealer at the outer edge or lip where the rear main bearing cap contacts the block.
Using this procedure i have never had a rear main oil seal leak or even seep. This applies to fords & chevrolets, big block or small block with the 2 piece rear main seals. william

 

[Anonymous]

Put a small daub at the butting surfaces of the neoprene rear main oil seal. Before you put the rear main bearing cap in place place a very small bead of this sealer at the outer edge or lip where the rear main bearing cap contacts the block.

William,

The first time I did my 170 I took everyone's advice and put a bit of sealer on the mating/butting surfaces of the seal, even though the directions tell you not to, and it leaked big time, although it might have been something else. The second time I followed the directions and did not put sealer there, and it leaked a lot less. (does not really leak enough to drip on the ground but seep's a bit- may be the bolts, though)

I will take your word and try it as you suggest along with the permatex on the bolts as Addo suggests. I'm hoping this sealer is not "lexus priced" Can I get an off-brand of the same stuff somwhere else? Are all the rear main seals neoprene, or do I need to specify this when I order it? Thanks guys!

S-man

 

[Anonymous]

can you replace a rear-mail with the engine still in? I fear that my newley built 200 is leaking back there. How can I check to be sure that's where it's coming from?

 

[LaGrasta]

You certainly can do it with the engine in, but the tranny will have to drop.

 

[Anonymous]

cool. I'm hoping that's not the problem, but I hvae to get in and under to find out. ANy suggestions on the best way to track down a leak in that region? Seems to be coming from and/or around the tranny inspection cover. I guess pulling that off would be a good start, huh?

 

[Anonymous]

'63,

I've done it with the trans installed, although with limited success but not because the trans was in, I think- more due to improper sealant use. Remove the converter to flexplate nuts, and it might slide back enough for the studs to clear the flexplate. If not, I've still been able to get the old seal out by loosening all the main caps enough to drop the crank a hair in the back and pushing the upper half of the seal around and out one side. Carefull with anything sharp, though, so as not to scratch the surface the seal ride's on.

Your leak may be the rear seal on the oil pan, or the flexplate to crank bolts as discussed above. I've tried removing the converter inspection plate (I acutually am not running one :roll: ) and puting a small mirror up there to find the leak, but not had much success at it.

S-man

 

[Anonymous]

I just went to shuck's to get some parts- I should have known I'd walk out with nothing. They had no Permatex #3- had not even heard of it. One guy say's there are three differant thread sealers, including one that will permanently lock the bolts, buy did not know which one that was

They had "thread locker blue" and "high temp thread sealant", but could not suggest one over the other. Other than finding a more competent parts dealer, any suggestions?

Sedanman

 

[Anonymous]

Hi again,

Just wanted to let you guys know how it worked out- IT DID! The engine swap was a success, although I still have a lot of fine tuning to do. I used the toyota sealant as instructed, gooped more into the area where the pan gasket meets the rubber end seals, and the blue thread sealant on the flexplate bolts. I've gone about 100 or so miles, and sofar, no leaks.

Whomever it was that suggested sealing the flexplate bolts ( I think it was Jack), I owe a big thanks as I had not thought of it the last time. When I pulled the 170 out, that is indeed where it was leaking, as well as on the low mileage 200 I just bought. Thanks again, guys

Sedanman

 

[wsa111]

Sedanman, congradulations, using the toyota FIPG or lexus sealant was a key to your success. How dry i am. William

 

[Anonymous]

OK, william (aka dry guy ) tell me how to seal a C-4 tranny pan! I've done this thrice- the last time with a brand new steel (not cheap chrome) pan from Scott Drake and a rubber gasket. Someone said soak a cork gasket (I've generally had better luck with rubber) in ATF before you assemble. Do you know if this works?

Sedanman

 

[wsa111]

Sedanman, if the rubber or cork trans pan gasket does not seal. go to a toyota or lexus dealer & get the FIPG sealer for transmissions, its orange in color & is compatible with atf. Clean both surfaces with carb cleaner,use no gasket & apply the sealer to the pan gasket sealing surface. Let it dry & refill the trans. this should solve your trans pan leaks.
I have had no problems before using a gasket, but check the straightness of your pan. Leakage is not common from the trans gasket.
The differential is a different story, don't use a gasket just the black FIPG toyota sealer or regular rtv. Keep it dry. William

 

[simon]

just curious... what makes that FIPG ´yota sealer superior to other rtv sealers/ gasket makers?

 

[Anonymous]

William,

The guy at the dealer mentioned the stuff for transmissions, but I wasn't sure I wanted to use it without a gasket. I've generally heard in the past not to use sealant on an automatic, but the real reason is that if I remember correctly, parts of the mating surface on the c-4 have an indented area along the flange, with thin contact surface to the pan on the side. I'm not real keen on filling those areas with sealant, and then having it ooze into the trans case after tightening it.

I'm surprised you've never had trouble with a trans leaking- that is the biggest problem area I've had on these old cars. I used black rtv and the gasket on my 8 in. centersection, and when I went to pull it 6 months later it really was glued in place!

Simon,

I hate to say this and burst William's bubble but I'm not so sure it was the toyota sealer that fixed my problem. When I pulled my old engine out, it was not leaking at the pan or rear main seal like I thought ( I used black rtv there before) but it was leaking out of the flexplate bolts as they go through the back of the crank, and oil seeped through the threads. The toyota sealer did work, but at $16/tube I'm not totally convinced it was that much better than a tube of black rtv at 1/3 the price. But all I really care is I'm leak free now

Sedanman

 

[wsa111]

Sedanman, i'm glad the rear main oil leak is fixed. I assumed you had already sealed the flexplate bolts, this is specified in the shop manual & is standard practice. So be it, but the extra precaution you did at the rear main is a definate plus. Why take a chance, it is a pain in the A to go back after you think you are finished.
Toyota & lexus on some of their models have not used a gasket for many years on their tranmission pans. they have used the FIPG orange sealer in place of a gasket & the sealer lasts for many years. I work at a lexus dealership & i know we have filed 1 warranty claim for a transmission pan sealer leak in the last year. Our products using a gasket have had numerous leaks compared to the sealer method.
The key to prevent sealer from getting into the transmission is to use a small bead as to not push sealant into the inside trans pan area.
On v-8 engines I use the black sealer on the front & back intake manifold seal areas in place of the cork or rubber gaskets, be it a chevy or a ford v-8 engine.
this sealer works. William

 

[Anonymous]

Sedanman, i'm glad the rear main oil leak is fixed. I assumed you had already sealed the flexplate bolts, this is specified in the shop manual & is standard practice.

I didn't know this before someone mentioned it on the forum- maybe it's time I get a shop manual I'll think about the trans stuff. I need to fix that, after I get a carb, fix my exhaust leak, install a new steering box, floor insulation, carpet.....this is why I don't like using my resto project as daily driver :roll:

 

[Anonymous]

Me not happy. There is now an oil drip on the garage floor- not sure yet but it's in the right spot for the rear main

 

[mluck]

What is the best real main seal gasket to get..the rope one or the other..can you get it at napa...

 

[wallaka]

The other--