• The Roadster Factory Recovery Fund - Friends, as you may have heard, The Roadster Factory, a respected British Car Parts business in PA, suffered a total loss in a fire on Christmas Day. Read about it, discuss or ask questions >> HERE. The Triumph Register of America is sponsoring a fund raiser to help TRF get back on their feet. If you can help, vist >> their GoFundMe page.
  • Hey there Guest!
    If you enjoy BCF and find our forum a useful resource, if you appreciate not having ads pop up all over the place and you want to ensure we can stay online - Please consider supporting with an "optional" low-cost annual subscription.
    **Upgrade Now**
    (PS: Subscribers don't see this UGLY banner)
Tips
Tips

Rear Main Seal Leak with Moss Retrofit

Chad Donner

Freshman Member
Offline
Has anyone continued to have issues with a rear main seal leak with the Moss main seal retrofit?

I haven't started the car yet, just primed the pump and cranking it over with the starter and i notoced a couple days later i had drips coming from the bell housing.

Is it possible that the drain tube off the bearing cap sitting below the oil level is causing oil to back up into the rear main seal cavity? ie..the head pressure of the oil draining from the bearing isn't enough to overcome the surface tension of the oil with the drain pipe below the oil level?


Thoughts?

I'm gonna try to post a picture as to what i am thinking about the drain pipe.
 
OP
C

Chad Donner

Freshman Member
Offline
Rear Bearing.jpg
 

steveg

Yoda
Gold
Country flag
Offline
Is the car all back together or is the tranny still out? Is it leaking from the area of the rear main cap or is it indeed leaking from the bell housing? If the latter, it could be the trans.

Mine leaked from the vertical joints on either side of the rear main cap until I smeared the joints with Permatex Aviation Form-A-Gasket.
 

Stretch

Jedi Trainee
Offline
I kinda gave up on this leak. I too put in the improved seal only to have the leak recur around the cork gasket inserts. I tried putting a 0.004 stainless cover and sealant over the cork. It lasted for a year or so but then oozed oil again. Too much work to try something different.
 
OP
C

Chad Donner

Freshman Member
Offline
There is no oil in the trans yet so I know it's coming from the engine, however, it is coming from the bell housing side of the rear engine plate. I used hylomar on all the joints and filled the verticle joints on the bearing cap with rev in lieu of the felt plugs. Not sure if the seal needs a break-in period, but I have not ran the engine yet and just cranked it over with the starter.
 

Patrick67BJ8

Obi Wan
Silver
Country flag
Offline
Has anyone continued to have issues with a rear main seal leak with the Moss main seal retrofit?

I haven't started the car yet, just primed the pump and cranking it over with the starter and i notoced a couple days later i had drips coming from the bell housing.

Is it possible that the drain tube off the bearing cap sitting below the oil level is causing oil to back up into the rear main seal cavity? ie..the head pressure of the oil draining from the bearing isn't enough to overcome the surface tension of the oil with the drain pipe below the oil level?


Thoughts?

I'm gonna try to post a picture as to what i am thinking about the drain pipe.
An improperly sealed rear engine plate gasket around the rear of the camshaft will give you a signifcant leak!!
 
OP
C

Chad Donner

Freshman Member
Offline
I had a leak on the cam before i took the engine apart so i was trying to be sensitive to that area. I know the RTV made it all the way down, i held the caps slightly up off the block and pumped them full until i saw it come out the bottom then i drove the cap home.

The one thing i didn't think about are and back plate bolt holes that are open to oil, do you know if there are any?

I gonna try to see if i can get my hands on a boroscope and take the starter bendix cover off and see what i can see...
 
5

57_BN4

Guest
Guest
Offline
Pretty sure it won't be the rear seal kit if it leaks while cranking on the starter motor. Did you have the oil gallery plugs out? Did you run a file over all gasket surfaces to check for burrs? I have a leak that drips from the bellhousing but it is actually coming from the cylinder head and sneaking down the back of the engine. Andy.
 

steveg

Yoda
Gold
Country flag
Offline
Some more thoughts:

If there's a problem with the pan gasket or the little cork piece at the rear cap, you can solve that in situ. Those would be leaking down the front of the carrier plate and not inside the bell housing.

Everything else is going to require you pull the trans. Even if you see the problem with a bore scope, you'll still have to pull it to fix it. Which will be easier at this point than when you've filled it with oil.

The other thing you may have done is drilled through the block with one of your mount screws for the moss kit.

If properly installed, the Moss kit isn't going to leak any more than your original setup did.

Regarding the situation in your picture and the mods contemplated: if this were a problem, the engine would have been modified long ago and/or it would be common knowledge that it needed to be done. Are you sure this pipe is open and does it go up to a matching hole in the bearing?
 
OP
C

Chad Donner

Freshman Member
Offline
I got a little closer look today and it does appear that the oil is coming down on the front side of carrier plate, so it may be the little cork piece. I didn't use the cork however, I used a bead of silicone instead. The front appears to be holding, maybe just not the rear.

Side note, I now have oil seeping from the outboard most head nuts around the threads at the very front and rear. Do these pass through an oily alley, should I have used sealant on these studs?
 

TimK

Jedi Knight
Silver
Country flag
Offline
I'd like to hear if anyone has solved all the oil leaks on their Healey. I have leaks in four or five places. I've installed British Car Specialist rear main seal. I've lived with mine for 33 years. Used up a lot of old newspaper and cardboard. Oil is cheap and as long as you check regularly, no harm will come to engine or transmission. Worrying about it will age you prematurely. Just live with it, is my advice...
 

steveg

Yoda
Gold
Country flag
Offline
My car leaks a drop a week or so from the rear main seal area; none from the front seal and none from the trans (toyota).

Front pulley & cover has speedi-seal and hylomar on both sides of gasket. Aluminum pan with hylomar on both sides of pan gasket; small cork piece carefully trimmed to size & coated with hylomar. Two felt plugs in place in rear main cap. Moss seal kit with seal pinned in place see: https://www.pbase.com/stevegerow/image/91637859. This permits spring side of seal to face toward engine. Moss seal carrier sealed together and to block with permatex aviation form-a-gasket. Area around camshaft also sealed as are vertical joints in rear main cap - see picture in previous posting above.

This setup has held for four years.

Am running pcv valve which I believe helps keep oil from forcing out rear seal.
 

TimK

Jedi Knight
Silver
Country flag
Offline
Rick and Steve: So, to stop leaks, use Toyota transmissions and Ford engines....
Thanks for the info!
 
OP
C

Chad Donner

Freshman Member
Offline
I wanted to thank you all for the feedback...I snugged up on the pan in the rear a little. I plan on getting it fired up this weekend after i get my headers back from Jet-Hott today:smile:

I'll see how bad/tolerable things are after i get it running.

Any thoughts on the head studs leaking?
 

Richard Dickinson

Jedi Trainee
Offline
The first time I rebuilt my engine and started it up I had a bad leak at the rear of the engine. I almost had a heart attack. I thought it was coming from the rear main. Turned out it was leaking around the back of the rocker cover. I don't remember leakage from the rear main ever being a significant problem, and in view of all of the above it seems questionable whether it is worth the trouble to install the extra seal. Besides a little oil blowing back under the frame gives it a little rust proofing.
 

bob hughes

Luke Skywalker
Country flag
Offline
I installed a rear oil seal some time ago, it did significantly reduce the oil seepage but not completely. However, now that I have taken the engine out a for refurbishing I can see that there has been some seepage at the bottom of the aftermarket kit, so must pay special attention to that when I put it all back together again.

:cheers:

Bob
 
Similar threads
Thread starter Title Forum Replies Date
J Rear Main Seal Kit Austin Healey 1
S TR2/3/3A rear main seal is leaking Triumph 13
D rear main seal Austin Healey 13
T BJ7 Slipping Clutch? rear main seal? Austin Healey 11
Gerard 1098 10CC rear main seal conversion Spridgets 4
W A-40 Somerset - Leakage at Rear Main Bearing / Oil Seal Other British Cars 0
KVH General TR Rear Main Seal--Minor Problem Triumph 4
Editor_Reid Rear Main Seal for BN2 Austin Healey 12
J BJ8 rear main seal kit - is it necessary and worth the risk to install? Austin Healey 33
T TR4/4A Oil drain hole from rear crank seal/rear main cap Triumph 3
C TR4/4A Rear main seal Triumph 36
S TR2/3/3A rear main seal Triumph 20
E 100 4 Does anyone recognize this rear main seal mod? Austin Healey 12
KVH TR4/4A Viton Rear Main Seal Triumph 12
TR3driver TR4/4A "Mad Marx" rear main seal for TR2-4A once again available Triumph 10
KVH TR4/4A Rear Main Seal Leak TR4A Triumph 1
B Rear main seal kit Spridgets 3
O TR2/3/3A TR3 Rear Main Seal Triumph 5
A TR2/3/3A More TR3 Rear main seal problems. Please Help!! Triumph 8
tinman58 TR2/3/3A Rear main seal TR3 Triumph 11
P how to replace rear main seal in 1500 midget Spridgets 2
R Rear main seal question. Spridgets 29
MGTF1250Dave Improved TR Rear Main Seal Kit Triumph 19
KVH TR4/4A Rear Main Seal TR4A Triumph 17
B 1970 XKE 4.2 rear main seal Jaguar 2
M TR2/3/3A TR3 crankshaft rear main seal opinions wanted. Triumph 8
58Custom 1275 Rear Main Seal Kit- - seek info Spridgets 2
glemon Rear engine main seal review Triumph 7
J Moss rear main seal. Austin Healey 5
TimK Rear Main Seal Kit Installation Austin Healey 24
M Rear main Scroll Seal Triumph 11
A Rear Main Oil Seal Conversion - Bearing Cap debris Austin Healey 5
V TR6 TR6 Rear Main Seal Triumph 17
aaronclark TR2/3/3A TR3 Rear Main Seal Questions Triumph 7
T TR2/3/3A Tr3A rear main seal conversion - adviced needed Triumph 11
spartan0199 rear main seal kit 833-145 Austin Healey 12
A TR6 TR6 rear main seal housing special bolt ?? Triumph 1
fad64b TR2/3/3A Rear main seal TR3 Triumph 12
S TR2/3/3A tr3 rear main seal Triumph 6
A TR6 TR6, Best front and rear main seal ??? Triumph 0
C rear main oil seal Austin Healey 4
K Usual 1275 rear main oil leak question Spridgets 0
G TR4/4A And the fun continues...rear main leak Triumph 5
B General MG Solutions for topical MG rear main leak? MG 7
Martinld123 Drain Pipe Rear Main Bearing Cap BN2, remove? Austin Healey 2
Gerard 1098 "10CC" rear main Spridgets 0
S TR2/3/3A tr3 rear main Triumph 24
TraceZ rear main leaks Spridgets 3
B rear main Spridgets 5
B rear main puller Austin Healey 6

Similar threads

Top