Coolant Leak Bellhousing - Rebuilt not started

[Alcyone]

I had a look on the forums and found this problem but not where someone had just rebuilt the engine and put coolant in without starting. My first thought was the rear main seal, gasket or housing but then I read that it can also be from the intake manifold gasket.

Had just put in approx 9L coolant in and within minutes I noticed the dripping. One drip every 30 seconds by the look of it.

Rather than rip the whole thing out again is there an easy way to establish what it could be?

Used the Permaseal kits for the seals, gaskets etc supplied form the machining shop;
(1) Permaseal Conversion Set E2037KY
(2) Permaseal Regrind Set V2037KCU (found out later this is 1995-2001 maybe VT era. Permaseal said would be okay but the upper intake to lower intake gasket was different but I didn't need it as I had already bought the metal one from Holden).

Rear plate was checked and cleaned at machining shop and they put the rear seal in for me when they checked it. I used those plastic bolt mounting things that came with the rear main gasket set when putting the cover and bolts back on. Torqued to spec inc degrees and used medium strength thread locker.

Intake gasket ends used Loctite Blue Maxx on the four corners and thought I had lined up the intake gaskets perfectly.

Trying to figure out the best way to proceed as I'm still in learning stage for all this stuff. Any help would be greatly appreciated!

For now gonna go take the intake off I guess and just hope that's all it is. Should I be sucking some coolant out first or is it gonna be obvious when I get there that that's where it's leaking from?

Just to double check, when tightening the head bolts, follow the torque sequence but do NOT ever go above 90Nm. Stop tightening a bolt during the procedure if you hit 90Nm and finish with that bolt. Does that about sum it up?

 

[Immortality]

If the leak was the intake manifold I don't think you would see coolant leaking from the bellhousing area.

I'd be dropping the transmission and taking a good look at that rear cover.

 

[Alcyone]

If the leak was the intake manifold I don't think you would see coolant leaking from the bellhousing area.

I'd be dropping the transmission and taking a good look at that rear cover.

Makes more sense. If I were to take out 5 litres of coolant and it stopped the leak, would that mean for sure it's the top coolant bypass section of the rear cover where it's coming from? Or is that me overthinking how to assess it? Is that the only place it could be coming from? Please don't think I'm doubting what you say because I agree with you as to where it's coming from. I just don't want it to be coming from there lol...

I've never taken a transmission out before. The manual says to drop the transmission oil but I only just put fresh in. Do I have to take the oil out or will the torque converter fall out when I'm doing this and make an absolute mess? I'll get back to reading the manual for removing the transmission...

 

[Alcyone]

Mate lent me something to stick in the back of the transmission to stop the oil coming out. Will keep reading and get onto taking the transmission out tomorrow...

 

[Alcyone]

Been reading up some stuff. Could this be caused by re-using the factory torque to yield bolts which hold on the rear oil seal housing/rear plate/cover? I'm guessing yes? I'm a wally for not getting new ones. Permaseal gasket had that beading on it which faced towards the block and was told not to use sealant on it. Everything aligned up rear well as I was full OCD about it but the bolts not being snug enough and the housing not sitting flush against the coolant ports would make sense.

 

[Immortality]

New bolts definitely a must. I would have used a thin smear of sealant regardless.

I have an old drive shaft yolk which we slip into the transmission to prevent the fluid leaking out.

 

[Alcyone]

New bolts definitely a must. I would have used a thin smear of sealant regardless.

I have an old drive shaft yolk which we slip into the transmission to prevent the fluid leaking out.

New bolts from Holden or from a fasteners? I think that's what my mate lent me - an old drive shaft yolk. Might help me save draining the transmission. I might put a thin layer of Blue Maxx around the coolant ports when it goes back together.

Do I have to drop the engine oil as well as the coolant? Put about 9L of coolant in today, emptied it via bottom radiator hose but only got just over 2 litres out.

 

[EYY]

Yep I've got a spare slip yoke I use for that too - very handy to have.

Try to lower the rear of the trans down to gain better access to the trans line fittings. Don't cut them whatever you do. Make sure you unbolt the torque converter from the flexplate and push the converter back into the transmission before undoing the bellhousing bolts - otherwise it's very easy to damage the converter or the pump in the box.

I've heard that you need to be very careful with those rear main seal plates - apparently there's a tool to align them properly. For stuff like that I always use permatex ultra blue. Threebond also offer some awesome products - 1104 or 1194 is also fantastic stuff but more expensive.

TBH though, I'd put a couple of stopleak blocks in it and start it to see what happens. You're not supposed to use coolant straight after a rebuild - always water. Then add coolant later on once its had a few heat cycles and it's been run in.

 

[Alcyone]

Yep I've got a spare slip yoke I use for that too - very handy to have.

Try to lower the rear of the trans down to gain better access to the trans line fittings. Don't cut them whatever you do. Make sure you unbolt the torque converter from the flexplate and push the converter back into the transmission before undoing the bellhousing bolts - otherwise it's very easy to damage the converter or the pump in the box.

I've heard that you need to be very careful with those rear main seal plates - apparently there's a tool to align them properly. For stuff like that I always use permatex ultra blue. Threebond also offer some awesome products - 1104 or 1194 is also fantastic stuff but more expensive.

TBH though, I'd put a couple of stopleak blocks in it and start it to see what happens. You're not supposed to use coolant straight after a rebuild - always water. Then add coolant later on once its had a few heat cycles and it's been run in.

I never knew that about the water/coolant - first rebuild and all. I'm guessing that's not the cause of this though? Too late to drop all the coolant now and save it. Should I do a full flush with water? I wouldn't have noticed the water drops funnily enough but the bright green coolant really stood out lol

Bloke from the machining shop who put the rear main seal into the plate said he had done that so it would be easy for me to align it. Having those plastic bolt inserts helped. Bottom of cover was perfectly level with bottom of block too. Is the tool only for putting the new seal in when the cover is already bolted on? I found a pic of it and read a couple posts about the tool but there was only steps on how to use it. Only other thing I found was to use a straight edge to make sure the bottom of the plate aligns perfectly with the bottom of the block which I am pretty sure I got right.

Was hoping to just slide the transmission back 20-30cm if possible and hold it up with some ratchet straps. Never done this before so will have to have a look at it tomorrow to get my head around it. Mate also said to put a strap around the engine onto the crane so as it doesn't tilt back into the firewall.

If it's dripping with no pressure, you reckon the stop leak would get it's job done before I pressured it up? I reckon I've lost a few hundred mill already with it just sitting there for 6 hours

 

[EYY]

Hard to say, but it's heaps of work to pull it apart again. Ideally you'd remove the box but you may get away without doing it.

Alignment is critical - read here: https://forums.justcommodores.com.au/threads/rear-main-seal-oil-leak-after-housing-replaced.204061/

Realistically you'll want to remove the box altogether, you don't want to have it leak again because you couldn't access the rear of the engine properly.