Rb26 Rear Main Oil Leak

[OFENSV]

Put my motor back in my gtr last weekend after a comlete rebuild. I have now done 500 k's and have come across a problem. There are drops of oil forming from the bottom of the bellhousing which im guess is most likely going to be the rear main leaking. Now heres the problem, when i sent the block and crank etc for machining they machined the surface where the rear main seals. He said that there should still be plenty of meat for the seal. When i re assembeled the motor i found that the seal felt very lose over the crank and i thought to my self this is gonna leak for sure, but anyway i took the risk and put it back in the car only to find that it is leaking Its not a huge leak but is only going to get worse once i wound the boost up and the crank case pressures increased.

So now i have been told that i will most likely need to fit a speedy sleeve to the crank. Has anyone ever come across this and had to fit one? Also do they make them to fit an rb26 crank and where can they be bought from? Im unsure how much has been machined off the crank either.

Any help would be good, Cheers

Edited May 11, 2007 by OFENSV

[OFENSV]

[RB30-POWER]

If he has ground it undersize, it will need a sleeve for sure to seal up.

Why the hell did he decide to machine that part for, if it wasn't hugely scored to begin with there is no need a new seal would have worked fine.

Its not gunna be cheap a sleeve that large in diameter.

Apparently from what i'm told, what they typically do now is metal spray the crank and then machine it back to factory measurements to save the sleeving process. To late now its all assembled though i guess...

Do a google search, most bearing shops carry the Speedi product range.

They are rather simple to install, choosing the correct size on is the hardest part, you have to measure exactly.

http://www.chicago-rawhide.com.au/Products/speedisleeve.htm

That might give an idea.

[OFENSV]

yeah the last thng i want to do is to have to pull the crank back out. Will pull the box out and measure the crank and give some bearing shops a call.

Thanks for your help

[kevboost7]

Hey, not sure if you are still active on here, but I am chasing the same leak. Its a slow drip from the bell housing. Can't figure out where its coming from. Did it end up being the rear main seal?

[Milhouse]

On 11/08/2023 at 2:57 AM, kevboost7 said:

Hey, not sure if you are still active on here, but I am chasing the same leak. Its a slow drip from the bell housing. Can't figure out where its coming from. Did it end up being the rear main seal?

Well I am also keen to know what happened in the end from this thread or even just to hear what you ended up discovering @Kevboost7?? I also have just put the engine back in my R32 after a rebuild and I have a large amount of oil leaking from nowhere very obvious at all and am worried about my rear oil seal as well as can't find any other leaks so far.. Oil seems to keep dripping from the bottom of the bellhousing even after I have cleaned and wiped up all of the oil mess after the previous spirited drive and I haven't even driven it again since..! That makes me feel even more that it is still just slowly running down from the higher rear main seal because so much oil is coming out...

[kevboost7]

@Milhouse Sorry to hear that brother. I never got to the bottom of mine, although i didn't have a large amount of oil like you described. I just wipe it up as best as i can everytime i'm under the car and if i ever have to remove the engine, then i'd find the root cause of this leak. 

It sucks that you just had your engine out though.

[joshuaho96]

On 2/6/2024 at 1:14 AM, Milhouse said:

Well I am also keen to know what happened in the end from this thread or even just to hear what you ended up discovering @Kevboost7?? I also have just put the engine back in my R32 after a rebuild and I have a large amount of oil leaking from nowhere very obvious at all and am worried about my rear oil seal as well as can't find any other leaks so far.. Oil seems to keep dripping from the bottom of the bellhousing even after I have cleaned and wiped up all of the oil mess after the previous spirited drive and I haven't even driven it again since..! That makes me feel even more that it is still just slowly running down from the higher rear main seal because so much oil is coming out...

Put some UV dye in the oil and see where it's coming from. It could be a lot of things like a valve cover leak at a hard to spot corner.

[Milhouse]

Yeah thanks never thought of doing that before so might give it a go. Got the intake manifold off at the moment looking but nothing there yet either. Have a rear head oil drain which I thought maybe leaking for some reason but doesn’t look like… 😕