Rear Main Seal While Clutch Is Out?

[MrStabby]

Can the engine's rear main seal be done when the clutch is out, and would you typically do it as preventative maintenance or only if it was leaking?

My throw out bearing has died so i'm getting together a list of work to do at the same time. So far the list is;

- Upgraded clutch

- New spigot and throw out bearings

- New mount bushes for crossmember to body connection (gearbox mount looks fine)

- Attessa bleed after install

Is there anything else that should be done while its out?

[GTRPowa]

Yes. It's extremely common to do the seal while the clutch/flywheel is out. Same goes with the oil seal on the gearbox inside the bellhousing. Do both of them.

Perhaps while everything's out, a good scrub of the body under there to remove deposits.

If you want to go further, get the flywheel and clutch assembly balanced (get flywheel face machined as well)

And again if you want to go all out, get the prop shafts balanced too. I hope you marked the mating faces for the prop shafts when you removed them because if they go back in the wrong way you can have balance issues. (Fixed by rotating shaft and trying all the mating configurations) Much easier to just mark before removal.

I'll be doing mine next weekend, might get the car raised up today in prep.

Edited May 29, 2011 by GTRPowa

[PM-R33]

Yep definetely swap the rear mail seal while it is out. I did my clutch about three years ago and didn't do it and am now kicking myself beause my rear main seal is weaping oil and I SO don't won't to take the box out again

[89CAL]

My box has been out 3 times now, pretty good at pulling them out now lol

It's doable for sure so if you want to do it, while the box is already out will be good

[MrStabby]

Yes. It's extremely common to do the seal while the clutch/flywheel is out. Same goes with the oil seal on the gearbox inside the bellhousing. Do both of them.

How easy is it to do the rear main? Obviously flywheel off first but then what?

Is that gearbox oil seal quite easy to get to? Does the input shaft stick through it? FWIW my input shaft bearings are noisy too (have been for years), but from what I understand its a fair bit of work to do that bearing, so I was just going to leave it for now and wait until i get the whole box reconditioned. Any comments on that?

FWIW the gearbox is still in. I dont know if i can be bothered doing it on the floor of the garage again myself this time... at least i have all the tools now but its such a bitch of a job. Prop shafts are already marked.

BTW - thanks to both of you.

[89CAL]

Gearbox input shaft seal is easy because it has a section the unbolts then you can just replace it out of the box. Just make sure you have some threebond or something to seal the section back up to the box.

The rear main should be easy enough.

[Ad's]

Might aswell do it whilst its all out. I knocked a flat head screw driver into the seal and leavered it out. Then with the new one i gently tapped each side of the seal to make sure it sat in nice and flush. Not overly hard!

[PIG747]

i didn't mine on saturday while the box is out.

It's very easy want doesnt take to long

i did it the same way ad's did his

[blk94r33]

RB's have a welch plug on the back of the block? Or any difficult to access hoses such as the coolant return line? Never hurts to be over cautious......

[ARTZ]

Im pretty sure the method we used to get the seal out was to first pack the hole with grease then get something round that fits in the hole and hit it into the hole and the grease should pop the seal out.

However this was on a holden so someone correct me if im wrong.

[GTRPowa]

How easy is it to do the rear main? Obviously flywheel off first but then what?

Is that gearbox oil seal quite easy to get to? Does the input shaft stick through it? FWIW my input shaft bearings are noisy too (have been for years), but from what I understand its a fair bit of work to do that bearing, so I was just going to leave it for now and wait until i get the whole box reconditioned. Any comments on that?

FWIW the gearbox is still in. I dont know if i can be bothered doing it on the floor of the garage again myself this time... at least i have all the tools now but its such a bitch of a job. Prop shafts are already marked.

BTW - thanks to both of you.

Input shaft bearing is another few, more expensive steps lol. If you were planning on replacing/reco'n the box, it'd be fine, just noisy. If you let it go for 'x' amount of time it could chew itself out, but worst case, the box is dead and replace it anyways. (Disclaimer, probably wont happen lol)

Doing the gearbox on a car makes you more of a man everytime you do one haha

Rear main is as mentioned, should be able to carefully pry it out with screwdriver. Tap new one in with hammer, try and keep it flush and level as you tap it in to save it getting jammed.

Gearbox seal (also as mentioned) has it's own holder which you unbolt, take the holder out, again pry the seal from it and replace with new one keeping flush and level. Use small (SMALL) amount of grease on the seals helps for a better seal too.

Excess grease on the seals/splines will run outwards into the clutch disc and ruin your new install early.

[89CAL]

Im pretty sure the method we used to get the seal out was to first pack the hole with grease then get something round that fits in the hole and hit it into the hole and the grease should pop the seal out.

However this was on a holden so someone correct me if im wrong.

Sound a bit like you are talking about the spigot bush in the back of the crank where your gearbox input shaft goes.

You cant push grease in behind the seal, its deisgned to keep pressure in, and you would contaminate the oil circuit in the engine by packing grease in there.

[ARTZ]

Sound a bit like you are talking about the spigot bush in the back of the crank where your gearbox input shaft goes.

You cant push grease in behind the seal, its deisgned to keep pressure in, and you would contaminate the oil circuit in the engine by packing grease in there.

yeah you're right thanks..

[GTRPowa]

Sound a bit like you are talking about the spigot bush in the back of the crank where your gearbox input shaft goes.

You cant push grease in behind the seal, its deisgned to keep pressure in, and you would contaminate the oil circuit in the engine by packing grease in there.

I'm taking my box off tomorrow. I heard this was also the way to remove the spigot bush. If that's a bad idea, how to you get it out? Can it be pried out? I don't wanna hit a brick wall at 6PM when everything is shut. Cheers.

[89CAL]

Nah packing with grease and pushing something that will fit down the guts should be fine. You may not need to replace the spigot bush but. May just need greasing

[MrStabby]

I'm taking my box off tomorrow. I heard this was also the way to remove the spigot bush. If that's a bad idea, how to you get it out? Can it be pried out? I don't wanna hit a brick wall at 6PM when everything is shut. Cheers.

That grease method is fine for the spigot - just not the rear main seal You just need a drift that's pretty much the same diameter as the input shaft.

How are you going to replace the throw out on the carrier? I dont have a press...

Also, what method are you going to use to stop the crank spinning when you do the flywheel bolts?

[blk94r33]

Bump

Does anyone know the part numbers for the rear main seal, gearbox input shaft seal, and spigot bush/bearing for an R33? Even rough dimensions would help?I imagine GTS and GTST would be the same?

My spigot is starting to get noisy, and though I might as well replace everything while the box is out.

[blk94r33]

Found something that might help for anyone searching:

Rear Main seal, most engine seals:

(note this is for R33 GTS, RB25DE, but the catalogue has other listings)

http://catalog.acl.com.au/aclwebcatalog/Modules/Catalog/UsagesSelector.aspx?parent=IT95712&type=TP80&listtype=0

Spigot Bush:

(anyone have a listing for a bearing?)

http://justjap.com/store/product.php?productid=18007&cat=&page=1

Thrust Bearings:

(most kits come with them anyway)

http://justjap.com/store/search.php?mode=search&page=1

If anyone has a number/listing for a needle roller bearing for the spigot, rather than a bush, i'm keen to know...

[MrStabby]

I got my parts straight from Nissan;

"bushing gear" (spigot) 32202-B950A $15

"seal oil crankshaft rear" 12279-58S00AU" $44

"seal oil front cover: 32114-Y4000AU" $6

I also heard from an apprentice mechanic that he had pulled a number of the roller spigots from RBs failed in pieces, so i'm going with a bush.

IIRC unique autos used to sell the roller ones - www.nismo.com.au

[blk94r33]

Cheers for that.

Being an "open" needle roller, rather than a sealed type, i'd say they'd fail regularly. Bush it is then.