: Rear main seal & case half seal - '98 Deville



KHE
12-15-09, 04:31 PM
I am working on a '98 Deville enigne - replacing the rear main seal, Timeserting, new rings, re-sealing case half, re-sealing oil pan, etc. and apparently, there was a change to the rear main seal for 1997+ and the installation tool is different than the 1996 model year. For the price of the special tool (even on ebay...), It would be cheaper to haul the engine and my parts down to my local dealer and have them do it for 1/2 hour of labor.

The '96 Shop manual I have for my Seville doesn't mention replacing the oil distribution plate but that seems to be part of the procedure per the bulletin. Anyone know why the existing plate can't be reused? Was there an engineering change to the plate?


Thanks!

tateos
12-15-09, 05:05 PM
I don't know to much about the plate, but there was a change. The rear main seal did definitely change - I had to buy that special tool - nearly $300 for 30 seconds use, but you really do need that tool. I did see it since then, maybe a year ago, for under $20 on e-bay, so that may be worth a try. The previous seal was a simple lip type seal - the new design is called a cartridge. The best way I can describe it is I think it's like holding your hands in front of you with your fingers curled and interlocked, as if you are trying to pull them apart. The one side of the seal is pressed onto the crankshaft flange - the other half into the block cavity. Make sure you either change the torque converter to crankshaft flange bolts per the service manual, or clean the threads on both the flange and the bolt and then apply a little RTV sealer to the threads during re-assembly (that's what I did).

cl1986
12-16-09, 09:36 AM
still having that same question, whats with the oil dist plate? I cant seem to find one anywhere, and why is it not to be re used?

Hmm....just called the dealer, this same TSB # on GM's computer doesnt read "oil distrubution plate" it says "engine manifold" .........everything else in the bullletin reads the same.

97EldoCoupe
12-16-09, 11:07 AM
The reason it can't (or shouldn't in most cases) be re-used is because it has a formed-in-place silicone seal. If it gets re-used it will leak. Unless you're really good at cleaning and spreading RTV silicone.

It is called an "oil manifold" plate (by GM). It basically keeps pressurized oil in it's passages in the lower part of the engine block, as well as provides a mount/pick-up hole for the oil pick-up tube.

They actually CAN be re-used. There's a trick I use with these that involves removing the original silicone out of the grooves and spreading a nice even bead of the AC-Delco RTV in the grooves. If anyone attempts this, it has to be done very carefully. Any mistake will cause a drop in oil pressure as well as potential external leaks. And the aluminum has to be 100% free of grease/oil residues. Lay the plate back in place with the RTV in it. Start the M6 bolts and finger snug them, but wait about 15-20 minutes before you go ahead and torque them to specs.

RTV silicone is not supposed to shrink as easily/as much as the original gaskets. There's a TSB on this. Just make sure you use the GM / AC-Delco RTV silicone. I've seen poor results in the past with other silicones, even the Permatex brands.

The ring of silicone around the oil pick-up tube needs to be left in place, there's no way to substitute that with an O-ring or RTV. If that ring is damaged, chuck it and use a new plate. Oil pressure rides on this being done right. A small bead of RTV around the pick-up tube never hurts either.

Usually there will be still some oil in the pistons (with the engine upside down) so when you have the whole bottom end together, allow the RTV to dry as long as you possibly can to prevent oil contamination and weakening of the RTV. Once it has had adequate time to set up/cure, flip the engine over and proceed with the heads or installation of the engine.

97EldoCoupe
12-16-09, 11:09 AM
Also- washing that plate with any type of solvents WILL destroy the silicone seal for the oil pick-up tube. Soap and water on this one.

97EldoCoupe
12-16-09, 11:12 AM
And the rear-main seal changed for the 2000 model year. I've seen some 99's that came factory with the upgraded steel sleeve seal but very few. 95-96-97-98- most 99's should all be the same.

97EldoCoupe
12-16-09, 12:34 PM
I just found another one of these damned inserts that let go in the block. So KHE - It's totally up to you whether you choose to go with but please don't use these time serts. I'll be posting a pic in a new thread in one sec...

KHE
12-16-09, 01:16 PM
Thanks for the detailed information on the oil manifold plate. I can't wait to see how much that costs at the stealership.

I thought there was a difference between the 1996 rear main seal and the 1997-1999 rear main seal.

buggin123
12-16-09, 01:43 PM
If you really need to replace the oil dist plate, this is an auction on E-Bay right now for one. auction #330385943451 Just so you know.

cl1986
12-16-09, 02:06 PM
I just found the plate at the dealer for $110, so ill skip the ebay thing.

So is this plate and seal something that will cause the external leak again?? or is this only internal and the gm rtv used on the case and oil pan?

97EldoCoupe
12-16-09, 02:53 PM
I never use just RTV on the oil pan. I use this in between the block halves and for the oil manifold plate, but for the oil pan, the groove is so deep that I use a new Fel-Pro seal as well as running a bead of RTV along the outside edge of the seal for an added measure of leak prevention.

cl1986
12-16-09, 04:34 PM
tell me more about this plate, is it in between the pan and the half case?? or completely inside?

KHE
12-16-09, 04:58 PM
I never use just RTV on the oil pan. I use this in between the block halves and for the oil manifold plate, but for the oil pan, the groove is so deep that I use a new Fel-Pro seal as well as running a bead of RTV along the outside edge of the seal for an added measure of leak prevention.

But it is OK to use the GM part no. 88861417 sealant on the case half with no seal correct? gmotors.com (Braisingtons/Palm Motors) said the seal is now just the 88861417 sealant.

I'll probably bite the bullet and buy a oil manifold plate from the dealer rather than attempting to salvage the old one.

Also, back to the oil pan - can Permatex Ultra Grey be used for the bead outside of the Fel-Pro seal or does the GM 88861417 sealer need to be used there too?

One last thing, when I removed the bolts from the oil pan, the threads appeared to have teflon pipe thread sealant (teflon pipe dope) on them. Do you use such a sealant on the oil pan bolts?

97EldoCoupe
12-16-09, 05:36 PM
The oil pan bolts go into blind holes. You shouldn't need any sealant there whatsoever. The factory never put sealant on these so I think yours might have been done by someone before. The bolts are on the outside of the sealing edge as well.

Ultra Grey is garbage when it comes to oil. So is ultra black. Use the GM sealant as well there if you can. It's expensive (I get a discount from the dealership) but worth every cent. That Ultra black stuff is OK but only when it comes to stuff involving coolant or other things where oil is not in contact with it.

I've seen a number of cars done with this thread sealant on the bolts. Are you located in Ohio or anywhere near south of the Great Lakes KHE?

97EldoCoupe
12-16-09, 05:39 PM
One more thing- the flexplate (flywheel) bolts need sealant put on the threads (FSM says to use new bolts; unnecessary) because these are not blind holes and go right into the crankcase. As well with the 3 camshaft seal screws(by the water pump drive)- these need sealant too.

KHE
12-16-09, 08:02 PM
The oil pan bolts go into blind holes. You shouldn't need any sealant there whatsoever. The factory never put sealant on these so I think yours might have been done by someone before. The bolts are on the outside of the sealing edge as well.

Ultra Grey is garbage when it comes to oil. So is ultra black. Use the GM sealant as well there if you can. It's expensive (I get a discount from the dealership) but worth every cent. That Ultra black stuff is OK but only when it comes to stuff involving coolant or other things where oil is not in contact with it.

I've seen a number of cars done with this thread sealant on the bolts. Are you located in Ohio or anywhere near south of the Great Lakes KHE?

I'm in Westen Michigan. Near Lake Michigan.

Will two tubes be enough to seal the crankcase halves, the oil pan (with the Victor Gasket) and the flexplate bolts?

Interesting information on the Ultra Grey Permatex. I would have guessed Permatex made the GM Sealant but they don't - I spoke with a Permatex rep. and asked him to cross reference the GM part no. and he told me they did not produce the sealant for GM. I have a tube of Ultra Grey that I bought to seal the front and back of the intake manifold on my RWD Fleetwood Brougham. It is leaking oil at the front where the intake manifold contacts the block. Not enough to leak to the ground though. It looks like the factory used black RTV there.

I bought a Fel-Pro gasket set for it and was going to replace it in the spring. I cleaned off the oil residue and it appeared not to leak for the whole driving season (I store the car for the winter) so I never replaced the gaskets. I noticed it starting to seep by the time I put it away for the winter so I'll replace the intake gaskets in the Spring. I should probably use the GM sealer there too since the Ultra Grey doesn't hold up to oil.

cl1986
12-16-09, 08:02 PM
I dont know where you are gettting this 88861417 number, but the bulletin calls for RTV sealant, P/N 12378521

Did you find the rear main installer? Theres one on ebay for your year for $20 buy it now.....i had to get the earlier version

KHE
12-17-09, 07:53 AM
I dont know where you are gettting this 88861417 number, but the bulletin calls for RTV sealant, P/N 12378521

Did you find the rear main installer? Theres one on ebay for your year for $20 buy it now.....i had to get the earlier version

The dealer provided the 88861417 part number as part of the quote for the parts. I believe 12378521 has been superceded by 88861417.

I haven't purchased the seal installer yet. According to the 1998 Shop manual, I need J-38817 which is the tool used for 1993-most of 1999 models. What was the ebay # for the $20 buy it now?

97EldoCoupe
12-17-09, 10:03 AM
I have had pretty good results with Permatex "The Right Stuff"- but when it comes to customers' cars it's GM sealant or nothing.

cl1986
12-17-09, 10:21 AM
The dealer provided the 88861417 part number as part of the quote for the parts. I believe 12378521 has been superceded by 88861417.

I haven't purchased the seal installer yet. According to the 1998 Shop manual, I need J-38817 which is the tool used for 1993-most of 1999 models. What was the ebay # for the $20 buy it now?

No, thats the tool i bought....

You need J 45930-A Crankshaft Rear Oil Seal Installer

If you read the items needed on the bulletin it says 45930, down farther it says 93-96 must use the 38817 tool which is what i bought, you have a different seal than i do.

http://cgi.ebay.com/ebaymotors/KENT-MOORE-J-45930-Rear-Main-Seal-Installer-V-8_W0QQitemZ220528084341QQcmdZViewItemQQptZMotors_A utomotive_Tools?hash=item33587f8575

97EldoCoupe
12-17-09, 06:22 PM
KHE - I'm not sue which cars I've worked on that have had the sealant on the oil pan bolts but they were all U.S. cars. I think yours might have been at the same dealership as a few other Michigan cars I've worked on.

KHE
12-17-09, 09:15 PM
No, thats the tool i bought....

You need J 45930-A Crankshaft Rear Oil Seal Installer

If you read the items needed on the bulletin it says 45930, down farther it says 93-96 must use the 38817 tool which is what i bought, you have a different seal than i do.

http://cgi.ebay.com/ebaymotors/KENT-MOORE-J-45930-Rear-Main-Seal-Installer-V-8_W0QQitemZ220528084341QQcmdZViewItemQQptZMotors_A utomotive_Tools?hash=item33587f8575

The bulletin I found on this site talks about a cartridge seal and special sealant - my seal is just a rubber seal about 4" in diameter and 1/2" thick with a garter spring. The 1998 shop manual says to use the tool J-38817. Do you have a link to the bulletin that says to use the J-45930 tool? With the case half removed, the seal can be installed by hand and then install the lower case half. I suppose it would be possible to not have the seal fully seated with that method though.


KHE - I'm not sue which cars I've worked on that have had the sealant on the oil pan bolts but they were all U.S. cars. I think yours might have been at the same dealership as a few other Michigan cars I've worked on.

Do you think one tube will be enough for the oil pan and one additional tube for the case half? The case half groove looks deep - Do you just use the GM sealant and no gasket for the case half or do you use a Victor or Permatex gasket and then use the GM sealant on the outer periphery like you recommended for the oil pan?

I'm trying to prepare myself for the re-assembly so it goes right - I don't want to do the job again. I've Timeserted a Northstar before (with Bigserts to fix a botched dealer repair) but never had one torn down this far until now.

I marked the pistons, rods, and rod caps - I need to have the block honed because the engine sat for a long time and a couple of cylinders have some mild pitting. I am then going to install new rings, new main bearings (there are some minor pits on the aluminum), new rod bearings and re-seal the crankcase. I won't order the parts I need until I get the block back from the machine shop (just in case there are any surprises).

97EldoCoupe
12-17-09, 10:10 PM
One tube should easily do the job and then some. I only use about one tube per two engines somewhere around there. No gasket for the case halves, just sealant. If you have just the rubber seal (and not the steel cartridge seal) you can press that into place easy enough using a large washer about the same size and a rubber mallet. It's better to use the correct tool but this will work for these older style seals. The steel cartridge seals need quite a bit of force to install so makeshift tools aren't quite an option here.

cl1986
12-17-09, 11:17 PM
half case reseal bulletin

http://www.cadillacforums.com/forums/cadillac-tech-tips/117232-case-halves-reseal-fwd-rtv-sealant.html

KHE
12-18-09, 08:44 AM
One tube should easily do the job and then some. I only use about one tube per two engines somewhere around there. No gasket for the case halves, just sealant. If you have just the rubber seal (and not the steel cartridge seal) you can press that into place easy enough using a large washer about the same size and a rubber mallet. It's better to use the correct tool but this will work for these older style seals. The steel cartridge seals need quite a bit of force to install so makeshift tools aren't quite an option here.

When you say one tube for two engines are you referring to the 75g (2.5 oz) squeeze tubes or the 150g tubes (5 oz)? The bulletin is not clear on wether a dispensing tool is required for the squeeze tube. I want to be sure I have enough to seal the case halves, oil pan, oil manifold plate and rear main seal.

The bulletin mentions that the work must be done quickly - But if the new cartridge seal is used, it requires another installation tool and a sealant applicator for the crankcase bore (EN-48072), etc. That seems like a lot of work to do in 10-15 minutes. If I have to buy all those tools, I'd be cheaper off to haul the engine to the dealer with my parts and have them install the rear main seal for me. My concern is the sealant at the case half would be cured and would there be a problem with new sealant on the block bore next to cured sealant for the case half - a potential leak point?

Thanks for your help!

cl1986
12-18-09, 09:07 AM
i think when they say dont reuse the sealant, i think they mean after a day or week dont use the anything out of the tube again, i think as long as you do the half case, then do the rear main you wont have issues? did you find out which rear main you have?

Can anyone explain this rear main a little better? It looks like you fill the cavity with sealant, somehow you arent supposed to get sealant in the drain back hole (how is this even possible?) and then push in the rear seal over top of this sealant and let it sqeeze out? Or am i looking at the diagram wrong?

KHE
12-18-09, 04:10 PM
i think when they say dont reuse the sealant, i think they mean after a day or week dont use the anything out of the tube again, i think as long as you do the half case, then do the rear main you wont have issues? did you find out which rear main you have?

Can anyone explain this rear main a little better? It looks like you fill the cavity with sealant, somehow you arent supposed to get sealant in the drain back hole (how is this even possible?) and then push in the rear seal over top of this sealant and let it sqeeze out? Or am i looking at the diagram wrong?

That is exactly what may happen in my case - the cost of all the special tools is way more than a half hour of labor at the dealer to install the rear main seal. My plan was to install and seal the lower case half and then take the engine to the dealer to have them install the rear main seal if I can't get a good price on the special tools. The original seal is the rubber seal which is described in the manual as needing the J-38817 tool. Once I get my new rear main seal, I'll know what installation tool I need.

Looking at the bulletin, the applicator housing is installed over the end of the crankshaft and then the cavity is filled with sealant. Then the housing is pulled off and it takes most of the sealant with it, leaving the correct amount on the engine block for the seal. The oil drainback hole will need to be cleared out.

KHE
12-31-09, 08:59 AM
Well, some bad news on the engine. There was a crack on the aluminum surrounding the cylinder liner on the #8 cylinder. It was discovered after hot-tanking the block. The crack looks like it goes all the way to the bottom of the cylinder.

I put the engine back together enough to transport it back to the junkyard to get my money back. I do not want to proceed with the engine as I'm not willing to risk $1200 in seals, rings, bearings, etc. only to have the #8 cylinder distort and start burning oil. Besides, rebuilding the lower end wouldn't make sense starting with a known problem.

The engine was burning a lot of oil - the exhaust valves were caked with soot as were the tops of the pistons. When I took the pistons out, the oil control rings were stuck in the pistons and wouldn't budge.

Now I get to start the search all over again for another engine...

cl1986
12-31-09, 10:51 AM
well thats sad to hear....how about looking for a wrecked 98 where the engine should be good?

just letting anyone else reading this some things ive found now that mine is apart

The oil manifold plate is external and another seal, so reall the half case area is 3 seals that can leak, and by how mine looks i think they were all leaking.

The rear main seal with the spring, is for the older engines, like my 94 and doesnt really need a tool, it can be pushed right in, krashed said to fill the back side with grease to hold the spring in and install will go better.

It seems that the half case seals are to be pulled out (black rubber) and rtv used in this area (according to bulletin) and then the oil manifold plate you buy new, it has the orange silicon seal, then you rtv around the outer perimeter right next to the orange silicon, and then rtv the oil pan on.

buggin123
12-31-09, 02:01 PM
Felpro has a really nice oil pan gasket, that can be backed up with sealant around the outer perimeter of seal. Thats the way I have done in the past with no leaks.

KHE
01-06-10, 12:46 PM
I found an engine with 137,000 miles on it for $250 but the junkyard that has it won't provide a warranty. Most yards have at least a 30 day warranty. Not worth the risk in my opinion.