rear main seal

[opelgtboy70]

Hey all. I had some mechanic friends install my 5 speed and while they were in there they replaced the rear maon seal. Now I have a leak from the back of the engine that could be the seal. Are there any things that are different about installing a rear main seal on a GT? Any pitfalls of things to worry about and any tricks.

Karl
70 GT

[soybean]

Karl, they might not have seated it correctly. The easiest way to remove it is to use a seal puller like the one I posted in the parts review. Otherwise you can drill a small hole in it, put in a screw and pull/pry it out. To install I used a big socket that fit the outer diameter of the seal and gently tapped it in. Of course most people don't have that large a socket in their tool box. I do because of my farm equipment. I'm sure others will add their suggestions for the install. The main thing is to coat the inner part of the seal with a little grease so it will slide on the back of the crank, and do it easily. Don't cock the seal or it will be ruined. I had to do it twice.:banghead:
Jarrell

[kwilford]

To add to what Jarrell said, the biggest problem with installing a rear main seal is to ensure that the seal lip doesn't get inverted. To do it "properly", you need a special seal installation tool, that pushes the seal lip BACK at the same time the seal is driven into place. You can do it manually, by VERY carefully pushing the seal lip back over the crank journal with a small wooden tongue depressor or similar tool, as you gently tap the seal around the edges to seat it. Be VERY careful that you don't tear the lip, or you will be replacing the seal again. And use a thin coating of RTV sealer around the outer edge of the seal or inside the bearing recess to ensure a good external seal.

HTH

[dallasmanta]

Another trick is to use a thin plastic ruler 6 inch kind that is is flexible and can be wrapped around the crank. This is some what similar to the tongue depressor technique. The ruler is half the thickness of a tongue depressor.
Take the rear seal and lube the inner lip with engine assembly grease. extend the seal over the crank gently and slip the ruler between the crank and the seal. Now gently and accurately engage the seal to the engine making sure that the seal is tapped in evenly around the crank shaft
Once installed gently remove the ruler by sliding it out evenly making sure that the seal lip stays oriented in the direction of the engine. This technique simulates the real main seal installation tool function.
This is the only way I have found to not stretch the spring that keeps the seal lip snug evenly around the crank shaft. Ron

[OpelJim]

Hey all. I had some mechanic friends install my 5 speed and while they were in there they replaced the rear maon seal. Now I have a leak from the back of the engine that could be the seal. Are there any things that are different about installing a rear main seal on a GT? Any pitfalls of things to worry about and any tricks.

Karl
70 GT

These are the Original Opel FACTORY recommended tools part # J-22928 and J-22928-2. Go to your Opel factory service manual and see page 60-34 figure 60-71 to install the rear main seal the tools are pictured there

I will RENT it out for a modest fee for a short period of time to Opel owners in the USA with a VERY HUGE refundable security deposit. Must have a certified check to process rental and security deposit, no credit card payments for this service/tool rental.

I reserve the right to refuse service to anyone.

[jordan]

Karl, I wish I could help you out with the real tool. But I guess the saying may be true for most "There's no free lunch" but I can at least still say that I serve free lunches all the time for any good fella in need.

[GTJIM]

The other important step in the process is to carefully clean the outside of the crankshaft after the old seal has been removed as all sorts of gunge builds up there ... on both sides of the seal. Any sharp edges also need smoothing off as well.

Also, just like the front pulley snout, the area the seal surface runs on can get grooved and worn - just a new seal does not guarantee a good seal. I guess that there are 'redi-seal' sleeves the correct size for the rear end of the crankshaft too.

A wee smear of Hylomar Blue or Loctite Gasket Maker around the OD of the seal where it goes into the Block/Cap also helps ensure a good seal - especially at the interface between the block and cap. A tiny dab of RTV is usually put here before the main cap is installed during an engine build (as Nobody later mentions). This is critical! If it has not been put there during the engine build you have no hope at all of sealing the area. As long as this has been done and not damaged during the old oil seal's removal and with care, a rear oil seal can be removed and a good seal re-established without removing oil pan or cap ... but it is a crap shoot!

[nobody]

Unfortunately this is one of the tricky areas prone to leak in a 1.9 motor if it's not done correctly. If the rear main seal was pulled it leaks around the edges of the rear main bearing cap not the seal itself. To get it to seal again you have to drop the pan and loosen the rear main cap to apply a wee dab of RTV to both sides for it to seal up again or it will always leak, this is basic motor building so please don't tell me it isn't common knowledge by now. Special rented tools? get serious

[opelgtboy70]

Im taking it back to the mechanics on saturday. I will show them all of your posts. Thanks for all your help.

Karl
70 GT

[opelgtboy70]

As far as common knowlegde, I never rebuilt an engine and never replaced a rear seal. I hope I can fix it without removal of the pan.

Karl

[nobody]

I didn't mean to offend anybody, this has been posted several times. The other common leak points are at the head gasket front edges and a common missplacement of the valve cover gasket in the back. If it's any consolation I've got a wagon with a motor in it that leaks in all 3 points from a previous owners work. I'm sure Todd and the girls can help you or Gill and Dennis too.I was only trying to point out the most common problem and the best and cheapest fix for it.

[73Manta72gt]

seems like the tool would be simple to reproduce..something like two pieces of concentric pipe where the outer one allows the seal to be hammered in place and the inner one to holds the seal lip from flipping around. If I remember the picture from the FSM, it just shows the tool being used and not any details on how it protects the seal. I have heard it's a good idea to let the new seal soak in oil for 24 hours before installing. I need to replace my seal and just have been lazy...the garage floor is really getting messy

[opelgtboy70]

I searched this site and came up with soooooo many posts it would take hours to go through. The search is not specific enough. I never took out or put in a rear seal in an opel before so all help is needed. I still dont understand where you guys say to put the rtv silicone after the seal is removed????

Karl

[GTJIM]

The area talked about above is the 'split' joint between the rear main cap and the cylinder block. There will always be tiny gaps and machining imperfections here - and a tiny gap is all that hot oil needs to escape!

When the old seal is removed a tiny bit of the original RTV that was in the inner corners of the parting line can get pulled out too. This has to be replaced or there will be a nice wee point the oil can get out through.

However - too much RTV is just as bad as too little! A very tiny smear on to oil free, clean surfaces is all that is required. RTV is a real engine killer if lumps of it get into the oiling system!

The corners and edges of the area shown in the attached pic is the "area of concern"

Also a page from the Holden Torana Factory Service Manual covering Rear Seal replacement showing the tools mentioned. Plus a line drawing of the tools, showing how the tapered sleeve has a recess at the 'big' end that locates over the end of the crankshaft and allows the new seal to be expanded as it moves up the taper onto the crankshaft.

HTH

[OpelJim]

Unfortunately this is one of the tricky areas prone to leak in a 1.9 motor if it's not done correctly. If the rear main seal was pulled it leaks around the edges of the rear main bearing cap not the seal itself. To get it to seal again you have to drop the pan and loosen the rear main cap to apply a wee dab of RTV to both sides for it to seal up again or it will always leak, this is basic motor building so please don't tell me it isn't common knowledge by now. Special rented tools? get serious

Dave
I imagine you are not aware of these tools
Check your factory service manual you will see that Kent tools made 2 installation tools to make it go in right and then ( as you say if it is not done correctly what a waste of time) there are no leaks after it is installed.
The right tool for the job used the first time makes life so much easier.

[Gary]

I searched this site and came up with soooooo many posts it would take hours to go through. The search is not specific enough. I never took out or put in a rear seal in an opel before so all help is needed. I still dont understand where you guys say to put the rtv silicone after the seal is removed????

Karl

Karl - You can make the search as specific as you choose. Use as many keywords as fit your question (rear seal silicone) or you can used the "advanced search" feature and search only the forum that is relevant. (Engine Mechanical) The Google search that is listed on the main page also helps to get answers quicker.
Hope this helps.

[73Manta72gt]

So the big end of the cone is slightly larger than the diameter of the crankshaft?...Is there any reason for it being hollow?..A simple tapered cone could be turned on a lathe quickly. Any idea what the two diameters of the tool would be and it's length?

Thanks

[nobody]

I'm sorry if I ruffled anybodys feathers by posting the easiest and cheapest way to fix this little problem, but Jim was correct on the issues of simply driving in a seal. I have the reciept were the local GM dealership drove in a new seal on the wagon, now it needs a new clutch and pressure plate from hammering in a seal and calling it good. full clutch job is over 200 bucks and a pan set is under 30.....it seemed pretty simple to me.

There is a simple solution to motors, you never ever use a hammer on anything.Right now I have 7 field cases for service work and there isn't a beating implement in them. If your going to beat on it then your gonna F it up. Everybody I've ever met hammers like lightning (never hit's the same place twice) For lip type seals you can press or finess and that's a quote from Parker Hannifin schooling. Press it in square or finess it in to be square
Parker uses an HXI 500 Kitamura and requires all techs to go through thier training first so sealing up a motor I've known for 30 years is pretty easy after setting up a machine for them that runs 1200 pounds of oil pressure and a goofy blood red coolant that would eat up policarbonate glass in under an hour.

[David McCollam]

If you need a rear main seal, contact Opel GT Source. When sending you the seal, they will include a guide for installation that contains the method for a leak free installation as is described here. I supplied that information sheet along with the other tech tips it contains to the shop that assembled the engine in my Manta Rallye. Doing that should take a large amount of the guess work out of the install.

[opelgtboy70]

Unfortunately I did get the seal form OPEL GTS and didnt get those instructions. I will have to take it apart on saturday.

Karl
70 GT