Dammit!

[chevy4x4grl]

So I have my truck scheduled for paint next week and yesterday I found a puddle of oil under it. Crap! I did a little research and took off the flex plate cover to find it's coming from the rear main seal. I've owned this truck for 2 years now and this is the first real problem I've had. I know this is a very involved job to take on and I'm not sure I'm up to the task. However, I don't have the $1500 to fork over to a mechanic for it. I've done some moderately difficult automotive tasks such as installing my trucks suspension lift, replacing my friends tranny, ect. but I am by no means a professional mechanic. The only person I'm going to have helping me is my bf who doesn't know how to change his own oil lol. Sooo any tips? I heard this is a 2 piece seal or something which makes it more difficult. Any help would be a appreciated. Thanks.

[john8662]

It's a pretty involved job, but something that can be done with some time and patience.

Having a two-piece rear main seal isn't the bad news, actually it's the good news considering you don't have to unbolt the transmission and move it away from the engine to replace the seal. You just have to remove the oil pan and nearby hardware to get to the seal(s).

How bad is the leak?

I'd suggest testing your CDR system (the big tuna can looking thing above the alternator on the passenger's side of the engine).

There are many resources on here and the "content" side of this site that cover the CDR. Check out "excessive oil consumption" under Troubleshooting guide on the main page found here (towards the bottom of the page):

http://www.thedieselpage.com/password.htm

If the CDR system isn't functioning properly, it's allowed pressure of blow-by gasses to build in the engine and force seals to start leaking.

But... The seals do fail, as they're a "rope" seal.

So, your BF doesn't even know how to change the oil? Send me a plane ticket I'll help ya out ;)

J

[83Blzr62]

That is awesome, I wish my girlfriend would help me work on my truck ... too bad she hates it. The rear main seal should be easier since yours is four wheel drive, just drop the oil pan and take off the rear bearing cap, slide in the new one and slap it back together. You might also want to change other things and check for problems while you are down there. Maybe change your oil pump and check for cracks on the main webs.

[RoverIIa]

My girlfriend cleans bolts and engine parts. She even detailed the engine bay while I have the engine out. I thought this was a good thing... until...

We pulled into the movies, next to a 68 mustang, and she said... I've always loved those cars... maybe I should get one someday.

How do I explain that we can only afford one car hobby?? Hmmm...

Anyway... about your seal... It is a fairly simple change, assuming that nothing else is wrong. It is also a very dirty job. You should be able to do it in 3 hours or so if you are not crazy about cleaning/ re-painting/ detailing parts. This is much easier if your suspension is in good shape too. Anything sagging, and the pan will be a pain to drop.

I'm only about 2 hours from you, in Coalinga, if you're really freaked out about doing it yourself, we might be able to get in touch.

Nate

[Robyn]

I agree on the CDR maybe being an issue.
If you have to replace the seal I believe there is a two piece neoprene one available now that is almost like any other bow tie V8 rear main seal.
In the 84 its not all that bad to get the pan off either.
You may have to jack the truck up a tad so the pan will drop clear of the crank and not hit the front pumpkin.
The rear main has to come off and then fish out the old rope seal. The new ones can be rotated in. Be sure to keep the bearing inserts in their original spot. (dont mix the top and bottom if they should fall out)
Good luck and keep us posted.
Robyn

[doncannon]

Hello All,

Chevy4x4grl: I will agree with the posts already. If you have done that stuff you should be able to do this. I would like to add that you will need a torque wrench (borrow from a friend save $$) for the rear main (100 outer & 110 inner both in ft lbs), oil pump (65 lbs), and oil pan (84 inch lbs except for two rear ones 17 lbs ) Maybe someone else can chime in for the conversion if possible from inch to foot lbs. They are a little time consuming but definitely do able. Save the $$ for another project.
When I did mine I had to replace the oil pickup screen on my oil pump (missing--oops). How is your oil pressure? If low could be a good time to change the pump.

torque wrench (the $$ you save could pay for this if you dont already have)
oil and filter
oil pan gaskets
rear main (of course...i know i know but somehow at the parts store you always forget something and probably will be the most important...lol)



If memory serves here is how it went:

drain oil
unbolt oil pan
unbolt oil pump (if you do decide to replace old oil pump dont forget to pack the gears in vasoline and tighten cover screws to 12 ft lbs)
unbolt rear main
i think i used a screw driver to get the upper rear main started out
i used the old one to push it in or screw driver but be carefull not to damage new seal ( here you want to make sure the wider part faces rear of the truck and put oil on the front side)

reassemble is just the reverse, but ofcourse I pained my pan before reinstalling (i know seems senseless but I had another leak to watch)

If you have to replace the oil pump screen for what ever reason have someone tack weld it from coming out (first make sure the pressure spring is out)

Remember dont get in a rush!! Yes it could take you 3 hrs but if you dont pay attention like i did it will all have to come back apart.

hope this helps,
Don

[doncannon]

Hello all,

to convert from in to feet multiply by 0833333

good luck hope this helps

Don

[NH2112]

Hello all,

to convert from in to feet multiply by 0833333

good luck hope this helps

Don


Or divide by 12, as 12 lb-in equals 1 lb-ft :) You'll have a hard time finding a 3/8" drive torque wrench that's really accurate that low, most manufacturers will tell you not to trust anything in the lower 20% of the range.

[Robyn]

If you need or want to replace the oil pump get a GM one as they come with the screen. There is a tool for installing the screen but Unless you braze the old screen in they can suck air and cuase trouble.
I have done it both ways. The last GM diesel I did I used a new GM pump with the screen from the factory. Cost was within a couple $$ of a parts store pump without the screen and no hastle.
Good luck
Robyn

[RoverIIa]

This is a good point about the screen / pickup tube. I was a little concerned about mine when I did the rebuild, as it stuck out about 1/16" or so from where it looked like it should go where it joins the pump.

I am kicking myself right now because I didn't even think to braze it in.

Does anyone have thoughts on this? It would be a major pain, but I could drop the pan down and braze the joint before I re-install this engine.

-Nate

[Dmax son]

Do you send in a pic of your truck to DieselPower? The October 2006 issue, pg. 18? I use to live in Marina. Anyways, I did this on my 84 Blazer, with no lift. I didn't have to lift the blazer just go slow taking the pan off, and reintalling it. I went with the rubber two piece seal, kragen, autozone and napa will have to order them. Napa carries the rope seal if you want to use. Personal I like the rubber seal, just go slow installing it, they are a tight fit. The rubber ones have metal inside to keep there shape, and you can bend them out of shape if you start rushing it.

Bryan

[doncannon]

Hello all,

Nate: If it was up to me I think I would drop the pan only because I have had some oil problems in the past (rub hole through oil line, screen fell off pump, oil line came apart again) now I am replacing the engine. I know nobody likes to hear to undo what you already have done (i sure dont). This is if were up to me which it is not. Good luck in your decision!! I am sure others will chime in.

Just my two cents worth,
hope this helps,
Don

[Robyn]

Nate
Do yourself a great favor and drop the pan, unbolt that oil pump and throw it as far as you can. Then go pick it up and toss it further.
Use a new GM pump that comes with the screen pressed in out of the box.
I was going to reuse my old screen on a Napa pump and braze the thing in but then thought better of it. I have brazed in screens on Big Rat chevies back in the race days.
If you have no choice here is how we used to do it.
You need to pull the pump all apart and then bolt the cover on tight after the gears are out. Also remove the bypass and spring. There can be no parts left that heat will foul up.
Next you must have the thing degreased well. Warm it up slowly untill it reaches brazing temp all while being sure the screen stays aligned. Flow the brass in around the screen tube. No need to gob it on just a nice smooth fillet.
Now pack the thing in scredded asbestos or some good insulating material that will not burn or melt and let the sucker cool slowly.
After its cold wash it up and remove the cover and reassemble the gears and small parts back into the pump. Check that it turns smoothly. Oil the gears with engine oil and your off and screamin.
Hope this helps
Robyn

[armadillo1]

I did the rear main on my '83 earlier this summer. It is not horribly hard, but it is time consuming. The worst part, unless your truck has had a bunch of work underneath is all the accumulated dirt, barnacles, and crap that will fall in your face when you start taking things loose. I was able to remove quite a bit of oil and grease by going to the car wash and spraying their engine degreaser stuff underneath as far as possible.

One of the major things to make the job easier is to jack the FRAME. Jacking the axle does not help. By jacking the frame and removing the starter you get considerably more room to access oil pan hardware.

Once the oil pan is removed, you can pull the oil pump off. With oil pump out of the way, remove the aft bearing cap. You will immediately see why you have a leak, the rope seal is complete garbage. Buy the two piece seal to go back in, do not waste your time with another rope seal.

When you are ready to put the pan back on, you can either buy a gasket (pretty cheap), or use RTV like it came out of the factory with. I recommend getting ALL of the pil pan bolts started before tightening any of them. It is very easy to induce more leaks if you do not get a good seal. Mine went pretty well, but it was a long day. Hope this has been a help.

[doncannon]

hello all,

Nate: Robyn did an excellent job of that. Oh you may want to mark the pump and screen just incase it gets bumped while cleaning. Oh armadillo is right that is the worst with the crap falling in your face.

just my 2 cents,
Don

[chevy4x4grl]

sorry it has taken so long for an update. I'm really busy with school and work right now so my dad said he would help me pay to have it done. Now I begin my rant. I pic it up from the shop and the transmission is slipping. I check the fluid level and its full. so I look around and notice the TV cable hadn't even been hooked back up. That fixed that problem and all was good until I got it home. After sitting outside over night I found it had a huge pool of tranny fluid underneath. It looked to be me to be coming from the under the pan on the drivers side. I checked the filler tube and it was dry. I took it back to the shop and they replaced the pan gasket. Of course this didn't fix it. They addmited to having my tranny out during the job. My tranny was fine before. I am soooo pissed! I wish I had just done it myself. It would have actually saved me time. I've been running back and forth to that shop which is 30min away. Since I can tell it isnt coming from the tail shaft and it definitely isnt coming from around the bell housing they must have cracked the housing. If they don't fix it I will certainly be taking them to small claims court. Fortunatly for me my dad is a lawyer lol.

[chevy4x4grl]

Do you send in a pic of your truck to DieselPower? The October 2006 issue, pg. 18? I use to live in Marina. Anyways, I did this on my 84 Blazer, with no lift. I didn't have to lift the blazer just go slow taking the pan off, and reintalling it. I went with the rubber two piece seal, kragen, autozone and napa will have to order them. Napa carries the rope seal if you want to use. Personal I like the rubber seal, just go slow installing it, they are a tight fit. The rubber ones have metal inside to keep there shape, and you can bend them out of shape if you start rushing it.

Bryan

Damn is it in diesel power too? I sent a pic of it into off road adventures and it got published in their mail section. I'm going to have to go pic up that diesel power tonight. I'm so proud of my baby!

[doncannon]

hello all,

grl: that is good to hear about your pic in the mag oh and also ur dad being a lawyer.

thanks for the update,
Don

[jackrabbit]

Chevy4x4grl

I came in this late, so I figured that I would ask this question.

Are you sure that it is the rear main seal that is leaking?

The reason I ask I had the same problem and I orginally looked and thought it was the rear main, however, I decided to drop the trans and take off the flex plate and discovered my leak was coming out of the camshaft seal. This haapenned after I had my engine rebuilt. The rebuilder forgot to put any RTV on the seal and it started to leak ~ a year later.

So, look a bit higher and check on that before you go through and drop the pan.

on edit:oops, never mind, I see you already had it done and the shop messed up your trans.

[wthif]

Check the trans cooler lines, those can be hard to get started sometimes and if they didn't connect the TV cable back up I don't have much faith in their patients to reconnect the trans cooler lines.

Oh and improper pressure (caused by improper TV cable adjustment) in a 700r4 can be really hard on the transmission. They can fail in a matter of miles.

I do hope all if fixed quickly and smoothly with as little headache to you.

[chevy4x4grl]

Thanks for all the input. Yeah I drove probably half a donzen miles with the tv cable disconnected. I was going to try and make it home but I couldn't so I went back to my dads office to check things out. I didn't think that short of a distance could have done much damage but you never know. I did tow a car I just bought back from San Jose last night which is about 120miles round trip. I made sure the trans fluid level was up and everything went ok.

Oh and I was thinking it might be the cam plug that was leaking. I trusted the shop to figure out what it was for sure once the trans was removed but obviously they are incompitent. I do still see oil leaking out also so I might have to remove the trans and flex cover myself and check out the cam plug.

[Dmax son]

What shop did you take it to???

Bryan