CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Can I replace the rear oil seal with the engine still in the truck?

mofugly13

1 ton bucket of rust
 Premium
Joined
Oct 6, 2002
Posts
2,867
Reaction score
26
Location
San Francisco
I'm having noise prob's with my engine. You can read about it here and here I am going to replace the main rod bearings, 'cause I think my thrust bearing is shot, causing the crank to come in contact with the block at highway speeds. (thanks for the heads-up Smitty.) I crudely measured crankshaft end-play with dial calipers and end-play was .012" When I replace the thrust bearing, will I be able to replace the two-piece rear oil seal without pulling the engine? I probably shouldn't reuse the old one, right? I think I saw a tool at a shop that would pull the old upper half and then fish the new upper half into the block. It was a thin cable that had some sort of clip at the end that clipped on to the seal. You push the one end of the cable around the upper seal recess and when It pops out the other side you pull the cable and it pulls the new seal in behind it. Sound about right? I need to put some band aids on this engine until I can afford a GM crate 350.
Once again, thank to those who try to help.
/forums/images/graemlins/usaflag.gif
 
Yes You can! You'll be in there anyhow, to replace the bearing's, the seal is right there. /forums/images/graemlins/grin.gif
 
You will have to drop the crank down to replace the mains. This will make the top half of the seal easly accessable so you wont need a special tool.
Also if your thrust bearing is showing that much wear there may be other problems that caused it to wear out that may need to be fixed before you put in a new engine. A bad trans, improperly installed torque convertor, Inproper engine alignment/bad mounts all can cause wear on the thrust bearing.
 
I hate to add to the "while you have the hood up, you may as well....", but .....go give the motor mounts a real good look. Chances are, they need replacing. It isn't much $$$ and you will be glad you did it.

/forums/images/graemlins/usaflag.gif /forums/images/graemlins/k5.gif
 
Yeah, you can replace the seal with the engine still in the truck. I never used a special tool, just used a screwdriver to push the old seal out, put oil on the new seal and slide it in with your fingers. Its pretty easy.
-Harrison
 
Thanks fo all the help fellas. I'm not dropping the tranny, so won't be able to drop the crank. All I am going to do is drop the oil pan. When I rebuilt my Toyota's 4-banger I was able to replace everything but the rear oil seal with the tranny and motor still in the truck. Looks like changing the mains on my Chevy is the same. I made a roll-out pin to push out the top half of the bearings. I was just wondering if The rear seal could/should be replaced while I am in there. The wasted bearing is due, I'm guessing, to the PO having installed a dipstick that was about 6" longer than the stock dipstick. The first time I changed the oil, I got about a quart out of the pan, so I think the bearing went bad from oil starvation. The engine runs smooth and strong, it just maked a horrid "clacking" sound when it warms up.
 
Your lucky that your truck is old enough to be able to replace the seal without taking the engine out. The only way to get mine out in my 87, is to take the engine or tranny out. Luckily for me, I just picked up my freshley re-built engine today (so obviously its already out of the truck), and it took all of about 25 seconds to put that seal in when it was on the engine stand. /forums/images/graemlins/thumb.gif Now, as long as nothing else I put on today leaks.... /forums/images/graemlins/thinking.gif
-Harrison
 

Latest Posts

Top Bottom