Detroit Diesel 671TI Rebuild

Jerry · Post by **Jerry** » Sun Mar 20, 2011 8:55 pm

As you can see the rear main was nice and dry.
I went back and forth with this for a while but there was no way I was going to go through all this work and not put new seals in.

To remove the seal we drilled holes and screwed in a few screws with washers on them. Then put a slide hammer on the washer and popped the seal out.

The new seal was then installed.

As you can see in that pic with the new seal, we took two bolts that fit in the crank and cut the head off and tapered the ends. We used those to guide the flywheel back into place. It worked like a charm.

alexander38 · Post by **alexander38** » Sun Mar 20, 2011 9:20 pm

Been waiting on an up date.

rossjo · Post by **rossjo** » Sun Mar 20, 2011 9:49 pm

Good to see progress again - not long now!

Jerry · Post by **Jerry** » Mon Mar 21, 2011 9:30 am

It does feel good to be making progress again.
My parents are both doing better but I am still fighting with my back. I have been to 3 doctors now and been going to PT but have not made any progress. I go this week finally for an MRI and X-rays.

Here is my friend Dave handing me up a main cap as we were replacing the main bearings.

A new set of bearings next to an old set.

Here is a shot of the rear main cap with thrust bearings.

Jerry · Post by **Jerry** » Mon Mar 21, 2011 9:41 am

The main went in very nicely with no issues at all. The were STD size that we replaced but I still checked the clearence with Plastigauge just to make sure.

Here is a pic of the old pistons and rods with sleeves.

Here is the bad piston with the stuck rings.

Jerry · Post by **Jerry** » Mon Mar 28, 2011 9:25 am

We finally got the front seal replaced. I thought for sure it was going to be much easier than the rear so we did the rear first..... Boy was I wrong.
We had to make a puller to get the pullys off. The round disc in the picture was cut out of the center of a brake rotor. It worked out pretty well.

I could not find bolts long enough for the next puller that we used so we found some short bolts that fit, then welded some all thread to them to make them longer.

Here is the final make shift puller that we used to get the vibration damper off.

I cursed Detroit for quite some time with the set up that they use on this thing. There is a small tapered cone that you are supposed to pull out BEFORE you start to use the puller. The manual does NOT tell you that until the page AFTER it tells you to use the puller!

Jerry · Post by **Jerry** » Mon Mar 28, 2011 9:31 am

The seal itself did not want to move at all so we had a heck of a time getting it out of there.
Finally after a very long time of trying.....

I never would have thought a seal could be in there as solid as this one was.

Jerry · Post by **Jerry** » Mon Mar 28, 2011 9:35 am

Here is a pic of the seal removed and the inner tapered cone still on.

The new seal went right in without an issue and all went back together as it should have.
We did end up relocating the seal just a hair as there was the slightest of a ridge worn into the inner cone.

BobCT · Post by **BobCT** » Mon Mar 28, 2011 7:54 pm

I know one school of thought is leave well enough alone when it comes to crank and rear seals. Let me tell you how that worked out for me a couple of weeks ago....

I did the timing belt job on my wife's Audi and debated whether or not to change the crank seal while I was in there. It was bone dry so I left it alone.

Three weeks later it was leaking like I removed it! Guess who got to do the whole job over again? And, I had a new seal on the bench ready to go.

Bob

rossjo · Post by **rossjo** » Wed Mar 30, 2011 11:19 pm

Larry -

Great to see the progress - this is one hell of a detailed Detroit rebuild! You should put together a book and sell it!

Don't have a Detroit (yet - looking at a boat with twin 12 cyls) .... but probably will someday.

Jerry · Post by **Jerry** » Thu Mar 31, 2011 8:07 am

BobCT,
I have had the same happen to me in the past as well. Fool me once.
Although. I guess I always run the chance of a new seal leaking also.... I hope that does not happen as I have tried to be very cautious about what I am doing.

rossjo,
I am up to about 41 pages of hand written notes and just over 900 pictures thus far. Hopefully it will be useful for someone else someday. Hopefully, someone other than me!

rossjo · Post by **rossjo** » Thu Mar 31, 2011 1:08 pm

Jerry - that's great information. Invaluable to anyone with a DD. I'd love to have a copy of this info n case I retire on board the boat I've been looking at (72' w/ twin DD 12 cyls).

Allen Sr · Post by **Allen Sr** » Thu Mar 31, 2011 7:51 pm

rossjo wrote:Jerry - that's great information. Invaluable to anyone with a DD. I'd love to have a copy of this info n case I retire on board the boat I've been looking at (72' w/ twin DD 12 cyls).

Planning on doing 2 for 1 are you? V-12's? Hope you have a real good retirement plan!

rossjo · Post by **rossjo** » Fri Apr 01, 2011 9:10 am

2 for 1?

Jerry · Post by **Jerry** » Sun Apr 03, 2011 10:47 am

I am happy to report that we have made some Great progress in the past week or so.
As of right now, all the new sleeves, pistons, rings and bearings are installed and we are ready to start putting this thing back together!

Here is a pic of the 2 piece piston taken off of a rod.

Cleaning up the rods, caps and bolts. The cage works great for putting small hardware in.

Dave loading the slipper bearings in the pistons.

Our first new piston assy back together.