7.3 engine removal/repair help...

locomotivemachinest · Nov 13, 2014

i have a 1999 7.3 with 378k on her. it has developed a slight miss wich im sure is an injector problem... upon more research ive decided to pull the engine to replace the pan rear main seal both manifolds up pipes and a new set of 180/100 injectors and reburn my ts chip for single shots. also i plan on replacing the stock converter with a racer x and valve body modded by racer x. also i ordered a riffraff fuel crossover system to help with deadheaded fuel. it burns no oil has minimal blowby. anyone have any suggestions/commnets for me before i pull this big turd?

neverkickn · Nov 13, 2014

Take your time and keep track of everything. Paper bags and a sharpe will help you label bolts and small parts.

If the rear main isn't leaking, leave it alone.

m j · Nov 13, 2014

rear main seals are a pretty rare fail point

97stoker350 · Nov 13, 2014

taking on a chore let me tell you. I've pulled my obs engine 3 times by myself and its not that much fun. Goodluck!

co04cobra · Nov 14, 2014

It makes it easier coming out the front if you pull the turbo. And I'll agree that if you aren't 110% positive the rear main is leaking, don't touch it.

ghohouston · Nov 14, 2014

Pulling a 7.3 on a super duty isn't bad. It's really pretty straight forward, remove all wiring from motor, torque converter bolts bellhousing bolts, put a ratchet strap across the frame under the trans, and a floor Jack. Remove motor mounts, turbo, unhook power steering lines, etc... If you're using an engine hoist you will need to remove all coolers from the front, unbolt core support, and remove the grill. That's the majority of the big things to be done, and you should be able to tackle it in a few hours, even alone.

locomotivemachinest · Nov 14, 2014

ok all good thoughts... ill look into the rear main... also i plan on pulling the heads to check for bad valves... has minimal blowby and no oil consumption. i dont know if its worth doing or not. the miss has me worried also has a slight thump noise on slight steady throttle has me worried. but i believe its manifold or up pipe related. any thoughts on that? a rebuild would cost more than trucks worth. has 380k has no thump with throttle or idle. might be over thinkin it. is it worth pulling the heads and renewing bolts and gaskets or bet let it be? i plan on 180 100s after i place it back in the truck. also hows the 4r hold up with a converter and valve body... thanks yall. trying to figure out what i gotta order to get it done in 1 shot. all 7.3 ive had but one sounded like it had a knock to me and ive had 8 of them

co04cobra · Nov 14, 2014

I would not pull the heads unless you have a for sure reason to. Headstud it one at a time while you have it out, and you won't have to worry about HGs.

If you are worried about the health of the engine I would do a compression test before you pull it. Maybe it's no worth putting back in.

CSIPSD · Nov 14, 2014

Almost 400k... I would not mess with it. Find a low mile take out, and just swap over.

JD3020 · Nov 15, 2014

CSIPSD said:
Almost 400k... I would not mess with it. Find a low mile take out, and just swap over.

I agree, with those miles that engine has some wear and probably not worth putting any money into. Low mile engines can be had cheap if you know where to look.

DEEZUZ · Nov 15, 2014

Not worth putting a dime into. Either buy a rebuild kit from Riffraff or just find a lower milege unit.

You guys with rear mains, everytime I pull an engine, it gets a new rear main... What is the issue you guys are having?

ghohouston · Nov 15, 2014

It's just the fact they almost never leak on a 7.3.

golfer · Nov 18, 2014

ghohouston said:
It's just the fact they almost never leak on a 7.3.

true..

add in the fact that every TomDick&HarryDieselPerformance shop that see's a drop of oil on the block/trans case...pulls the trans...replaces rear main which not only didn't fix the leak...generally creates a legitimate rear main leak (in addition to the original oil/fuel leak in the valley of the engine).

think we've seen a total of 4-5 true rear main leaks on the 7.3L (in 10+ years)..and we see an average of 100 trucks/month through our shop.

CSIPSD · Nov 18, 2014

CTC DEEZUL said:
Not worth putting a dime into. Either buy a rebuild kit from Riffraff or just find a lower milege unit.

You guys with rear mains, everytime I pull an engine, it gets a new rear main... What is the issue you guys are having?

I've never swapped a rear main... Simply because they never leak. Why would you piss away time and money doing rear mains?

DEEZUZ · Nov 18, 2014

Why would it create a leak? I've never had that happen. And the 15 or so minutes it takes to change it is better than wrapping it all up, and giving the customer a leak free truck, and than 6 months later they bring it back saying it's leaking again, now you have a PISSED off customer that says you should have done it while it was apart.....

blcsmok · Nov 18, 2014

I'd take a good look at the rear main and figure out if it's leaking , a lot of times its a leak up stairs running out the holes in the back of the block . The rest you can do with the motor in and save you a lot of time! Along with the good chance of the new rear main leaking . What's done to your truck so far ? What hp are you shooting for ? I just built a high mileage truck 320k and love it !!!

co04cobra · Nov 19, 2014

As if Dave saying it isn't enough. Why fix something that doesn't break? You create a lot more chance of leaking by screwing with it. Not enough silicone on it, not fully cured before refilling, people that don't know use the wrong silicone...and so on...

Lots of reasons to not do it, but few reasons TO do it.

DEEZUZ · Nov 19, 2014

Oh so you guys are talking about if hacks change it, but OK Yea that makes sense now.

CSIPSD · Nov 19, 2014

I'm talking about why change it at all... I've driven the 7.3 for almost 2 million miles now... in that time, with 6-8 trucks I've owned I have never had a rear main leak. I've worked around these trucks for 15+ years, and I've seen ONE real rear main leak...

DEEZUZ · Nov 19, 2014

And that's great, but I'd rather sell them a rear main while it's apart whether leaking or not. Why? To avoid a guy coming back PISSED as hell cause he just spent several thousands to fix all his oil leaks and now his rear main is pissing. Is rather head that conflict off and change the rear main and NEVER have to worry about it.