6&7-Bolt 4g63 Front Case & Oil Pump Rebuild

Here we disassemble, clean, inspect and rebuild both popular 4g63 front cases. This is not difficult, you just need to know what to look for.
Something else that happens in this video is the analysis of one of the factors that caused my 7-bolt engine to fail. It wasn't the only cause, and we'll talk about that later, but left to its own devices and without the other contributing factors, it would have been the only cause.
Edit: Ryan Eaton suggested I put the proper lubricants to use in this description. Do not use multi-purpose grease here. Use Lubriplate or Vaseline. Using multi-purpose grease makes the valve train extremely noisy for the full first heat cycle. Lubriplate and vaseline have far lower melting points and won't cause the lifters to clog until the grease melts.

[@autotalon]

I'll let you know at the shootout this year, but in all practicality you helped me rebuild my engine this year, always appreciate the helpful tips.

[@DromeDroid]

I have no use for the information in this video, but I still watched the whole thing, I was engaged the whole time. Very informative and clear, great video!

[@tehkeet]

Awesome awesome awesome. I never get tired watching these jafro. Beautiful work.

[@nicholasgeere5125]

This was a good video thank you for the information. I'm going to be investigating an oil pressure issue in my 97 deville and I want to get as much hands off exp I could before I tackle it. Very detailed and explained thoroughly.

[@bitpixpr]

yes! longer videos for the win! so informative and fun as always love your work Jafro :)

[@JPilot2]

Dear Jafro, I'm totally diggin' your work, (6&7-Bolt 4g63 Front Case & Oil Pump video) and plus not to mention, these videos are very inspiring!! Thank you! Cheers! :-)

[@tonkatoytruck]

At least you know what caused or at least contributed to your engine failure. Nothing worse than never really discovering a true cause. Thanks for taking time to share. It is appreciated.

[@damham5689]

thank you for a well articulated instructional video. Too many of videos on You Tube ramble on with personal or unrelated, unnecessary comments.

[@revolutionzerox]

kitty! these videos keep me inspired to work on my car when I start feeling lazy.

[@dreams2memories]

Good thing I'm building my 6 bolt at a steady pace. So I can continue getting excellent tips from Mr. Jafro. ^_^

[@tooltrt87]

Thanks again jaffro!! As i have said before and as others I'm sure have. Im doing an engine build and it progresses when you post another video haha. People would charge by the minute to distribute this information. I think its safe to assume that sharing this information is something you enjoy to do, and your profit is only pleasing the curious minds of other enthusiasts. Thanks again!!!

[@uRaceIfilm]

Could not stop watching, just finished the whole thing.

[@ciprianbenec4091]

This is the place where quality control means something! 👏

[@cliffk4965]

When I rebuilt my motor, I did not check out all that you mentioned and is why I have a leaky oilpump...will do it again in time and do everything right and get it fixed once and for all. If only you had put this up this time last year.... ;)

[@split150]

Great video! Packed full of awesome info. Thanks.

[@Twinturbo120]

This is great, will come in handy when I do my build.

[@TheYAMAMAHA]

I wish there were Bimmer ppl like you Jafro, Miss having my dsm and watching your vids for the benefits.

[@micko1404]

awesome video mate, I'm in the process of doing this rebuild when I found a big oil leak on my Mitsubishi express van with a 4G63

[@Jafromobile]

I'm happy to be here for you. Remember that oil flows downhill. What looks like is leaking can be deceiving sometimes. It's a fairly invasive job, so that's just advice suggesting to be thorough. Anyone would hate to go in there twice. Another good video is my 4g63 oil system video. It explains the entire oil system path, and I've made several flowcharts (literally) that are hosted on my Patreon page. It's everywhere oil goes, and in what order. Best of luck with your 4g63!

[@BlakDawnman]

Excellent video!

[@TheDarkHero]

LOL Like a Seal boss hahaah! Great videos by the way. I am getting ready to tear apart a 6g72, good information that definitely applies on my end.

[@izumimarcelo]

Its help me to lot! Now I know that my oil pump is junk! Special tnks from Brazil!

[@deadman12078]

That was fun. Thank you for posting

[@gmbsk8]

The shop i use actually cut my existing balance shaft down and sealed the backside with a set screw and made a stub shaft for me, worked out well

[@ODMIJ084]

Wow Jafro great video. Nice to see someone taking an interested in imports, even better to see an intelligient and articulate person talking about it, usually it's only wanna be rappers and general slim balls. All the tv programs usually only talk about domestics like fords chevy and mopar engines, not that there;s anything wrong with them it's just that change is nice. I can hardly beleive you've picked up all your knowledge from yourself and forums. I can't wait to see the engine done. More pl

[@9095TSI]

great stuff as always, thanks

[@DJDevon3]

LIKE A SEAL BOSS. Chalk up another awesome video.

[@goldgargoyles6265]

your knowledge is massive, thank you!12345

[@markgeletzke6328]

I don't own a Hyundai or Mitsubishi but the lessons I've learned from you are invaluable.. I have a friend that says I over think & over engineer everything I do.. I told him I like to do it right the 1st time to the best of my ability.. A small example, 15 yrs ago I got into Subaru's ej25 for a sand car engine.. The phase 1 block was still being used which only has a 48mm bearing journal on the crank, it was an na motor that got turboed, head studs, je pistons and pauter x beam 4340 rods.. People soon started going over to the phase 2 block as it came with 52mm journals.. When it came time to rebuild I bought an Outback Motorsports at the time as they are of now Outfront Motorsports ej25 closed deck block but still phase 1 as the phase 2 weren't being used at the time. I pulled the pauter rods out as they were 587 gr ea, and replaced them with a one off set of Greg Cunningham titanium rods, They're shot peened, plasma moly coated, they have an interesting theory as the grain on the beams is verticle and the caps are horizontal to keep the big end round and they weigh only 332gr ea..That's 2.2lbs less than the Pauters.. I saw it as less pounding on a smaller crank bearing, plus added quicker spool time.. A lot more good parts went into that build like a one off light weight aluminum flywheel that fit both Subaru & Mendeola gearbox with removable & replaceable ring gear & disc contact face..Factory Subaru flywheel were 30#'s this one is 9.20#'s. Again better spool.. This is a labor of love that has been on hold for several yrs but is gaining momentum again.. Saving for billet crank, but it again will be one off as no one offers one for a 79mm phase 1 crank, they offer phase 2 all day long..And it needs to be U.S made, no Chinese cranks.. This needs to get done in my lifetime as the rods were $1900/4 - 15yrs ago & today those same rods sell for $4000/4.. I can only afford to keep moving forward and not start over, plus I have a vision to see to the end.. Thank you for your wisdom, as I too must turn over every rock to look underneath to see if it can be improved upon..

[@madinatore]

Great Vid! No Problems with audio. Feel educated in a good way now.

[@AdamGen88]

awsome video man, going to do my oil pump cleaning and put new seals in tommorow, gonna keep my balance shafts for now though. looking to get another 7 bolt or 6 bolt 4g63 so I have an engine I can work on and do all the things I want to it while I can still drive my dsm.

[@Hondatech26]

Great video! I now understand why your cats name is caboose.

[@gmbsk8]

Cant wait to see the oil cooler video i have recently experienced an engine failure due to the orange oil cooler o ring i may start replacing this part every other oil change after what happened to me

[@drronald]

If you use the Mitsu plugs for the balance shaft hole DO NOT use RTV or any other sealant. The previous owner of my car used one of those plugs and and it came out due to RTV. Unfortunately, I did not notice this during the 2 hour drive home. I lost nearly all my oil, which resulted in a spun rod bearing. From then on, I have just used a little bit of JB weld and an aluminum freeze plug. I have never had a problem since.

[@4G63addict]

Jafro, I've always torqued the oil pump gear sprocket once the case is not yet installed by holding the stub shaft with a wrench from the backside. I totally get you want tension from the belt which in turn lets you torque it, but I'd be worried someone would forget to torque this with the excitement of building their first 4G63, and forget to torque it. Just a thought man. Once again..awesome video. Go skins!

[@snapc33]

Great video thanks man.

[@RIDEREU]

Great video! Thanks.

[@TechT1999]

Very informative video, thanks. I am going to start working on my 99 GST, I need to do the timing/balance belt for sure. I have a leak somewhere by the oil filter housing and I cannot find it for the life of me. The oil pressure sensor, wire, and L shaped cover are covered in oil. I have even replaced the sensor wire once already. My car has around 190k miles so I know I have some work cut out a head of me. 8/

[@RJ67.]

Bro, your cat looks just like my Ollie, I found Ollie as a stray cat dodging cars on Cranberry Highway in my town I stopped 4 lanes of traffic to capture him with .y energancy can of tuna. He was a kitten then, all of 2 months or so old. 6 years later he rules the house. When PoodPood let's him that is

[@Jafromobile]

I like this. "...my emergency can of tuna." I'm afraid I wouldn't be able to prevent mine from dangling off a string at a pier with holes poked through it to make a chum slick when we're fishing, just because of the company I keep... I'd have to buy emergency tuna by the case, but *you* do it for the cats. I applaud you, oh gracious one!

[@The_Mechanic_Dad]

Jafro, what's your thought on the AMS and GSC "race" balance shaft kits where the oil pump shaft is machined down and retained instead of completely replacing it with the usual stub shaft.

[@oktogo8501]

i feel like i should pay for this info haha good stuff

[@mrg7243]

This would be on a high boost car. I'll do what you suggested and rebuild the spares in case I have any issues. Gotta send them to the machinist to get that damn screw out. Keep on with the info!!!

[@TheSomedrewguy1]

Thanks Jafro! Love your videos man, I am building a garage to do this. Why do you use carb cleaner instead of getting a filtered parts washing bay?

[@moesix]

Jafro, I love you. Also your mom is awesome.

[@jomjast8861]

Hi jafro. i've been watching all your videos and they are very useful to me since im in the process of rebuilding my 2g gst engine. have a question though, my oil pump has a little bit of circular scratch on it (front case side) maybe a dirt fragment from oil that was not filtered, should i buy a new set of front case or just re-use it? i followed the manual and your video regarding measuring the drive gear and driven gear and it seems all are still in spec. Thanks!

[@speedfreak247]

The reason to replace the o ring behind the castle nut is an oz of prevention style. I have seen at least 2 of those o rings cracked due to hardening. I made a tool out of a socket on the mill and it works nicely for breaking the castle nut loose. When I do a rebuild I throw a new o ring in no matter what the failure was if the o ring has over 60k miles.

[@SockPuppetKr3w]

Thank you so much!

[@gst69man]

great vid thanks

[@ihatejavier]

So I’m replacing an oil pump I have the case. I’m not sure what else I need do I need new gears or what else do I need

[@EmakulateRB]

Great video man...... 3

[@kevinw2491]

awesome video! gotta love subliminal images.

[@Stang97]

Hoping you see this! I have a random front cover Leak on customer car I can't find. Can I spin the oil pump gear and get enough pressure to have it leak while I have everything torn down?

[@lDDD587]

DUDE YES! i needed advice on how to get that tapered screw out of the housing cause i broke my timing mark for the oil pump on the case. i love having a spare 4g64 i can steal parts from

[@teetersalad]

Glad to see Im not the only one thats picky with oil pumps. I spend hours cleaning mine only to pull the gear cover off and find where someone else had used a gasket scraper and created gouges. Any way to fix that up or is it time for a new case and pump?

[@MidLifeCriTSIs]

Jafro, been watching all your videos again as i build a 2.3. I have a stock oil pump from the 7 bolt with 70k miles on it that spun a bearing, and a brand new ACL oil pump i bought. I have my short block assembled and back home finally from the machine shop. Im looking at the differences in the cases/pumps after watching this video and im worried about this new ACL one. It seems to have a few small differences in the casting and also the gear housing has very poor galleys. Seeming how my low mile Mitsu one ate some bearing guts i assumed it was bad, but after checking it like you mention it seems in spec. Any input on the ACL pump quality?

[@yenyen33089]

good video bro..dsm ftw

[@TooslowTA]

Is it necessary to deburr or detail your oil pump gears? If so what is the best way to do it? Some people say if you dont you will wear out your case.

[@juanyboo12345]

thanks master!!

[@190Bmxer190]

The bolt that holds the alternator gong through the front case I think is leaking oil on my dsm. Wondering where the video of yours is that talks about this

[@davidnguyen4143]

Can you use the 6 bolt oil pump and gear on the 7 bolt housing?

[@Cam-qt3xu]

Hi Jafromobile, firstly thanks for the lessons, however i'm learning that double checking things is good practice. I was looking at the torque specks for the 4G63T engine from evo1-6 and they are mostly the same. In regards to the oil pump sprocket, you say 29foot but the service manual says 39 or 54nm. I don't know who's right ?

[@DSMattitude]

Jafro, do you by chance know what how much a 4g63 oil pump flows? I have been looking and searching and have not come up with anything.

[@dropdraw]

another question. is the whine from straight cut gears really noticeable at idle and also is it ok to use an oem stub shaft with helical gears?

[@CJ5EVOLUTION]

What do you think about the GCS oil pump balance shaft elimination kit

[@romanjanke5923]

Hello Jafro. Very good video! I have two questions: Does this balance shaft elimination kit match to 4G64 engine? Without balance shaft from oil pump side causes that driven gear hase only one bearing left (like console) . Is it critical for oil pump? Thanks a lot

[@Boosted98gsx]

LIKE A SEAL BOSS

[@awdroket]

Hi Jafro. I thought straight cut gears were only in the 1990 cars. Can anyone else confirm or deny this? From 13:13 in the video.

[@Jafromobile]

They were used in DSM manufacturing from March of 1989 until the end of April 1991. May 1991- end of production was the helical set. Same helical gear used for both the 1g and the 2g oil pump assemblies. If one part fits the other, then so do the gears. Same hole. You can put straight cut gears in anything if you can get them.

[@izumimarcelo]

Jafro, tks a lot. Can you help me with a question? What can you tell me about removing/blocking the oil squirters from the 7 bolt block? I really appreciate your opinion about that.

[@DSMattitude]

Jafro, do you by chance know the oil flow of a 4g63 oil pump? ad in GPM. any input would be appreciated

[@mods245]

People ask me how I know these things and the first thing I think of is JAFRO!!! Thanks for educating the dsm community

[@jdmfreak92]

Jafro I need your input man. I have an evo 9 and I'm getting low oil pressure while cruising. But normal oil pressure on idle and start up. Do you think it could be a worn oil pump? I was thinking this because it's belt driven and it may not be able to move the amount of volume needed at higher rpm while cruising. Thanks man I really appreciate it.

[@TrueBlueEG8]

The most descriptive and detailed automotive videos on the tube, and the principals apply to any car or engine,be thorough, keep shit clean and in order, and check everything twice or twenty times if need be. Jafro, do you think the whole engine failure stemmed from that little stub shaft without the oil groove?

[@BRKmaddox]

Great video jafro, as always! Whens the next video coming?

[@LayZeeDawg]

OK , commenting a thousand years later... I replaced the front cover and pump with a new Mitsu pump in a bone stock 4g64. Couldn't pack the pump but I did use my grease gun to inject grease into the mount for the pick up, now I cant build oil pressure. Is grease too thick, I would think it wouldn't make too much difference considering it will spin and create negative pressure. I'm stumped! I really hate to think I need to pull this apart again (although I am becoming an expert) Is there a way too build pressure without pulling this apart? Like injecting into the pressure relief port or where the pressure sensor is installed?

[@zx8401ztv]

Smashing tutorial and comical comments :-) Love the cat :-), very cute. Ha ha payback time, you joker lol :-) Really enjoy your videos mate, that pump will work spot on :-)

[@mrg7243]

You talk about rebuilding the oil pump in this video. I bought a new oil pump from rockauto for my 8g galant 4g64/3 build. I have 2 oil pumps laying around still do you recommend the rebuild or just use the rockauto one?

[@LucasAgainstTheWorld]

Hey Jafro!Audio is ok,little bit quality loss but it's ok.Is glass beating safe for this kind of components?

[@TooslowTA]

Jafro! Im seeing people deburring there oil pump gears and polishing them to a mirror finish. Is this necessary? I tried to smooth mine out doing it by hand with some sand paper. I was afraid of removing too much material and messing up the tolerances so i didnt go crazy. The gears feel much smoother now so hopefully this helps with wear on the case.

[@mikep6982]

help me out buddy my engine leaks oil only when boosting its a 7 bolt 4g63. leaks by the right side of the engine. could this be the oil pump failure?

[@Dragracer187]

Nice video. Why glasbead it, leaves so much junk behind, I use icebeads, leaves nothing behind. what dremel tool do you use?

[@NOLA_dad]

I scrolled thru all the comments in a search for any questions about deburring the gears. I found three but none with an answer from you, Jafro. Could you help us out with your opinion on the need to deburr the gears? Thank you for all your hard work by the way.

[@COINEXVEN]

Hi, press oil light is on when is hot and ralenti . What i can do? thks

[@SCORPION7712]

Should I buy new gears for my new built engine? I bought a new oem case but not the gears

[@nojokesniper]

hey jafro i just purchased a 6 bolt bottom end to replace my 1g 7bolt that ate a bearing. the motor does not have any timing components attached to it and is missing some bolts from the front case . what is the best way to figure out what im missing and source them and also where they all go? ive never had a 4g63 torn down this far and am afraid to put a bolt in the wrong place or forget something. also is there somewhere i can lookup what pieces i will need that i cant swap over from a 7bolt

[@dropdraw]

when buying a new front case is it extremely necessary to debur both gears?

[@booztdks]

good video ,question though ....my front case was bead blasted like the one in your video . The journals which the stubby shaft and oil pump shaft ride on was blasted also . The finish on these journals is no longer a shiny machined surface .was yours the same way ?(from the video it looks like journals were blasted also . Do you think this would pose a problem ?

[@iconone5]

Thumbs up!!

[@tonkatoytruck]

Baking soda seems to be a safer media to blast with. A little vinegar, and not a trace left of its existence.

[@MikeB1972]

8:50 "Alignment dimples punched into their buts." OH MAN! That was funnier than it should of been...

[@R6iness]

jaf whats you accent? i know its "american", but from where? love the periodic spurts of comical relief and of course.. awesome informative video! you're a master !!!

[@TymmVonD]

Thanks.

[@therockalaska]

like a seal boss!

[@goodhart253]

Is there more than one 6 bolt front case?

[@lanselotpower]

Hi Jafro, love the channel , i have one question that bothers me for the oil pumps and you may solve it, there is a 4g63 6 bolt oil pump with helical gears too, it`s from 4/91 to 4/92, before 4/91 they are with straight cut gears.OEM part number is different for the case itself for pre 91 and after 91.... but i sow everebody at forums and internet to swap gears from helical to straihgt cut ....and saying no issues.....? did you been aware of that issue ? :) thanks if you have answer for me. sorry for my bad english , i am from Bulgaria (Europe)

[@skatershawn410]

Question... Those curved groves cut out in the pump gear (18:48) housing that contact both sides of the large gear are for what exactly? I have a ACL pump i was going to use, as my original 1990 finally died, and noticed that the cut outs are significantly larger on the OEM pump than the ACL pump. I was thinking of take a Dremel to it and widening them a bit to match. Would you recommend this?? I know Dremeling the oil pump assembly is a VERY sketchy thing to do but I completely understand and will take ALL precautions necessary to avoid mistakes.

[@Jafromobile]

They capture the oil runoff from the shaft of the gear, from its lubrication. The channels create a low-resistance area where pressurized oil can be re-routed to the low pressure side of the pump gears (note the intersecting gallery cut through it on the rear part of the housing). It's intended to take lateral pressure off of the sides of the gear faces. I'm not sure that it's a very big deal if they're shallow. I suppose that all depends on how tight the side clearances are, and how tight your journal clearances are on the stub shaft. If it's loose and it leaks a ton of oil, then yes it would help. If the clearances on the stub shaft and driven gear are correct, then there should be no side-loading at high RPMs. The shaft runoff has to go somewhere, and it's looking for a low-pressure drain to relieve itself. That's what the grooves are for.

[@kyogie12]

The 7 bolt oil pump looks like a Melling, not OEM. Care to chime in?

[@stanislavsmoked8438]

Hello, please tell me why you are working with oil channels?

[@nextchapter2343]

sensei!! 🙏

[@Jafromobile]

Hajime!

[@amyasseektruth8246]

@ 4:07 get ready to hit pause - Seal boss!!! LOL

[@fontekk]

can I replace my Mitsubishi 2G 4G63 N/T Front Case & Oil Pump with a one from Mitsubishi forklift 2.0 4G63 ?

[@dalejustice9207]

Hey buddy, im putting my motor together n decided to do a balance shaft delete n notixed some scaring on the oil pump back plate where the main gear touches also where the balance shaft goes thru on the back plate where the shaft goes thru has a lil scaring just in side the hole goin in from outside of the plate. Should i just order a new oil pump? Thank's.

[@Jafromobile]

+Dale justice You need the whole front case. The oil pump and front case are 1 unit. The parts are machined as a matched set. I know that it sounds crazy, but when oil clearance specs are within a range of less than .003", a slight variation from one part to the next can be lethal to the oil system. Ask yourself which part or problem with the gear alignments led to that kind of wear? You're going to cuss when you see how much the front case costs. They've become ridiculously expensive since the '90's.