Removing the rear spark plugs

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hanger
Posts: 93
Joined: Sun Dec 16, 2018 8:09 am

Removing the rear spark plugs

Post by hanger »

Hello. I’m new here and hoping for some advice. I just bought my first Jeep, a 87 grand wagoneer that spent its life in Oregon and Washington until October of 2018. It started missing out and so far replaced the distributor cap, rotor and new plug wires. Now I’m working on the plugs and having a hell of a time with the back plugs. I’ve got a deep well socket but just don’t have the room to get at it with the ratchet. Is there a special socket or wrench for these? Thanks in advance.
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Cecil14
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Re: Removing the rear spark plugs

Post by Cecil14 »

I haven't worked on a V8 in a long time, but I want to say a lot of people go up through the wheel wells for the rear plugs. Space to work is one of the reasons I kept my I6.


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank

will e
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Re: Removing the rear spark plugs

Post by will e »

Like he said. Normally it's the passenger one that is the hardest. I think the driver side I can usually get to from the top. Use a spark plug socket and a wrench on the socket if you have to.

Welcome to the board!
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

candymancan
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Re: Removing the rear spark plugs

Post by candymancan »

i never had a hard time.... you should use a socket for spark plugs they have rubber rings to grab and pull the plug out once you unscrew them.

I just used that and a swivel adapter and extensions and thats it wasnt really hard for me.

Are you using a swivel attachment so you can angle it and keep your socket wrench in a spot you have room in
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)

Cheap Hobby
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Location: Central Valley

Re: Removing the rear spark plugs

Post by Cheap Hobby »

On plugs that have been in for awhile, I've had luck going up from underneath with a long extension and wobble joint on the plug socket. You may have to play with the angle on the extension. Thin socket may also help.
79 Cherokee WT QT Golden Eagle white with gold windows "Pigger" only blows hubs the night before a road trip or the clodest night of year. Has only been towed cause of stupid.

GrandW
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Re: Removing the rear spark plugs

Post by GrandW »

Have an 87 as well, the rear are a pain but you can get them. Extensions plus wobble / knuckle. Also they go in at a angle which makes catching the thread less than fun.

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1987 Jeep Grand Wagoneer
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dodgerammit
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Re: Removing the rear spark plugs

Post by dodgerammit »

84 here. No issues. You need to have a wobble and differing extensions for ease of removal. As far as rethreading, I always hand tighten all spark plugs before I snug them down. Eliminates cross threading.
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

92 Wrangler Islander 4.0/32RH/231 D30/D35 RHD

weeegoneeer
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Re: Removing the rear spark plugs

Post by weeegoneeer »

Same - don't usually have a problem. You might want to pick up the special socket for sparkplugs - it has a rubber washer inside to grab the plug, and also has a hex end so you can get a box end wrench on it if it's easier to get at with a right angle. Wobble adapter helps as well.
1984 GW

candymancan
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Re: Removing the rear spark plugs

Post by candymancan »

dodgerammit wrote:84 here. No issues. You need to have a wobble and differing extensions for ease of removal. As far as rethreading, I always hand tighten all spark plugs before I snug them down. Eliminates cross threading.

Yea i had a little surpise on my 90 when i first got it i changed out all the plugs. vacuume lines ect full tune up.. And the number 2 plug had this round ring on it.. Its like a helicoil basically... Someone somehow cross threaded cylinder 2 and they drilled it out and used a spark plug like helicoil thingy... I just dont see how you can cross thread spark plugs... But i guess some people just tighten and dont pay attention... Thankfully someone fi ed it properly.


My biggest worry on spark plugs isnt cross threading.. it overtightening and stripping the threads.. I always worry for some reason that the threads will strip... So i just make my plugs snug and thats it.. Basically tighten until it stops from very little pressure.. then i tighten maybe 1.2 a turn and leave it at that lol
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)
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kansasboy001
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Re: Removing the rear spark plugs

Post by kansasboy001 »

I've found using a flex head ratched with a spark plug socket works the easiest. Some of the better flex head ratchets are pretty thin and work really well for getting to the passenger side back 2 plugs from underneath. Put a bit of copper anti seize on the threads before you install the new plugs too. It will make removal way easier
1983 Cherokee Laredo. 360/ 727/ np228/ Junkyard 7427 TBI/ Msd ignition

will e
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Re: Removing the rear spark plugs

Post by will e »

candymancan wrote:
dodgerammit wrote:
My biggest worry on spark plugs isnt cross threading.. it overtightening and stripping the threads.. I always worry for some reason that the threads will strip...
There is almost nothing worse than the feeling you get when you are tightening something and then it gets a bit too easy... Strip city. :o
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

candymancan
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Re: Removing the rear spark plugs

Post by candymancan »

Yea i dunno why but changing spark plugs always has me biting ny tongue when tightening them... When using some antisoeze on the threads it makes it worse because you cant really feel how tight they are as it makes it easier to tighten and then the plugs have those cruashable gaskets and it makes it seem like the threads are stripped when you tighten and it keep spinning lol then it stops and you phew
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)
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Fast79Chief
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Location: Eastern Pennsylvania

Re: Removing the rear spark plugs

Post by Fast79Chief »

I remove/install the rear plugs on both sides from under my Chief. Much easier than cutting your hands to shreds against the heater box or trying to contort your hand between the manifold and brake booster bracket on the other side.
You'll get to learn these things after a short while.
1979 Cherokee Chief S, V8, MSD Pro Billet Distributor with New Factory Ignition Box (are these 2 even supposed to work together?), HEI Wires, Edelbrock 1406, Edelbrock Performer manifold, 3.54 gears, Tru-Trac Locker in the rear, Turbo 400, New Quadratrac, Dual gas tanks, new 32 x 11.50's, Big 9000 winch, Homemade 2.5" full length exhaust, Custom Headlight Harness, Custom front bumper working, Custom Rear Swing-out Bumper, Class V receiver hitch ... and a lot of work to do yet. :)

Topic author
hanger
Posts: 93
Joined: Sun Dec 16, 2018 8:09 am

Re: Removing the rear spark plugs

Post by hanger »

I got it done. Made a tool to get it done. Runs much better and doesn’t miss fire anymore. Don’t know which plug was bad as they all looked really good.

candymancan
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Re: Removing the rear spark plugs

Post by candymancan »

Fast79Chief wrote:I remove/install the rear plugs on both sides from under my Chief. Much easier than cutting your hands to shreds against the heater box or trying to contort your hand between the manifold and brake booster bracket on the other side.
You'll get to learn these things after a short while.

You think thats bad.. my 5.9 magnum on my zj has these round heat sheilds for all 8 spark plugs.. and they are sharp as F...
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)
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Fast79Chief
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Location: Eastern Pennsylvania

Re: Removing the rear spark plugs

Post by Fast79Chief »

Candymancan,
I had a 1995 Grand Cherokee Orvis edition and I think it had those shields too. Amazing what those engineers can do when they put their minds to it. Lol
1979 Cherokee Chief S, V8, MSD Pro Billet Distributor with New Factory Ignition Box (are these 2 even supposed to work together?), HEI Wires, Edelbrock 1406, Edelbrock Performer manifold, 3.54 gears, Tru-Trac Locker in the rear, Turbo 400, New Quadratrac, Dual gas tanks, new 32 x 11.50's, Big 9000 winch, Homemade 2.5" full length exhaust, Custom Headlight Harness, Custom front bumper working, Custom Rear Swing-out Bumper, Class V receiver hitch ... and a lot of work to do yet. :)

candymancan
Posts: 3652
Joined: Tue Mar 22, 2016 11:32 pm

Re: Removing the rear spark plugs

Post by candymancan »

Speaking of spark plugs i think i need to replace mine.. i did a full tune up when i got it.. and it had i think 112k its got 131k now and i used copper plugs. So 20k miles on coppers.. Probly need replacing.

Not looking foward to it. I really cringe at cylinder 2 that has that helicoil like thing done to it for the spark plug..

Have you guys usedcplatinum or iridium plugs on these vehicles ? Ive always used copper on the 4.0 and 5.9 zj because thats what those old engines were made for. Just dunno if itd be worth it to try a longer lasting spark plug
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)

letank
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Location: SF bay area

Re: Removing the rear spark plugs

Post by letank »

candymancan wrote:Speaking of spark plugs i think i need to replace mine.. i did a full tune up when i got it.. and it had i think 112k its got 131k now and i used copper plugs. So 20k miles on coppers.. Probly need replacing.

Not looking foward to it. I really cringe at cylinder 2 that has that helicoil like thing done to it for the spark plug..

Have you guys usedcplatinum or iridium plugs on these vehicles ? Ive always used copper on the 4.0 and 5.9 zj because thats what those old engines were made for. Just dunno if itd be worth it to try a longer lasting spark plug

Plain copper champion 404, our ignition is not suited for expensive plugs, as for #2, you can skip it...
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)
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