Trouble removing the fill plug on my 91 d21 - Infamous Nissan

Yamero · 05-01-2022, 09:37 AM

ok, I am having a lot of trouble removing the fill drain plug on the rear differential. It seems that the wrench and breaking bar with the little small doesn't set all the way inside and it makes it very difficult to get a good grip. I stopped before I did any damage to the plug. Is there a socket that doesn't have that ball bearing that I could use? or what else could I try?

LugNut1990 · 05-01-2022, 11:36 AM

Scrape out the inside of the plug's socket. Try some different extensions.

Use PB Blaster to soak the threads overnight, spraying every few hours and tapping the plug with a hammer.

Cusser · 05-01-2022, 02:20 PM

Quote:

Originally Posted by Yamero

ok, I am having a lot of trouble removing the fill drain plug on the rear differential. It seems that the wrench and breaking bar with the little small doesn't set all the way inside and it makes it very difficult to get a good grip. I stopped before I did any damage to the plug. Is there a socket that doesn't have that ball bearing that I could use? or what else could I try?

Quote:

Originally Posted by LugNut1990

Scrape out the inside of the plug's socket. Try some different extensions.

Use PB Blaster to soak the threads overnight, spraying every few hours and tapping the plug with a hammer.

LugNut has some great suggestions. Very wise to loosen/remove the fill plug before the drain plug !!! Can you post a good photo, I am not hands-on with your truck (I have 1998 and 2004 Frontiers).

Realize that you can remove the differential rear cover quite readily if you need to work on that on the bench, or even replace it.

cadillacdude1975 · 05-01-2022, 02:35 PM

When I worked in the auto service industry, we had a couple of tool options. Check out https://www.mechanicsurplus.com/prod...SABEgKoefD_BwE

That is a tool you can grind down to fit the 1/2 inch pipe thread fitting. You hammer it in the plug and it has teeth that dig into the inside lip or the plug. Once you have it hammered in real good, get a 12 point socket that fits the other end and use a big breaker bar. Heating the diff case around the plug with a propane torch can make the metal expand for easier plug removal. Just be 100095488483% sure there are no fuel leaks when using a torch.

Yamero · 05-02-2022, 12:22 AM

Quote:

Originally Posted by Cusser

LugNut has some great suggestions. Very wise to loosen/remove the fill plug before the drain plug !!! Can you post a good photo, I am not hands-on with your truck (I have 1998 and 2004 Frontiers).

Realize that you can remove the differential rear cover quite readily if you need to work on that on the bench, or even replace it.

ok, sorry for the delay, I'm just figuring out how to add pictures on the forum. Here is a picture of the rear differential. I did clean it.

Yamero · 05-02-2022, 12:26 AM

Quote:

Originally Posted by LugNut1990

Scrape out the inside of the plug's socket. Try some different extensions.

Use PB Blaster to soak the threads overnight, spraying every few hours and tapping the plug with a hammer.

I have been using wd-40, but not the tapping with the hammer. So direct hit to the plug? Wouldn't it damage the plug?

jp2code · 05-02-2022, 12:53 AM

Quote:

Originally Posted by Yamero

I have been using wd-40, but not the tapping with the hammer. So direct hit to the plug? Wouldn't it damage the plug?

As long as you have the right size ratchet, I think it just pops in there.

I think it's the 3/8-inch drive.

If it isn't going in easily, something is blocking the way.

Like others have said, make sure you can get the top one free before tackling the bottom one. You'd had to dump out all of your gear oil and not be able to refill it.

cadillacdude1975 · 05-02-2022, 01:17 AM

1/2 inch drive ratchet or breaker bar is the correct size. Put the ratchet in there and use your leg to break it loose. Someone probably tightened the plug way too tight.

SBJ · 05-02-2022, 01:23 AM

Yep, it should be a 1/2" square drive. If you have a 1/2" impact gun just put a socket extension on it and use that to break it loose. It'll come out. You can also put a jack under the breaker bar and push up on it to break it loose if it's really stuck. It's kinda sketchy but it works.

LugNut1990 · 05-02-2022, 03:03 AM

Firmly tap, not whack, a rust-frozen bolt. WD-40 not the best at anything, but I still use it a lot for other things, including in locks.

05-01-2022, 09:37 AM	#1
Yamero Join Date: Apr 2022 Location: Usa Posts: 48 Vehicle: Nissan d21 1991 Thanks: 18 Thanked 6 Times in 2 Posts	Trouble removing the fill plug on my 91 d21 ok, I am having a lot of trouble removing the fill drain plug on the rear differential. It seems that the wrench and breaking bar with the little small doesn't set all the way inside and it makes it very difficult to get a good grip. I stopped before I did any damage to the plug. Is there a socket that doesn't have that ball bearing that I could use? or what else could I try?

05-01-2022, 11:36 AM	#2
LugNut1990 Join Date: Jul 2015 Location: N.E. Kansas Posts: 943 Vehicle: 1990 Nissan Hardbody Thanks: 0 Thanked 146 Times in 127 Posts	Scrape out the inside of the plug's socket. Try some different extensions. Use PB Blaster to soak the threads overnight, spraying every few hours and tapping the plug with a hammer. __________________ Original owner 1990 Nissan Hardbody, Aztec Red Standard cab, 4x4, KA24E, 5-speed Intentionally near-stock Mods: Second OEM horn, stereo/speakers/sub, mud and snow tires, HD trailer hitch (cat 3+), liquid bed liner, G1W dashcam Definitely not for sale!

05-02-2022, 01:23 AM	#9
SBJ Total Buzzkill Join Date: Nov 2016 Location: OR Posts: 3,138 Vehicle: 1994 Pathfinder XE Thanks: 348 Thanked 605 Times in 536 Posts	Yep, it should be a 1/2" square drive. If you have a 1/2" impact gun just put a socket extension on it and use that to break it loose. It'll come out. You can also put a jack under the breaker bar and push up on it to break it loose if it's really stuck. It's kinda sketchy but it works. __________________ FS5W71C transmission teardown and overhaul threads: http://www.infamousnissan.com/forum/...t=38961&page=2 http://www.infamousnissan.com/forum/...ad.php?t=39233

05-02-2022, 03:03 AM	#10
LugNut1990 Join Date: Jul 2015 Location: N.E. Kansas Posts: 943 Vehicle: 1990 Nissan Hardbody Thanks: 0 Thanked 146 Times in 127 Posts	Firmly tap, not whack, a rust-frozen bolt. WD-40 not the best at anything, but I still use it a lot for other things, including in locks. __________________ Original owner 1990 Nissan Hardbody, Aztec Red Standard cab, 4x4, KA24E, 5-speed Intentionally near-stock Mods: Second OEM horn, stereo/speakers/sub, mud and snow tires, HD trailer hitch (cat 3+), liquid bed liner, G1W dashcam Definitely not for sale!

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05-01-2022, 02:35 PM	#4
cadillacdude1975 The Gear Jammer Join Date: Apr 2013 Location: Chattanooga, TN Age: 50 Posts: 10,745 Vehicle: 87 VG33 Pathfinder SE 4x4 & 87 D21 SE Thanks: 462 Thanked 1,415 Times in 1,279 Posts	When I worked in the auto service industry, we had a couple of tool options. Check out https://www.mechanicsurplus.com/prod...SABEgKoefD_BwE That is a tool you can grind down to fit the 1/2 inch pipe thread fitting. You hammer it in the plug and it has teeth that dig into the inside lip or the plug. Once you have it hammered in real good, get a 12 point socket that fits the other end and use a big breaker bar. Heating the diff case around the plug with a propane torch can make the metal expand for easier plug removal. Just be 100095488483% sure there are no fuel leaks when using a torch.

05-02-2022, 01:17 AM	#8
cadillacdude1975 The Gear Jammer Join Date: Apr 2013 Location: Chattanooga, TN Age: 50 Posts: 10,745 Vehicle: 87 VG33 Pathfinder SE 4x4 & 87 D21 SE Thanks: 462 Thanked 1,415 Times in 1,279 Posts	1/2 inch drive ratchet or breaker bar is the correct size. Put the ratchet in there and use your leg to break it loose. Someone probably tightened the plug way too tight.