Recent Topics
Gas trimmers
by weeksjake. 01/22/19 09:11 AM
Supertech Heavy Duty 15W40 ...$9.64
by dblshock. 01/22/19 08:53 AM
Trooper recommends dash cameras
by FordBroncoVWJeta. 01/22/19 07:14 AM
New Harley synthetic 80w-140 gear released
by shanneba. 01/22/19 06:43 AM
Registering a Vacation Car
by ssamaroo01. 01/22/19 06:23 AM
Starter cross reference?
by dlundblad. 01/22/19 05:11 AM
Barkeepers Friend
by jerseyguy123. 01/22/19 02:23 AM
Bag-in-a-box motor oils
by jtr990. 01/22/19 02:10 AM
Inventions of the 1950's - 1970's
by StevieC. 01/21/19 10:26 PM
Fireplace cleaners and price
by 97prizm. 01/21/19 10:23 PM
M1 0w40 extended oci??
by Pinoak. 01/21/19 09:46 PM
Best propane fireplace insert?
by SOHCman. 01/21/19 08:51 PM
Save 1/4 on gas!! Guaranteed!!
by Linctex. 01/21/19 08:50 PM
Funny names
by Chris142. 01/21/19 08:45 PM
Kendall vs Total Qaurtz
by zeke1985. 01/21/19 08:32 PM
Got a weird one - Helping a friend
by StevieC. 01/21/19 08:32 PM
Thanks 14Accent
by clinebarger. 01/21/19 08:07 PM
Mobil 1 5W30 C7 Z06
by PLRX. 01/21/19 07:40 PM
Newest Members
Binco, Coolbreez1973, jmcast1127, DF8005, FT86dude11
67009 Registered Users
Who's Online Now
91 registered members (4WD, 2015_PSD, 53' Stude, A310, 69Torino, 11 invisible), 1,884 guests, and 34 spiders.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums67
Topics296,969
Posts4,962,601
Members67,009
Most Online2,821
Jan 21st, 2019
Donate to BITOG
Previous Thread
Next Thread
Print Thread
Hop To
Page 1 of 4 1 2 3 4
rear differential cover bolts #4734957
04/22/18 05:18 AM
04/22/18 05:18 AM
Joined: May 2010
Posts: 9,628
out there
spasm3 Offline OP
spasm3  Offline OP
Joined: May 2010
Posts: 9,628
out there
When i went to change the rear diff gear oil, the fill plug was completely rusted up ( i always check the fill bolt first). There is no drain bolt on this rear end. The previous owner towed a boat and the rear has seen salt water, so there is rust on the bolts.

Are differential cover bolts hard to get out when rusted? Or do they come out okay since they are not open on the back side?

My option is to leave the rear end alone and just drive it until if fails without changing gear oil.

Or remove the rear cover and replace it with one that has a fill bolt on the cover.

I don't want to have a bolt shear off in the diff body trying to remove the cover.

I tow with this truck.

What would you do in this situation?

Last edited by spasm3; 04/22/18 05:19 AM.

13 elantra 72k 5w30 QSUD
03 chevy avalanche 80k synpwr 5w30
17 mazda cx-5 7300 miles m1 0w30
Re: rear differential cover bolts [Re: spasm3] #4734973
04/22/18 05:53 AM
04/22/18 05:53 AM
Joined: Sep 2004
Posts: 7,912
Marshfield , MA
andyd Online content
andyd  Online Content
Joined: Sep 2004
Posts: 7,912
Marshfield , MA
Clean them off and see what you're dealing with. Typically ,the screws are a female torx head. You'll need a gasket. I'd spend the money on a cover with a drain plug.


'16 Camry LE STP synth 0w20 and STP filter. the Fridge

1994 Ranger ,the Rat, 5w30 dino, STP filter

'16 Camry SE, Valvoline HM 0w20 and OEM filter
Thick oil is better grin2
Re: rear differential cover bolts [Re: spasm3] #4734979
04/22/18 05:58 AM
04/22/18 05:58 AM
Joined: Jun 2013
Posts: 525
Albany, NY
ford46guy Offline
ford46guy  Offline
Joined: Jun 2013
Posts: 525
Albany, NY
Originally Posted By: spasm3
When i went to change the rear diff gear oil, the fill plug was completely rusted up ( i always check the fill bolt first). There is no drain bolt on this rear end. The previous owner towed a boat and the rear has seen salt water, so there is rust on the bolts.

Are differential cover bolts hard to get out when rusted? Or do they come out okay since they are not open on the back side?

My option is to leave the rear end alone and just drive it until if fails without changing gear oil.

Or remove the rear cover and replace it with one that has a fill bolt on the cover.

I don't want to have a bolt shear off in the diff body trying to remove the cover.

I tow with this truck.

What would you do in this situation?


This is very common where I am, and I'm no where near the water. Road salt does the same thing.

What type of fastner is it? Square? Torx? Hex? Make sure you use the right tool.

Take a stiff steel brush, and clean it up.

Get some PB blaster, WD-40 (yes it helps), and Liquid wrench or go to Family Dollar/Ask the old lady for Acetone nail polish remover. Mix(don't need much, maybe 2 oz of each) it up 50/50 with some used or cheap ATF, spray down the plug. I use a dollar tree spray bottle, it is all deformed but it works for years. Maybe pick two products. Let it sit overnight.

Get a Yellow mapp torch, heat the iron around the plug. Take a candle and melt it into the threads.

Try working the bolt out. Impacting, banging on the breaker bar is better than brute force sometimes. A weak impact helps too. You don't want to destroy the fastener.

Last edited by ford46guy; 04/22/18 06:03 AM.

95 Tbird V8 240K PP SYNTH ULTRA 5W30
98 MGM 160K M1 HM 5W20
96 Explorer EB V6 159K PP SYNTH HM 5W30
95 Conti 155K MC 5W20
11 GS350 90K PP HM 5W30
Re: rear differential cover bolts [Re: spasm3] #4734982
04/22/18 06:03 AM
04/22/18 06:03 AM
Joined: May 2010
Posts: 9,628
out there
spasm3 Offline OP
spasm3  Offline OP
Joined: May 2010
Posts: 9,628
out there
The plug is high up on the front of the axle, its a square type, there is not enough left to get a grip and its rusted solid. Its not coming out.

They way it looks i'm not even considering trying to get the fill bolt out. Its the diff cover bolts i'm worried about. There is no drain plug so the only way to dump the gear oil is to remove the cover. I'm worried about bolts shearing off in the body of the diff. I recently had transmission pan bolts shear off.


13 elantra 72k 5w30 QSUD
03 chevy avalanche 80k synpwr 5w30
17 mazda cx-5 7300 miles m1 0w30
Re: rear differential cover bolts [Re: spasm3] #4734990
04/22/18 06:20 AM
04/22/18 06:20 AM
Joined: Sep 2013
Posts: 10,787
Indiana
dlundblad Offline
dlundblad  Offline
Joined: Sep 2013
Posts: 10,787
Indiana
Pictures would help. Is the fill plug the recessed 3/8" square style or is it an actual bolt head?

I would think you could siphon some out through the fill hole, but you certainly don't want to proceed with the cover until the fill plug issue is resolved. Let the cover bolts soak for some time, but they should come out issue free.

If all else fails, get a new cover and have one of these installed. https://www.jegs.com/i/Currie/272/95070/10002/-1
Have a second one installed as a drain plug and get some easy Toyota style diff drain and fills.


03 Jeep WJ 4.0 202k Edge 10w40 HM Fram XG16
02 Volvo S60 2.4T 186k M1 0w40 Mahle OX149D
97 Chevy Blazer 4.3 153k Synpower 5w30 Supertech ST3980 (Ecore)

Re: rear differential cover bolts [Re: ford46guy] #4734996
04/22/18 06:35 AM
04/22/18 06:35 AM
Joined: Jan 2013
Posts: 2,280
Texas
WyrTwister Offline
WyrTwister  Offline
Joined: Jan 2013
Posts: 2,280
Texas
I agree , penetrating oil , heat & then penetrating oil again .


Wyr
God bless
Re: rear differential cover bolts [Re: spasm3] #4735005
04/22/18 06:54 AM
04/22/18 06:54 AM
Joined: Jan 2017
Posts: 207
Michigan
64bawagon Offline
64bawagon  Offline
Joined: Jan 2017
Posts: 207
Michigan
Clean them good with a wire wheel/brush and then soak them with PB blaster a couple days ahead of when you want to remove them. I have done a lot of them and never had a screw break. The importance of cleaning them is so you dont round the head out. I always clean them once they are out and then put some anti sieze on the threads for next time. A 1/4" impact driver should get them out.


64 Chevy wagon, 10 Jeep Wrangler, 18 Silverado 1/2 ton
Re: rear differential cover bolts [Re: spasm3] #4735006
04/22/18 06:54 AM
04/22/18 06:54 AM
Joined: Jun 2013
Posts: 525
Albany, NY
ford46guy Offline
ford46guy  Offline
Joined: Jun 2013
Posts: 525
Albany, NY
Originally Posted By: spasm3
The plug is high up on the front of the axle, its a square type, there is not enough left to get a grip and its rusted solid. Its not coming out.

They way it looks i'm not even considering trying to get the fill bolt out. Its the diff cover bolts i'm worried about. There is no drain plug so the only way to dump the gear oil is to remove the cover. I'm worried about bolts shearing off in the body of the diff. I recently had transmission pan bolts shear off.

Diff bolts should be encircled with RTV, and the chances of breaking off are slim. I know on a Ford 8.8 it is a pretty heavy duty bolt, because it provides some support to the case.

If they do break off they should be easy to take out, you will have plenty of access to heat and drill out.

A welding place can put a nut on the plug easily, that can be an option too. Once it is welded it will break any rust bonds. Maybe $25-30 to do something like this. I have a guy that I hand a $20 for this work. Takes him 3 minutes.

An easy out may be an option too. If it is 3/8" square drive you can probably get a big one in there, less chance of breaking off.

If you have to leave the plug in place, make sure you can find a rear end cover with the fill plug that can fill to proper level. They are quite pricey too.


Last edited by ford46guy; 04/22/18 06:57 AM.

95 Tbird V8 240K PP SYNTH ULTRA 5W30
98 MGM 160K M1 HM 5W20
96 Explorer EB V6 159K PP SYNTH HM 5W30
95 Conti 155K MC 5W20
11 GS350 90K PP HM 5W30
Re: rear differential cover bolts [Re: spasm3] #4735013
04/22/18 06:58 AM
04/22/18 06:58 AM
Joined: Sep 2010
Posts: 7,903
Texas
4WD Online confused
4WD  Online Confused
Joined: Sep 2010
Posts: 7,903
Texas
Buy the cover … you will love it.

The G2 normally has a “tattle tell” port (in addition to drain and fill plugs) …
There since the capacity goes up a bit … you can still get the oil level to the bottom of axle tubes …

Re: rear differential cover bolts [Re: spasm3] #4735058
04/22/18 07:37 AM
04/22/18 07:37 AM
Joined: Oct 2004
Posts: 8,487
Cincinnati, OH, USA
bullwinkle Offline
bullwinkle  Offline
Joined: Oct 2004
Posts: 8,487
Cincinnati, OH, USA
I had this problem on the GMC in my sig-bought a cheap steel cover, drilled it, had my welder weld a bung in it, and painted it with Rustoleum primer & black spray paint. It's been on & fine for almost a year. The key is getting the fill plug level correct, needs to be right below the bottom of the axle tubes.


06 Ram 3500 CTD 4X4(FG Venturi), 93 GMC C3500 6.2, 89 F-450 7.3, 98 XJ 4.0(XG8A), 05 xB(XG3600), 18 Transit 3.7, 03 Merc Grand Marquis 4.6 2V(XG2)
Re: rear differential cover bolts [Re: spasm3] #4735060
04/22/18 07:40 AM
04/22/18 07:40 AM
Joined: May 2010
Posts: 9,628
out there
spasm3 Offline OP
spasm3  Offline OP
Joined: May 2010
Posts: 9,628
out there
Ok here are some pics. I'm not going to mess with the fill bolt, i'm just not.

I'd rather add a new cover as suggested above that has a fill bolt.



How much chance of these bolts shearing?



Last edited by spasm3; 04/22/18 07:49 AM.

13 elantra 72k 5w30 QSUD
03 chevy avalanche 80k synpwr 5w30
17 mazda cx-5 7300 miles m1 0w30
Re: rear differential cover bolts [Re: bullwinkle] #4735061
04/22/18 07:41 AM
04/22/18 07:41 AM
Joined: Sep 2010
Posts: 7,903
Texas
4WD Online confused
4WD  Online Confused
Joined: Sep 2010
Posts: 7,903
Texas
Originally Posted By: bullwinkle
I had this problem on the GMC in my sig-bought a cheap steel cover, drilled it, had my welder weld a bung in it, and painted it with Rustoleum primer & black spray paint. It's been on & fine for almost a year. The key is getting the fill plug level correct, needs to be right below the bottom of the axle tubes.


Yes … If you go homemade … be careful how you read this … target is this picture:




See ports on G2



Last edited by 4WD; 04/22/18 07:43 AM.
Re: rear differential cover bolts [Re: spasm3] #4735080
04/22/18 08:02 AM
04/22/18 08:02 AM
Joined: Nov 2012
Posts: 2,486
Nowthen, MN
KD0AXS Offline
KD0AXS  Offline
Joined: Nov 2012
Posts: 2,486
Nowthen, MN
I didn't have any problem with the diff cover bolts on my F-350 after 10 winters of road salt here in MN. Soak them with PB Blaster or something similar, and use a good 6 point socket.

Re: rear differential cover bolts [Re: spasm3] #4735089
04/22/18 08:09 AM
04/22/18 08:09 AM
Joined: Jun 2013
Posts: 525
Albany, NY
ford46guy Offline
ford46guy  Offline
Joined: Jun 2013
Posts: 525
Albany, NY
Hard to give you a probability of shearing. Best for someone with GM rear end experience in the salt belt to chime in. Transmission pan bolts are small diameter.
For starters I would take wirebrush and spray the bolts down.

Since it is gasketed you can try to tighten 1/8" turn to break things. Then loosen a bit more. Once it breaks a bit and leaves a gap, spray each bolt with penetrant.

You can also heat the diff case where the bolts are.

If you don't force things with a long breaker bar(take it slow) you should be ok.


95 Tbird V8 240K PP SYNTH ULTRA 5W30
98 MGM 160K M1 HM 5W20
96 Explorer EB V6 159K PP SYNTH HM 5W30
95 Conti 155K MC 5W20
11 GS350 90K PP HM 5W30
Re: rear differential cover bolts [Re: KD0AXS] #4735091
04/22/18 08:11 AM
04/22/18 08:11 AM
Joined: Jun 2013
Posts: 525
Albany, NY
ford46guy Offline
ford46guy  Offline
Joined: Jun 2013
Posts: 525
Albany, NY
Originally Posted By: KD0AXS
I didn't have any problem with the diff cover bolts on my F-350 after 10 winters of road salt here in MN. Soak them with PB Blaster or something similar, and use a good 6 point socket.

Not surprising, because RTV always makes itself into the threads.


95 Tbird V8 240K PP SYNTH ULTRA 5W30
98 MGM 160K M1 HM 5W20
96 Explorer EB V6 159K PP SYNTH HM 5W30
95 Conti 155K MC 5W20
11 GS350 90K PP HM 5W30
Page 1 of 4 1 2 3 4

BOB IS THE OIL GUY® Powered by UBB.threads™