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Discussion Starter · #1 ·
Getting everything together for my switch. I'm getting 80/90 GL-5 gear oil ( 3.5 gts as @Woodchuck posted on a prior thread). Is there any particular brand I should get? I have the friction modifier for my 3.55 Trac Loc.

Also do people put anything on their gaskets? I'm planning on getting new copper washers.

Thanks

Peter
 

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You can use any number of gear oil brands, but the friction modifier is far more application specific. When I purchased my 3.55 Trac Loc from Currie Enterprises, they shipped it with this . . . .

742572
 

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Discussion Starter · #3 ·
Mine also came with friction modifier. Just need to get the right oil.
 

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67 coupe, 69 Sportsroof, 86 hatchback
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These days I prefer to use synthetic myself. Usually Valvoline 75w/140. Not because of the name brand, just because I can consistently find it on parts store shelves. I've moved over to synthetics on about all my lubricant choices these days. Nothing wrong with plain old 90W if you though. Use whatever is on the parts store shelf. A known national brand name gives me a little more faith in the product. I'd avoid the squirrely small time names, even if they are double the price and claim to be manna from heaven. And a pretty color.

Extra note: This is for rear ends, NOT manual transmission use.
 
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I am doing the same with my 9" 3:50 Traction Lok and also adding new Dutchman axles. From a little research, I decided to go with Red Line 75W90 GL5 HP lube for Hypoid Limited-Slip Differentials. I spoke to the engineer at Red Line and he said the friction modifier is already in this and there is no need to add more. I think he said 2 oz is in each quart. My only debate at this time is to add a drain plug on the bottom of the differential housing.
 

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If you're going to run it hard I recommend SAE 75W140 GL5, else 75W or 80W90 GL5 and this...
 

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Discussion Starter · #8 ·
Got a little bored after church today so...
742820



brake backing plates were blasted and primed. Thinking I'll send the axle housing for powdercoating.

2 questions, whats the best way to clean out the residual gear oil? I've wiped out as much as I can with many paper towels.

And, what color semi-gloss black, matte black?
 

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Got a little bored after church today so...
View attachment 742820


brake backing plates were blasted and primed. Thinking I'll send the axle housing for powdercoating.

2 questions, whats the best way to clean out the residual gear oil? I've wiped out as much as I can with many paper towels.

And, what color semi-gloss black, matte black?
Powder coat the backing plates also. Use a degreaser on the inside. I had mine powdercoated in Satin/semi gloss Black one step down from Gloss black.
 

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Discussion Starter · #10 ·
Powder coat the backing plates also. Use a degreaser on the inside. I had mine powdercoated in Satin/semi gloss Black one step down from Gloss black.
Sounds good, thanks. My wife will be happy since the basement won't smell like paint!
 

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Discussion Starter · #11 ·
So i got everything installed today. One questions, I figured that the diff would take 3.5 qts, so I split up the friction modifier between 3 of the qts. I filled the diff up thru the hole in the back. It only too 2.5 qts to flow out. Shouldn't it take more? Should I let it settle and re-try?

I'm worried I don't have enough friction modifier in there? There weren't any instructions, so I assumed one bottle was enough for the whole diff. I used the Yukon one @2nd 66 posted.

As a side note, I remember everyone posting about the smell. When I pulled my old pumpkin out I didn't notice anything. Filling up the new one, however.............:sick:
 
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Discussion Starter · #12 ·
Just re-read a post from @Woodchuck. He said 3.5 pints and I read 3.5 qts! So should I add a little more friction modifier or see how it sounds? If you don't have enough will the diff make a noise I can hear? I probably have 3/4 of the modifier already in there.
 

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if your just doing street duty ,run it if your sure you have at least 3/4 of the bottle. If your gonna beat on it run it a little then change it and add the FM 1st then the gear oil
 
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