1999 4.2 Auto, 3.31 Open

I'm looking at replacing my axle seals in the near future. The passenger side is leaking visibly (though, not profusely!). I'm thinking that I should just go ahead and do both at the same time - rather than have to buy the liquid gold twice.

Has anyone used Redline or Royal Purple rear gear oil rather than the Motorcraft oil? I was thinking of using one of these brands with an additive when I do the replacement. RP is $8, and Redline is about $12 a quart. I'd have to order either one because no speed shops in my area seem to carry them - even the authorized RP dealers.

I've heard Mobil1 makes the correct fluid, but can't find that either.

BTW - Does anyone else find it strange that its so hard to find the correct gear oil for what is supposedly the number one selling truck???

If anyone has tried these gear lubes, how have they worked out? I'm probably going this route unless someone has a real horror story to share!

Thanks

 

Sorry - must have double clicked or something.....

 

Call Redline and tell them what you have. Nice folks, will ship @ $8.00/Qt, phone # on website....jb

 

Amsoil!!!

 

I installed a Mag-Hytec rear differential cover today.
I filled it up with 5 quarts of AMSOIL 75W-140W synthetic gear oil.
I did not add any friction modifier and drove it 25 miles today. I will not add any friction modifier unless it starts clattering.

 

Would it be really obvious if there were a chatter and you needed to add fluid? I suppose if you needed it, you would have to pump some out to add it then...

 

Is that Redline any good? Which is best?

Do you think that the Motorcraft Friction Modifier will cause any problems with other brands of fluid?

What is the recommended off brand?

Any ideas where to get them, none of my local stores carry the 90w-140..

Can you belive 20.-- a quart from Ford? WOW

 

It is December here in Kansas and I drove about 150 miles today. It did puke some gear oil out the vent tube. I drained ONE quart out of it after the trip. I just installed a Mag-Hytec differential cover and the instructions said to add 5 quarts and drive it some. Then I am supposed to check the lubricant level. I drained it shortly after the trip so the fluid was warm and expanded some. The gearoil had some stuff suspended in it after only 150 miles of driving.

I think I paid about $12 a quart for the Amsoil 75w140 gear oil. I got a little of the oil on my hands when I drained that quart out and it kind of smells like garlic.

I get my info about Amsoil at www.amsoil.com

 

friction modifier if for limited slip diffs no need for it in an open diff. ford says to use synthetic gear lube but ive seen people put in reg. cheap gear lube thats like $2 a quart dont know if they had any problems. but redline oil should work good alot of people swear by the stuff

 

Hello,

I have been having a hard time finding alternative gear oil for my 99 F-150 Supercab. I just called Redline Oil, which I found out is only fifteen minutes from where I live. They had excellent customer service and their tech called me back within a minute and a half to talk to me about what is best for my truck. He was already familiar with my truck and their fluids as well as many mechanical instances.

If their fluid, which I will be picking up within the next few days, is anything like their service, then it must be good stuff!

I will post later about my experience with the fluid and the change.

Oh, B.T.W. Dave (The Redline Oil Tech) said that anyone can feel free to call him or email him if they have any questions about their products and how they interact with your specific vehicle.

Dave
(800) 624-7958
Redline@RedlineOil.com
or
Dave@RedlineOil.com

Does anyone know where I can get a great deal on a Mag Hytech differential cover for my 99 F-150?

Thanks,

Dave H.
Dave@Hobley.com

 

One thing I forgot to mention, there is a limited amount of Friction Modifier built into the redline gear oil so usually the additional additive is not necessary unless you experience chatter.

Also, Redline is not blended. It is 100% fully synthetic.

Regards,

Dave H.

 

Sorry about the reposts. But in my hurry, I forgot to mention another major plus for Redline:

Redline 7.99 compared to 20.00 plus for motorcraft

This based on the 75w-140 for many F-150's

 

Red Line is the Best gear oil IMO.

Make sure to add friction mod., but call Dave to make sure.

www.redlineoil.com

 

Thanks,

No Friction Modifier With Redline Unless Chatter, According to Dave @ Redline.

Now I just have to get over there when they are open.

Dave

PS What is best to use to seal the rear end once clean out old fluid and stuff?

Thanks!

 

I think that Motorcraft now makes Gaskets if you're worried about leakage. From the factory there is no gasket, just some high temp. sealant.


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