XL-3 Fricton Modifier

[Oldwolf]

Getting ready to change the fluid in my 02 Exp XLT with LS rear end.

I noticed that Mobil 1 already has the friction modifier in it. Does it have enough or should I go ahead and add the XL-3 friction modifier?

Also saw that Autozone has CRC friction modifier for LS diffs. Is this an OK product or should I stick with the Ford XL-3?

Thanks.

 

[estell]

Try it and see if it gets rid of the chatter. You may need more friction modifier.

I replaced the gear oil in the rear diff with Redline 75W140, which contains friction modifier. However, it did not have enough. I had to add more. I put in 3 ounces of Amsoil and that is almost enough. I plan to add a few more ounces.

 

[thepotroast]

I just bought the Mobil 1 75w-140 and the CRC friction modifier you're talking about for my 03 4x4 with the LSD 3.73....doing the fluid change tonight, will let you know if it gets rid of some of the whine going on back there.

My pinion/ring and diff clutches were already replaced by Ford back in 2005 per the TSB, but I believe that when I had Cottman doing the fluid swap in the diff(s) they either put the stock 75w-90 with no friction modifier in the rear, or very little.

I will make a post this evening with some pictures to help others doing this on their 3rd gen's, as I was not able to find one on here using the search function.

 

[Oldwolf]

I don't think the FM will help with the whine. If it does, let me know!