PwrSmoke
Full Access Member
Bear in mind that weight does have an effect on how the LS works and you said you were carrying a load.
Rear diff options
- Thread starter Kevin 007
- Start date
Hey there Kevin,
I personally would be very apprehensive about adding a friction modifier if you have already installed synthetic.
If you are going to a different weight, contact the manufacturer of the LSD and see what they recommend. IIRC Ford posi's require 85/140 synthetic but don't quote me on that. Thus you may want to consider that as an option.
Read the label on your gear lube bottle if it says no friction modifier required I'm not one for adding to it myself.
What brand of oil did you utilize?
I agree with PwrSmoke and suggest you do the figure 8 tests forward backward and see what comes of it however I suggest doing some empty, then go get a load and do it loaded...for direct comparison of action.
Good luck keep us posted.
I personally would be very apprehensive about adding a friction modifier if you have already installed synthetic.
If you are going to a different weight, contact the manufacturer of the LSD and see what they recommend. IIRC Ford posi's require 85/140 synthetic but don't quote me on that. Thus you may want to consider that as an option.
Read the label on your gear lube bottle if it says no friction modifier required I'm not one for adding to it myself.
What brand of oil did you utilize?
I agree with PwrSmoke and suggest you do the figure 8 tests forward backward and see what comes of it however I suggest doing some empty, then go get a load and do it loaded...for direct comparison of action.
Good luck keep us posted.
PwrSmoke
Full Access Member
Riot... LSDs are not the least bit sensitive to viscosity (within normal ranges) and the Powr-Lok was a Dana product. So was the Trac-Loc. The Ford Traction-Lock (appearing only in the Sterling or Ford-built axles) was a completely different animal, though it operated similarly to the Trac-Lok. Powr-Lok is very different (and better IMO). I had my Powr-Lok file out earlier and you would be surprised to learn it's history (which goes back to 1955).
I generally agree about FMs in synthetics but sometimes you just have to add some. Personally, I'd live with a little chatter before I'd add FM but a LOT of chatter, frequently occurring, can be detrimental. But some people just can't stand the chatter. As I said, FMs can reduce the oxidation resistance of the oil, meaning it will oxidize more quickly with heat. With a "normal" amount, it's not unreasonable but if you overdose the oil trying to make a seamless unit out of one that normally carries on occasionally, it's not a good thing.
It's a good idea, doing a loaded vs unloaded test if you are willing to go to the trouble.
I probably should qualify my coming on strong on this topic. I wrote a book on axles. Not "THE" book but "A" book. Google "Differentials" with "Jim Allen" and you'll find it. I worked with Randy Lyman of Randy's Ring and Pinion/Yukon Gear and spent a couple of months at his place in Washington totally emerged in axle stuff. I previously had Ford and Land Rover factory training on axle work, plus a fair bit of experience wrenching back when I was a tech... and I thought I knew something. But, as I learned, writing a book will show you how much you really don't know... especially having around some serious gearheads at Randy's with decades of experience.
I generally agree about FMs in synthetics but sometimes you just have to add some. Personally, I'd live with a little chatter before I'd add FM but a LOT of chatter, frequently occurring, can be detrimental. But some people just can't stand the chatter. As I said, FMs can reduce the oxidation resistance of the oil, meaning it will oxidize more quickly with heat. With a "normal" amount, it's not unreasonable but if you overdose the oil trying to make a seamless unit out of one that normally carries on occasionally, it's not a good thing.
It's a good idea, doing a loaded vs unloaded test if you are willing to go to the trouble.
I probably should qualify my coming on strong on this topic. I wrote a book on axles. Not "THE" book but "A" book. Google "Differentials" with "Jim Allen" and you'll find it. I worked with Randy Lyman of Randy's Ring and Pinion/Yukon Gear and spent a couple of months at his place in Washington totally emerged in axle stuff. I previously had Ford and Land Rover factory training on axle work, plus a fair bit of experience wrenching back when I was a tech... and I thought I knew something. But, as I learned, writing a book will show you how much you really don't know... especially having around some serious gearheads at Randy's with decades of experience.
Kevin 007
Full-floater
Ok so with the truck still loaded this morning I did a great number of figure 8s in a parking lot until I got the attention of too many people, still binding up unloaded on left turns and the usual rumble when load is applied, via throttle. So, I put a 4 oz bottle of AC Delco LS additive and drove around some and it DID start to mellow out on those unloaded left turns. I will be driving it more later and over the next few days and will post back.
Al, the shop that installed it, used a 75w-90 synthetic. Don't know what brand but I asked and he said he always uses it with LS rears
Al, the shop that installed it, used a 75w-90 synthetic. Don't know what brand but I asked and he said he always uses it with LS rears
Kevin 007
Full-floater
Drove the same distance back home today, no weight this time and with the AC delco additive in it. It MUCH better then it was. So, I think the weight had an effect on it and the LS additive was lacking. It still seems lo grab when I need it. But much quieter when its unloaded now. Im happy, I was worried I would have to pull the diff in the middle of this oncoming cold snap.
Thanks guys for your support!!
Thanks guys for your support!!
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