I can't add to your "issue" Lance --- but to others reading this -- please note the use of PETROLEUM vs SYNTHETIC gear oils.... cone and helical gear rear ends require PETROLEUM gear lubes. NOT synthetic.
I've posted this info on Lat G before... and while it seems "odd" - since it's common for us to want to use "the best"... and we have come to embrace Synthetics. Not all applications want it. It's TOO slippery.
I picked up the rebuilt TracLoc and had my local shop install it in my third member. There was then plenty of discussion about what gear oil to run in it and friction modifier or no friction modifier... etc etc...
I've used just about every combination in the last one in the past 5 years, dino oil only, dino with modifier, synthetic, synthetic with modifier and lastly Royal Purple with a modifier already in it.
Frankly, for driving purposes I could not tell any difference between the different oils. Temps felt pretty much the same when being beat on...only difference I noticed was when I was fighting sealing issues, the synthetic would leak more than the dino oil. It's had the same ring and pinion gear in it since new, and they still look great.
The main part of the discussion was around the friction modifier and how it worked with the clutch pak. I always thought that the modifier was to help the clutch discs grab, but apparently the opposite is true. It is in there to help the clutches slip turning. I was talked into NOT running the friction modifier to help the clutches grab more therefore creating better torque bias when cornering on track.
So in went 3 quarts of Lucas Synthetic blend 75W-90 gear oil (new for me, about the only one I haven't tried before) and a test drive. The Lucas was the only synthetic without a modifier already added.
The car is barely driveable...it's fine in a straight line but acts and sounds like the whole rear end is coming out from under it while in any sort of a turn. While doing multiple figure 8s in a parking lot it gets much better, but as soon as you drive it in a straight line for a bit it starts to get very noisy and grabby in a turn again.
I decided to go to the horses mouth and talked with the person that did the rebuild on the TracLoc. He said Most Definitely a friction modifier of some sort is necessary with this type of clutch posi...no matter what gear oil you run. He also said that he set it up a bit tighter than a stock setup knowing that it was going into a 3500# car that will see abuse. His advice was to put some friction modifier in it and be patient as it breaks in...it'l take a bit longer to wear the clutches in a bit but it'll be better in the end than a stock type rebuild.
So I put 7 ounces of friction modifier suitable for synthetic gear oil in it before driving home last night and stopped in a parking lot on the way home and did many more figure 8s trying to get the modifier to embed into the clutch discs. So far, no difference. I've only got about 50 miles on it so far, and only 17 or so with the modifier in it...so I'll keep driving it and see what happens. It pains me though to hear and feel noises like that coming from under the car.
Maybe I should have found the extra $1,000 it was going to take to set myself up with a Trutrac...time will tell I guess. If this wears in and settles down like the guy that built it says it will, it should work fine for me, I just don't remember my last one having this much trouble breaking the clutches in.
__________________
Lance
1985 Monte Carlo SS Street Car
If you go straight to the rear end manufacturer - you know - the people that actually build them - test them - race them.... they'll tell you the correct info based on having manufactured millions of 'em.
I can't add to your "issue" Lance --- but to others reading this -- please note the use of PETROLEUM vs SYNTHETIC gear oils.... cone and helical gear rear ends require PETROLEUM gear lubes. NOT synthetic.
I've posted this info on Lat G before... and while it seems "odd" - since it's common for us to want to use "the best"... and we have come to embrace Synthetics. Not all applications want it. It's TOO slippery.
so just to play the devil's advocate, why then does Mark Williams recommend and supply Synthetic with their diffs? the guy who builds our center sections recommends Synthetics, I have only ever used synthetics with no issue UNTILL we had Currie build some third members and they will void the warranty if you use synthetics. all 3 of these companies use the same gears and diffs (because you really have no option) we have actually started to spec US Gear.as Motive seems to be really inconsistent.
I know this just confuses the matter but there seem to be some differences of opinion.
So when I finished my Nova we loaded it up at took it to the local road course. put 15 laps on it, this is brand new Royal Purple 85-140 gear oil, well SOMEONE didn't install a breather in the housing it got SO hot and built up enough pressure that it pushed the pinion seal out. and all the oil with it. loaded the car in the trailer back to the shop......... 3 hours later it was still to hot to hold on to!! and that was with an Aluminum Center section also...no abnormal gear wear new seal oil off we go still running strong today.
i like synthetic
There are a couple of different scenarios at play here Greg, each with different circumstances, needs and results. In regards to strictly gears...I agree that new ring and pinion gears need dino oil used with them until they are broken in. Once broken in though, I see no reason why synthetic gear oil can't be used on ring and pinion gears. My ring and pinion gears were broken in on dino oil but have had synthetic run on them for the last couple of years...and they have seen a ton of abuse and still look perfect.
Now, differentials...are another circumstance. Gear type lockers...I'm not sure what's best to use with them and when as I've never owned one.
Clutch type posi's though...from one horses mouth that builds and races a lot of these...dino or synthetic gear oil is fine either way...as long as a friction modifier is used to help the clutches slip. I can't see why being "too slippery" would be a deterrent at least when breaking in a new clutch type posi, especially after dealing with this the last few days...
Now I'm not an expert, but I have just listened to a LOT of them...with lots of different thoughts on this. I just wanted to post this to show that not all diffs are apples to apples, different scenarios are at play here.
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Lance
1985 Monte Carlo SS Street Car
Don't think for a second that that hasn't crossed my mind...
It's gotten much better since I put the friction modifier in it. I'm going to try to get it to 200 miles before my race on Sunday and hopefully it'll be fully broke in by then.
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Lance
1985 Monte Carlo SS Street Car
Just go to the manufacturer website. I don't need to argue it further. Some of their rear ends can use synthetics and some can't. The key is to know which can and can't. I'm just using the data off eatons website.
If you go straight to the rear end manufacturer - you know - the people that actually build them - test them - race them.... they'll tell you the correct info based on having manufactured millions of 'em.
NO SYNTHETIC GEAR LUBE.
Okay - that's all I'm going to say about that.
I was told this multiple times but after smoking several gears in succession, 1 set didn't even make it through 1 trackday, these were REM finished gears and the 3rd member was dynoed. I changed to Mobil 1 LSD on recommendation of C&R Racing and have had zero issues with the Tru-trac or gears since.
Lance, if you can't get this worked out... I have a freshly rebuilt 31 spline wavetrac if you need it. You pay for the shipping and install it, if it works out for you pay me whatever you feel it worth, if it doesn't work in your car use it for a paper weight or throw it in the dumpster... I have no use for it since it doesn't work with a floater unless you capture the axles somehow.
Brian Hobaugh SCCA National Tour June 2014
First Hemi 'Cuda Convertible Ever Built
Short clips: Goodguys Pleasanton autocross and pit videos
it got SO hot and built up enough pressure that it pushed the pinion seal out. and all the oil with it. loaded the car in the trailer back to the shop......... 3 hours later it was still to hot to hold on to!! and that was with an Aluminum Center section also...no abnormal gear wear new seal oil off we go still running strong today. 
I just wanted to post this to show that not all diffs are apples to apples, different scenarios are at play here.
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