Ford 302/C4/8" 3.25 with Posi Will be installing the new center section with posi soon. Any recommendations for gear oil? Weight, capacity, etc? What break in procedure would you recommend?
Talk to the supplier or manufacturer, no literature came with? If new it should have some warranty, don’t screw that up by taking recommendations from a forum
No literature. Built by Quick Performance using new parts. Just arrived today. I did reach out to them but haven't heard back. Just thought I'd ask on here in the meantime.
It will depend on the Diff..some require a friction modifier..I have a Eaton Tru Trac, which uses helical gears, not clutches, also didn’t require a friction modifier…I’d call Quick…good company to deal with
I'm assuming a clutch type limited slip? If so get the gear oil with additive for clutch type. Otherwise it will pop and clunk. Also do about 10 tight figure 8's in a parking lot to work the lube into the clutch packs. The usual gear break-in process is to run it easy on throttle and letting off smoothly during first 50 miles. Also at first drive about 15-20 minutes and then let cool. Do this about 3 times, in addition to lighter throttle. After that you should be good for spirited driving.
In addition to what 38Chevy454 posted, the shop that did an 8.8 in one of my fleet trucks advised light usage for the first 100 miles.
i'd get 2 qts of the cheapest, lightest weight GL5 gear oil i could find. Even it comes from the dollar store. Once its filled, get the engine warmed up, go out and immediately do a couple burnouts to make sure both back tires leave equal black lines. That's what i do. Who cares about the clunking in corners, it a hot rod. That lets you know its a posi. And that additive, it smells bad, i don't like the smell when (i mean if) i drain the oil to change it as regular maintenence .
I found a Pennzoil product that met what QP said to do. I dumped it after 3 years and re-filled it, added a bottle of Ford friction stuff. It always made funky noises going slow on sharp turns.
Hello, When we got a 58 Impala new off of the showroom floor, it had a 4:11 Positraction gearing. So, my brother arrived and drove it to our house about 5 miles away. He did not beat the crap out of the new gearing as been described in other posts. He just drove it home with the stock 4:11 Positraction gearing. The teeth and gears will get plenty of meshing and in the normal mode. As it gets driven over time, it will wear evenly. No one did burn outs or drove radically to get anything “warmed up.” Daily stop and go driving gets plenty of action for all running gear. But, my brother did drive it normally for a week or so, before he ventured to Lion’s Dragstrip to see how it was going to perform. By this time, it had been driven normally to give everything time to “get settled” and work properly. Jnaki If in doubt for oil or weight, there are Ford dealers that have gear oil available. The one thing I remember each time I crawled under the 58 Impala on a Thursday night, was the odd smell/odor coming from the Positraction third member when it was draining. To me, it smelled like day old fish and was very thick. I spent the next several hours under the car replacing the stock 4:11 Positraction third member with a complete 4:56 Positraction third member. My brother’s idea was that everyone had to follow the rules in racing in the stock class. As long as it was listed as a Chevy part and in the catalog, then it could be used in the stock classes. So, despite some cars with 3:55 gears, the 4:11 and/or the 4:56 Positraction gears gave us an advantage in the class eliminations. We always had extra cans of the Positraction oil handy. But, for the early time we drove places, it was all normal driving. The whole car worked well and without bashing it from the beginning, when it was called upon to accelerate with power, it did that and then some. That “fishy” smell from the oil still stays in my mind and sometimes when we have a fresh fish barbeque, I make sure not to get the aroma of the fresh fish on my hands. Note: One of the only products that gets that fresh fish odor or aroma off of the skin is a product from Amway called L.O.C. (Liquid Organic Cleaner.) One small dab will take away any fishy handling smells on the hands and fingers. YRMV
Disc and cone LS differentials need the additive (GMs do) but I recently put together a Torsen for my daughters car, and it’s all gears. Can’t recall who I checked with, but was told the additive wasn’t needed.
I just installed a new Speed Master 3rd member and they call out to not use any synthetic oils. They recommend a mineral based extreme pressure 140 w gear oil. I found out that Grainger sells Nimbus which is exactly what they call out. 0 to 160 degree range. Valvoline also sells the same oil but the cost is about double.
The old friction modifier from GM was Whale oil. As was the early automatic transmission fluid. That’s why it stunk so bad.
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