Gear Lube: Howe has rebuilt quick-change rear ends since the 1970s, and recently, the guys in the shop noticed that the gears of customers using Maxima 75-90 ProGear tend to look better and stink the least of the lubricant that we have seen. Since switching more customers to Maxima, the differentials have returned to better shape at comparable intervals. This conclusion is somewhat anecdotal, and there are other satisfactory options, but we have not found anything better. Because of this, we added Maxima gear lube to our inventory. (pn: MX49-449128)
Rear End Filters - Quick-change rear ends, especially those with differential gears, create a significant amount of metallic flakes. These flakes can affect the performance of the life and performance of the internal gears and external pumps and coolers. You can not install a typical fluid filter because it would plug quickly from the large flakes, so a few years ago, Howe made a special coarse screen filter to install on the rear ends and transmission with cooling pumps (pn: HP4000).
Unfortunately, excessive silicone sealant from the assembly will collect in the filter, potentially plugging the fluid flow. Therefore, you must clear the reusable screen after the first run and inspect it regularly. Silicone does not harm the gears but will plug pumps and coolers, causing the gears to overheat quickly.
You can reuse the lube after a gear change, except for the last few ounces in the drain pan, which will be dense with metal flakes.
Axle Life -Inspecting your axles regularly and cycling them out before failure is advisable. There is also a visual indicator of axle condition. Axle manufacturers recommend marking new axles with a paint stripe to monitor the degrees of twist and replace them at 90 degrees.
Lower Shafts -One tolerance we inspect during a quick change rebuild is the run-out of the lower shaft. Over time, the lower shaft will bow from twisting. The best way to check for this is with a dial indicator while the rear end is apart; it should not exceed .007".
There is also an external symptom to watch for. If you always install your spur gears with the numbers facing out, watch for excessive wear or pitting on one side of the spur gears.
If you notice this, throw away the gear set and change the lower shaft as this indicates they both are nearing failure.
Products mentioned available on howeracing.com:
MX49-449128 OIL, MAXIMA 75W 90 - PRO GEAR LUBE - 1 GALLON
HP4000 INLINE FILTER HOUSING #6 TO #8 INCLUDES SCREEN AND FITTING
HP4000DET5 SCREEN FOR HP4000/ HP4001
TG2503 TIGER Q/C LOWER SHAFT SOLID
TG2049 R&P 4:12 TIGER, W/HEX DRIVE WITH TG2900, TG2902 & TG2910