WhalePirot
Well-known member
4+3: How to Preserve It
Some of you know I just got my 4+3 working again(minor issue). You may also know that I am in the minority, here, by actually liking the unit. The problem with mine was spelled out in other threads, but I just talked with the current exper on these units. His name is Brian; he took time to chat with me despite having more business than he can handle.
I am running the unit behind a hot 406 putting our well over 500ft.lbs. and 500 hp. Brian http://www.skspeed.com/ has been in the biz since 1963 and started doing 4+3s with Paul Cangliosi (5-speeds) when the units came out. They built them for Callaway and have installed them behind 454; in everything from street rods to Chevelles, to Rustangs. These two guys are probably the foremost experts on these units anywhere. Brian quoted me a lower price than other, for a filter kit, should you need one.
Like everything else, ya gotta know how to take care of them and what fluids to run. He is not some old-school, stick-in-the-mud. He knows these boxes and has seen it allHe speaks with assurance, based upon knowlegde and experience.
I asked him how to ensure mine would survive behind this nasty
motor.
He said most problems with the O/D arise from guys messing up the O-ring or using the wrong fluid or not totally filling it or screwing up the pan, etc. He recommended NOT changing the fluid unless you overheat it, but rather checking it periodically for level and condition, by sticking your finger through the fill-hole; topping-off, as needed. The likelihood of ruining it has been shown, in his experience, to be higher with routine, if improper, maintenance. DO NOT run synthetic ATF in them. It will ruin it. Use standard Dextron, as listed in your literature. The unit will withstand 450 ft.lbs. (or more if he or Paul modded it). The stock unit is a great unit, if misunderstood, even by GM techs, not to mention your chain tranny dudes.
With the Super T-10, DO NOT RUN SYNTHETIC gear oil. Use either standard gear oil or GM's 12345-349 gear oil with synchro fluid, which has a small amount of synthetic, about 3%, and can ease grinding-while-shifting problems. He explained that the shape of the cones and the synchros demands a thicker fluid; that the synthetics are too good, and the internals don't work properly. The gears need spin-down time to mesh properly and the thicker oils allow that to happen, AS DESIGNED. The general's fluid might totally solve shifting issues, after a bit of time.
Also, the most common breakage of this T-10 is due to the case. The cases usually fail near the reverse idler shaft input, along the side. This takes internal parts along, noteably first gear. This case was strengthened from the standard T-10, but in this area, it needs more thickness for high power applications. His shop modifies cast iron cases to work, for racers, but the cost is more than installing a Richie, and not usually the best for a street car.
I am not an expert, myself, on this, but I consult with those who are and am passing along what I learn. It should work for you owners, those interested and for Brian and Paul, who are REAL busy fixing our mistakes.
Mike
Some of you know I just got my 4+3 working again(minor issue). You may also know that I am in the minority, here, by actually liking the unit. The problem with mine was spelled out in other threads, but I just talked with the current exper on these units. His name is Brian; he took time to chat with me despite having more business than he can handle.
I am running the unit behind a hot 406 putting our well over 500ft.lbs. and 500 hp. Brian http://www.skspeed.com/ has been in the biz since 1963 and started doing 4+3s with Paul Cangliosi (5-speeds) when the units came out. They built them for Callaway and have installed them behind 454; in everything from street rods to Chevelles, to Rustangs. These two guys are probably the foremost experts on these units anywhere. Brian quoted me a lower price than other, for a filter kit, should you need one.
Like everything else, ya gotta know how to take care of them and what fluids to run. He is not some old-school, stick-in-the-mud. He knows these boxes and has seen it allHe speaks with assurance, based upon knowlegde and experience.
I asked him how to ensure mine would survive behind this nasty
motor.He said most problems with the O/D arise from guys messing up the O-ring or using the wrong fluid or not totally filling it or screwing up the pan, etc. He recommended NOT changing the fluid unless you overheat it, but rather checking it periodically for level and condition, by sticking your finger through the fill-hole; topping-off, as needed. The likelihood of ruining it has been shown, in his experience, to be higher with routine, if improper, maintenance. DO NOT run synthetic ATF in them. It will ruin it. Use standard Dextron, as listed in your literature. The unit will withstand 450 ft.lbs. (or more if he or Paul modded it). The stock unit is a great unit, if misunderstood, even by GM techs, not to mention your chain tranny dudes.
With the Super T-10, DO NOT RUN SYNTHETIC gear oil. Use either standard gear oil or GM's 12345-349 gear oil with synchro fluid, which has a small amount of synthetic, about 3%, and can ease grinding-while-shifting problems. He explained that the shape of the cones and the synchros demands a thicker fluid; that the synthetics are too good, and the internals don't work properly. The gears need spin-down time to mesh properly and the thicker oils allow that to happen, AS DESIGNED. The general's fluid might totally solve shifting issues, after a bit of time.
Also, the most common breakage of this T-10 is due to the case. The cases usually fail near the reverse idler shaft input, along the side. This takes internal parts along, noteably first gear. This case was strengthened from the standard T-10, but in this area, it needs more thickness for high power applications. His shop modifies cast iron cases to work, for racers, but the cost is more than installing a Richie, and not usually the best for a street car.
I am not an expert, myself, on this, but I consult with those who are and am passing along what I learn. It should work for you owners, those interested and for Brian and Paul, who are REAL busy fixing our mistakes.
Mike
