Factory or Shop rebuilt transmission????

[gr_mich_mush]

Assuming the shop know how to rebuild a transmission, which is recommended? A factory rebuilt, or a shop rebuilt? This is a 700R4 going into a "every day driver" 1989 chevy k1500. The pros of the factory rebuilt is that it has a 3 year nation wide warranty vs the 1 year local warranty for the shop rebuild. The questions on the factory rebuilt is, do they address any of the weak points that a trans shop would? For example the trans shop is going to put a transgo shift kit in. They are going to beef up the 2-3 clutches, put in a larger oil pump, etc... The prices are the same. At this point I have no clue which one to do. So bottom line is, are the factory rebuilts as good as a properly rebuilt transmission?

[jrecken]

That 3 year warranty for the factory rebuilt is something to consider. I can only tell you of my experiences with transmissions. I had a Buick that the trans was acting up, it took the dealer 7 times to get it fixed so it would last more than a day. I blame a very bad mechanic for those problems.
My k2500 trans went and I had it rebuilt by a trans shop in Gaylord, Mi and it is better than new even after 5 years.
Good luck on your decision.

[Blue Bowtie]

The clutches to be enhanced should be the 3-4 stack. It should get a full compliment of steels and 7 standard friction plates instead of spacer, or 10 thin plates and steels for higher output use.

The oil pump isn't going to be substantially larger but should have 13 vanes to limit pulsation and a hardened rotor guides to survive high RPM operation and higher operating pressures.

The "Transgo shift kit" doesn't really mean much, since Transgo offers multiple kits to solve several problems as well as kits to alter shift points and pressures in various stages, most of which are completely inappropriate for a daily driver and especially a truck.

Whoever builds the trans needs to select accumulator pistons and springs based on the intended use, including the 2-4 servo instead of just blindly installing a "Corvette servo" kit and thinking it's a great setup. Since the 2-4 servo also acts as the 3rd accumulator, piston size and springs are important, but very few people talk about that.

The governor needs to be set up with the proper weights and springs for the intended pressure curve. The TV valve spool and sleeve also need to be sized and ported to match the governor.

The factory can do this, but I don't know that they actually do. A good shop can also do this, and will if you ask. Or, you can do it yourself.

[gr_mich_mush]

As far as I know the factory rebuild is only a stock trans. You call chevy parts and ask for a transmission. I don't think there are any options. So in your opinion, should a properly rebuilt trans last longer than a stock factory rebuilt?

Originally Posted by Blue Bowtie

The clutches to be enhanced should be the 3-4 stack. It should get a full compliment of steels and 7 standard friction plates instead of spacer, or 10 thin plates and steels for higher output use.

The oil pump isn't going to be substantially larger but should have 13 vanes to limit pulsation and a hardened rotor guides to survive high RPM operation and higher operating pressures.

The "Transgo shift kit" doesn't really mean much, since Transgo offers multiple kits to solve several problems as well as kits to alter shift points and pressures in various stages, most of which are completely inappropriate for a daily driver and especially a truck.

Whoever builds the trans needs to select accumulator pistons and springs based on the intended use, including the 2-4 servo instead of just blindly installing a "Corvette servo" kit and thinking it's a great setup. Since the 2-4 servo also acts as the 3rd accumulator, piston size and springs are important, but very few people talk about that.

The governor needs to be set up with the proper weights and springs for the intended pressure curve. The TV valve spool and sleeve also need to be sized and ported to match the governor.

The factory can do this, but I don't know that they actually do. A good shop can also do this, and will if you ask. Or, you can do it yourself.

[Elbert]

as noted...give some consideration to the warranty offered by the GM "crate" tranmisssion. A stock vehicle does very well with a stock transmission.