# SD 40-2 VS SD70 USA



## rocketrider (May 6, 2008)

I have contemplated a new SD 70 MAC from USA but am concerned becuase the SD40-2 was basically junk. My Union Pacific SD 40-2 has had 3 set of gears and currently needs another set........but I think I will junk it out or make a dummy battery car. USA has done nothing to make this right.

Anyway is the drive system any better in the SD 70 MAC??


----------



## Nicholas Savatgy (Dec 17, 2008)

Ralph, the SD-70 is the same as the SD -40 except the wheel size is different, but i have never had the issues you are having with my SD - 40. mine runs flawless,







maybe you should convert to aristo motor blocks maybe you will have better luck


----------



## Greg Elmassian (Jan 3, 2008)

I've heard sporadic stories of chewing up drivetrains... I'm not having those problems, but it is VERY easy to incorrectly assemble the USAT motor block. 

I've had nothing but success... 

Regards, Greg


----------



## W3NZL (Jan 2, 2008)

I converted both my 40 & 70 to Aristo motor-blocs, I think they work a lot better... Never had any 
problems to speak of with the USA floppy trucks, just don't like the whole idea... These days though, 
the price of converting one with new parts is prohibitive, think I'd just have to learn to live with the 
floppys at today's prices...
Paul R...


----------



## aceinspp (Jan 2, 2008)

Actually I had more problems with the SD 70 and none with the SD40s. So far they have been running great. Later RJD


----------



## jr747 (Feb 7, 2008)

About a year and a half ago, I bought a USA Union Pacific SD-70 and I noticed that one of the trucks was louder than than the other one but didn't think anything of it. Last November, I bought another USA Union Pacific Heritage Southern Pacific SD-70 and it ran quieter than my first SD-70. I decided to bring it back to Charles Ro to see what was wrong with it. By the time I brought it in, it had been about a year since I bought it and the warrentee was just about running out. They ended up replacing the whole truck, no questions asked and it didn't cost me anything. They never told me what was wrong with it but it now runs quieter and seems to run better with the Heritage unit than it did before I took it in.

J.R.


----------



## Nicholas Savatgy (Dec 17, 2008)

USA all the way for quality and runabilty, 2nd to none.


----------



## Paul Burch (Jan 2, 2008)

I have USA SD40-2's,SD70's and PA1's and have not had any problems. All have had the traction tire's removed and replaced with metal so the wheels are able to slip under heavy load. I most always run multiple units which spreads the load. Ralph,are you running single locos with a heavy load?


----------



## rocketrider (May 6, 2008)

I have converted to steel wheels and alwasy run MU with another USA unit either GP-38-2 or GP-30. I have not had any issues with either the GP-38-2 or the GP-30 which also have been converted to steel wheels.

This SD40-2 might have something miss aligned in the drive line??


----------



## Greg Elmassian (Jan 3, 2008)

Yes. the bass bushings on the wheels, as my first alluded to... The alignment of this "square" bearings sets the distance between the gears, and I have found MANY people who do not know which way they go, and MANY people who have opened motor blocks, allowed the bushings to go back in wrong (or did not even notice) and tear up their gears. 

Has this loco had the motor blocked opened EVER? 

For something as simple as removing the sliders? 

Regards, Greg


----------



## rocketrider (May 6, 2008)

The locomotive is in the hands of USA trains, I sent it in this week.

Out of frustration I converted another SD40-2 to Aristocraft motor blocks and now this one runs like a swiss watch, and is a good puller, and the motor block rides in the USA truck side frames more realestically.

I am going to hold off onthe SD70 in favor of a Dash 9.


----------



## rocketrider (May 6, 2008)

I am impressed the locomotive has returned from USA with new trucks installed. I returned under warranty and the unit was returned to me within 2 weeks, in great shape!! USA repaired under warranty. Good customer service.

If it would stop raining I will test it.


----------



## Nicholas Savatgy (Dec 17, 2008)

Its good that USA was able to get the loco up and running to your standards.... and in a timely fashion


----------



## aceinspp (Jan 2, 2008)

I've always had good luck with USA repairs. Good service and quality persons to deal with. later RJD


----------

