The transmission slams into gear when driving and when I put it in reverse. Can I replace the valve body which I ws told it was, by myself?

I means the transmission pumps pressure regulater is failing
that VAC line tells the box engine load. and if bad can cause
transmission to shift wrong. upshifts early or late.
but none the less it is bad fix what you see is bad.
does this box have TV cable, from TB TV valve top transmisssion
if yes it too must never be jammed, it is, transmission damage deeper happens./
they both control pump output main control pressure.
VAC modulatori and the TV cable. (throttle valve = TV) from TB throttle body
it is pump pressure issue on the main line(inside)

yes 800 rpm is slower than 1500 cold RPM an the pump runs slower so yes, pump output is less.
the transmission manual has page covering pUMP output port tests.
in all gears to see it fail. all transmission shops this is one of the first tests. besides, cable TV bad or VAC mod bad.

Is that a used unit?

If so-- then that is some elses junk

That valve body is dirty
Solenoids dirty

Can't be rebuilt or a decent unit,
with those problems

your trans needs a new throttle body, they can be found (rebuilt) on the internet for less than $150 and can be replaced without removing the transmission-it is a very common issue with Saturns. try not to let it 'slam' into reverse, if you do, you'll end up having to repair the output shaft (best case) plus do the valve body, and worst case, you will have to have the trans rebuilt/replaced.

2001 Saturn SL1. Transmission (automatic) shifts hard when putting it in gear and every gear there after. The only codes I get is PO442 and PO410. Any help would be greatly appreciated.

Your valve body and possibly input shaft nut need to be replaced. The valve body's booster valve is worn down and won't create pressure. Before it went completely out it slammed on the input shaft nut and loosened it.

You need to replace the valve body and retorque the input shaft nut. The transmission is not junk. The above needs to be replaced and change the filter and fluid and do it every 20K miles.

If reverse does not engage or only moves when flooring the gas then you have a typical valve body problem. In fact it may be a two part fix which is usually the case but not always.

The valve body is the "brain" of the transmission and has valves and bores inside of it along with 5 solenoids. There is one valve called the booster valve that will wear down due to poor manufacturing and debris and gunk build up from lack of transmission fluid changes (suppose to be done every 30,000 miles but more strongly suggested every 20,000 along with the transmission spin on filter).

Once the problem gets bad enough but before reverse is lost completely it will delay going into reverse, meaning when the shifter is moved to reverse it takes several seconds for it to engage. Then once it does it will slam/clunk/bang into gear. The banging into gear causes what is known as the input shaft nut to loosen and untorque. Once it untorques enough it won't allow reverse to engage. However, it will cause problems in 2nd gear as well.

Since you only have issues when warm it sounds like a valve body issue. It is time to replace it. A shop will tell you the transmission is shot and the entire thing needs to be replaced. IT DOES NOT! The dealer will charge you $1,000 to replace the valve body...again TOO EXPENSIVE. I sell rebuilt valve bodies for a fraction of the cost and it can be done in 45 minutes by someone who has never seen a valve body before. The Saturn transmission (and car as a whole) is easy to work on and does not require any special tools or knowledge. I send my customers instructions with pictures and my e-mail for any questions.

You can search this online and on saturnfans.com to verify. My name is Special Forces on Saturnfans, look up my threads about this common problem. Good luck!

Sounds like this is an automatic s-series. Sounds like you previously had a reverse slam in the car. Meaning when you put it in reverse it would delay then slam. As this gets worse it begins to untorque what is known as the input shaft nut. Eventually this nut will get so loose that you lose reverse completely.

The transmission itself is fine and does not need replacement. $1,600-$2,200 is probably not even what the car is worth. The valve body needs to be changed out with a rebuilt one and the input shaft nut needs to be replaced and torqued down properly. Both of these are easily done by any backyard mechanic. Roughly 3 hours will have your transmission shifting like new.

I rebuild Saturn valve bodies (check my ad for more information) and provide instructions on how to do the repair. It costs much less than what any shop will tell you and they'll tell you the transmission is toast...IT IS NOT!

Any questions, just let me know.

Soes it take a couple seconds to engage in reverse? Does it seem to slam into gear when it does engage? If so you need a Valve Body. It' in the top of the transmission and it is about $350 to replace with a good used one

You have a mechanical problem with the Transmission. Try to replace the Valve Body , if not you need to fix your transmission or replace

more than likely you will need a valve body rebuild. you are probably looking around $500+. don't let them try to sell you a transmission. you could search ebay and see if you can find a "rebuilt valve body" but make sure it is for a '00 to '02 SL2