Question: Hi, all. I have a 1993 SW2 (I know this is the SL section) with 40,000 actual miles and an auto transmission. When I shift it into reverse, it pauses, and then the transmission shifts into reverse after a lag. Often, there’s a thud also. It’s worse when cold. The car has been flat towed behind a motorhome, but before I had it.
Any thoughts will be appreciated.
My Thoughts: Since I was a transmission shop owner from 1981 to 2006, I have lots of experience with this issue. I was fortunate enough to have a man buy my shop, right out of nowhere before the economy declined so much. So, in a certain sense, I have had even more time to study transmissions.
This problem creeps up on almost every one of the automatic Saturn transmissions that reach high mileage. High mileage is usually defined as over 100,000 miles, but that will vary according to usage. When i say usage, I’m referring to your driving style depending on what your load.
A pizza delivery person runs around town in a rush, putting the car in reverse 100 times a night as they pull into and back out of driveways, using reverse a lot. Even though they may not actually put a lot of miles on the car. As opposed to a person who puts lots of miles on the car on the highway, buy does not have to use reverse very much.
Use of reverse embellishes the problem. Why is this? Because every time you put the car in reverse, it activates the reverse valve in the valve body, which strokes back and forth in the bore. The valve body is the brain of the transmission. Since the valve body is made of a very low grade cast aluminum, the actual casting is subject to wear.
It is very simple. Anytime you have a piece of metal or plastic inside a hollow bore or hole with a tight clearance between the two pieces of material you have a situation for wear. As the valve goes back and forth, from the front of the bore to the back of the bore, we have a situation where the valve or piece of material that is sliding back and forth in that area will wear the bore out, from the sliding action. That makes sense, right?
Using the crappy sand cast aluminum allows the reverse bore to wear out first. this is because reverse uses the most line pressure of any gears and therefore causes casting wear. The only true solution is to buy a brand new valve body right from the dealer along with the appropriate gaskets and have it installed by a professional. Don’t forget to refill your automatic transmission with factory approved synthetic transmission fluid.
First and foremost, have it diagnosed by a professional, or you are wasting time and money. If it turns out that your transmission is worn out anyway, you may want to look into one of our used transmissions with very low mileage, from 15,000 miles to 35,000 miles on it. GotTransmissions.com has a large inventory of low mileage used transmissions that are all pre-tested for perfect function. Call us @ 1-888-344-8044.