Q45 Transmission

[Article Manager]

The Q45 Transmission is a delicate piece of machinery. While it can last quite a while with proper care, it is not expected to last the life of the car. Many Q45 transmissions without proper care will lose a transmission anywhere from 140k-180k miles. There are four recommended steps by this board to take in order to guarantee maximum life out of your transmission:

1. Get your transmission flushed at least once a year. This is not simply a pan drop and refill. Find a shop (e.g. Jiffy Lube, NAPA, etc) that has a transmission flush machine. Have you transmission flushed and the fluid replaced. Then have the pan dropped and cleaned and the filter replaced. Now refill whatever spilled out with more transmission fluid and replace pan and filter.

2. When you replace transmission fluid, use MOBIL 1 ATF. This is the board-recommended transmission fluid to use for maximum life on your Q45.

3. Install an after-market transmission cooler. The best brands to use are B&M and Hayden. This will help to cool your transmission. The cooler in the radiator only helps to heat the fluid when the temperature is near freezing in the winter months but does not cool the tranmission when it is hot. This is very important as heat is the number one transmission killer, not wear.

4. (optional) Purchase a Transmission Control Unit (TCU) upgrade from Jim Wolf Technologies that allows 1st-gear start. The 1990-1992 Q45's are set up to start in second gear and then shifts down to first. This can and does cause much slippage in the transmission and can be deadly for it. This TCU almost completely eliminates this so-called 'slippage'.

Transmission Flush - HOW TO!

My 4th gear was having a bit of minor slipping.. I thought to myself, this cant go on any longer, i gotta get some fresh fluid in there... If you run the car at idle for exactly 2 minutes, then all the fluid in the pan will be replaced...

So here's what I did... I drove the car a little bit to get the transmission warmed up, then I drained the pan... Let it drain for a while and while its draining shift the transmission through all the gears... this releases a little bit more fluid... Once you drain the fluid completely, you simply put the drain back in, put about 3-4 quarts back into the car, and start/run the car for exactly 2 minutes....

I did this procedure 4 times... The first 2 times I added 3 quarts of ATF and the last 2 times I put in 4 quarts...check it and adjust as necessary....

The bottom line? I think this worked SURPRISINGLY well... better than I thought it would.. The first 2 drains the fluid looked pretty bad, and then the 3rd time it looked a little better.... I feel like I got a very good exchange... I didn't use M1, i just used valvoline conventional.. IMO its more important to change the fluid more often than it is to spend extra and go longer.... Ill probably do it again in one year and next time replace the filter and drop the pan (I didn't do it this time)...

Again, I was pleasantly surprised how well this worked... I used a total of 14 quarts of ATF.... Id recommend people do this, it was certainly a hell of a lot better than paying $100 + fluid for a mechanical flush.... I feel that if i got, at worst, a 80% exchange, then it was completely worth it...