I have a 1999 Dodge Durango, 8cyl., auto transmission with about 211K miles on it.
For several months now the car has problems shifting from 2nd to 3rd gear. It goes from first to second without trouble, but to get to third I have to over-rev the engine and then let off the gas and then give it a small bit of extra juice for it to catch the third gear. In the past it seemed to happen only AFTER the engine got hot. Interestingly for the last couple of months it shifted just fine, maybe because it’s very cold outside.
Today, the transmission gave me a ton of problems and I was afraid it would give up on me before getting home. It just wouldn’t shift into 3rd gear at all. I limped the last 5 miles home in 2nd gear. Checked fluid and that was fine. I added a 1/2 quart. After a few hours I drove the car for short distances at various speeds to force the transmission to shift. At first it seemed to be OK again, but as soon as the engine got hot I ran into the same problem again.
I last changed the fluid 3K miles ago, but before that I drove it for 120K miles without a change Any ideas or suggestions what to look for now or is this a job for a specialist? A neighbor of mine suggested to poor a cup of acetone down the transmission and this would “clean up” and cut through the gum and varnish. I am not so sure this is a good idea, but wonder what it could do to seals and other rubber-type things inside the transmission.
At 211K…I would just pour in a can of Berryman’s B-12 Chemtool. It works. I would be afraid to use acetone. I’ve used this product for years on iffy transmissions with no harmful effects.
You can try the chemical, but at 211,000 miles you’ve reached the expected lifespan of the transmission (the whole car really) and the problem is likely mechanical wear inside the transmission.
That’s a fairly simple transmission and I would expect you would be able to have it overhauled at a local transmission shop for about $2000. Or you could try to find a good used one and have it installed and take your chances on that for about half the price.
The symptoms are pretty consistent with the transmission just being worn and needing an overhaul. The insides work on the assumption the pressure is correct, not only the pump, but in every circuit. But small internal leaks can occur from gaskets deteriorating. And the clutches can wear out, making it even more important the pressure is able to reach the peaks needed for the shifts. If you haven’t done a proper service on it recently – draining and putting in new fluid and a new filter – that couldn’t hurt. If it doesn’t help straight away, try it again. It takes 2-3 times to get most of the fluid out, a lot of the old stays in and doesn’t drain out each time you do it. Re-torqueing the valve body bolts can tighten things up too, if they’ve worked themselves loose. If this one has bands, those can be adjusted to compensate for wear. All that might get you some more miles before a rebuild becomes necessary just to shift into 2nd.
Any of several transmission “snake oils” offer some hope. I am familiar with Trans-Medic, Trnas-X and Trans-Tune. Those and similar products often soften seals and remove gum from piston bores to significantly improve shifting. It’s a crap shoot though. I have seen the $5 bottles pay off on several occasions.
I’ve used B-12 in desperation situations for about 35 years and in most cases it cured or helped the problem. Never seen a problem because of it.
That said, I tend to agree with asemaster about the transmission having reached, or close to it, its service life. Seventeen years and 200k+ miles is a good run; especially if the trans was never serviced.
update: so, a couple of days ago I pored down the transmission 16 oz. of B-12 carburetor, fuel system and injector cleaner. Since then I drove the car a little over 200 miles. The first 20 or so miles were kind of rocky. The shifting problem remained and I had to sort of play with the gas to keep the car in the proper gears. Literally from one mile to the next the transmission started to shift normally again and I have not had any problems at all since then.
I hope it stays like that because I hate to junk the car. It has been well taken care of (except the transmission) and the engine runs very very strong.
You may have a clutch/band/servo problem. The pump can’t get enough pressure to the servo to actuate it
Most likely, you could have a vacuum line/leak problem. That’s one of the inputs the computer uses to determine which gear the transmission should be in. If the computer thinks the transmission should be in 1st gear, it will keep it in 1st gear. Some transmissions use a vacuum modulator with a vacuum line running to the engine intake manifold instead of using the computer to control up shifting.
Now that you’ve got the tranny to shift properly. I’d do as @insightful suggested and get a filter and fluid change. Then keep up with the fluid and filter changes every 30,000 miles.